"Bruce L. Bergman wrote
On Sat, 08 Sep 2012 19:01:50 -0400, Wes
wrote:
Ignoramus29252 wrote:
``There is no such voltage as 460 Single Phase. 460 volts is Three
Phase''
Iffin you use all three conductors.
They only sell it to you from the Utility as 460V (now nominal 480V)
3-Phase 3-wire, or 277/480V 3-phase 4-wire - and if you can get it
in
as 277/480V 3-Ph 4-wire Wye it's worth the extra expense.
(They sell lots of different 277V Shop Lights that will run straight
from the service Hot to Neutral, 480V is only available in a few
High-Bay styles. For 120V lights and outlets you need a transformer,
or a separate lighting service.)
But iffin' you only use two of the hot lines instead of all three
lines, you've got 480 Volts Single Phase there, just like you want.
But don't try to cheat and use a 480V Single Phase receptacle - they
don't exist - or if someone does make them (probably in a Pin and
Sleeve Device) they'll be REAL expensive because they won't sell
many.
Just use a plain old 480V 3Ph twist lock receptacle and only use
3-conductor cord. Hot, Hot, and Ground.
If you have several of these devices, balance the loads - First one
is
connected to the A & B phases, second is on B & C, third on C & A.
Repeat as needed to keep the Power Utility from getting annoyed at
you
for unbalancing their system.
Oh, and make sure the portable cord you use is rated for 600V, a
decent percentage of the cheap stuff at the hardware store is only
rated at 300V. In a few years when the cord insulation starts
breaking down from age, that can cause you some serious excitement.
per wikipedia:
http://en.wikipedia.org/wiki/NEMA_connector#NEMA_L8
NEMA L8 connectors are used with circuits with a maximum specified
voltage of 480 V AC. Supply connections are intended for two-pole,
three-wire hot-hot-ground circuits with a nominal supply voltage of
460 V.
I could not find them on McMaster or Grangers, but did find
http://www.automationdirect.com/adc/Shopping/Catalog/Power_Products_(Electrical)/Wiring_Devices/Electrical_Plugs,_Connectors,_-a-_Receptacles/Locking_Plugs,_Connectors,_-a-_Receptacles/70820FR;jsessionid=5e304e92319b048c22ca2a5356412a3 c2f44?utm_source=google&utm_medium=product-search&gclid=CIutmoePrLICFUhN4AodAVkALQ
at 12.50 I would not call it terribly expensive.
Balancing is indeed important. Using the correct outlets saves breaker
space and I think is the best way to assure balancing.
--
Stephen B.