I'm working on a strange project - we are building a CNG compressor on a flatbed trailer. There are three areas on the trailer, the front of it is exposed to the atmosphere and is non-hazardous, the middle section is a compressor unit in an enclosure (C1D2), and back of the trailer which is exposed and contains more piping (C1D2).
I have one run required from the front of the trailer's MCC (non-hazardous) to the back of the trailer (C1D2); its a solo 480V run to a heater.
The first way, and not-preferable way, is to run conduit from the MCC to the enclosure wall of the compressor unit, seal it on outside, penetrate the wall with a myers bulkhead etc. and land the wires inside the enclosure in a small Crouse EAB junction box, then come out of that with cable and tray and run towards the back of the trailer out of the compressor wall.
Another simpler way, is to run cable tray from the MCC up over top of the Compressor Enclosure and towards the back of the trailer. The only issue is, how do I seal this cable from the hazardous to non-hazardous atmosphere? It does not seem to fall under any of the circumstances in the NEC. What you might ask is what cable am I using, well, I'm using a non gas/vapor tight cable - which is probably the root of all my problems. But we never purchase type MI or vaportight cable and I'm still not even sure that would get me through this scenario.
Any ideas?
I have one run required from the front of the trailer's MCC (non-hazardous) to the back of the trailer (C1D2); its a solo 480V run to a heater.
The first way, and not-preferable way, is to run conduit from the MCC to the enclosure wall of the compressor unit, seal it on outside, penetrate the wall with a myers bulkhead etc. and land the wires inside the enclosure in a small Crouse EAB junction box, then come out of that with cable and tray and run towards the back of the trailer out of the compressor wall.
Another simpler way, is to run cable tray from the MCC up over top of the Compressor Enclosure and towards the back of the trailer. The only issue is, how do I seal this cable from the hazardous to non-hazardous atmosphere? It does not seem to fall under any of the circumstances in the NEC. What you might ask is what cable am I using, well, I'm using a non gas/vapor tight cable - which is probably the root of all my problems. But we never purchase type MI or vaportight cable and I'm still not even sure that would get me through this scenario.
Any ideas?