Table Saw Repair (fuse blows) Project - your suggestions...

[Steve Blackdog]

Hi folks,

I have just bought a 'pig in a poke' on eBay. I have paid £20 for a new customer return faulty SIP 01930 10" Table Saw. I like a challenge and even though this isn't a top (or medium) level saw (by any means), if I can get it working and set it up carefully, it will be a relative bargain. If I have to give up on it, I haven't lost an arm and a leg, and hopefully will have had some fun trying to get it up and running.

So, I put in a £20 bid and forgot about it and I've won the auction. I'm still trying to work out whether or not this makes me happy

As far as I was able to find out the only thing wrong with it is that when you plug it in, it pops the fuse. Now, I realise there could be something fundamentally wrong, but I've had machines blow fuses before, but only because of the current overload surge on start up.

If anyone has any experience of fault finding fuse problems on table saws (this one is 2hp - 1600W, 240v 13Amp single phase motor), please can you share your experience and any useful solutions.

I have in mind looking at
the start-up capacitor;
the NVR;
the cable and plug;
checking for damage to windings;
trying with no blade and checking for mechanical interference.

The circuit in my garage (where I will test it) is on a 32A B rated MCB circuit with a 30mA RCB plug socket. The garage sockets share a circuit with a bedroom and utility room (so I can't change anything on the circuit board). I have no 16A socket and don't really want to invest in one.

I am thinking that I might try plugging it in to 50m extension cable to 'slow' the surge, but not sure if it will make any difference.

Any ideas, I'm all ears - btw -please don't say throw it in the skip - it hasn't even been delivered yet

Many thanks

Steve

 

[blackrodd]

As you know there are a couple on here who will know the answer, which is way beyond me, the only suggestion I would have is if you plug it into you're cooker panel if you have one, that's usually the biggest cable in the house and may stop the saw tripping.
Sounds like you have done well with you're purchase anyway.
Regards Rodders

 

[Steve Blackdog]

As you know there are a couple on here who will know the answer, which is way beyond me, the only suggestion I would have is if you plug it into you're cooker panel if you have one, that's usually the biggest cable in the house and may stop the saw tripping.
Sounds like you have done well with you're purchase anyway.
Regards Rodders

I'm working on the basis that the push stick, the fence and the mitre gauge must be worth at least a fiver!!

 

[sunnybob]

no point in speculating before you get it.
It could be as simple as a badly wired plug. or a squashed or cut cable. Or even a 5 amp fuse in there by mistake.

Relax, have a coffee.
dont get too technical at this stage.

 

[Paddy Roxburgh]

Do you have 16 amp sockets with breakers? If so try it on these unless there are any obvious faults. 13amp is a little low for a 2hp motor as they can often draw twice the wattage on start up.
Paddy

 

[sunnybob]

Manufacturer states 13 amps. So it shouldnt blow a fuse when plugged into a 13 amp socket.

normal fuses are "slow blow" to allow for start up peaks, but I expect this has a capacitor so there shouldnt be any problem.

 

[mindthatwhatouch]

I have in mind looking at
the start-up capacitor;
the NVR;
the cable and plug;
checking for damage to windings;
trying with no blade and checking for mechanical interference.

Steve

You are on the right lines, start there and see what happens.

 

[scosarg]

1 - take the belt off and see if the motor starts on its own - if not it's a motor/ wiring problem.
2 - if motor does start on its own, refit belt, check bearings and take blade off.
3 - if that works ok put blade back on... if that blows fuse you probably are lacking in cable capacity or need to connect to a 16 amp plug not 13 amp
hope that helps.

 

[Steve Blackdog]

1 - take the belt off and see if the motor starts on its own - if not it's a motor/ wiring problem.
2 - if motor does start on its own, refit belt, check bearings and take blade off.
3 - if that works ok put blade back on... if that blows fuse you probably are lacking in cable capacity or need to connect to a 16 amp plug not 13 amp
hope that helps.

Thanks for this advice. I think this model is a direct drive, so no belt. It still hasn't arrived!

Will report back on what I find when I plug it in!

 

[Steve Blackdog]

Update:

The saw arrived today. If is in average condition and looks like it has been used - possibly for quite a while. From the state of a couple of the screw heads it looks like the owner was a bit ham-fisted.

It doesn't blow my fuses. But there is a problem. I notice that it now has a 13a fuse, but the manual says it should have a 5a fuse.

It will run but makes a very loud electrical arcing/popping noise and blue sparks flash out of the motor. I reckon it would set itself on fire if you ran if for more than a few seconds.

I took the motor out of the saw and stripped it down. The first thing to strike me is how dirty the armature is. There is some really ugly soldering on the armature coils but that could just be because it is cheaply made.

When I pulled out the armature, there was no sign of the carbon brushes. After a little shaking the carbon pieces rattled out, but they were not attached to the springs as I would have expected. One of the bushes was virtually worn away (2 or 3 mil).

What happens when brushes wear down? Does it cause functioning issues?

So, is it possible that the motor running with the springs contacting the armature would (a) trip the fuse and/or (b) account for the massive sparks and loud popping?

I am loathe to put in new brushes and find it makes no difference. I'm not sure I can get the field out to inspect it.

Does anyone know if I can test the armature with a multi-meter?

If i need to replace the motor, do you think it will be worth spending the money on?

All suggestions gratefully received.

Cheers

Steve

 

[OLD]

The arcing will have overheated the armature and caused the solder to melt and could have been spun off . Brushes are not expensive and you can make the wrong size fit by cutting ,just to see if it will run ok having cleaned the armature segments.If not new armature and brushes .

 

[Steve Blackdog]

The arcing will have overheated the armature and caused the solder to melt and could have been spun off . Brushes are not expensive and you can make the wrong size fit by cutting ,just to see if it will run ok having cleaned the armature segments.If not new armature and brushes .

Thanks for your comment. I've ordered a set of brushes off that site for £4 delivered. I will give the commutators a good clean up and see if it makes any difference.

 

[Steve Blackdog]

Update:

After a few attempts to get the motor working (and about 20 fuses!), I decided to give up and buy a new motor. Motor was around £75, so not too expensive.

SIP Industrial Products sent me a replacement for one of the top pieces FOC (Thanks SIP!).

Everything is now working as it should be. I have a decent working saw for under £100 - not bargain of the century, but with a new motor, it does what I need it to and should last me a long time.

All's well!

Thanks for your comments, folks.

All the best

Steve

 

[cammy9r]

Hi, I have a mitresaw that had the same issue of loud popping and sparking from the brush/armature area. I stripped and tested the armature and found it to be in good condition with no dead sections, the field coil did however look suspect, I ordered another, just under £60 delivered from bosch, and it cured the problem. Was happy to get my saw back, It is 9 years old and has done a lot of work now it can do a lot more. I think I may have caused the problem by running the saw too long using a 45m extension cable, not sure though but the cable was only 1.5mm. I also noted that the cooling system on the motor was not very effective and the motor body became very hot to the touch, I few holes in the belt cover allows air to freely flow through the motor and now keeps it cool when trench cutting. Time will tell if I did the right thing.