On Sun, 09 Jun 2019 21:37:01 -0400, Clare Snyder
wrote:

On Sun, 9 Jun 2019 20:01:54 -0500, Terry Coombs
wrote:


Â* When is it necessary ? I've just replaced the panel out in the shop
(aluminum buss bars on the old one were giving problems) and I have a 3
wire service run out there . At this time the only place the neutral is
bonded to ground is in the meter box . It has been suggested to me to
bond them in the main panel too ... but that seems redundant to me ,
they're only the thickness of a piece of plywood apart . I have
considered installing a ground rod at the new panel but am concerned
about the potential for ground loop currents .
by cide the seb has to be "floating" - the neutral and ground bonded
pnly at one point DOWNSTREAM OF THE MAIN DISCONNECT. The main panel
gets "bonded" - nothuing else does - including a connected generator

You float the neutral if you have a 4 wire feeder but if you are still
working with that older 3 wire feeder, you need to reground the
neutral. That was only legal in a second building. In a single
building, all sub panels needed a 4 wire feeder and always have.

Generators will depend on what transfer equipment you are using. If
you switch the neutral, the generator is a separately derived system
and you bond the neutral since the main bonding jumper in the service
disconnect is not in the system anymore.