Just in from Square D [RE-wrenches]

[hugh piggott]

<x-flowed>At 8:27 am -0800 11/3/01, Drake Chamberlin - Electrical Energy wrote:
>
>Part of the reason is the in the US, our National Electrical Code 
>requires that all ungrounded conductors have overcurrent protection. 
>I don't know how this would apply to British systems.

Yes it does, but that's not a reason for the requirement, it's just a 
requirement.  While it is useful to know the wording of the code, I 
am actually more interested in knowing the logic behind it.

For example there has been some chat on this list about double pole 
breakers being able to withstand twice the voltage of the individual 
breakers.  That's fine so long as both breakers are in the same fault 
circuit, but I suspect that the whole point of having a breaker on 
each pole is to guard against faults which occur in one conductor 
only.  (Otherwise one breaker would have been sufficient.)  If that 
is a true understanding, then it means that we cannot rely on both 
poles breaking the fault circuit, and so we cannot change the voltage 
rating.

At 9:52 pm -0800 11/3/01, Bill Brooks wrote:
>My understanding from these emails is that this is dealing with a signal
>circuit. As long as the wire is protected by a properly sized fuse, pick any
>wire size you like. No Fascism necessary.

But if you want to feed a low power light circuit then it's 'Zeig Heil'?  :-)
-- 
Hugh

Scoraig, Scotland
http://www.scoraigwind.co.uk

- - - - - - -
To send a message:
 RE-wrenches at topica.com

The archive of previous messages: 
 http://www.topica.com/lists/RE-wrenches/

List rules & etiquette:
 http://www.mrsharkey.com/wrenches/etiquete.htm

To unsubscribe send a message to: 
 RE-wrenches-unsubscribe at topica.com

To check out the other RE-Wrench participants:
 www.mrsharkey.com/wrenches/index.html

Hosted by Home Power magazine: 
 www.homepower.com

For info contact list moderator by email:
 michael.welch at homepower.com

____________________________________________________________
T O P I C A  -- Learn More. Surf Less. 
Newsletters, Tips and Discussions on Topics You Choose.
http://www.topica.com/partner/tag01

</x-flowed>