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?