Between a rock and a hard place.

[ptonsparky]

Two brand new pieces of equipment came in to a customers last week. We integrate new equipment (usually well used) with what they have now. These came in with two UL listed Industrial Control Cabinets on each piece of equipment with brief instructions and wiring diagrams in each cabinet. Nice, but the equipment mfg tied the two ICC together in a fashion that they were never meant to be. This stuff goes in the field Tuesday, so come Monday it will work one way or another.

Do you refuse to work on it?
Make the changes you feel are necessary voiding UL listing of ICC?
Do one of the above then place call to Equipment Mfg and tell them they have a severe cas of HUA syndrome?

 

[Dennis Alwon]

Why do you think the manufacturer tied it together incorrectly? It may be just fine unless there is some nec violation. 110.3(B) is the art. you feel is violated?? I would let the inspector make the call unless you see some inherent danger in the design.

 

[ptonsparky]

Why do you think the manufacturer tied it together incorrectly? It may be just fine unless there is some nec violation. 110.3(B) is the art. you feel is violated?? I would let the inspector make the call unless you see some inherent danger in the design.

They fed the two motors controlled by one ICC via the VFD in the second. Used one of the MCPs in the first to provide protection to the VFD. One of the contactors that would have started a motor in ICC 1 now starts the Vfd via control of Vfd. Neither motor now has individual over current protection. Discounting the fact that the ovedload settings do not go low enough for 480v operation, even if they had been used. Both motors connected directly to the Vfd.

What inspector?

 

[kwired]

What inspector?

:lol:

Some people can't get around the fact that some things are done with no inspections (by some third party anyway).

There are places much stricter than here, there are also places that still make someone from around here shake their head and say what the ..... I won't mention Iowa,(oops I just did), but they are still in somewhat early stages of statewide permit and inspection program, most of what I have seen there that made you shake your head has been a few years back now.

 

[__dan]

You cannot make the changes on your own, you would be liable for them, right or wrong.

It does not matter if it's a ten dollar part or a million dollar part, I am quick to call factory engineering and hammer them with questions when I have them. I like to test factory support for their responsiveness and straight answers. Determine which brands deserve loyalty.

I'm guessing in your case the OEM does not want the load opening at the load side of the drive because that may damage the drive, going from loaded to open circuit instantly at the drive output (they may have a reason). Individual motor OL's would open the line side of the drive.

The drive would do motor Ol protection internally, but you are saying the have two motors paralleled on one drive and no individual motor running OL protection. They may be OK on the motor short circuit protection.

They may have factory engineered it to run two motors simultaneously and calibrated the running Ol for both motors, with control circuit protective shutdown if it detects single motor failure.

Really all you need to do is call the factory first thing Monday and get their clarification of your concerns, in writing if necessary. If the factory and the owner are OK with it after hearing your concerns, if it smokes later, you should be in the clear.

 

[ptonsparky]

You cannot make the changes on your ownis the you would be liable for them, right or wrong.

It does not matter if it's a ten dollar part or a million dollar part, I am quick to call factory engineering and hammer them with questions when I have them. I like to test factory support for their responsiveness and straight answers. Determine which brands deserve loyalty.

I'm guessing in your case the OEM does not want the load opening at the load side of the drive because that may damage the drive, going from loaded to open circuit instantly at the drive output (they may have a reason). Individual motor OL's would open the line side of the drive.

The drive would do motor Ol protection internally, but you are saying the have two motors paralleled on one drive and no individual motor running OL protection. They may be OK on the motor short circuit protection.

They may have factory engineered it to run two motors simultaneously and calibrated the running Ol for both motors, with control circuit protective shutdown if it detects single motor failure.

Really all you need to do is call the factory first thing Monday and get their clarification of your concerns, in writing if necessary. If the factory and the owner are OK with it after hearing your concerns, if it smokes later, you should be in the clear.

You really have a lot more faith than I do. I believe this the same group that sent us equipment last year that ran 480v thru the vfd aux contacts. No, they are not rated for it.

 

[__dan]

You really have a lot more faith than I do. I believe this the same group that sent us equipment last year that ran 480v thru the vfd aux contacts. No, they are not rated for it.

No. My base case is always that there will be some bad thing that could happen, due to willful intent, incompetence, clueless pretend professionals faking it ... I like to see it in advance and cite it, but the effort commonly does not yield the necessary result. I document it and try to let the liability fall elsewhere.

Had this golf course irrigation controller to wire early in my time as a contractor. Town Public Works bid job, designed, spec'd, by a professional golf course irrigation engineer, professionally built custom controller, for two 10 stage 20 hp Goulds pumps. All I had to do was bring power to it. But I went through the control scenario from the wiring diagram, then I saw at zero flow, the off condition, it would pump for three minutes on a timer into a closed valve (a two port, in and out, PRV, pressure reducer, a monster the size of a fire hydrant).

I told the town they were nuts and they could not cavitate a ten stage 20 hp pump for three minutes on a timer into a closed valve. They had no clue what I was talking about but they did pay the engineer door to door travel from out of state to come to the job, watch me point to the wiring diagram and show him the problem, then he says "it will work perfectly".

I had a contract to perform on and I wired it and put it into service. I also called Goulds Pump and got the right person on the phone and asked him if his pump was rated for zero flow and full load, the on condition, for three minutes. He says "where is that job, I'm pulling the warranty off that pump".

Town calls me six months later. They had now discovered the problem, but not the problem I had thought. The PRV was pinging the 400 psi inlet pressure gauge, so they had replaced it with a 1000 psi guage to get a reading. The PRV failed at six months and they took it apart and sent it out for rebuild. They said all the metal parts at the inlet were pushed in.

 

[kwired]

You really have a lot more faith than I do. I believe this the same group that sent us equipment last year that ran 480v thru the vfd aux contacts. No, they are not rated for it.

In the meantime you probably have a customer that wants production from the equipment, yesterday, and yet the manufacturer, supplier, or whoever is to stand behind this will take 4-6 weeks to get things straightened out, and the owner wants you to do whatever is necessary so production can happen ASAP

 

[ptonsparky]

In the meantime you probably have a customer that wants production from the equipment, yesterday, and yet the manufacturer, supplier, or whoever is to stand behind this will take 4-6 weeks to get things straightened out, and the owner wants you to do whatever is necessary so production can happen ASAP

He doesn't pay our wages to argue on the phone that's for sure.