Multiple 240V Outlet Strip

[RFEngineer]

Looking for an answer if anyone has seen this concept present local code issues.

I am in the process of constructing a 4-wire, 240V relocatable power tap (i.e., multiple port outlet "strip.") on a 30A circuit. A NEMA-4 enclosure forms the "strip" distribution. Four 10/4 cables are connected to the enclosure through Heyco PVC compression connectors. Wiring is all stranded, portable 10/4 cabling. Jumbo wire nuts will join four #10 wires together inside the NEMA box. According to the Thomas and Betts datasheet, these wire nuts are meant for the wire gauge and number of wires.

Two 30A ceramic-type fuse cartridges will be installed to fuse both line side wires. On one side of the NEMA box are three 2-ft serving cables, each terminated in an L14-30R Twist-Lock receptacles. On the other side of the NEMA box is a L14-30P Twist-Lok pug used to plug this assembly in to the 30A wall circuit. In an nutshell, one 10/4 cable from the box goes into the wall, then gets split three ways to separate pig-tail receptacles with the input side being double-fused.

Since this is not a premise wring issue, NEC should not be involved. Otherwise, I would have posted in the NEC forum. From a local products code perspective, is this practice generally accepted?

Paul

 

[don_resqcapt19]

... Jumbo wire nuts will join four #10 wires together inside the NEMA box. According to the Thomas and Betts datasheet, these wire nuts are meant for the wire gauge and number of wires. ...

Paul

Are they listed for the fine stranded conductors that are used in flexible cables? The standard listing for wire nuts is for use with Class B or C stranding. Flexible cable is not Class B or C. See the UL Guide Information for Wire Connectors and Soldering Lugs (ZMVV)

 

[RFEngineer]

Are they listed for the fine stranded conductors that are used in flexible cables? The standard listing for wire nuts is for use with Class B or C stranding. Flexible cable is not Class B or C. See the UL Guide Information for Wire Connectors and Soldering Lugs (ZMVV)

Good point. Looking at the T&B packaging, the installation instructions limit use of Cu/Cu, and that "frayed strands must be aligned," leading me to conclude that these winged wire connectors can be used with both solid and stranded conductors.

I'm ready to discard the use of the wire connectors and instead use double-row barrier terminal strips with #10 screws. Flat jumpers can be purchased to straddle and short across the barrier, allowing for a common bus bar of four crimped terminal connections as needed.

Many thanks for bringing up this issue. I would not have otherwise considered it.

Paul

 

[don_resqcapt19]

The can be used with both solid and stranded conductors, but not with finely stranded conductors unless specifically marked as suitable for use with those types of conductors. You will have the same issue with terminal strips and most any other wire termination device that you can think of. Standard termination devices are most often not suitable for use with the conductors found in flexible cords and cables.