Contactor Energized by purge controller

[harmon.konrad]

Does a contactor with 480VAC on the line side count as "energized"? I am looking over a design where a purge controller runs in a C1D2 environment and energizes the coil after a purge cycle.

Therefor sparks are only created when the inside of the cabinet is an unclassified location.

Does this seem reasonable or would an inspector have a fit?

 

[petersonra]

Where is the contactor? If it is inside the pressurized enclosure it should be fine The potential ark won't happen until the coil is turned on and by that time the inside of the box would be unclassified.

 

[rbalex]

Energized is a defined term in both NEC and NFPA 70E Articles 100. (It’s the same definition)

 

[harmon.konrad]

I think the mindset of digging into what actually causes the explosion might be pressing too far, and though it follows the intent of the code it doesn't necessarily follow the letter.

Anyone have an example of a purged system contained wholly in Class I Division 2. I am curious how other people have solved the issue of energizing control electronics not rated for the area.

My previous solution:
C1D1 Connector 100A
NEMA 7 w/breaker, 24VDC supply, and contactor
Purge controller supplied by 24VDC supply
Main Cabinet purged by controller then supplied by contactor after purge

The other engineer was trying to get away from having a big 10x10x8 internal NEMA 7 enclosure.

 

[petersonra]

The other engineer was trying to get away from having a big 10x10x8 internal NEMA 7 enclosure.

Where would this 10x10x8 NEMA 7 enclosure be?

 

[harmon.konrad]

Where would this 10x10x8 NEMA 7 enclosure be?

In C1D2 area.