Q. When installing electric heat-tracing cables and heating panels in industrial installations (where ground fault alarm indication is provided and the operation cannot tolerate a ground fault condition that would normally open the circuit overcurrent device), which of the following choices best meets the requirements outlined in Art. 422 for protection of these components?
A) Ground fault protection for equipment is not required for the heating cables and the heating panels where qualified persons service the installation and continued operation is necessary for safe operation of the equipment or process. However, the heating wires or cables must have a grounded conductive covering.
B) GFCI protection is required for the heating cables only, and the cables must have a grounded conductor covering.
C) GFCI protection is required for the heating cables and heating panels.
D) Ground fault protection for equipment is required for the heating cables and the heating panels, and the cables must have a grounded conductor covering.
Answer: A
Explanation: It is the intent of 427.22 for designers and installers of heating cables and heating panels to provide ground fault protection for equipment for the heating cable and the heating panels. In some industrial installations, continued operation of power systems is necessary for safe operation of the equipment or process. Thus, a ground fault condition, which opens an overcurrent device protecting the heating cables and heating panels, cannot be tolerated. Alarm indication of ground faults is provided. This is found in the second sentence of 427.22.
In addition, the heating wires or cables must have a grounded conductive covering as noted in 427.23.
Owen is the owner and president of National Code Seminars and the holder of master electrician certifications in 46 states. He can be reached at [email protected].
