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Title: New power cables for mains
Post by: Mike Sullivan on October 15, 2015, 12:58:09 AM
I'm building some power boxes to make sending power for my mains easier, which would consist of 4 duplex outlets with each pair on it's own circuit, one for tops and one for subs.  I'm trying to find the best connection to run to a small power distro (less than 100A for the time being, won't be pulling anywhere close to that)...I will be making runs of 50ft with some 25ft extenders, so never more than 75ft or at most 100 foot if absolutely necessary, so I will probably use 12/4 or 10/4 to be safe.  What would be the best locking connection to use that would use the least space?

As an alternative idea, I had thought about using the 32A Powercon (NAC3FC-HC) but to use it as it is only a 3 pole connector, I would have to bond neutral/ground to get both separate hot legs, correct?  And from what I understand, that is a no-no even on a properly wired distro.  What about if I could use 30A breakers and just run a single hot circuit for each side?  That has me thinking of the easiest solution with the least hassle possible...
Title: Re: New power cables for mains
Post by: Geoff Doane on October 15, 2015, 09:20:42 AM
As an alternative idea, I had thought about using the 32A Powercon (NAC3FC-HC) but to use it as it is only a 3 pole connector, I would have to bond neutral/ground to get both separate hot legs, correct?  And from what I understand, that is a no-no even on a properly wired distro.  What about if I could use 30A breakers and just run a single hot circuit for each side?  That has me thinking of the easiest solution with the least hassle possible...

Yeah, you don't want to bond ground to neutral.

I was hoping Neutrik would manufacture the 32A PowerCon as a 5-pole connector (it's based on the NL8, so there is enough room) so it could be used for 3 phase applications if desired.  As it is, they don't even make an outlet connector and mating line plug.  Since it's not a NEMA device, it wouldn't have to be used exclusively for one configuration.  The regular PowerCons can be used for either 120 or 240V distribution.

Your best bet is probably NEMA L14-20 connectors.  If you use L14-30, and connect to a 30A supply, then you need to have a breaker at the far end before it goes to a pair of 5-20R duplexes.  Even if you only use 20A connectors (L14-20), you can still size the wire for 30A (10 ga.).  All it takes is more money and weight.  :)

GTD

P.S.  The only reason I mentioned L14-30 connectors is that they seem to be more common in the industry, and you may have an easier time renting extra cable from a local production house for those few times you need to make a longer run.  Check around locally, and see what other people are using.
Title: Re: New power cables for mains
Post by: TJ (Tom) Cornish on October 15, 2015, 09:48:40 AM
Yeah, you don't want to bond ground to neutral.

I was hoping Neutrik would manufacture the 32A PowerCon as a 5-pole connector (it's based on the NL8, so there is enough room) so it could be used for 3 phase applications if desired.  As it is, they don't even make an outlet connector and mating line plug.  Since it's not a NEMA device, it wouldn't have to be used exclusively for one configuration.  The regular PowerCons can be used for either 120 or 240V distribution.

Your best bet is probably NEMA L14-20 connectors.  If you use L14-30, and connect to a 30A supply, then you need to have a breaker at the far end before it goes to a pair of 5-20R duplexes.  Even if you only use 20A connectors (L14-20), you can still size the wire for 30A (10 ga.).  All it takes is more money and weight.  :)

GTD

P.S.  The only reason I mentioned L14-30 connectors is that they seem to be more common in the industry, and you may have an easier time renting extra cable from a local production house for those few times you need to make a longer run.  Check around locally, and see what other people are using.
Agreed on the no bonding and also agreed on the L14-20 system being a good option. 

Two potential options:

1. You can use 12/4 SOOW cable with L14-20 on both ends to a box with duplex outlets as you describe.  The downside is due to the size of the L14-20 connectors, they would either have to be tails, or you need a large box for panel-mount L14-20 in/out.  The upside is you have two independent general purpose circuits.

2. You can use a 12/3 SOOW cable that is a L14-20 Male on one end with Powercon blue on the other end wired hot, hot ground to a Powercon distro like this: http://whirlwindusa.com/catalog/power-electrical-distribution/edison-boxes/pl1-420-nac3  The upside is 12/3 wire with small boxes and more power than a single 120V/20A circuit.  The downside is this is 208/240V only, so would potentially work if your mains/subs can run at 208/240v (many can), but wouldn't work for general power, and you have to be careful to not confuse this 208V/240V Powercon application with any other 120V Powercon devices in your world.

I like the L14-20 concept for a main distro, because you can mix and match ideas 1 and 2 depending on your needs and usually not need downstream breakers. With more and more gear capable at running at 208v/240v, this is attractive.

Title: Re: New power cables for mains
Post by: Mike Pyle on October 15, 2015, 10:23:03 AM
...I will be making runs of 50ft with some 25ft extenders, so never more than 75ft or at most 100 foot if absolutely necessary, so I will probably use 12/4 or 10/4 to be safe.  What would be the best locking connection to use that would use the least space? ...

The best locking connection would be whatever matches the receptacle at the venue where you are providing. When I was using a passive system & lights requiring distribution most of the hotels & venues that I worked had either L14-30 or L21-30, so I had rack mounted distribution prepared to plug in to either of those. Some venues would have 50a California connectors, which would then require the addition of a fused or breakered disconnect box between the receptacle and my feeder.

Since I am not hauling amp racks now with the self-powered system I use most often, I have switched to a floor box type distro with 50a CA in & through, and 50a feeder. This can be adapted to a 30a service using an adapter tail, no breakered disconnect required. I also have a variety of small distro items, like a couple of 3 phase 30a "drops", 30a x 2 "poor mans" distro, 75' soca with breakouts, etc. that can be handy when needed.