Parallel Generator Grounding at Generator

[natfuelbill]

Kind of a technical question, but here goes.

Not being a generator power or generator controls expert, are there any commonly known reasons why system bonding jumpers must be installed at generators?

Consider a system where grounding resistors are not used.

 

[JohnJ0906]

It provides an effective path for ground fault current, same as a main bonding jumper

 

[dereckbc]

Kind of a technical question, but here goes.

are there any commonly known reasons why system bonding jumpers must be installed at generators?

Consider a system where grounding resistors are not used.

I assume you mean a generator configured for an Seperately Derived System where the neutral is switched. For an SDS application the best place to bond is at the Genset as it presents the lowest impedance.

If you are considering using an impedance grounding type of genset, you really need an professional engineer making design decesions and purchases as this is specialized and requires ground fault detection, breaker coordination schemes, and equipment.

 

[Natfuelbilll]

Here is some more information.

Yes the generators are SDS.
No transfer switches are present.
No utility service is present.
Multiple generators.
Paralleling switchboard.
Prime generator power.
No grounding resistor(s) present.
SBJ can be at either the switchboard or at the generators.
Reference IEEE Orange Book

Are ther reasons why the SBJ must be at the generators and not elswhere?

If there are no grounding resistors, can the SBJ be at the generators?

 

[don_resqcapt19]

If there are no grounding resistors, can the SBJ be at the generators?

Not if you have the generators connected in parallel.
Don