Multi axis servo and conductor sizing

[touge]

Hi experts,

Recently, I received a machine from a manufacturer. The equipment itself is not UL certified and is imported from Asia. It is a multi-axis control machine that integrates up to 30 axis in one panel. The nameplate on the panel indicates FLA = 63A.

Upon closely examining the design, I found that there are 30 servo drives inside, each with an input current of approximately 5A.

Therefore, if I directly calculate the conductor for the feeder line of this panel, my understanding is 5A * 1.25 * 30 = 187A.

So for this panel, it should have a 200A breaker for feeder protection and 3/0 AWG wire for the feeder condutor inside the panel power distribution.

Currently, only a 3 AWG conductor and an 80A circuit breaker are used.

I inquired with the manufacturer, and they replied that due to the design logic, it is impossible for all servos to drive simultaneously. Moreover, each servo's actual load is below 50%, so they do not assess based on maximum full load.

In actual tests, I have never seen its full load current exceed 40A.

Due to space limitations in the panel, it is challenging for me to further increase the feeder conductor size and change a breaker for this panel...
Or a minumum change solution....

Section 430.26 provides guidelines regarding demand factors. Does this situation apply?

 

[Eddie702]

If the manufacturer can provide some documentation, and if the AHJ will allow an unlisted piece of equipment to be installed that is a lot of maybes to start with.

I don't know about electrical equipment listing.

But we had some gas equipment that was not listed (I am a gas fitter as well) and the customer had to hire an engineer to come in and check the equipment and certify to the state that it could be installed.

Don't know if certification after the fact is possible with electrical equipment .

I would toss it back into the owners lap. They bought it.