[Amps] 4 wire 240VAC service? What to do now?

[Gary Schafer]

Being that it is only 120 volts you have a hot, neutral and a ground wire
run out there. You should have the ground wire from the main panel connected
to the ground buss in the sub panel along with the local ground rod out
there. Do not bond the neutral to the sub panel ground.

If you were running 220 to the building with only 3 wires then you would
bond the neutral to the ground at the sub panel. In this case the neutral
and ground lead would be one and the same.  In the US the NEC no longer
allows this type of connection but has grandfathered old existing systems.

No matter how things are connected always remember that there must be a wire
connection between your safety ground connection and neutral somewhere in
the system in order for a reliable means of tripping a breaker in case of a
fault of hot to equipment cabinet.
 That somewhere should be at the main service entrance point to avoid any
normal current on the ground lead.

73
Gary  K4FMX

> -----Original Message-----
> From: Doug Renwick [mailto:ve5ra at sasktel.net]
> Sent: Monday, April 04, 2011 7:23 PM
> To: garyschafer at comcast.net
> Cc: amps at contesting.com
> Subject: RE: [Amps] 4 wire 240VAC service? What to do now?
> 
> Is this OK?  I ran 3 wires (120v only) to a sub panel in building #2.  I
> installed a ground rod at building #2 and grounded the sub panel.  I
> will
> have to check to see if the neutral is connected to the sub panel
> ground.
> 
> Doug
> 
> >-----Original Message-----
> >
> >Jim,
> >Your method #1:
> >
> >This method was allowed several years ago but NEC no longer allows
> this.
> You
> >must now run 4 wires to building #2 and NOT bond neutral and ground in
> >building #2. that panel is treated as a sub panel and it also requires
> a
> >ground rod in addition to the ground wire from the main panel.
> >
> >Under the old method as you describe neutral and ground would be bonded
> at
> >the sub panel.
> >
> >Your Method #2:
> >
> >You say to run two hots and neutral. You didn't mention a ground wire.
> Did
> >you mean to say that 4 wires would be run?
> >If so then ok. However a local ground rod is STILL required at the
> panel in
> >the 2nd building. The only time a ground rod is not required at a sub
> panel
> >is when the sub panel is located in the same building as the main
> panel.
> >
> >73
> >Gary  K4FMX