Many industrial processes use electrically powered heat trace systems. Installers with little experience in this application think that heat trace cable is used to keep water pipes from freezing, but this is just the beginning.
Wiring methods for Class I, Division 2 locations are addressed in Section 501.10(B) of the NEC. Here, in addition to those wiring methods that are permitted for Class I, Division 1 installations in Section 501.10(A), the NEC covers other wiring methods that are permitted for Class I, Division 2.
Before we get into the details of conductors, currents, and circuit protection on the AC side of the PV system, let’s step back and try to get a bigger picture of where are some of the dangers or hazards that need to be considered.
A supply-side interconnection is any connection to the service conductors on the supply-side of the service disconnecting means. The 2017 National Electrical Code (NEC) contains nine categories of equipment. A list of allowed supply-side interconnections is provided in NEC 230.82.
This subject appears to create some confusion and inconsistency among electrical designers, electrical contractors, and regulators. Let’s clarify this issue to improve consistency in design, installations, and inspection of electrically-connected…
One common way of minimizing possibilities of electrical wiring and equipment becoming an ignition source in hazardous (classified) locations is to locate the equipment and wiring outside of the hazardous (classified) location wherever possible.
The basic process to select the right overcurrent protective device (OCPD) for this discussion of 80% rated versus 100% rated, begins with a calculation of the load, includes a journey through conductor selection based on the calculated load current, and ends with the right OCPD to protect the conductor.