# Fuse blowing BS400



## Gordon T (7 Feb 2011)

Hello all, my new BS400 Record power bandsaw blows its fuse on start up almost every single time I turn it on,(except when I remove the drive belt-no load ). It is supposed to run on a 13 amp 240 v supply but clearly can not cope, what can do to solve this? anybody


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## 9fingers (7 Feb 2011)

This machine possibly has a 1.5 -2hp motor? At this power it is marginal whether a 13 amp supply is genuinely suitable. Clearly it benefits a vendor to say that it can run on 13 amp plug. For every user who has a problem, there will be another who has no difficulties

Some of the problems can be with your installation or the voltage from your supplier that you can do little about.

Best course of action is to install a 16amp radial circuit and use a type C circuit breaker and you should have no further such problems.

Bob


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## Gordon T (7 Feb 2011)

Thank you Bob, the motor is 2 horse power......it is strange because my lathe is 3 horse power and works perfectly even with other machines, lights heaters etc running at the same time. Strange Recordpower advertising the bandsaw will work on 13amp when it seems unable to!!


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## 9fingers (7 Feb 2011)

What i was trying to say was that there WILL be some supplies that it will start on but clearly not yours.
This is not necessarily a fault of your installation.
A lathe is a lot easier to start than a bandsaw. It is the combination of startup current AND the duration that blows fuses. Type C breakers are capable of taking overload currents for longer hence their use on motor circuits.

HTH

Bob


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## Stoday (8 Feb 2011)

If you have an extension lead, try plugging it between the motor and the mains socket. That will introduce a little resistance that will reduce the starting transient somewhat. If it dosn't work, it will have cost you nothing.


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## OLD (8 Feb 2011)

Friction is a factor try turning the wheels by hand and may be reduce tension or increase guide clearance checking blade runs straight true and is turning freely .The motor needs to get moving quick and generate some back emf to reduce current requirement.


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## Digit (8 Feb 2011)

Years ago Gordon there was a programme on the good old fashioned wireless entitled 'Round the Horn' with such titbits as 'Are Exits on the Way Out?', or 'how much is a fourpenny loaf?'
It's the same with Horsepower, one manufacture's HP is not the same as anothers.
The only reliable figure these days is the Full Load Current.
Horsepower now-a-days is a salesman's figure.

Roy.


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## Gordon T (8 Feb 2011)

Hello all, I had an electrician here today, my supply is 240 v and on startup only dropped to 239, blew the plug fuse immediately, think I have a faulty machine, ( workshop has its own 30 amp supply from house via a 4mm underground sheathed cable , and earth shows a 4 which I believe is good ).
Record are taking it back to test it at their place, I am not holding my breath.


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## 9fingers (8 Feb 2011)

Hi Gordon, 
Your installation sounds like it is solid. It does rather sound like a machine problem - rare if it is a new one. Hope you get it sorted in a reasonable time.

Bob


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## Digit (8 Feb 2011)

I dunno Bob, it runs without the belt remember, but time will tell.

Roy.


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## JanneKi (9 Feb 2011)

Will it start up, if you 1st rotate the wheels (give them a spin, so that they are on the "move" already) and then turn it on? That sometimes helps, but that's usually a sign that either the condensator is busted OR there are some more serious issues with the actual motor.


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## Gordon T (10 Feb 2011)

Hello all, today I plugged my extension lead into the kitchen ran it out to the workshop plugged in the new bandsaw and it worked every time I turned it on!!!!!!!!!
Then the electrician called again with his megga meter, checked my wiring, my sockets and fuse box and is baffled, can not find the problem, clearly the machine will work but not in my workshop. What the ****


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## 9fingers (10 Feb 2011)

Whack a 16 amp socket in from a type C breaker and you will have no further problems.

Bob


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## Gordon T (10 Feb 2011)

Hi Bob, if I have a 16amp system fitted will the cables on the machine cope with the extra ampage, I know an amateur question, but better to ask than guess and make a bad job worse, 
G


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## 9fingers (10 Feb 2011)

The cable should be fine Gordon, the extra current is only during starting, and the cable is carrying that now.

I expect the flex is 1.5mm^2 which is rated at 15 amp continuous. If I were selecting a new cable I'd possibly use 2.5mm^2 but in this application I'd not bother to change whatever you have got fitted.

Bob


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## Stoday (11 Feb 2011)

Gordon T":1o4u5uuc said:


> Hello all, today I plugged my extension lead into the kitchen ran it out to the workshop plugged in the new bandsaw and it worked every time I turned it on!!!!!!!!!
> Then the electrician called again with his megga meter, checked my wiring, my sockets and fuse box and is baffled, can not find the problem, clearly the machine will work but not in my workshop. What the ****


Now try plugging the extension lead into a socket in the workshop. I'd expect it to work OK.


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## 9fingers (11 Feb 2011)

I had a visit from a UKW member today in order to check over a motor from a scheppach planer.

Out of interest I made some measurements on the starting current.

It was plated as 1.5kW and 9.5 amps running current. Using a peak hold ammeter, the peak starting current averaged over about 4 attempts was a whopping 24amps. This was with no load, just sitting on the bench! Furthermore it did not blow a 13amp fuse in the plug.

Bob


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## Digit (11 Feb 2011)

Based on some experiments I carried out years ago Bob I found that 13 Amp fuses would stand more than double their rating, briefly.
At between 26 and 30 amps some would survive for more than one second. There was an additional time factor that I think we are all aware of, the fuse may stand it once, repeat the current surge too soon and the fuse would then rupture at a lower rating.
I tend now to rely more on suitably rated MCBs.

Roy.


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## 9fingers (11 Feb 2011)

Agreed Roy, an MCB offers better protection.
I was just running this motor up as a test using a SafeBlock which has an integral 13 amp fuse as well as a second one in its plug.
As it happened, the SafeBlock was plugged into a 4 way socket strip which would have has a third 13 amp fuse!

Bob


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## Digit (11 Feb 2011)

Makes me wonder what my SIP TS draws as it blew 13 Ampers as when it felt like it.

Roy.


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## Gordon T (11 Feb 2011)

Hey you guys, do you think changing the plug to the blue 16 amp system will affect my warranty , I ask because I am having a new fuse box fitted and could order one with the type c and 16amp as you suggested
Gordon


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## Digit (11 Feb 2011)

I've never met a circumstance where a plug change caused any difficulties myself.
As regards the MCB, a change to the C type will help, whether a 16 amp would do is a matter of how long it takes for the machine to spin up. A 20 Amp may have to be used, but they're cheap enough so try the 16 first and see.

Roy.


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## 9fingers (11 Feb 2011)

I can't see why they would object. Any way you could always pop on a 13amp plug before sending it back.

Bob


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## Digit (11 Feb 2011)

Read this Gordon, it may surprise you and explain why I said that the 16 Amp MCB not be rated high enough.....

_BS 1362 specifies breaking-time/current characteristics only for fuses with a current rating of 3 A (marked in red) or 13 A (marked in brown). Examples for the required breaking-time ranges are

* For 3 A fuses: 0.02–80 s at 9 A, < 0.1 s at 20 A and < 0.03 s at 30 A.
* For 13 A fuses: 1–400 s at 30 A, 0.1–20 s at 50 A and 0.01–0.2 s at 100 A.
_

...'orrible ain't it?

Roy.


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## Pond (11 Feb 2011)

Have you tried plugging the saw into a different socket in the workshop?

It sounds like it could be a combination of two things:

1. If the saw motor is a capacitor start, the cap is probably knacked.

2. you could have a dodgy socket with a fault on the neutral. are the sockets double pole isolating, ie does the switch isolate the neutral as well as the live?

Or it could be something else, but if it's been meggered the earth should be Ok, if it doesn't trip the breaker the earth is Ok, and if it runs on a separate power supply it's not an over-current problem.


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## Gordon T (11 Mar 2011)

Hello again,
When bandsaw plugged in to extention plugged into house works fine every time,

for the third time I have had my wiring and sockets checked, all fine


I have had my fusebox changed for a new modern mcb, 

the bandsaw now has its own dedicated 16amp radial socket, and guess what, £150 later and my bandsaw still blows the 13 amp fuse in the plug.

It draws 5amp when running but 32 amps to start up.

Yesterday I used it a lot and used only 4 fuses, this is going to cost me a lot over the coming years.

My electrician is BAFFLED and can not explain the fuse blowing,

Sorry to harp on but any ideas?????


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## NetBlindPaul (11 Mar 2011)

Gordon T,
Yes I already have a few, however, I have only just picked up this thread, and not read anything except your last post.
Is this a Record BS400?
Can you please post all of the data from the motor rating plate.
Do you have electrical certificates for any of the works done on your wiring?
Can you please describe in detal what work you have had done please?


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## Digit (11 Mar 2011)

> My electrician is BAFFLED and can not explain the fuse blowing,



Eh? 32 Amps for more than a fraction of a second is bound to blow a 13 Amp fuse!

Roy.


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## NetBlindPaul (11 Mar 2011)

Digit,
No it is not necessarily going to blow the fuse!
This will depend on the time of the overload and its time/current characteristics.
The 32A is probably the locked rotor current existing for a few milliseconds when the motor establishes its magnetic field and starts the mechanics turning.
Perhaps Gordon T can advise how his spark measured this 32A current and with what equipment?
This would give me more information to look at why the fuse may be "blowing".

Re-reading the last post, you say the machine has its own dedicated 16A supply on a 16A breaker.
You are still putting this through the BS1363 13A plug though?
Why?
Did the machine come with a 13A plug on it?


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## Digit (11 Mar 2011)

> No it is not necessarily going to blow the fuse!



It certainly will if it lasts long enough.



> This will depend on the time of the overload and its time/current characteristics.



What timer and overload?



> Perhaps Gordon T can advise how his spark measured this 32A current and with what equipment?



Which would suggest that it lasts long enough to rupture said fuse unless said sparks has some pretty smart equipment.

Roy.


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## CHJ (11 Mar 2011)

*Gordon T,* if you have a new 16amp rated power supply installed specifically for the Bandsaw and it is fed by a dedicated 16 amp MCB why did you not have a 16 amp IP44 outlet socket fitted (blue) and change the plug on your bandsaw.


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## Digit (11 Mar 2011)

Exactly, nothing was gained I'm afraid GT.

Roy.


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## andycktm (11 Mar 2011)

16 amp socket & plug is the way to go,but just out of curiousity try the fuse out of the extension lead in the bandsaw plug :wink:


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## NetBlindPaul (11 Mar 2011)

Digit":1l6roy16 said:


> > No it is not necessarily going to blow the fuse!
> 
> 
> 
> ...



Roy,

I never stated anything about a timer or overload device.
My statement was in relation to an overload current of a certain duration.
i.e. the time / current characteristics of the overload, that is the duration of the overload and the current value of the overload.

It does not suggest that the overload lasts for any length of time.
IF the spark is investigating such a fault then he should have the equipment & knowledge to do so.
I have a meter in the back of my van that I carry at all times that will capture the 1st 100ms of inrush current and register the peak value, this will over such a short time span the approximate locked rotor current for the motor and will almost be an average!

A BS 1362 13A fuse will carry 95A for just <0.4 seconds without blowing, it will carry around 60 amps for just <5 seconds without blowing, at full 230V a.c. UK mains voltage.
Thus a 32A current inrush if measured with my equipment would be almost insignificant.

Thing is we don’t know the situation, perhaps the OP only has 200V a.c. available at his machine due to poor design in his installation and thus volt drop in his distribution cables?
We don’t know. This is the problem, neither obviously did the spark he called in, else the problem would be sorted.
Unfortunately there are many so called “electricians” out there now who have no real understanding of what I consider to be basics as they are no longer taught this.
We call them 5 day or 5 week wonders, they do a short course & register under limited scope with one of the registration bodies, but do not have the depth or breadth of knowledge to undertake competent fault finding.
IF the guy has not found the fault which is causing the fuse to blow then he has not done enough testing, or perhaps he does not understand the readings he is taking.


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## Digit (11 Mar 2011)

I'm well aware of all that Paul, as I expect you are aware that those figures apply to one off situations. Try it several times and the fuse will rupture.
If the GT's 'sparks' is an electrical engineer he might wll have such equipment of course. A 'sparks' is rather unlikely to I would suggest.
Not withstanding all of this, if the fuse is being ruptured the overload/time is exceeding the fuse capacity.
I would start with re-testing with the band removed.

Roy.

Re reading your post Paul I see that I misinterpeted your statement on overload etc.
As regards the 5/5 wonders that unfortunately applies to many supposedly skilled trades today. It makes me wonder who concluded that you turn out a plumber in five minutes. All I learnt in my first year was how to make tea!


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## NetBlindPaul (11 Mar 2011)

As long as the flex from the plug to the bandsaw is rated at or in excess of 16A then there is no reason not to change to what is technically known as a BS EN 60309 plug/socket, this may well eliminate the issue as long as all othe electrical safety requirements are met, as per CHJ comment above.


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## 9fingers (11 Mar 2011)

I think the fact that GT's Spark fitted a 16amp radial supply, knowing that the issue was one of blowing 13amp fuses and then put a 13amp socket on the end shows that he is more of a domestic spark than one with wider experience/training to know about 'commando' plugs & sockets.

No doubt he is accredited and part peeee capable :roll: 

Bob


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## NetBlindPaul (11 Mar 2011)

Digit":4simbzim said:


> I'm well aware of all that Paul, as I expect you are aware that those figures apply to one off situations. Try it several times and the fuse will rupture.
> If the GT's 'sparks' is an electrical engineer he might wll have such equipment of course. A 'sparks' is rather unlikely to I would suggest.
> Not withstanding all of this, if the fuse is being ruptured the overload/time is exceeding the fuse capacity.
> I would start with re-testing with the band removed.
> ...



Roy,
It is doubtful you will find many true electrical engineers who undertake practical works, I am one of the few, I enjoy the hands on. Most electrical engineers are in design type roles well away from the tools, and that is why they studied for their qualifications.
Any "spark" who is attempting to investigate & diagnose a fault, must to be competent under the electricity at work act, and have sufficient knowledge and experience, that is competence to prevent danger and where appropriate injury to himself & others.
If this "spark" cannot indentify the root cause of the fuse blowing then he is not sufficiently competent under EAWR89 to be undertaking this work.
This remember does not apply to the DIYer but it DOES apply to any "spark" or other person you pay to come in and work on any electrical equipment in your premises, or any of your electrical machinery equipment at any time.
It is doubtful that if the guy was incompetent that you could be prosecuted, however, the legal responsibility may well lie with you the householder, rubbish I know but that is one interpretation of the law that has been withheld in courts.


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## NetBlindPaul (11 Mar 2011)

9fingers,
I'm not going there as there is no soap box big enough for my rant with regard to this, on this forum!

Suffice to say that I voted against Part P when I had the opportunity as a member of the Institute of Electrical Engineers!


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## Digit (11 Mar 2011)

I don't deny any of that Paul. But my observation was simple.
If that overload lasts long enough, the fuse must rupture.
That stands!
The only question, is why?
My storage scope would measure that transient, but as I said, a sparks ain't likely to have such to hand.
To GT, remove the band and spin the the motor pulley if such is fitted or the band driving wheel.
Does the motor spin freely? Does the driver wheel spin freely?
Repeat for the band's driven wheel. This will prove/eliminated tight bearings etc.
This would be a logical first move.

Roy.


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## NetBlindPaul (11 Mar 2011)

Digit,
We aint gone into fault finding the machine yet!
However, yes you are correct IF the overload lasts over 5 seconds at 32A then at some point, the fuse will rupture.
However, the exact point of rupture is not easily defined, it is certainly not defined in BS7671 as far as I can see as I have my copy along side me at the moment

I have a much simpler device than a DSO to do this, however, it is a dedicated piece of test equipment.
However, as this is the sort of fault upon which I pay my mortgage then it is only to be expected IMHO.
Any "spark" attempting to diagnose such a fault must have the competence and equipment to undertake adequate testing!

The motor may have an electro mechanical brake, which could be malfunctioning?
This would also restrict the ability to rotate the motor with the power off, even of there were no fault present.


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## Digit (11 Mar 2011)

> This would also restrict the ability to rotate the motor with the power off, even of there were no fault present.



Yep! But bandsaws are notorious for dust in bearings, first things first. After all, there's not much point in dragging an electrical engineer in if the bearings are tight.

Roy.


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## NetBlindPaul (11 Mar 2011)

Digit,
Correct, though my previous point about electrical engineers still stands, I doubt that many would come out to look at a diy bandsaw!
By the by, dust in bearings is a very valid point, but if the machine has an electro magnetic brake it may not be possible to rotate the motor with the power off anyway as the brake will clamp the rotor to a standstill. Unless this could be disabled.
It may not be safe however to attempt to work on the motor with any electrical power to the machine


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## 9fingers (11 Mar 2011)

It's been a while since this thread started but I'm pretty sure this was a new machine - so there should not be faults.

Bob


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## Digit (11 Mar 2011)

Once again I would agree, but I covered that with a question to GT as to whether it is belt driven or direct drive.
When he comes back with some answers we may be able to move him along.

Roy.


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## Digit (11 Mar 2011)

Agreed Bob, in fact I rather doubt that it has a fault. If GT has overtightened the band, for example, the start up load will rise, he also stated that he used it many times then states it blew 4 fuses.
From that I conclude that it ran sometimes, and as I pointed out to Paul, fuses may well stand a high overload once or twice, repeating that overload will eventually rupture the fuse.
If the machine is new then it's reasonable to ask what the line voltage is when the machine starts up, if that's OK then I suggest that a 13 amp plug is not suitable.
My table saw was supplied with a 13 amp plug, and like GT's BS, it blew fuses at various times.

Roy.


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## NetBlindPaul (12 Mar 2011)

Digit,
I fully understand the thermal stress on fuses, it is something I have to explain regularly to my customers when fuses fail for no obvious reason.

Now you took it that the fuses blew after a few starts, I took it that the fuses blew on every start?...

This is one of the problems trying to fault find machines over the internet!!!

IIRC the BS400 is belt driven, and as has been suggested, there can be several reasons for increased starting current, blade & belt tension being the most obvious.

The volt drop issue is what I think I intimated in an earlier post, just because the final circuit from the local DB is on a 16A breaker to its own 13A socket, we do not know the length of this final run, whether this is fed from the origin of the installation at the main fuse box nearest the DNO cut out/meter.
If it is on a sub main, is the sub main adequate for the overall load?
Is there excessive volt drop in the sub main, if there is one?
Is there excessive volt drop in the final circuit.
For a motor load there may well be.
Is there adequate capacity in the incoming DNO supply cable?
This could be looped form next door believe it or not, we don't know.
This may be a mechanical issue all along, perhaps there is a tight bearing in the motor/bottom pulley/top pulley.

Now 1.5mm sq flat twin & cpc will carry 20A when clipped direct to a wooden or masonry wall. Reference BS7671:2008 Table 4D5.
However, with a starting current of 32A and say a nominal starting voltage at the mcb of 230V a.c. (the official UK voltage), say a 10m run of cable, you would have around 7.4 volts dropped, (BS7671:2008 table 4D5) thus your machine voltage at the socket outlet would be 222.6V.
The machine cable would be around 2m?
This will almost certainly be 1.25mm sq flex, this carries 13A, (BS7671:2008, table 4F3A), value engineering suggests that if the machine maker considers a 13A supply cable to be adequate then they will not fit a larger one as this adds cost for no benefit, thus reduces the competitiveness of their offering. This flex alone would add another 2.4 volts drop (BS7671:2008, table 4F3B) , thus now at the machine contactor you are looking at 220.2V, then there is the volt drop in the machine wiring out to the motor.
This becomes significant, you may see as low as 210V a.c. at the motor terminals for the instant of start up.
This does not allow for DNO volt drop in their install or any wiring between the DNO cut out & the final circuit MCB.

This IMHO is why 5DW can struggle with domestic installs when “industrial type” loads are added. This may not be the case.

However, there is a reason for this issue, and with the information we have and the access we have to the actual install & machine, which in my case is none, all I can do is theorise and make suggestions that need to be considered by those who do have access to the machine & install, the same as the rest of us.

The fact is, if, it is an electrical issue, then the fault has not yet been found, therefore I would say that not enough testing has been done!


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## Digit (12 Mar 2011)

> However, there is a reason for this issue, and with the information we have and the access we have to the actual install & machine, which in my case is none, all I can do is theorise and make suggestions that need to be considered by those who do have access to the machine & install, the same as the rest of us.
> 
> The fact is, if, it is an electrical issue, then the fault has not yet been found, therefore I would say that not enough testing has been done!



Yep! I remember telling students that, "out there is someone who has the info you need. Getting it out of them is like getting teeth out of a Duck!"
The number of times I've been told, "it stopped!"
No doubt you've been there as well! :lol: 

Roy.


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## Gordon T (12 Mar 2011)

Hello all,
I will do my best to answer the last two pages of questions.
The machine is a brand new Record BS400. it came with a 13amp plug and has blown fuses regularly every time I have used it.
My installation is 30amp MCB in the house fuse box, 6mm sheathed cable to the workshop which now has a brand new fuse box with a 16amp MCB radial 4mm cable to a 13amp plug socket.
I was also suprised that a commando unit like the one pictured above was not fitted.
The ring circuit to all the other sockets has a 20amp MCB.
The machine will cut several times then blow a fuse, or start the day blowing a fuse.
The motor will start every time when the belt is removed ie no load on the motor.
the bearings are free running, the wheels turn by hand easily enough, the brake does not seem to bind.
The electrician used a megga meter to check all my wiring, sockets, earthing values and a thing with a red claw like end which measured the voltage drop and ampage on startup etc.
The voltage started at 240 and dropped to 239on startup
32amp startup drain with 5amp running drain.
The figures and the part p certificate have not yet arrived in the post so I can not quote them.
Record tell me they have not had this problem with any of the other machines they have sold.
They say it must be my wiring, but just how much more can I do,
I just get on and use it and keep putting fuses in it.
If as suggested I fir a commando unit to solve the fuse blowing, this would if I am right eliminate the 13 amp fuse, then this would solve my problem.............then why was it not supplied with one, 
The fact is this is my seventh Record machine and the first one to cause me any problems like this, how much more money and time and effort is this going to cause, when I have the manufacturer telling me its my wiring at fault and my electrician telling me it is not?
Almost forgot Bob,drivebelt tension is fairly slack, and blade is not overdone in my humble opinion.
As a non electrician, I find all this very frustrating, but if fitting aq commando unit will do it I will have a go at fitting one

GT


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## Digit (12 Mar 2011)

> The machine will cut several times then blow a fuse,



Do you mean it will 'cut out' or saw several times before blowing the fuse?
Is the motor getting hot?

Roy.


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## Duncan A (12 Mar 2011)

Gordon

Induction motors typically take 6 to 8 times full load current for a brief period on startup. This is quite enough to stress a fuse so that it blows after a couple of starts, or even to blow it on the first attempt to start. Axminster suggest fitting a 20A supply to the (1.9kW input) Jet 16" Bandsaw and a 16A supply to their own (1.5kW) AP4300 16" bandsaw. This is in recognition of the fact that they are too big to start up on a 13A plug. Even my 18" Jet bandsaw (2.6kW input) came with a 13A plug which is no use at all, but I read somewhere that there may be a regulation stating that a 13A moulded plug must be supplied.

I suggest you purchase a blue commando plug and socket and your problems will be over, for a very modest outlay.

Hope that helps

Duncan


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## Digit (12 Mar 2011)

Exactly! That is why I said to 9F that I suspect that there is nothing wrong with the machine. Just run it on a sutable plug/socket/MCB and your problems will probably be all over.

Roy.


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## 9fingers (12 Mar 2011)

Digit":2981wh46 said:


> Exactly! That is why I said to 9F that I suspect that there is nothing wrong with the machine. Just run it on a sutable plug/socket/MCB and your problems will probably be all over.
> 
> Roy.



Which in turn is what I suggested to the OP on 7th Feb in reply to the original question.

We are all violently agreeing :lol: 

Bob


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## Digit (12 Mar 2011)

My memory doesn't go back that far Bob! :lol: 
I'm at a loss as to why the sparks put in a dedicated radial main and a 13 amp socket though.

Roy.


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## 9fingers (12 Mar 2011)

He can't have been a real spark Roy!


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## Digit (12 Mar 2011)

Certainly not a bright one! (sorry!)

Roy.


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## Stoday (13 Mar 2011)

Gordon T":3mth8ysi said:


> Hello all, today I plugged my extension lead into the kitchen ran it out to the workshop plugged in the new bandsaw and it worked every time I turned it on!!!!!!!!!


No need to run the extension from the kitchen; you could have plugged it into a workshop socket with the same result. Indeed, that would be the cheap fix — "lose" an extension lead in your workshop. But I guess you want to do the job properly.

If the sockets wiring in your workshop is a radial on a 20A MCB, then you can add as many 16A sockets as you like (provided you don't exceed 20A by the machines you want running at the same time). You are allowed to do this yourself.

Unfortunately, most garage/DIY workshop sockets are connected to a 30A ring. The regulations don't allow you to add 16A sockets to a ring. You would have to connect it through a 13A FCU and you'd get the 13A fuse problem back. Your electricain would have to add a new 20A radial circuit for your 16A socket. You are not allowed to do this yourself unless you jump through some Building Control hoops that will cost you more than employing an electrician.


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## ondablade (13 Mar 2011)

I'm guessing the issue regarding fitting a 16A plug and socket is the implications for warranty - and for fairly good reason in that if the saw throws up other problems you could be left with it. You could possibly refit the 13A if needed as long as it's not sealed on.

It seems to me that one very basic option is to take Record at their word to the effect that it should run on a 13A socket - not some special socket, but any reasonable socket. It isn't, and they won't it seems help - so put it in the car/trailer, drive it down to wherever it was bought and metaphorically speaking slap it on the counter and demand a replacement or your money back.

You could demand they test it on the spot with a 13A socket, but you would in that case risk it not performing to order. 

Some other possibilities to consider. (1) Bum/slightly low blowing fuses - buy a few alternatives by other makers to try out. (2) I don't know quite what the mechanism is, and you may have covered off this possibility - but I know from experience that it's possible to get a rogue 13A socket that for some reason (like maybe a bent/misaligned contact - which might suggest the possibility that a poor contact elsewhere might have the same effect) causes fuses to blow when starting a motor when others do not.

It seems likely that many of these makers of small machines sail close to the wind to be able to sell a machine that runs on a 13A socket - so maybe (3) you have got one where various tolerances are stacking up to leave you on the high end of the current draw - which requires replacement unless they are prepared to have you run a 16A socket.


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## Digit (13 Mar 2011)

But one mystery remains Ian. Why does it run on an extension lead from the house?
The 'logical' deduction is a line fault between the 13 amp socket and the incomer connection point.

Roy.


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## CHJ (13 Mar 2011)

Extension lead is introducing resistance I would think, reducing surge current due to momentary voltage drop.

The better the wiring, bigger gage shorter length etc. the greater the surge current is likely to be, the new system is probable making the chances of blowing the fuse even greater.


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## 9fingers (13 Mar 2011)

I reckon the extra lead length adds resistance and inductance to slow the build up of current. Even though this will mean start up takes longer, less current for longer might just suit the fuse characteristic better.

Bob


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## NetBlindPaul (13 Mar 2011)

Without a full and proper investigation into the fixed wiring installation from the origin of supply to the point of connection we cannot really surmise the exact reason, all we can do is make suggestions.
I have to write to Startrite Record tonight about another customer query so I'll mention this to their tech/management guys.


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## Digit (13 Mar 2011)

> less current for longer might just suit the fuse characteristic better.



True enough Bob, a check of the voltage drop would help on that, plus if used for any time I would expect the lead to be getting warmish. 



Roy.


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## 9fingers (13 Mar 2011)

Digit":2h01r3u0 said:


> > less current for longer might just suit the fuse characteristic better.
> 
> 
> 
> ...



Yebbut, somewhere I read the running current is only 5 amps so even 1sq mm cable would be in spec.
The analytical side of me would like to know why but on the other hand I'm convinced that fitting a fuse-less connector will sort it out. It is at least 5 weeks this has been going on and minimal sawdust made by the OP. Sometimes a JFDI approach is the best way ahead overall.

Bob


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## Digit (13 Mar 2011)

Oh naughty. :lol: 
Yes I agree, it will either solve the problem or it won't, that way at least we will have further info to go on.

Roy.


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## NetBlindPaul (13 Mar 2011)

9f & digit,
It seems the OP is worried about his warranty?
He did report the running current to be only 5A, this would actually be OK on 0.75mm sq according to BS7671, however, that does not allow for the starting load!
Unfortunately I don't have a copy of BS1362, which is the standard for the fuses in BS1363 plugs.
There are no time current characteristic curves given for these fuses in BS7671.
If I can find any I'll post a link.
I do however suspect the 1V drop measured on start up of the machine is not quite exact.

The suggestion of changing the start up characteristics with the increased impedance of the extension lead is a valid one, especially as the lead may be coiled, thus offering a little “back emf” by the transformer affect of the coiled lead, this would be minimal, but we may be chasing small changes as apparently sometimes the machine starts!

Perhaps this could be proved by using the same lead with the same length uncoiled on the “normal” socket for the machine then plugging the machine into this lead from there?

Also it is possible that the volt drop on the kitchen socket is higher, even though this will probably be a ring circuit.

Thing is we don’t know enough about the fixed wiring to blame it or discount it.

BTW, deed is done have emailed maker with my other question and mentioned this at the end. I await their reply. They are normally very good at getting back to me, so we should not have to wait long.


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## Ateallthepies (13 Mar 2011)

I found this link for BS 1362 fuses... http://wiki.diyfaq.org.uk/index.php?title=Fuse and it has a time/current chart for 3 and 13 Amp fuses.

HTH,

Steve.


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## NetBlindPaul (13 Mar 2011)

Steve,
Nice one, however, that is an old bulrush chart probably a scan from an old version of BS7671 / IEE Wiring Regs.
It will however give some idea.


I don't have any old copies of the regs here at the moment only the latest version and this graph has been removed from this.
As it is old it will differ from any up to date version related to current UK standards due to the voltage changes even though it only graphs current against time!


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## ondablade (14 Mar 2011)

It's a very uninformed view Roy, but my assumption was just that the extension was in some way reducing the load on the fuse - I didn't know how. The point for me was that Stoday in one of the first posts on the thread suggested an extension lead as a possible solution, which implied that it's a recognised temporary fix he'd seen help in a similar situation before....

It's interesting to theorise about possible wiring issues, but TBH my instinct (born of hard experience) is to make sure a new bit of kit is sound (while it's still new and in warranty, and before the supplier works up an alibi/loses interest) - which would tend to make proving that this saw is OK/replacing it my first priority. 

I'd want some assurance that it's not drawing more current than it should - because (a) this might just point to issue(s) with implications for longer term reliability, and (b) might leave it sailing too close to the wind for longer term reliability on a 13A fuse. The extension lead is surely not reducing the draw by very much, meaning that if there isn't a significant wiring issue it's possible that something is up with the saw.

Another reason to involve the supplier ASAP (presuming they know saws) would be to rule out set up/adjustment/operational issues.

If the vibe coming from the supplier wasn't confidence inspiring then I might even be inclined to up the ante and immediately demand a replacement, because if suppliers are not interested then returning stuff for testing tends only to provide an opportunity for them to claim they tested it and that it was fine.

The realpolitik is surely that a supplier can't reasonably demand that a customer proves the wiring is perfect before meaningfully engaging??? The saw is the new variable in the situation, and it'd surely be OTT for a supplier in these circumstances to demand that a customer rule out wiring issues in a previously functional installation before taking the saw back.

When you buy a piece of electrical kit and it doesn't run right when you plug it in then surely this is the normal response???


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## Stoday (14 Mar 2011)

ondablade":1jxh1qmq said:


> It's a very uninformed view Roy, but my assumption was just that the extension was in some way reducing the load on the fuse - I didn't know how. The point for me was that Stoday in one of the first posts on the thread suggested an extension lead as a possible solution, which implied that it's a recognised temporary fix he'd seen help in a similar situation before....


Yeah I've worked in electricity for 50 years, retiring last month at 70. I've seen it all before...

I thought the problem was that Gordon T's electricity supply was of unusually low impedance. I'm now rather more convinced of this because there's only 1 volt drop from a starting current of 35A and a running current of 5A or so. His house is probably quite near to the local distribution transformer to which he's connected through the street main. 

Normally, the starting current would cause the voltage at the motor to drop more than just one volt; a starting voltage that falls rather more than this would reduce the size of the starting current (if the supply impedance to the motor were zero, you'd expect a starting current of 6 times the full load current). So, a "fix" is the extension lead because that adds impedance to the supply. I was looking for confirmation of what I thought was the problem, but Gordon did'nt try the extension in his workshop. Happily the other snippets in the thread confirm the problem, so I can suggest solutions. Since Gordon's supply is probably of abnormally low impedance, the problem wouldn't normally arise and it could well be the case that Record hasn't come across the problem before.

Cheapest solution would be to include the extension lead between the 13A socket and the 13A plug on the bandsaw. But that looks messy. In any case you must not coil it up because the cable might overheat if you do so.

A better solution would be to incorporate "soft start" gear. Click here for an example

A solution that won't work would be to fit a Commando unit. 



NetBlindPaul":1jxh1qmq said:


> that is an old bulrush chart probably a scan from an old version of BS7671 / IEE Wiring Regs.


Yep, that's a theoretical worst case, I think. Why else do you think there are kinks in the curve?

The main manufacturer of BS1362 fuses (a US company) publishes the curves of his fuses: Click for pdf



ondablade":1jxh1qmq said:


> It seems to me that one very basic option is to take Record at their word to the effect that it should run on a 13A socket - not some special socket, but any reasonable socket. It isn't, and they won't it seems help - so put it in the car/trailer, drive it down to wherever it was bought and metaphorically speaking slap it on the counter and demand a replacement or your money back.


And you'll look a right burk if the shop manager plugs it into one of their 13A sockets and it works without a problem.


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## Digit (14 Mar 2011)

> Cheapest solution would be to include the extension lead between the 13A socket and the 13A



I was today about to suggest the same test, but not as a permanent solution. My own TS, a SIP, caused the same problems, but unfortunately the lead move didn't solve it. The motor, despite the manufactures claims, simply will not do repeat starts etc on a 13 amp fuse.
Posters on here with the SIP have had the same problem, the extension lead as a test is fine, but personally I would not suggest it as permanent solution based on the dangers of leads all over place.
In the end a dedicated supply must be the best bet.
Returning the saw for a replacement might solve the problem, but based on the variabilty of SIP TS motors it might not.
The one volt drop reported by GT, _if consistant,_ along with the 32 amp initial surge, would suggest that replacing the socket with a suitable unit and MCB would be sensible.
If the one volt drop is not consistant then a supply fault, loose connection etc, might be the cause of the intermittant fusing.
Frankly I doubt that there is a fault with the machine, but time will tell!

Roy.


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## ondablade (14 Mar 2011)

That's true S, but bear in mind I'm thinking tactics/positioning rather than technicalities. It's in the end a judgement call though.

It sounds very likely that you are on to something in suggesting that the supply is probably a bit gruntier than is typical, but as before surely the maker's fuse should have enough in reserve to tolerate this? (unless that is it emerges e.g. that fuses and appliances routinely go pop in the house)

It wouldn't stop me continuing to investigate the supply, or with the supplier involved and still standing over the saw trialling it with possible solutions - but I'd feel an even bigger burk if it panned out in a few months that the saw had problems and I hadn't acted to place the guys I'd bought it from firmly behind the 8 ball.

A co-operative supplier opens up all sorts of possibilities, but if on the other hand they weren't supportive/didn't want to know then unless I badly needed a saw now I'd as before be thinking strongly of bunging it back to them...


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## Digit (14 Mar 2011)

Haven't seen a supply lead used to control voltage/current since I last worked on a 'Universal Wireless Set!' 



Roy.


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## Stoday (15 Mar 2011)

You must be as old as me, Digit. Those old radio sets had the valve heaters wired in series with a dropping resistance in the supply lead. They must have become obsolete in the 1940's.

:-({|=


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## Stoday (15 Mar 2011)

Gordon T":2uxds64c said:


> The machine will cut several times then blow a fuse, or start the day blowing a fuse.


What do you mean by "machine will cut"? What cuts? You haven't mentioned this before and it could throw a completely different answers to your problem.


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## Digit (15 Mar 2011)

Morning S. I asked GT that as well, haven't had a reply yet.
A little older than you I believe. At school etc I was deeply into radio/TV etc, built all sorts of things and started work in a radio and TV shop.
In those days, mid 50s, Luton was still partly on DC mains supply, so the 'universal' was still around. part of my work was recharging accumulaters! :lol: 
Lovely job!

Roy.


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## CHJ (15 Mar 2011)

Digit":hurh0mbf said:


> .... part of my work was recharging accumulaters! :lol:
> .....


 Into acid a couple of generations earlier than most then,  aah the smell of bubbling accumulators.


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## Digit (15 Mar 2011)

> Into acid a couple of generations earlier than most then,



Trend setter that's me.
Yeah! Rubber apron, large glass bottles. What did they call them things?
Large console TVs, small tubes, test card C, Andy Pandy, mini skirts.

Roy.


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## CHJ (15 Mar 2011)

Digit":15n02v4s said:


> > ...... large glass bottles. What did they call them things?


Carboys


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## Digit (15 Mar 2011)

Ta!

Roy.


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## Gordon T (15 Mar 2011)

Hello again, I must learn to be more clear, when I said the machine cuts several times I meant cuts pieces of wood, then blows a fuse.
Out of interest Record rang me yesterday to ask if my machine was running ok ans sounded suprised when I related my problems and attempts to solve them.
The substation is about 150 yards down the road from me,
and yes I have tried using an extension cable in the workshop, but that time it blew the fuse in the extension, and yes I have tried different extension cables with same result.
Why I wonder would using a commando unit as recommended previously, not work???? surely it would remove the weak link ie the 13amp fuse or I looking at this too simply!


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## 9fingers (15 Mar 2011)

Gordon T":2xvnyy99 said:


> Hello again, I must learn to be more clear, when I said the machine cuts several times I meant cuts pieces of wood, then blows a fuse.
> 
> Why I wonder would using a commando unit as recommended previously, not work???? surely it would remove the weak link ie the 13amp fuse or I looking at this too simply!



Yes Precision is vital! do you mean that the saw will start, perform cuts and then on the next start, blow a fuse? or does it blow a fuse DURING cutting?

Provided that it is the former then fitting a 16amp plug and socket will solve the problem (99.9% - I will bet a pint on it!!)

Bob


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## Digit (15 Mar 2011)

I'm with Bob! 



Roy.


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## NetBlindPaul (15 Mar 2011)

^ As Bob & Roy, as long as the plug is competently fitted I doubt it would compromise your warranty, though I am not in a position to guarantee this.

We could do with understanding the failures of the fuse, i.e. every start, every few starts, when cutting etc.

Paul


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## 9fingers (15 Mar 2011)

Digit":zyl8dn1c said:


> I'm with Bob!
> 
> 
> 
> Roy.




Mwah! Big hug? OK maybe not then :shock: 

Bob


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## Digit (15 Mar 2011)

Promises! Nothing but empty promises!

Roy.


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## Eric The Viking (15 Mar 2011)

Right you two! Get a shed somewhere...

Seriously, I've been keeping out of this discussion (better men tham me, etc.), but I do wonder if 'fixing' it with a 16A fuse-less plug/socket might actually be exposing a bigger problem: 

If the right measurements were made, we'd know, but it seems the startup current is, well, pretty big for a machine of that sort. It's nominally 1.5kW after all.

Could it be that the starter winding either has a few shorted turns or is wound to the wrong spec? One does wonder a bit. 

You'd hope Record would be taking more of an interest really, as the other obvious thing to do is test by substitution. Assuming one was available, I'd start by swapping the entire bandsaw, and if that cured the problem, go back and swap the motor in the bad one. If that doesn't work it's too much friction in the mechanical parts, if not, er, it's the motor. 

If neither bandsaw works consistently in that situation, it's the wiring (or both being faulty!).

Perhaps I'm missing something...


E.


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## Digit (15 Mar 2011)

> Seriously, I've been keeping out of this discussion (better men tham me, etc.), but I do wonder if 'fixing' it with a 16A fuse-less plug/socket might actually be exposing a bigger problem:



Yes! GT is trying to help but we still don't know, for example, if the fuse blows mid way through a cut, or at start up after having been turned off after a number of cuts.
My TS drove me nuts at one time, it would turn off then straight back on again. The fuse didn't even wave good bye!

Roy.


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## Gordon T (15 Mar 2011)

In an effort to help, the fuse fuses/blows always on start up and never during a cut.
The motor starts the blade begins to spin then within seconds and before full running speed the fuse goes ( and not for a walk). But not every time, which is why I have one of the channels in the bed full of fuses, and a screwdriver at the ready .

The switch has been replaced by Record, this was their first dfiagnosis.

Then a new motor arrived and I fitted that but no improvement, so I swapped it back for the original one.

Then the new fuse box fitted etc etc,

and thanks guys subject to what Record come up with next, I will fit a commando switch if nothing else works.

To answer an earlier suggestion, I suggested them taking the bandsaw back for them to test, but having already paid £95 for delivery to my place, and being told I would be paying for redelivery the same amount again once they found no fault with the machine I decided against it, my pockets are almost empty now.

Hope I have coverred all points raised, sorry if I have not answered all , will try to do so.

GT


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## Digit (15 Mar 2011)

GT, the machine runs on the domestic circuit.
Therefore we know two things.
1-there is nothing wrong with the machine.
2-the problem lies with your workshop supply.
After those conclusions we can only surmise, one of the possibilities is the 13 amp socket itself, I've known them duff new from the box.
If you have another suitable circuit in the shop, connect to that and let us know. If you don't have another circuit but have another 13 amp socket available, please swap them and let us know.
Each step will help narrow the problem.

Roy.


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## Stoday (15 Mar 2011)

To fix a fault you first have to find it. So you work out what you think it is and test a cheap fix. If that confirms the fault is what you thought, you can make a permanent fix; otherwise start over with another theory.

Circuit protective gear such as fuses and MCBs protect the downstream circuit, not the upstream. In this case, the 13A fuse protects the bandsaw and its connecting lead. The 16A MCB, the radial circuit to the 13A socket; the 32A MCB in the house, the cable to the workshop and the consumer unit in it. So it's difficult to think of anything upstream of the 13A fuse that could cause it to blow or the machine to overload, unless the machine itself were faulty. The rather remote possibility of the proximity of the substation is ruled out because it's quite a long way away.

The commando fix will cost. It provides a better connection than the 13A plug & socket. You can test the effect of a better connection cheaply by swapping the 13A socket for a 20A switch (£2.55 from Screwfix) and connecting the machine directly into it, since it's on a dedicated radial protected with a 16A MCB. Of course if the perceived fault is that the machine blows 13A fuses, eliminating the fuse cures the fault. But it's the real fault that is causing the fuses to blow; eliminating the fuse won't cure the real fault that still there.

I'm not so sure there's nothing wrong with the machine. Record has no other customer who can't run their machine using a 13A plug & socket. My table saw uses a more powerful (2kW) motor on a 13A plug & socket and I haven't blown the fuse (or tripped its MCB) in six years. That suggests that if the machine won't run without blowing a 13A fuse, it is faulty.

Although ETV's suggestion that the starter windings might be faulty was plausible, it's ruled out because GT swapped the motor as well as the starter switch. That leaves the possibility of a mechanical problem that's extending the time it takes to get up to speed, thus causing the starting transient to take too long. Perhaps there's a way of checking this out.


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## Digit (15 Mar 2011)

I can't see how the machine can be suspect if it runs on the domestic circuit S.
Upstream faults would be difficult to suggest, I agree, but what else is there?
With the machine running on the domestic circuit a machine fault would have to be intermittent, hence, damn difficult to find.

Roy.


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## Eric The Viking (15 Mar 2011)

I'm a fan of the too-low source impedance theory myself . 

- Knowing that the motor has been replaced eliminates the original motor.
- GT has told us the machine turns freely with no obvious friction or binding.
- Introducing impedance (extension lead from the house) keeps the fuses intact. It's a reasonable working assumption that the house supply has a higher impedance than the workshop (as that's just had new heavy cable, etc).
- the local xfmr (sub-station) is relatively close. If this is a semi-rural or rural area GT's property may have a nice fat bit of copper in the road, with few other taps off it before his.
- It hasn't yet been tried on a fuseless 16A circuit. Bob M. reckons that a 16A plug/socket will fix it. I think he's right.

Goodness knows how you might measure the source impedance of the mains (I think I was probably told about 30-odd years ago but have long since forgotten), but if someone did it, my guess too is that it would be atypically low. As long as the motor is happy with the startup surge as it could be in those circumstances, and it probably is, then there's no real problem beyond fitting a blue plug+socket.

Weird stuff, electrickery.

E.


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## Digit (16 Mar 2011)

> As long as the motor is happy with the startup surge as it could be in those circumstances, and it probably is, then there's no real problem beyond fitting a blue plug+socket.



If that turns out not to be so then by heck it will get to be interesting, ie, weird!

Roy.


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## Tierney (4 Jan 2012)

Hi,

I thought that rather than start a new thread, I would continue an old one. I have the same problem with my table saw - I think it might be worse due to the cold weather!

Anyway, I think it worked fine in my old house. My new house was completely re-wired, so along the lines of some previous suggestions it may be that unusually low impedence is the problem. 

Anyway, the facts are:

Machine
Scheppach TS2500 table saw (the old aluminium top, bought second hand so no option to return it)
I think running wattage is 2kw, startup 2.7kw
The label on the saw states 11.5A; but, the label on the one-off switch has 'IE = 13.5A'

Wiring
My new garage has a separate new MCB in the garage, running off a new MCB in the house, I think the house or the main MCB has new tails (whatever that means).
The cable to the MCB in the garage is either 2.5mm or 4.0mm; just usual domestic stuff
The garage has a ring; I think 2.5mm on a 32A breaker
The saw is connected to an extension lead; both have 13A fuses (only the fuse on the table saw lead blows)

Fault

I think more often than not it now blows a fuse on startup. When it starts it runs fine and has never blown a fuse (even though I am ripping 2" thick stuff on a blade that could do with a clean / sharpen.
I had been spinning the blade and then pressing the start button; which, I think helped; but, not always and it's not exactly safe
As said previously the fuse only blows in the plug on the table saw lead (I think I've gone through 8 now)

Solution
A number of people have suggested using a 16amp plug/socket connected to a 16amp breaker; which, seems like a solution (even if it doesn't mean that I understand what the root cause); however, does it need to be on it's own spur (i.e. not a ring), and does it have to be a 16amp breaker (I have a spare 32 in the MCB, that is the only reason I ask). 

I was sort of hoping that I could install a ring of 16amp sockets as I have a large bandsaw and planer, both three phase and about 40 years old - one has a dedicated converter, and the other has god only knows what connected to the motor to do the same. From what I have read on this and other threads, it seems to be that a ring may not comply with regulations if you are using 16amp plugs. Interestingly both never blow the 13amp fuse; but, they do cut-out when starting, so I need to press the start button, then off button and then repeat numerous times allowing them to build up momentum!

Anyway as I said, quite happy to try the 16amp socket; so I guess my question is as much about how to connect that to the MCB, unless I have missed something major, or someone has any other easy ideas.

Regards,

DT


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## condeesteso (4 Jan 2012)

I have a 500 and first time I ran it, it tripped the 16A supply. Whilst they rate at say 2hp (about 1500 watts i think) they draw a lot more starting ( a short hefty peak). Once running they stabilise, but you may just need to give it more headroom on startup.


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## 9fingers (4 Jan 2012)

16a sockets are fitted to radial circuits, each one protected by an MCB rated at 16a or quite often 20a.
For motor applications, these are better if type C providing the earthing is low enough impedance.
Each radial can be wired in 1.5mm2 cable although unless you have a source, you might just as well use 2.5mm2
You should not install a ring of 16amp sockets

Bob


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## Digit (4 Jan 2012)

Frankly it sounds like a mess!
It would help if you could tell us for certain whether the incomer is 2.5 or 4 mill, and the length.
The most logical reason reason for your problem is the actual start up current, (as opposed to what it is supposed to be,) this is supported by the cold affecting it.
'Tails' are the leads from the meter to the consumer unit.

Roy.


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## Tierney (7 Jan 2012)

Thanks for the replies. Ok, had another look and can give some more details:

1) I have a new consumer unit in the house, this has a 32amp MCB (on an unprotected part of the consumer unit, i.e. not through an RCD).
2) The consumer unit in the house is connected to a consumer unit in the garage with what looks like 6mm twin and earth cable (the live and neutral each have about six copper strands of about 1mm diameter). The length of this cable is somewhere between 20 and 30 feet.
3) The consumer unit in the garage has a ring circuit of 2.5mm on a 32amp MCB.
4) I have the saw connected to a short extension lead (only about 6 feet long with four sockets on it).

Hope this makes sense.

Roy, hopefully this sounds less of a mess (well maybe except the extension lead bit), otherwise I'm going to start feeling a bit ripped off. I told the spark and he saw what machines I had.

DT


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## Digit (7 Jan 2012)

Without carrying out some checks on conducter dia I am not certain but that does not sound like 6mm to me.
As Bob says a 32A ring and 16A sockets is a no no. Physically it could be done, but it would negate the whole idea of correctly guaged protection for the machine.
A dedicated radial main is the answer, the extension leads and lack of RCD is worrying!
You must understand that the MCB protects the machine, it does nothing for you!
If you cannot get an RCD plus a further 16/20A MCB in the existing CU a replacement is on the cards.

Roy.


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## 9fingers (7 Jan 2012)

That sounds fairly standard. In your position, I would fit an additional MCB -ideally type C rated at 16 or maybe 20 amps into the consumer unit in the garage and using a single 1.5mm2 or 2.5mm2 cable, wire to a 16amp socket near the machine.

This should solve your problem

hth

Bob

Roy beat me to it! (at least we agree!!)


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## Digit (7 Jan 2012)

Any disagreement with me Bob is likely to be based on my general disregard for what I consider to be over regulation, such as Part P.
I suspect that I am considerably older than you Bob and have seen Regs come and go and colour blind sparks as well, don't ask me how he got the job! :lol: 

Roy.


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## 9fingers (7 Jan 2012)

I did not mean to imply that we disagree - more that I wrote my reply before seeing yours and what we said was virtually the same!

Quite agree Roy on the over regulation. I tend to avoid wiring questions other than when they relate directly to motors as I am not a qualified sparky.
My posts on here are generally on a (I suggest that you)" Do as I say not as I do" basis.
I am quite confident that what I do in my own workshop is safe but not always to the letter of the Regs especially when that letter is "P" !!

Bob


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## Digit (7 Jan 2012)

Frankly Bob I loathe domestic wiring, I'd rather run conduit than chase walls. I have little regard for lots of rules, but I don't compromise safety, this place had two sockets when I moved in so had to be rewired.
We have 3 rings in the house, 2 lighting circuits, radials to the washing M/C and T/D, separate circuits for green house, metal workshop, garden shed, wood working shop, 3 separate radials for outdoor sockets and 3 for out door lighting! All RCD protected!
Overkill? Yep!

Roy.


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## Tierney (7 Jan 2012)

So I checked my CU in the garage and it is 80A with a 30ma RCD Incomer, so good news there. I also checked the cable from the Main CU to the one in the garage, and that has 2*6mm written on it. At least I think I have the right cable.

Ok, so now I'm going to get a new 20A type C MCB (I have a spare way in the CU in the Garage) and will connect one Commando socket to a radial main. I'm going to go for 20A because I may extend the radial and add more sockets at a later date.

Lets hope this solves the problem.

Thanks for all the advice.

DT


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## Digit (7 Jan 2012)

Good luck.

Roy.


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## andycktm (7 Jan 2012)

What i cannot get my head round is people say you want this ,you want that.Yeah 16 amp dedicated circuit,
but bang a 20 amp breaker in for good luck! Does anyone use a hobby machine that requires 20amps running load? :?


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## Digit (7 Jan 2012)

It's not the running current that determines an MCB's rating and type Andy, it's the start up current and its duration.
I've known machines that will happily start/run on a 13A plug in warm weather but blow a fuse in cold weather, or when the user has made a number of repeat starts, or simply changed to a larger and heavier blade.

Roy.


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## andycktm (7 Jan 2012)

Type and rating are two different things shurely?
If the motor is rated at 17 amps and one day decides to take20 amps to self destruct if cannot unless of course you have a 20 amp breaker fitted.


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## Digit (7 Jan 2012)

Type and rating are indeed so.
Bear in mind that I have been retired for some time, and things change.
But, if not, here is the Bible according to Digit!  
There are 3 TYPES of MCB, B, C, and D.
All are designed to trip within one tenth of a second when the over current reaches a specified level.
Those levels are thus....
Type B trips at 3 to 5 times the rating.
Type C trips at 5 to 10 times the rating.
Type D trips at 10 to 20 times the rating.
Allowing for the spread in tolerances you can see that a 20A type B should trip somewhere in the range of 60A to 100A
A 16A type C between 80A to 160A.
For that reason I personally always try a B type first.

Roy.


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## 9fingers (7 Jan 2012)

andycktm":1ugzo57y said:


> Type and rating are two different things shurely?
> If the motor is rated at 17 amps and one day decides to take20 amps to self destruct if cannot unless of course you have a 20 amp breaker fitted.




The function of a breaker/fuse is to protect the downstream cable NOT the load.
Any decent quality machine will have motor protection built in either by means of temperature measurement or in the DOL starter.

Bob


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## joemarkey6 (18 Sep 2013)

Hi all, I just stumbled accross this thread by accident, I know its an old thread but i thought i would tell my experience for anyone else was looking for an answer to a similar problem.

Weve got a record bs400 in our workshop and when it was reaching about a year old, our machine started intermittently blowin fuses, and over about a 2 month period blew about 15 fuses, until in the end it wouldnt start without blowing a fuse. It was the capacitor, record sent me a new one as i agreed to fit it, and its been ok ever since.


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