contactor burning out

[mcm]

I recently fitted a new contactor three phase 10amp with 230volt coil, now it was working fine for about two weeks and now seems to have burnt out. I can not manually push the contactor in even using a screwdriver as it is solid. The overload is set to 4 amps so shouldn't be a problem with that has anyone have any ideas why it has burnt out? I have heard it could be caused by a drop in voltage on a phase but what would cause this as it all tested out at 230volt before it went wrong.

 

[mcm]

Not sure what the rating was ac1 or ac3 I will need to take a look. I sent the old contractors to the wholesaler who then spoke to brook crompton to order the part. Could it be a faulty contactor or do you think there is more to it?

 

[Pete999]

Sorry kin ell

 

[Deleted member 72666]

Not sure what the rating was ac1 or ac3 I will need to take a look. I sent the old contractors to the wholesaler who then spoke to brook crompton to order the part. Could it be a faulty contactor or do you think there is more to it?

If like you say its a crompton contactor then the smallest they do in a AC3 is 9amp (its ac1 rating is 25amp) They currently do 2 ranges, a 3 pole and a 4 pole, they also sell a (their words ' contactor style' relay, which is black and orange in colour) which one did you use and what size of motor is fitted?

 

[Darkwood]

Is the coil voltage correct for the control circuit ... overvoltage on an incorrect coil can last a while depending on duty of the load ... this would have been the first thing to check.

 

[mcm]

If like you say its a crompton contactor then the smallest they do in a AC3 is 9amp (its ac1 rating is 25amp) They currently do 2 ranges, a 3 pole and a 4 pole, they also sell a (their words ' contactor style' relay, which is black and orange in colour) which one did you use and what size of motor is fitted?

The contactor is a 3 pole and is a brook crompton cc0910-230v. This is the one they said replaced the original contactor that has been discontinued now

 

[Marvo]

A few photos of the control panel and of the contactor would be helpful. If this is woodworking machinery it could also be a reversing starter. Interlocks could also be mechanical as well as electrical. Like I say photos would help answer a lot of questions.

 

[mcm]

Is the coil voltage correct for the control circuit ... overvoltage on an incorrect coil can last a while depending on duty of the load ... this would have been the first thing to check.

The coil voltage is 230v and I have checked this.

 

[Deleted member 72666]

The contactor is a 3 pole and is a brook crompton cc0910-230v. This is the one they said replaced the original contactor that has been discontinued now

That one is rated at 5.5kw with a ac3 rating of 12 amps. Can you remember the size of motor used and how often is it stopped and started per hour?

 

[netblindpaul]

Unlikely it will be a reversing starter in the UK.

 

[mcm]

That one is rated at 5.5kw with a ac3 rating of 12 amps. Can you remember the size of motor used and how often is it stopped and started per hour?

Im not sure on the motor rating but the machine is in a joinery shop so would be on and off all day long I would of thought.

 

[showerman]

I have over many years had dealings with contactors , relays etc and I have had more
problems with Brook Crompton than any other make . Brook coils have a habit of
swelling and restricting movement of the contactor or relay . I change to a different make of unit wherever practical and never have had a problem . Hope this helps , Ken .

 

[Deleted member 72666]

When you go back check motor size, see if the contactor is physically 'stuck in' (in the energised position) also does the coil smell of burning and check it's resistance. Is there any debris ie sawdust in the panel? Have you still got the 'old' contactor if so what's the part number? Also as been mentioned earlier get some photo's up as well!

 

[mcm]

When you go back check motor size, see if the contactor is physically 'stuck in' (in the energised position) also does the coil smell of burning and check it's resistance. Is there any debris ie sawdust in the panel? Have you still got the 'old' contactor if so what's the part number? Also as been mentioned earlier get some photo's up as well!

The contactor coil is smelling of burning and not getting any continuity through the coil now so take it the coil is gone. The contactor is stuck not allowing any manual operation ie with a screwdriver, think it is stuck in the open position rather than energised and has no saw dust in the panel.

 

[mcm]

I have over many years had dealings with contactors , relays etc and I have had more
problems with Brook Crompton than any other make . Brook coils have a habit of
swelling and restricting movement of the contactor or relay . I change to a different make of unit wherever practical and never have had a problem . Hope this helps , Ken .

Hi Ken, room around the contactor is limited and has another two brook crompton contractors next to it. That's the reason why I choose a straight replacement with brook crompton due to spacing.

 

[Deleted member 72666]

The contactor coil is smelling of burning and not getting any continuity through the coil now so take it the coil is gone. The contactor is stuck not allowing any manual operation ie with a screwdriver, think it is stuck in the open position rather than energised and has no saw dust in the panel.

Could be a bad batch but I would still check stop circuit for intermittent high resistance that would cause under voltage and maybe chattering of the contactor. Speak to Cromptons to see if there's been a problem (doubt they'll own up) and see if they'll replace it foc!