[Amps] 220V wiring: Was Question about safety ground connection

[Gary Schafer]

> -----Original Message-----
> From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com] On
> Behalf Of Peter Chadwick
> Sent: Thursday, November 17, 2005 3:09 AM
> To: R.Measures; Jim Brown
> Cc: amps at contesting.com
> Subject: Re: [Amps] 220V wiring: Was Question about safety ground
> connection
> 
> Rich said:
> 
> >Bonding the enclosure to the neutral wire insures that the enclosure
> can not become a shock hazard if the safety-ground wire is severed by
> an anomaly.<
> But an open neutral in such a case leaves the enclosure at some
> undetermined voltage above ground. Depending on how good the neutral
> grounding is at the service entrance, an open neutral in the feed to the
> property can float enclosures above ground. It comes down to the
> probability of opening a safety ground or a neutral, and if they run
> together, the probability is that severing one severs both.
> 73
> 
> Peter SM/G3RZP

Very good point Peter! 
That is the whole reason in a nutshell for having a safety ground separate
from neutral. An open safety ground does not force the chassis hot. An open
neutral WILL force the chassis hot if it is used as ground.

73
Gary  K4FMX