I have recently been called to install power to one of these units. There is an explosion proof box on the exterior of the cabinet that houses the motor and pump. When I opened the cabinet the wiring from the exterior box is installed in car-flex over to the explosion proof switch and then car-flex down to the motor that has another explosion proof box. After NEC 515.3 I think that this unit should be Class 1 DIV 2, however the gas company says that the manufacturer of these units "made them this way". How could this be possible?