Station Service Switchgear 1

[CuriousElectron]

Hey Guys,
For a service entrance rated switchgear, is the neutral bus and ground bus both bonded to the enclosure? I don't believe you would have a system bonding jumper like you would for a service disconnect in residential, for a switchgear where you have the ground bus spanning the length of the gear it would make sense to have the two busses bonded to the enclosure. The neutral bus would not be insulated.
We're talking 208V, 3 phase, 4 wire system.

Thanks,
EE

 

[Kiribanda]

If it is a 3-phase 4-WIRE system then the neutral has to be isolated from the ground and
should be sloidly grounded at the transformer star point ONLY before it enters the swgr.

 

[dpc]

If this is an installation in the US covered under the NEC: At the service entrance equipment, the incoming grounded conductor from the utility is connected to the neutral bus at the service equipment. There is a main bonding jumper that connects the neutral bus to the ground bus. The enclosure must be grounded. In addition, a grounding electrode must be provided. Downstream of the service equipment, the neutral must be isolated from the grounding conductor. Outside the US, I don't know.