Hello,

I have run into the following situation while modeling an industrial facility. In this facility there are power factor correction units located throughout the facility, usually off of major panels. This is at 480V. Here are the issues uncovered as part of data collection and building the model:

1. The manufacturer's nameplate lists the fault duty of the power factor correction devices as 18kA. However, inside of the unit is a main circuit breaker that is rated at 480V, 10 kA. This would then make the unit rated at 10 kA, not 18 kA as stated on nameplate.

2. In one power factor correction unit, a main breaker rated at 240V (this is 480V system), 5 kA was found.

My concern is that these are UL listed devices, so:

1. Is there an obligation to report this to UL?

2. If so, who is obligated, myself as the PE or the owner of the equipment?

3. If the 10kA rating is not suitable for the installed application and the internal breaker is changed out to a higher rating one, what does one do about the rating indicated on the manufacturer's nameplate? Can it be legally changed?

My concern is that these are UL listed devices, so:

1. Is there an obligation to report this to UL?

2. If so, who is obligated, myself as the PE or the owner of the equipment?

3. If the 10kA rating is not suitable for the installed application and the internal breaker is changed out to a higher rating one, what does one do about the rating indicated on the manufacturer's nameplate? Can it be legally changed?[/QUOTE]

Lots of good questions here. My usual disclaimer - I am not an attorney etc. but....

Q1 - unless there is some series rating (I have never heard of one on this type of arrangement) then I would think something is not correct as you suspect.

Q2 - 5kA is an NEC minimum default rating. I wonder if it is a molded case switch and not a breaker. Either way, 240V on 480V? Again something here is suspsect.

Q1 / UL - not a bad idea but I don't know of anyone that has done this. If something is deficient as part of a standard design for this capacitor bank, then I would think it would be prudent to bring it some authorities attention. See next question.

Q2 - This is usually something that would be flagged in your report. You rendered your service and identified problems. The Owner should then follow through, although my experience is they don't always follow through.

Q3 - usually I would say you can not change the nameplate. That rating is from some test or design.

Just a few thoughts. I would be very interested to hear what others think too.

FYI - The bkr referenced is definitely a breaker. To be specific, it is a Fuji EA53BUL, 50A. From web search this is obsolete.

Then something seems wrong. Can you contact the capacitor bank manufacturer first to see what they say? I have run into a few "tin benders" over the years that attempt to build equipment. It looks good until you look under the hood.

Either way, I would document it in your report, discuss it with the client, then perhaps follow up with UL. Worst case scenario is if something goes wrong and there is legal action, someone will bring up this issue which leads to the question - why was no one notified?

Good luck. I'm sure we would all be interested to hear how it turns out.

I've run into this with Fuji breakers. I was called to investigate an 18kA mccb that explode when turned on. There was enough breaker pieces left to make out the rating. The available fault current at the breaker line lugs was 41kA. Fuji sales rep informed me the 18kA line was discontinued several years ago and offer direct replacements in 25kA and 65kA. There is very little price different between 25 and 65kA units. I would note it in the study report the breakers are under rated for the duty and discontinued and should be replaced.