[Amps] 240V Outlet
w9ac at arrl.net
Sun Aug 9 12:12:36 PDT 2009
> Our electrician recommended that we pull both phases, neutral and
> ground to each location, regardless if the device needed a neutral.
> This would allow flexibility should we install new equipment.
> * To oversize the wire by at least one gauge size (on a 20 amp
> circuit, use #10 wire instead of the #12) to address potential
> voltage drop issues.
It's been a while since I've reviewed that section of the NEC, but I suspect
over-sizing the wire size is fine, but I would never oversize the breaker
current rating, nor would I over-size on the receptacle and plug. In the
latter case, I've seen instances where a 20-amp 120VAC receptacle is used,
but the conductors are sized at #14 AWG. Looking at the receptacle gives
the incorrect impression that the branch is rated for 20-amps, when in fact
it's only rated at 15-amps. The breaker rating, wire size, receptacle and
plug should all match the intended current-carrying capacity.
> * Use twist-lock or IEC 309 pin and sleeves, instead of straight
> blade connectors.
Love that idea too. I use 4-wire, 30-amp Hubbell or Leviton Twist-Lock
types on all amps and 240VAC service to the shack. Conductor size is #10
AWG to match that of the 30-amp breaker and 30-amp Twist-Lock receptacle.
If I were running smaller amps, I would also consider running companion
4-wire, 20-amp service to better match the amplifier's current draw with
that of the electrical distribution system.
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