Startrite 352 wiring

[BorisTheBlade]

Disclaimer: Hi there I've spent the last couple of days searching Google and these forums and found threads discussing this problem but I couldn't understand the best response given by Fitz. I have dm'ed him in the hopes he can put it into simpler/step by step terms for me but am guessing he's busy and I really want to get this sorted so I can use the machine.

I bought a Startrite 352 that the owner had simply put in a 230v motor where there had been a 3 phase and wired it directly to a plug bypassing all existing electrics on the 415v machine. I was told by a friend that I can simply use L1 and L2 on the existing 415 wiring to use the start/stop button and brake. Obviously it's no surprise it didn't work and lots of googling later I realised it's much more complex and I need to get a new coil and relay. My question is will this enable me to use the foot brake and how exactly do I do this? Please read the disclaimer re: older posts.

Would I be better off buying a new switch? Would I be able to still use the foot brake?

Any help would be welcomed as I'm going round in circles googling and searching the workshop site.

The new motor is a Clarke 1hp

 

[Spectric]

If it was a three phase machine with a brake then fitting a 230 volt motor will make the brake and existing wiring mostly obsolete. It is not just a case of using the existing DOL ( direct on line starter ) because that will have a 400 volt coil, all you need to do is remove the old three phase 400 volt wiring and just get a new 230 volt DOL starter and the starter will have a wiring diagram with it and your problems are solved. Make sure all the parts are properly earthed.

 

[rogxwhit]

Parts here -
https://www.machinespares.net/produ...andsaws/351351s352-352s/electrical-equipment/

fitting a 230 volt motor will make the brake and existing wiring mostly obsolete

I understand the brake to be a simple friction device with an associated switch - which wouldn't be voltage-dependent. I think that the starter coils need to be 240V though.

 

[rogxwhit]

I think the starters were Danfoss & its very likely that you can still get parts. It would be neat to keep the original arrangement of having the starter encased in the column rather than adding an external housing.

 

[Argus]

I have a single phase 352, vintage around 1990..... I also have the manual that I can email to you - about 1.3 mb - if you send me a PM with an address.

There's a detailed1 ph wiring diagram on page 7.

It shows a 230 v starter with a suitable overload. There should be a series of safety interlocks on doors etc all in series with the starter switches and the emergency stop. The foot brake operates a friction brake, connected to a micro-switch.... all in series.

It is a simple setup, though you will probably need source a 230 v starter with an overload matched to your motor's consumption. Other than size and the electrical spec, any off the shelf starter will do the job. On my machine, it's a set of starter guts mounted on a top-hat rail in a control-box at the back, so if you have the same thing, any top-hat mounted starter with the right spec will work.

As a selection rule-of-thumb, the overload's adjustable range should be about 115% the motor's maximum input.
BUT if in any doubt, please get a professional to do the job.

 

[Spectric]

I understand the brake to be a simple friction device

Thats older than I thought, most brakes use regenerative braking but if this one is friction then what is the switch for, is to cut the motor ?

 

[BorisTheBlade]

Parts here -
https://www.machinespares.net/produ...andsaws/351351s352-352s/electrical-equipment/

I understand the brake to be a simple friction device with an associated switch - which wouldn't be voltage-dependent. I think that the starter coils need to be 240V though.

Hey thanks I got thank link when I bought a startrite table saw and don't have the money to splurge £60+ on a switch. Need to do it as cheaply as possible as I went into overdraft to buy the machine .

 

[Argus]

I've just had a look at the picture........ The design motor speed for a Startrite 352 is 1450 RPM (i.e. a 4 pole motor).
Your motor is 2800 RPM..... twice the speed!

Be careful with blade friction if you get it working!

 

[BorisTheBlade]

I've just had a look at the picture........ The design motor speed is 1450 RPM (i.e. a 4 pole motor).
Your motor is 2800 RPM..... twice the speed!

Be careful with blade friction if you get it working!

The 3 phase motor it had to start was 2800. I was surprised too and thought the guy had got the wrong one but he matched it to the brook Crompton it came with so must have been geared like that before

 

[rogxwhit]

don't have the money to splurge £60+ on a switch

:-( Whoops! That points to a 'cheap' far eastern starter then, that's 240V & surface mount ...

 

[BorisTheBlade]

:-( Whoops! That points to a 'cheap' far eastern starter then, that's 240V & surface mount ...

Surface mount and working is ok with me. I bought it not for it's aesthetics but to do a job. Is this one sufficient?

https://www.axminstertools.com/kedu...8fSDBNR9oh753Oy9EpS58VjOftV8yMPBoCekEQAvD_BwE

 

[BorisTheBlade]

Could I use this one I salvaged from a old plastic fantastic table saw? The switch costs almost the same as what I would get for the saw anyhow

 

[deema]

The normal motor for a 352 is 2850 RPM, so you have the standard motor fitted, I have come across them with slower speed motors normally when they have been used for metalwork. I’m happy to help and share any info I have on machines, I have restored one or two 352’s, but I won’t ever help with electrics to anyone who is not familiar with electrical installation. Electrics bite, you are lucky if it lets you have a second chance. Unlike gas, which lets you know there is a problem by having a smell and requiring the right concentration before getting fussy, electrics just needs one wrong decision. Its one of those things, most people wouldnt dream about messing about with their domestic gas installation, but seem happy to tinker with electrics. The later is far more likely to kill you! If you need advise on electrics get an industrial electrician to sort it out. The bits you need are relatively cheap and very easy to install properly.
Anyway, I’ve attached a copy of the manual, it details how to setup the manual foot break. Chancers are that the friction material plate is worn out.

 

[rogxwhit]

The Ax one's rated ok to cover your 1hp motor. Can you work out how to mount it because it seems to lack a backing box? And NVR is more important than overload protection.

Yes the salvaged switch is marked 15A - that's more than enough.

 

[deema]

Unless you are an industrial electrician, electrical engineer qualified in this area, or something similar that means you fully understand the subject please stop providing advise on electrics. A lot of what I read on this forum about electrics is either wrong, or down right dangerous.

 

[BorisTheBlade]

The Ax one's rated ok to cover your 1hp motor. Can you work out how to mount it because it seems to lack a backing box? And NVR is more important than overload protection.

Yes the salvaged switch is marked 15A - that's more than enough.

'Ax'... 'nvr'?

 

[BorisTheBlade]

Unless you are an industrial electrician, electrical engineer qualified in this area, or something similar that means you fully understand the subject please stop providing advise on electrics. A lot of what I read on this forum about electrics is either wrong, or down right dangerous.

It's the push-stick police here to doll out unhelpful remarks that don't answer the thread and to push their own insecurities onto others. I'm posting in a forum precisely because I'm not an electrician, otherwise I wouldn't need to. My word butt out and read another thread if you're going to be unhelpful.

 

[rogxwhit]

'Ax'... 'nvr'?

Axminster - what you posted. No volt release - trips if there's a power loss so that the machine doesn't start up by itself if the power comes back on.

Make absolutely sure that the incoming earth wire connects to the metal frame of the saw ...

 

[Fitzroy]

Hey-up Boris, saw your DM, was a busy family weekend walking up hills I'll happily try and help you sort it out. When I've converted my machines I wanted to keep them as original as possible so I wanted to use the same start and stop buttons, which added some complexity to the task.

It sounds like the main thing you want to achieve is to ensure the mechanical door interlocks and the foot brake are useable. This will need you to wire the existing mechanism into a new DOL, or perhaps you can replace the 415v relay in the bandsaw with a 240v one.

The interlocks, foot-break and stop button are all part of the same mechanism. The stop switch pushes on the red area in the image, opening the normally closed circuit in the relay, the door interlocks push forwards the blue pin, so they hold the circuit open unless the doors are closed, the green bar pushes out when the foot break is applied, again opening the NC circuit.

The start button pushes on the top of the grey metal strip that closes the normally open circuit on the relay.

PS. As Deema said electrics are dangerous. I personally find them terrifying and i think I'm pretty competent. Please do be wary if you think you're out of you're depth. People on here comment on this stuff as they are worried about each other not to be nosy nor annoying, they've likely seen or felt the impact of an industrial accident on friends and family and would hate to see someone else hurt.

 

[BorisTheBlade]

Hey-up Boris, saw your DM, was a busy family weekend walking up hills I'll happily try and help you sort it out. When I've converted my machines I wanted to keep them as original as possible so I wanted to use the same start and stop buttons, which added some complexity to the task.

It sounds like the main thing you want to achieve is to ensure the mechanical door interlocks and the foot brake are useable. This will need you to wire the existing mechanism into a new DOL, or perhaps you can replace the 415v relay in the bandsaw with a 240v one.

The interlocks, foot-break and stop button are all part of the same mechanism. The stop switch pushes on the red area in the image, opening the normally closed circuit in the relay, the door interlocks push forwards the blue pin, so they hold the circuit open unless the doors are closed, the green bar pushes out when the foot break is applied, again opening the NC circuit.

The start button pushes on the top of the grey metal strip that closes the normally open circuit on the relay.

View attachment 141254

Yes that's a real head scratcher. What outlay would I be looking at to replace the relay? It would be nice to be able to use the old buttons and have the safety features.