# Contactor won't reset



## Peter E (Aug 14, 2015)

I have 2 - 120/208V 3 phase start/stop stations for an exhaust hood that won't reset or lock in anymore. It happened right after phase was lost from utility company for about 3 hrs. It was the typical ones used as seen below. The low voltage conductor to coils are dead as well. Is there any to reset these and remove the low voltage wire and just use as a start stop station.


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## chicken steve (Mar 22, 2011)

Check if the coil is still good first

~CS~


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## telsa (May 22, 2015)

Single phasing ==> check your fuses... even check your thermal cut-outs// OL 

If even one of them is dead// crippled the contactor won't pull in.


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## varmit (Apr 19, 2009)

1. Make sure that all three lines to the starter are on (no blown fuses or faulty breakers).

2. Reset the starter O/L relay and check for continuity through the O/L contacts.

3. Verify that you have control power. 

4. Check the starter coil.

5. Turn off power to the starter. Check the coil for proper in/out movement. (Often on single phasing conditions the contacts can burn up or weld closed.)

6. Check the motor for ground fault or open winding. ( This will not stop starter from engaging, but motor could have been damaged by the phase loss.)


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## micromind (Aug 11, 2007)

7. Since it's a hood, the Ansul system may need to be reset.


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## JRaef (Mar 23, 2009)

With no reset button on the cover, that's probably an IEC style manual motor starter inside. The reset on those sometimes is like a circuit breaker, where the Trip is a mid-ground between Stop and Start, so to reset it you must push the Stop button first, then the Start button. If that doesn't work, then you likely have an Under Viltage Coil on the starter and until it sees Viltage, it will not allow a reset. 

Hard to tell what you actually have however from just that picture. A part number would be better.


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## John Valdes (May 17, 2007)

There is no control circuit in a manual starter. There is an overload.
If it will not reset, replace it.

Note: There is no coil either.


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## Jhellwig (Jun 18, 2014)

John Valdes said:


> There is no control circuit in a manual starter. There is an overload.
> If it will not reset, replace it.
> 
> Note: There is no coil either.


Some of them have phase loss/ under voltage detection that will kick them out whether the motor is running or not.


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## Bootss (Dec 30, 2011)

Make sure you bill the utility company for all the time and money spent on this too


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## Cow (Jan 16, 2008)

Lep said:


> Make sure you bill the utility company for all the time and money spent on this too


Why would he waste time trying to do that? If the customer called him to fix the contactor, the customer pays the bill unless another arrangement is made first. Let the customer fight with the utility if they want to be reimbursed for the bill.


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## varmit (Apr 19, 2009)

Yep, the picture appears to be a manual starter. Is this what is actually on this equipment?


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## hardworkingstiff (Jan 22, 2007)

Peter E said:


> I have 2 - 120/208V 3 phase start/stop stations for an *exhaust hood* that won't reset or lock in anymore. It happened right after phase was lost from utility company for about 3 hrs. It was the typical ones used as seen below. The low voltage conductor to coils are dead as well. Is there any to reset these and *remove the low voltage wire and just use as a start stop station*.


I would caution you about doing this. As others have said, if there is an Ansul system, then doing what I think you want to do would be a violation of codes that require the Ansul system to be able to control the hood.


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## telsa (May 22, 2015)

Single phasing is as tough on the OL // 'heaters' as anything. 

If they are not totally squared away -- the contactor will not pull in -- you stay 'dropped out.'

These are usually so reliable that they get entirely overlooked // totally forgotten.

The common schematics for OL do not detail their connection// circuit path. It's in series as far as the contactor coil is concerned. The second that one out of the three 'pops' -- the relay drops 'open.' 

Simple designs ( ie the one cited in the OP ) commonly require that you explicitly, manually, reset them with the magic button -- which may well entail opening up the lid to look inside. 

The magic button usually is red plastic with the surprising legend "reset" on it -- poking out when it needs the human touch.

But it's not unheard of for OL failure. So, if a mere reset does not work, kill the power and poke around. You can mechanically force the coil into the run position -- to test the continuity of the coil circuit in the 'hold' position.

Somehow, single phasing does not figure to have tripped the Ansul system -- without it being mighty obvious. 

You could have glitches anywhere. After starting with the basics, work back through the control circuit to find out what's up.


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## John Valdes (May 17, 2007)

telsa said:


> Single phasing is as tough on the OL // 'heaters' as anything.
> 
> If they are not totally squared away -- the contactor will not pull in -- you stay 'dropped out.'
> 
> ...


huh?


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## telsa (May 22, 2015)

John Valdes said:


> huh?


Now that's a quotable quote. :laughing::laughing::laughing::laughing:


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