On Nov 17, 2005, at 5:25 PM, Gary Schafer wrote:
>
>
>> -----Original Message-----
>> From: amps-bounces@contesting.com
>> [mailto:amps-bounces@contesting.com] On
>> Behalf Of Peter Chadwick
>> Sent: Thursday, November 17, 2005 3:09 AM
>> To: R.Measures; Jim Brown
>> Cc: amps@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.
Good point, but given the possibility that a copper-muching rat happens
along, severs the neutral wire and severs the safety-wire, would it not
be advisable to have a braided-steel armoured, coaxial safety-ground
wire with a Cu center-conductor as a backup?
>
> 73
> Gary K4FMX
>
>
>
>
Richard L. Measures, AG6K, 805.386.3734. www.somis.org
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|