[Elecraft] (OT) Grounding Mat

[Jim Brown]

On Sat, 27 Mar 2010 16:09:36 -0400, Tom W8JI wrote:

>> NO! This is a summary of NEC (National Electric Code) 
>> requirements: The
>> NEUTRAL of a transformer on the secondary side MUST be 
>> bonded to the
>> equipment ground (steel conduit, the green wire, building 
>> structure, etc),
>> and that green wire must be carried from the breaker panel 
>> to each outlet and
>> to the transformer.  The neutral conductor that feeds the 
>> primary side of the
>> transformer must be bonded to ground at the service for 
>> the building (that
>> is, the main breaker panel). And, as we all know, all 
>> groundes must be bonded
>> together. Thus, an isolation transformer does NOT isolate 
>> either the neutral
>> or the equipment ground.

>I wonder when that changed? All of my isolation 
>transformers, probably manufactured in the 70's or 80's, 
>float the mains terminals on the load side. We used them all 
>the time working on AC/DC radios and I still use them now 
>working on SMPS. Only the case and safety grounds are 
>grounded. 

I have some UTC or Triads like that too. You can probably get 
away with using them on a service bench, but an electrical 
inspector would red tag you if you tried to install them 
without bonding the neutral. If I'm not mistaken, there also 
needs to be a breaker or fuse somewhere. 

73,

Jim K9YC