New main breaker panel practices

[robertjo24]

It has been standard practice for some time to tie the neutral and ground bus bars in the main breaker panel. Then, all subesquent sub-panels and devices the neutral and grounds are kept seperate.

Is it a new standard or code to not tie the neutral and ground bus bars in the main panel and the neutral is grounded at the transformer only?

 

[rbulsara]

It depends on your local codes.

In the NEC world, new or old, that is not the code requirement. NEC requirement is to bond the neutral to ground at the service entrance panel (not all main panels are service entrance).

If it is a service and the transformer is outside, the bonding of transformer neutral to ground is the additional requirement.

If the main panel is not a service and fed by a transformer, the neutral has to be grounded only one point, either at the transformer or the first disconnect.

For better understanding, look up your applicable codes.


Rafiq Bulsara

http://www.srengineersct.com

 

[dpc]

Agree with Rafiq. If you are in NEC-land, there is a distinction between a "main breaker panel" that is a service entrance and one on a separately-derived system.

For a service entrance, look up "Main Bonding Jumper" in the NEC.

David Castor

http://www.cvoes.com