We design control panels for class 1 div 2 areas. We have found every component we need to build panels that are suitable for hazardous areas without using a NEMA 7 enclosure, except for a hourmeter.
UL will not certify a panel for use in a hazardous area unless all electrical components in the enclosure have markings showing that it is suitable for use in a hazardous area. However, NEC 501.3b seems to give an exception for meters in hazardous areas if the meter does not have any sliding or braking contacts.
This same exception mentions solenoids and yet hazardous area solenoids are available.
Questions, who one is correct UL or NEC? Can a hourmeter be installed in a class 1, div 2 area without sealing it in a NEMA 7 instrument housing.
UL will not certify a panel for use in a hazardous area unless all electrical components in the enclosure have markings showing that it is suitable for use in a hazardous area. However, NEC 501.3b seems to give an exception for meters in hazardous areas if the meter does not have any sliding or braking contacts.
This same exception mentions solenoids and yet hazardous area solenoids are available.
Questions, who one is correct UL or NEC? Can a hourmeter be installed in a class 1, div 2 area without sealing it in a NEMA 7 instrument housing.