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Discussion Starter · #1 ·
I'm installing a couple PDUs for a high-density server deployment. I'm hoping to use a couple of the 208v circuits that the datacenter has available.

I've been told that the circuits are three phase 208v with a L6-30R receptacle.

However, I can't seem to find any 208v three phase PDU with a L6-30P plug. After further research, I'm led to believe that a L6-30P plug will only work with single phase 208v.

Is it possible for this L6-30P plug to support three phase 208v?
 

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Simply put, no. L6-30 is single phase and only has 3 prongs, 2 hot, 1 ground. 3 phase has 4 prongs, 3 hot, 1 ground. That's not to say the circuit pulled to that location might not have an additional conductor. That would be an issue for your electrician to figure out for you.

IBTL
 

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Discussion Starter · #3 ·
That's not to say the circuit pulled to that location might not have an additional conductor. That would be an issue for your electrician to figure out for you.

IBTL
Yeah, that's where I think the confusion is coming from. The circuit could be 3 phase, but they've perhaps used a 10awg cable to provide a L6-30R receptacle.

Of course this issue is made worse by the fact they won't let me talk with their electrician directly :p

Thanks for clearing that up.
 

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Yeah, that's where I think the confusion is coming from. The circuit could be 3 phase, but they've perhaps used a 10awg cable to provide a L6-30R receptacle.

Of course this issue is made worse by the fact they won't let me talk with their electrician directly :p

Thanks for clearing that up.

IBTL


Gauge wire size has little to do with phase, rather the number of wires will dictate this. 10 gauge copper wire means 30 amps under the NEC code.

If you need 3 phase power you will have to pull another hot conductor.

Do you do electrical for a living?
 

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Sorry to post on such an old thread. There really isn't a condition where a NEMA L-60Plug would fall under three phase.

I see two single phase scenarios here:
1st) A 208V high leg system where you can have the 208 high leg to neutral and the 3rd wire on the plug be the ground.
2nd) A 208V 3 phase system where two of the hot conductors are used and a ground for the 3rd wire. This would still fall under single phase use.

btharmy said it best, an actual 3 phase system would use 4 total conductors. It sounds like you are using 208V single phase.
 

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Sorry to post on such an old thread. There really isn't a condition where a NEMA L-60Plug would fall under three phase.

I see two single phase scenarios here:
1st) A 208V high leg system where you can have the 208 high leg to neutral and the 3rd wire on the plug be the ground.
2nd) A 208V 3 phase system where two of the hot conductors are used and a ground for the 3rd wire. This would still fall under single phase use.

btharmy said it best, an actual 3 phase system would use 4 total conductors. It sounds like you are using 208V single phase.
There isn't really such a thing as a 208v high leg. It is the voltage of the high leg on a 240/120 delta system, but it should not be used as a line to nuetral voltage.

Sent from my SM-G970U using Tapatalk
 

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Sorry to post on such an old thread. There really isn't a condition where a NEMA L-60Plug would fall under three phase.

I see two single phase scenarios here:
1st) A 208V high leg system where you can have the 208 high leg to neutral and the 3rd wire on the plug be the ground.
2nd) A 208V 3 phase system where two of the hot conductors are used and a ground for the 3rd wire. This would still fall under single phase use.

btharmy said it best, an actual 3 phase system would use 4 total conductors. It sounds like you are using a 208V single phase. He wanted to explain everything to me in a coomeet free at once, but he advised me to come here.
208v high leg? What do you mean? I don't fully grasp
 

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Keep in mind it's google searches bringing people to the old material here that pays for the site. Occasionally revisiting the old stuff could improve the content, getting a fresh perspective. I would rather someone revive an old thread with a new comment than fresh content on Oscar antics etc., any day.

This post is before my time on here but I would have told the OP (likely an IT person, not an electrician) that PDUs with L6-R30 plugs are typically fed either 240 or 208 with two hots and a ground, no neutral. Most large commercial places that run these PDUs have three phase power so it's usually 208. In almost all cases, whatever you feed the PDU, the PDU feeds the equipment. It's not like a UPS where the line side voltage and load side may be totally different. Review the documentation for your PDU.

Just be careful, this is one situation where the plugs and receptacles do not make things idiot proof. Make sure the equipment will run on that available 208, and confirm that the PDU is rated for 208. If you feed the PDU 208 and plug in equipment rated for 120, bad expensive things happen.
 
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