Mike Dolt Enterprises
Mike Dolt Enterprises
User: TheJed, Location: Lockport, IL
Asked on: Friday, April 22, 2011 at 9:47 am EDT
Answered on: Tuesday, May 14, 2024 at 4:32 am EDT
Question: I have a question regarding secondary DC distribution on -48vDC plants.When the connection type on the distribution is a mechanical compression set screw, is their a code/spec that requires the use of a pin lug? The thread of the screw does not come in contact with the conductor of the cable, but rather its compressed between two metal surfaces --(0).
National Electrical Code (NEC) NEC 110.14(C) requires the use of suitable terminal lugs for terminating conductors in a manner that maintains the original shape and integrity of the conductors.
IEEE Std 484-2002 (Recommended Practice for Installation Design and Installation of Secondary DC Power Systems) Section 4.3.
2.2 states that "Terminals should be equipped with pressure wire connectors or other suitably listed fittings."Other Considerations
Even though the screw may not directly contact the conductor, the use of a pin lug provides several benefits: It evenly distributes the compression force along the conductor, ensuring a secure connection. It provides a larger contact surface area, reducing the risk of electrical arcing. It makes it easier to visually inspect the connection and ensure proper torque.
Recommendation:
Based on the above code and industry standards, it is highly recommended to use a pin lug when terminating conductors in a mechanical compression set screw connection on a -48vDC distribution system. Flag for review