[TenTec] Station power supply??

[Jim Brown]

On 9/6/2012 4:36 PM, GARY HUBER wrote:
> Jim, just verifying my understanding of the following;
>
> Green (Grounded) and White (Neutral) bond ONLY at the MDP (Main 
> Distribution Panel). Green wire must run with neutral to main or 
> supplemental panel and MAY also be grounded elsewhere but those 
> grounding points MUST be bonded to the system / site / premise ground 
> in accordance with the National Electrical Code.

Right.

The key here is that there MUST be ONE, AND ONLY ONE  bond between 
neutral and Ground (the Green Wire) in any System, and it MUST be where 
the System is established.  A "System" is established 1) at the Service 
Entrance (where power comes into the building) and 2) at a transformer.  
A typical residence or small building has only one System. Larger 
buildings may have several systems.

One of the most common wiring errors made by electricians is to have 
additional bonds between Neutral and Green.  This most often happens two 
ways. First, when you buy a breaker panel, there's a bonding screw that 
automatically bonds the Neutral bus to the Ground bus (the Panel 
chassis).  That's fine if it's the Main Panel, but if it's a Sub-Panel 
it MUST be removed, and sometimes that isn't done. The other way that 
extra Neutral bonds happen is in older laundry equipment.

By contrast, the Green wire can be taken to earth as many times, and in 
as many places, as you like.

BTW -- someone correctly observed that in many localities, most wiring 
is three conductor cable with black, white, and bare copper for ground. 
Yes, that bare copper is "the Green Wire." It's called the Green wire 
partly because of history, partly because when wiring is in conduit or 
other metal raceway the dedicated ground wire must be Green, and partly 
because, in North America, the ground conductor in portable cables is 
usually Green.

73, Jim K9YC