220v Petrol Alternator Earthing 1

[Pieterxstrata]

We are using 220v portable aternators on site, we need to install earth leakage units onto them, is there enyone who can assist me with some information on the above.What will happen to the sinus wave if I connect the N to earth on this machine.We measured voltages between L-N=230v ,L-E=151v and L-N=71v.
Thanks

 

[waross]

The generator frame should be grounded first. This may be a driven electrode or a cable to nearby grounded structural steel. It is a good idea to make the physical connection near the hitch in trailer portable units so that it is readily visible to a truck driver about to move the set.
Once the frame is grounded, check that the generator neutral is bonded to the frame of the generator.
The primary reason for grounding a portable generator is to maintain the frame at the same potential as the surrounding earth surface so that a person standing next to the generator may touch the generator without danger of electric shock.
For earth leakage consider ground fault trip breakers on all outgoing circuits. I have connected a number of generators where the generator fed a distribution panel and every breaker in the panel was a ground fault breaker. With this arrangement a fault on one circuit will only shut down that circuit.
If you must apply earth leakage trips on the entire generator output then install the sensing CT on the conductor between the neutral terminal and the frame of the gen-set. This will allow the use of line to neutral loads. An alternative method is to instal a sensing CT so that all three phase conductors AND the NEUTRAL conductor pass through the CT window. The ground jumper must be connected to neutral on the upstream side of the CT so that normal neutral currents will pass through the CT but ground fault currents will bypass the CT and the trip will operate on the resulting unbalanced currents.
Grounding will have no effect on either the sine wave or the sinus cavities.

Bill
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"Why not the best?"
Jimmy Carter