Cable ran through C1D1 area

[jjs2089]

My company received some equipment with 3-phase explosion proof motors mounted in a C1D2 area wired with 4-conductor cables. Information on the cables state it is direct burial cable along with E171371 and type MTW on it. The cables run from the C1D2 area through a C1D1 area, back out through wireway to an electrical panel, which contains a PLC, motor starters, and intrinsic barriers for some I/O. There are no seals poured for this (the cables are not run in conduit). Also the wireway connected to the C1D1 area is wide-open to the panel. The C1D1 area is an enclosure with flammable gasses, which is vented by use of an exhaust fan. There is a flow switch on the exhaust line, but no pressure switch for checking negative pressure in the C1D1 area. Is this a legal installation?

 

[petersonra]

I am curious why you would put explosion proof motors in a C1D2 area.

I don't think the exhaust fan, flow switch, or lack of a pressure switch is relevent.

I don't see how an unbroken run of cable through a C1D1 area would allow hazardous gases to transfer through the cable into the C1D2 or unclassified areas.

However unless it complies with 500.11 I don't see how it meets code.