Question: Class 2 or Class 3 power sources shall not have the output connections paralleled or otherwise _____ unless listed for such interconnection.
a) connected
b) interconnected
c) isolated
d) serialized
See answer below.
Answer: b) interconnected
As stated in Sec. 721.30(B), "Class 2 or Class 3 power sources shall not have the output connections paralleled or otherwise interconnected unless listed for such interconnection."
Ryan Jackson is a National Electrical Code instructor and textbook author in the Salt Lake City, Utah area. He is also a technical consultant for the Steel Tube Institute. He is a member of Code-Making Panels 3 and 17 for the National Electrical Code and serves on several technical committees for UL Standards and Engagement. He is certified as an inspector in electrical, building, mechanical, and plumbing codes, and has taught the NEC and NFPA 70E at the national level over the last three decades.
