[TowerTalk] Grounding, portable generators, field day

[Jim Lux]

At 08:00 AM 1/21/2005, Gary Schafer wrote:
>Why do you install a ground rod at the generator?
>Do you also install ground rods at each operating position?
>
>You may be better off without a ground connection. Let the ac float. 
>Neither side is at earth ground like it is with ac mains from the power 
>company.
>
>Just use a gfi breaker. That will give more protection than any grounding 
>you may do.
>
>73
>Gary  k4FMX

This is one of those electrical code things.. better to have a definite 
ground, the properties of which you are certain, than a varying and casual 
ground.  It's very hard to "just let the ac float"... at some point, you're 
going to have something metal touching ground (like the generator frame?). 
Most likely you'll have multiple places with "poor grounds" (wet feet 
touching the ground, for instance). Even without an actual internal fault, 
the capacitance across the power transformer will float the case (or the 
audio grounds, or the coax ground, or...) towards the line voltage.  Yes, 
it's high impedance, but can cause all sorts of trouble.

It's perfectly ok to have a full floating AC system (and even permitted by 
code), but VERY hard to actually implement.