Motor starter, confusion.

[Stuart J]

Ok, so I might be being a bit stupid here, but how is this start meant to work- is there a bit missing?
Stop button lines up perfectly with white button on the overload, but the start button, which is more or less straight up from the stop, will only push against the black plastic bit, nowhere near the start button.
What am I missing??

 

[milkloss]

Did it work before you took it apart?

 

[Stuart J]

Spare one kicking about the workshop.

 

[bobk]

Should there be a bar on the stop button ? they obviously don't line up .

 

[Stuart J]

The starter itself works perfectly. .with the lid off...

 

[milkloss]

Spare one kicking about the workshop.

could well be the wrong box for the contactor then. Bit of plastic oil can, hole drilled to fit under c clip and twisted to the correct angle to push the starter button.

 

[Cjm]

That’s correct. Start button lines up with the black strip between 33 and 34. Assuming it’s powered up the coil then pulls the contactor down to make the circuit. The small black “button “ is just an indicator on the end of the contactor

 

[milkloss]

In that case there may have been more to the plastic strip than you have now. Some contractors use an external push button switch that mounts on the front of the contactor to energise the coil momentarily.

 

[Cjm]

That’s correct. Start button lines up with the black strip between 33 and 34. Assuming it’s powered up the coil then pulls the contactor down to make the circuit. The small black “button “ is just an indicator on the end of the contactor

Your buttons should line up with these.....

 

[Stuart J]

That’s correct. Start button lines up with the black strip between 33 and 34. Assuming it’s powered up the coil then pulls the contactor down to make the circuit. The small black “button “ is just an indicator on the end of the contactor

In that case there may have been more to the plastic strip than you have now. Some contractors use an external push button switch that mounts on the front of the contactor to energise the coil momentarily.

Ah ok, black strip does nothing when pressed or when stop button has been pressed. I suspect something isn't working completely soundly somehow.
Which is a shame because it works perfectly otherwise.

 

[Cjm]

It won’t do anything without power connected.

 

[Stuart J]

That was with power connected.

I'm maybe thinking something must be miswired before it's not working.
I'll start again.

It won’t do anything without power connected.

 

[Deutzdx3]

Brand new one is £25 depending on power from screwfix. Cheaper from electrical wholesaler but needs must some times.

 

[Stuart J]

Brand new one is £25 depending on power from screwfix. Cheaper from electrical wholesaler but needs must some times.

No overload relay on those.

 

[milkloss]

I think it should be like the picture below. The white strip is the momentary coil energising circuit. I think you're missing that bit..... well, the rest of it anyway!

 

[Stuart J]

I think it should be like the picture below. The white strip is the momentary coil energising circuit. I think you're missing that bit..... well, the rest of it anyway!

No I think the white bit is my black bit. It is certainly a connector that closes the circuit between 13 and 14 on my contactor.

I think I'm maybe wired wrong so that circuit isnt being powered or something.

 

[milkloss]

No I think the white bit is my black bit.

yeah, but it's supposed to be a button...... you've only got the back plate of the button, I reckon the button unit itself has been broken off leaving its mounting plate behind.

 

[Stuart J]

yeah, but it's supposed to be a button...... you've only got the back plate of the button, I reckon the button unit itself has been broken off leaving its mounting plate behind.

I'm doubtful as there is very little extra space available between the start button and the black bit.
I took off the seal round the two enclosure halves, and without it, the start button didnt even move, it was that close to the black strip.

 

[Stuart J]

Too much confusion for one night.

 

[milkloss]

Stumped then...... I guess you know this but here goes....

a momentary switch is required to power the contactor coil which then powers itself via the output from the thermal overload. The momentary switch should be powered via the overload (usually a special 'tripped' circuit through the overload for this purpose) so that you can't force the motor into action when it's tripped by holding the go button down.