installing a 30 amp circuit

[ejsimcox]

Group,

I am installing a computer equipment rack in my home office. The Power strip (PDU) that I want to use is the Geist VRTDN200-10310TL. It terminates in a NEMA L5-30P. The specs on the PDU are 30 Amps, 125V,

3750 Watts, 2 x 15 Amp circuits, 2 15 Amp internal circuit breakers, 10 duplex recepticles per circuit (total of 20).

Here is a link to the PDU's specs:

The question is: do I need to install a 2 pole 30 Amp breaker or a single pole 30 Amp circuit? The specs on the PDU are 125V but the cable is 10/3 and the connector is L5-30P. Isn't that a 2 pole configuration? If I need a single pole configuration, how do I wire the L5-30R?

Thanks, Ed

[Palindrome]

No need for any of that. Run a couple of bare wires straight from the PDU through a couple of holes in the wall. Space the holes a few inches apart, for safety. Run the wires up to the nearest overhead cables and wind them around the conductors for two or three turns. Bind them in place with string. Whilst you can use a ladder to get to the cables, backing a truck up underneath is quicker. That should do it! Whilst you are up there, you might as well tap off some cable tv.

Of course, if you don't live in Haiti, your local accepted practice may be different. In which case, you may like to say where you *are* located...this *is* an international group.

[Pete C.]

L5-30 is a 125V configuration (hot - brass screw, neutral - silver colored screw, ground - green colored screw), L6-30 is the 250V configuration. Unless your home office setup is absurdly large, remove the L5-30 plug and replace with a 5-20 or 5-15 "normal" household plug and plug into a normal outlet. Highly unlikely your home office computer setup will draw in excess of 15A.

[Chris Lewis]

>

Perhaps what the OP is getting confused about is the fact that the powercord is "/3". Flexible cord designations _include_ the insulated ground in the "/n", whereas solid building wire with bare grounds do not. In other words, 10/3 flex cord has three insulated wires, one used as a ground. "10/3 wg" (we don't use "wg" designations in Canada, all building wire has bare grounds) solid building wire has four conductors, one bare.

In other words, 10/3 flexible cord is what you use with a single pole circuit with a ground. 10/2 flexible cord doesn't have a ground.

10/3 could also be used in a 240V circuit _without_ neutral. But not two pole (split) 120/240V like a modern stove/dryer circuit.

I've seen "home systems" with power requirements in excess of 20A (especially when you factor in laser printers), so the OP should check his actual requirements. If it's

[Terry]

Use a 30A single pole breaker.

[mm]

Absolutely.

[Paul Hovnanian P.E.]

>

Well, we have underground distribution where I live. So the advice about the ladder and/or pickup truck wouldn't apply. We estimate the location of the buried feeder and go to work with a pickaxe. The bit about wrapping around the cables is OK once you've scraped off the insulation with a couple of good swings.

Note to humor impared: Don't try this at home, kids.

[Doug Miller]

[snip]

"NEMA" = National Electrical Manufacturers Association, a United States trade group. It's a pretty fair assumption the poster is located in North America.

[Doug Miller]

Right, that's because the ground conductor is included in the count in a cord-and-plug connection. Your 10/3 cord set is hot, neutral, and ground.

The NEMA 5-series connectors are 125V devices, and hence the circuits that supply them use single-pole breakers.

Plugs and receptacles are designated as 2-pole, 3-pole, etc. to indicate the number of current-carrying conductors in the receptacle. This is not the same as the pole count on the breaker supplying the receptacle: the 5-30R and 6-30R are *both* designated as "2-pole" receptacles, but the 5-30R has hot + neutral and uses a single-pole (125V) breaker, whereas the 6-30R has two hots and uses a double-pole (250V) breaker.

Use a 30A single-pole breaker and 10/2 cable with ground -- yes, that's right, ten-TWO cable -- connected to the receptacle thus:

- black wire to the gold screw

- wite wire to the silver screw

- green wire to the green screw

[Palindrome]

Normally for questions involving 120v stuff, you are right that the poster is likely to be in the US or Canada.

However, this is an international group and there is an every-present danger that someone will be given incorrect advice because posters assumed that the OP must be in the US..

Such connectors are widely used -in countries other than the USA and Canada. Just because there aren't going to be many posters from those countries posting in English, doesn't preclude the possibility...

Heavens, I even use such connectors myself, here in the UK...

[Doug Miller]

You use NEMA connectors in the UK?? I thought your plug and receptacle configurations didn't even remotely resemble ours.

[phil-news-nospam]

| I am installing a computer equipment rack in my home office. The Power | strip (PDU) that I want to use is the Geist VRTDN200-10310TL. It | terminates in a NEMA L5-30P. The specs on the PDU are 30 Amps, 125V, | 3750 Watts, 2 x 15 Amp circuits, 2 15 Amp internal circuit breakers, | 10 duplex recepticles per circuit (total of 20). | | Here is a link to the PDU's specs: | |

| | The question is: do I need to install a 2 pole 30 Amp breaker or a | single pole 30 Amp circuit? The specs on the PDU are 125V but the | cable is 10/3 and the connector is L5-30P. Isn't that a 2 pole | configuration? If I need a single pole configuration, how do I wire | the L5-30R?

A NEMA L5-30P is a plug for a SINGLE POLE 125[1] volt 30 amp circuit. So your breaker would be ONE pole 30 amp, and the wiring would be a AWG 10 or larger (smaller number). If wired in conduit or cabled in metallic, the wires will have colors green, black, and white. If in non-mettalic cable, the ground wire will most likely be bare instead of green.

The L5-30R will have connections for ground (connect with the green or bare wire), hot/live (connect with the black wire), and neutral (connect with the white wire).

The designation "10/3" is an example of where someone counts the ground. This is a common source of ambiguity. Find out what insulation colors those wires have to tell you the circuit type.

If wiring in metallic conduit/cable, it might be wise to go with an "isolated ground" circuit. To do this you need a receptacle that has a specific isolated ground capability (no connection between the ground pin and the frame). The wires will include a 2nd ground wire colored with a green/yellow stripe. This allows grounding the frame and metal conduit separately from the receptacle ground pin (but they still meet at the circuit source in the breaker box).

[Ben Miller]

It is better not to modify the UL Listed device by putting a smaller plug on it. To answer the original question, use a single-pole 30A breaker. Have a qualified electrician install the circuit.

Ben Miller