# Odd delayed shut off



## paulengr (Oct 8, 2017)

Troubleshot a weird lift station controller problem today. The pump would start just fine but took a long time to stop. And it’s not a fluid thing, the contactor held in fir minutes. Looking through the panel it had two potential relays and an odd 1 second timer. Checking each of those they worked as expected.

No more timers so I started walking the meter down the start/stop chain and realized there was no power on the contactor. Hard to believe so I tripped the breakers and...it didn’t open then suddenly a minute later popped open. Coil ohmed 23 ohms same as the second pump starter. Can’t open starter (IEC design).

So something is jamming the contactor. I’ve seen busted springs (won’t ever open), no closing (coil swelled up),welded contacts even but not a contactor that was sticky.


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## Wirenuting (Sep 12, 2010)

paulengr said:


> Troubleshot a weird lift station controller problem today. The pump would start just fine but took a long time to stop. And it’s not a fluid thing, the contactor held in fir minutes. Looking through the panel it had two potential relays and an odd 1 second timer. Checking each of those they worked as expected.
> 
> No more timers so I started walking the meter down the start/stop chain and realized there was no power on the contactor. Hard to believe so I tripped the breakers and...it didn’t open then suddenly a minute later popped open. Coil ohmed 23 ohms same as the second pump starter. Can’t open starter (IEC design).
> 
> ...



I just ordered a replacement contactor iec in a dual Quincy air compressor.
Similar issue. Couldn’t see why it was hanging and can only guess it’s just worn down cheap plastic. A light tap and it pops open. 
Running on just a single compressor till the new contactor shows up. Then I’ll take it apart and see..


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## micromind (Aug 11, 2007)

That's one of them there new-fangled true off-delay timers........

Or maybe just a chintzy IEC contactor.......

I haven't seen one delay like that either; guess there's a first time for everything.


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## varmit (Apr 19, 2009)

Yes, this happens some times. The coil can bind on the plastic housing or contamination and hold in until the residual magnetism of the coil fades away or vibration causes the coil to release. Sometimes a snubber on the coil will help.


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## MDShunk (Jan 7, 2007)

I'd just chalk up the weird observations to "It's an IEC contactor" and not let the exact nature of the failure rent space in my brain. Going any more in depth than simply throwing it away would be equivalent to doing a metallurgical analysis on a chinese screwdriver from the dollar store to find out why it broke.


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## MechanicalDVR (Dec 29, 2007)

MDShunk said:


> I'd just chalk up the weird observations to "It's an IEC contactor" and not let the exact nature of the failure rent space in my brain. Going any more in depth than simply throwing it away would be *equivalent to doing a metallurgical analysis on a chinese screwdriver from the dollar store to find out why it broke.*


Exactly!


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## MikeFL (Apr 16, 2016)

I'm in the sticky camp too. Something's binding, maybe spring lost its zest, caked up grease, chip of something wedged somewhere, could be anything.


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## paulengr (Oct 8, 2017)

It’s a Cutler Hammer AN16GN0AB. Looks like IEC but built to UL/SA/NEMA specs. Still seen it with any contactors but such a long delay (minutes) without totally seizing up was a new one on me.


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## MechanicalDVR (Dec 29, 2007)

MikeFL said:


> I'm in the sticky camp too. Something's binding, maybe spring lost its zest, caked up grease, chip of something wedged somewhere, could be anything.


Tiny bugs, baby roaches, mold, dust, there are a thousand things that screw up contactors.


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## Jlarson (Jun 28, 2009)

Eh I've had issues with IEC's jamming, less so with the CH ones but it was happened, had the CH's jam on compressors that are in round the clock service.

Easy fix is to grab it, rip it from the panel, toss over the shoulder and then install a NEMA starter.


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## MechanicalDVR (Dec 29, 2007)

Jlarson said:


> Eh I've had issues with IEC's jamming, less so with the CH ones but it was happened, had the CH's jam on compressors that are in round the clock service.
> 
> Easy fix is to grab it, rip it from the panel, toss over the shoulder and then install a NEMA starter.


Which is great when you have the room for a NEMA started.


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## Jlarson (Jun 28, 2009)

If there isn't room for a good old fashioned NEMA product it's time to make room, loose some more euro trash or a bigger box. :laughing:

Or if the customer is a cheap ****er put the cheapest *********** industries IEC starter in there and get em for another emergency service call down the line when the **** pump stops working again. :yes:


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## varmit (Apr 19, 2009)

Most of the things that I work on are space limited, so there is no choice but IEC. I always try to upsize the contactor a couple of sizes and this seems to improve life span, but does away with any material cost savings.

Overloads are another problem entirely. I keep a range of IEC overload relays and contactors on the truck for the most common starters. It is more simple to replace the entire starter than hunt for some obscure brand overload.


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## sparkiez (Aug 1, 2015)

I've seen sticky contactors and relays many times. Generally, when I see them sparking I try to take them apart and use some emery cloth on the contacts and that breathes new life into them for a while. It can even smooth out some of the arc burns in the contacts if you are in a bind. What you are noticing is a contactor in the process welding shut. The arcing leads to high-carbon content deposits, which are conductive, and can build up over time. One other thing that I would check for is some source of bleedoff in the neutral for the contactor. A short, even a lone strand, poking the TB next door could cause something like this that is intermittent.

Also, I disagree with others on here. A problem like this should have a root cause failure analysis done to determine the age of the component and the source of failure, and potential solution, as it can likely be critical to the process given that you have two pumps.


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## Wirenuting (Sep 12, 2010)

Jlarson said:


> Eh I've had issues with IEC's jamming, less so with the CH ones but it was happened, had the CH's jam on compressors that are in round the clock service.
> 
> Easy fix is to grab it, rip it from the panel, toss over the shoulder and then install a NEMA starter.


Just replaced a CH one today with an Eaton on a compressor. Was filled with carbon causing it to stick on at times.. 
Over the shoulder it went.. Took two weeks to get the replacement. But hey, we be slow around here..


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