NEC Wiring QuestionMichael, The 1996 version of the NEC addresses this issue by saying that if a connector is not specifically listed for an application, it is not OK. The reference is: 300-15(c) - "Fittings & Connectors shall be used only with the specific wiring methods for which they are designed and listed."
IMHO, this means that unless the device, connector, terminal is specifically listed for use with multiple wires of different sizes in the same hole, then it is not allowed. At Fluke, when I was working with IEC 61010 and UL 3111, our standard practice was that one terminal location could have one wire. Connector and terminal block manufacturers make bridging or shorting bars to connect multiple terminals together. The rationale is that multiple wires in a terminal can work themselves loose over time and with stress. Best regards, Daniel E. Teninty, P.E. Managing Partner DTEC Associates LLC (509) 443-0215 (509) 443-0181 fax http://www.dtec-associates.com Streamlining The Compliance Process While Advancing New Products To Market This email transmission is confidential and intended for the addressee only. It may contain privileged and confidential information. If you are not the person or organization to whom it is addressed, you must not copy, distribute, or take any action in reliance upon it. -----Original Message----- From: [email protected] [mailto:[email protected]]On Behalf Of Michael Taylor Sent: Wednesday, May 08, 2002 10:15 AM To: [email protected] Subject: NEC Wiring Question Greetings all, An issue came up in a product 61010 safety evaluation and no one here can remember if you can / can't do it. Does anyone out in Cyberland know if the NEC allows 2 wires of different sizes (awg) to be clamped together in a clamping type PC mounted wiring terminal. The wire is striped bare & inserted into a slot on the side of a terminal block that has a screw on top for tightening. I seem to remember the code does not allow wires of different gauges to be clamped together under a single compression clamping terminal. I have searched the NEC and can't find anything on this. Can anyone remember chapter & verse on this issue. If I'm wrong, please be kind, the 60 hour weeks are getting to us. Thanks in advance Michael Taylor Colorado
