Listed industrial control

[ptonsparky]

Installing some nice looking controls made by xxx, all the nice labels etc. We fired the first one up today to see if the radio controls we supplied worked as planned. Tripped the GFCI immediately. A white wire was bonded to the enclosure via one of the green din rail terminal blocks. Hmmm. Thought maybe the labels would mean something. We modified the wiring. Does that mean we voided the Listing?

As a side note the GFCI is on a small step down that was never grounded on the secondary. Transformer has been there for 20 years or so. We put the GFCI in several years ago.

 

[templdl]

Installing some nice looking controls made by xxx, all the nice labels etc. We fired the first one up today to see if the radio controls we supplied worked as planned. Tripped the GFCI immediately. A white wire was bonded to the enclosure via one of the green din rail terminal blocks. Hmmm. Thought maybe the labels would mean something. We modified the wiring. Does that mean we voided the Listing?

As a side note the GFCI is on a small step down that was never grounded on the secondary. Transformer has been there for 20 years or so. We put the GFCI in several years ago.

It appears as though the mfr screwed up. There may be UL tags all over it but it is up to the mfr to assure that it complies with their UL listing. I once worked for a manufacturer who had its production shut down by UL, not pretty. As a mfr you don't want to mess with your UL listing. The manufacturer's QC most likely missed something during inspection. Persue the issue with the mfr like a bird dog but realise that there are times when things like that do slip out once in a while unfortunately.

 

[ptonsparky]

Thinking I will send them a picture captioned "Find the problem" or "Do you see what I see?"

We have eight more controllers we have not tried or looked at yet.

 

[templdl]

Thinking I will send them a picture captioned "Find the problem" or "Do you see what I see?"

We have eight more controllers we have not tried or looked at yet.

If you suspect that there is an issue you have to get a competent factory rep there not just a peddler, someone who knows something. I had no problem myself in visiting a customer should there have been a question about product integrity.
Don't be shy and be persistent.

 

[Tony S]

Why are you using a GFCI on industrial control/instrumentation circuits?

 

[iwire]

Why are you using a GFCI on industrial control/instrumentation circuits?

Our code does not generally pick GFCI protection by the equipment it runs but by the location of the outlet.

So if this equipment is in an area where GFCI is required than it must be connected to a GFCI.

 

[ptonsparky]

Why are you using a GFCI on industrial control/instrumentation circuits?

You are most likely picturing an area that has well maintained equipment with qualified personnel working on or with it. Erase that image entirely. The GFCI happened to be providing power for the existing cord connected equipment. I see no reason to remove it and more to leave it there, protecting the new.

 

[petersonra]

Installing some nice looking controls made by xxx, all the nice labels etc. We fired the first one up today to see if the radio controls we supplied worked as planned. Tripped the GFCI immediately. A white wire was bonded to the enclosure via one of the green din rail terminal blocks. Hmmm. Thought maybe the labels would mean something. We modified the wiring. Does that mean we voided the Listing?

As a side note the GFCI is on a small step down that was never grounded on the secondary. Transformer has been there for 20 years or so. We put the GFCI in several years ago.

Is the GFCI in lieu of grounding the secondary of the transformer as is likely required by the NEC?

We often run white wires to green ground blocks as a way of grounding control circuits such as small transformers or DC power supplies. UL508a requires such circuits be grounded. You could well have made it worse.

 

[ptonsparky]

Is the GFCI in lieu of grounding the secondary of the transformer as is likely required by the NEC?

We often run white wires to green ground blocks as a way of grounding control circuits such as small transformers or DC power supplies. UL508a requires such circuits be grounded. You could well have made it worse.

Sorry, no control transformers. We were to supply the 120v.

 

[ptonsparky]

Is the GFCI in lieu of grounding the secondary of the transformer as is likely required by the NEC?

We often run white wires to green ground blocks as a way of grounding control circuits such as small transformers or DC power supplies. UL508a requires such circuits be grounded. You could well have made it worse.

You could very well be right on why the jumper is there to begin with, but no one removed it for this build. They were consistent, all the same.

 

[Jraef]

You could very well be right on why the jumper is there to begin with, but no one removed it for this build. They were consistent, all the same.

That makes sense to me too. Their standard assembly is based on there being a CPT, so the wiring drawings have the terminal bonded. But in this case you told them you were supplying the 120V separately, then they failed to catch the detail about removing the bond. The shop people are not savvy enough to know what it all means, they are just wiremen (wire persons). It should have been caught by an Engineer or whomever processes the order that had the specific changes you requested. But in a lot of places now, that person no longer exists or is so overloaded after cutbacks that they let small tasks be handled by the shop, who as I mentioned, aren't qualified. I've been seeing that sort of thing happen more lately. It is theoretically a risk of losing their UL listing, but its not like UL immediately punishes you for making one mistake, it has to be a pattern of disregard. Still, they should hear about it so they can address it internally before it DOES become a pattern of disregard.

 

[petersonra]

You could very well be right on why the jumper is there to begin with, but no one removed it for this build. They were consistent, all the same.

It would not surprise me that it was not supposed to be there but some helpful worker in their shop added it because he thought it was needed. What does their drawing show?

 

[ptonsparky]

It would not surprise me that it was not supposed to be there but some helpful worker in their shop added it because he thought it was needed. What does their drawing show?

I have not seen a drawing. Pretty simple control wiring. A few inputs and four out, all labeled, to a small Plc or smart relay.