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The dreaded start/stop issues

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The dreaded start/stop issues

Postby JasonvG » 29 Jan 2021, 11:29

So after a period of intermittent issues, followed by weeks of no problems, then back to intermittent issues, my start stop on my tablesaw has finally given up.

I've spent most of lockdown tidying/sorting the garage into a workshop, which included building the saw into a new bench. Replacing the saw is not a financial option right now so I need to get this repaired as efficiently as I can.

The problems have basically been that some time back the saw refused to stay running. Pressing start would run, then releasing start would break the connection. Holding start depressed allowed the machine to run, as SWMBO can attest as I got her to crouch down holding the button whilst I made a few cuts and showered her in sawdust. :twisted:

We then recently had a period of no issues and yesterday it went downhill rapidly. Only by, what I can only describe as "jabbing" at the start button and holding it for a few seconds would the saw run. I stripped down the start/stop and cleaned it out, applied some WD40 to the coil etc and we had normal operations for a few hours on and off. Later on though I lost this functionality too. Now jabbing the button produces a momentary motor noise and slight twitch in the blade rotation followed by nothing. The start and the coil are not engaging to keep things running.

I'm 99.9% it is the start stop button, not something further down the line so with that in mind I visited Toolstation to get a new DOL starter. https://www.toolstation.com/axiom-dol-starter/p56285

Ok here goes the bad news: It's a Scheppach TS30 table saw, which doesn't use a straight forward start stop or wiring arrangement. I know, I know, but I was young and naive. It does have a powerful motor, great cut depth and now thanks to my bench I've built round it a new fence and mitre slots parallel to the blade.

Here is the info I have:
IMG_0461.jpeg
switch diagram
(213.95 KiB)

IMG_0465.jpeg
wiring
(381.73 KiB)

IMG_0464.jpeg
motor plate
(215.43 KiB)

IMG_0462.jpeg
capacitor?
(151.09 KiB)


I could do with a little help / re-assurance in choosing the overload relay, and with the eventual wiring solution. As you can see this particular saw is powered from a schuko inline plug with L N & E but after the coil and switch uses a 3 core + earth arrangement going to the motor. I'm not sure if the 3rd core is a return feed to indicate high temperature or overload and cut the power or if it is an additional power to something else? Capacitor perhaps?

From the info I have I went with the 4Kw DOL as I saw 2.2Kw on the plate and thought double for startup load. From there I'm thinking this https://www.toolstation.com/axiom-thermal-overload-relay/p31837 relay as the 5-8 amp range covers the 6A I can see on the pictures.

Then it's the wiring. I get how to wire up the DOL for 2 core + earth, but to be honest, that 3rd core is really throwing me off. :?

From reading around I know we have some good guys on here when it comes to electrical, so...
Help?!?
JasonvG
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Re: The dreaded start/stop issues

Postby TrimTheKing » 29 Jan 2021, 11:40

Fear not Jason, Bob will be along soon!
Cheers
Mark
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Re: The dreaded start/stop issues

Postby novocaine » 29 Jan 2021, 12:37

thats a kedu KJD12-14.
it has 6 terminals but you cross terminal 4 and 6.

RS components should stock it.
Carbon fibre is just corduroy for cars.
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Re: The dreaded start/stop issues

Postby 9fingers » 29 Jan 2021, 16:14

I'd favour going down the path you are already on with a proper DOL starter.
The overload relay you have selected is fine too.

Just ignore the black wire coming from the motor. It goes to a thermal sensor inside but that function will now be provided by the overload relay. Wrap the end in some insulating tape tucked safely out of the way.
Set the thermal overload to as low a setting as possible that will allow the machine to run.
Good luck
Bob
Information on induction motors here
https://drive.google.com/file/d/1dBTVXx ... sp=sharing
Email:motors@minchin.org.uk
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Re: The dreaded start/stop issues

Postby JasonvG » 29 Jan 2021, 16:38

9fingers wrote:I'd favour going down the path you are already on with a proper DOL starter.
The overload relay you have selected is fine too.

Just ignore the black wire coming from the motor. It goes to a thermal sensor inside but that function will now be provided by the overload relay. Wrap the end in some insulating tape tucked safely out of the way.
Set the thermal overload to as low a setting as possible that will allow the machine to run.
Good luck
Bob


Bob you make it sound so simple!
Thanks very much for your response though. Much appreciated.
JasonvG
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Re: The dreaded start/stop issues

Postby novocaine » 29 Jan 2021, 16:46

I failed to read the bottom of your post, sorry Jason.

Bob is as ever correct.
Carbon fibre is just corduroy for cars.
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Re: The dreaded start/stop issues

Postby Lurker » 02 Feb 2021, 14:07

Most likely not your problem, but.....
I bought a table saw and almost immediately I had intermittent problems with it stopping.
Long story short, the silicon like dust cover on the nv switch was fouling the off button. I removed the dust cover and the problem went away.
The supplier in the meanwhile had sent me a spare switch, so I am ok if the switch gets full of dust, but the issue was a good 5 years ago.
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Re: The dreaded start/stop issues

Postby 9fingers » 02 Feb 2021, 14:13

Are you all sorted now Jason?

Hope so and I'll knock it off my "pending" list

Bob
Information on induction motors here
https://drive.google.com/file/d/1dBTVXx ... sp=sharing
Email:motors@minchin.org.uk
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