I received an email today with this Question from the Pinellas County area..


I recently found the following scenario and would like to know what code if any was violated. It certainly was not a good idea in my opinion and I have ordered the switches to be reworked with the exhaust fan put on a relay controlled by the local AHU as per specifications.

Scenario: a double pole toggle switch rated for 15 amps and 120-277 volts ac was used to control a 120 volt fractional horse power exhaust fan and a 277 volt compact fluorescent light fixture. (from 2 separately derived systems)

Further, the electrician used a purple #12 for the unswitched side of the 277 volt circuit with#12 yellow for the switched side and used a black #12 for the unswitched side of the 120 volt circuit with#12 yellow on the load side of the switch. (thus using two yellows for switch legs with a purple and black for the unswitched conductors)



The code does not prevent
colors other than white or green to be used for un-grounded conductors regardless of the voltage but in this inspectors opinion, we should have a color coding system ( like brown, orange and yellow for 277/480 and black, red and blue for 120/208 or black, orange and blue for 120/240 D)

Thanks for your time.

Hello Mr. Rocha,

(Assuming that the switch was rated for that voltage..)

Well, you mention that you had something corrected to make it "as per specifications." If it was not installed as the manufacturer's specifications intended, it would be a violation of 110.3(B).

Also, the switch would have to indicate whether it was in the ON or OFF position, or it would be a violation of 404.7, as well as other codes that require the marking.

I agree with you about the color coding. There is nothing to prevent it from being done that way to the best of my knowledge.


:rolleyes:

Depending if the job had any specs? If it did there is a 90% probability that the spec called for a color code to be followed. The specs, regardless, need to be follwed. As far as the switch goes you can have different voltages in the same box as long as one is not part of an emergency system.

AGREE SPECS MUST BE FOLLOWED HOWEVER:
1. double pole switch is not listed to switch diferrent loads
2. the voltage difference between conductors probably exceeds 300 vac
As to the colors there a problem in this instance because the hole install is wrong. If this had been a proper install the issue of color would not stand out so bad.

According to the UL white book under snap switches,multi pole general use snap switches have not been ivestigated for more than single circuit operation unless marked 2-circuit or 3-circuit, and I also agree a change in the phase color coding would be a welcome change in the code

That is a very important point, my friends, and I admit I totally forgot about the white book. You and Rob hit the nail on the head. So we are back to using something not according to it's listing and we have an NEC violation of good old 110.3(B) (i love that code ).

But please, someone clarify for me....If we have a 277v two pole circuit and a 120v single pole circuit from two separately derived systems (two different circuits from two different panelboards derived from two different transformers).....here is where I am not following. Would that not, in and of itself, short itself out?

Nick,
From the question it seems to me that we have a double pole snap switch. One pole switches the hot on the fan and the other pole switches the hot on the fixture. This will funcion and work but I agree that the white book prevails. I have never seen a field installed switch rated for multiple voltages and loads. That does not mean one does not exist.