Surges from Generators

[LeeB]

Has anyone experienced issues with Generator transfer from normal to emergency or emergency to normal, causing Network switches to trip?

 

[GoldDigger]

Has anyone experienced issues with Generator transfer from normal to emergency or emergency to normal, causing Network switches to trip?

Are you referring to Network Protection Relays (NPR), also called Reverse Power Relays?
It has been discussed in another thread that the sudden change in load current based on a UPS cutting in during the transfer may actually cause a momentary reverse power indication in an upstream feeder, particularly when two generators are paralleled.
A lot depends on the relative location of the UPS and the NPR and the relative proportion of normal and UPS-driven loads.
If you have only a single generator and no UPS in the mix, then I have not seen it mentioned before.

Or are you talking about data network switches?

 

[templdl]

Has anyone experienced issues with Generator transfer from normal to emergency or emergency to normal, causing Network switches to trip?

Are you saying that you have this problem when going from normal to emergancy? I find it to be a none issue when transferring from a normal source to emergancy you have already lost normal source power. As such the genset starts and comes up to speed pond as soon as it is up to voltage the transfer occurs and reestablishes power. The only way that there would be a chance to trip a breaker is if you are testing the gender by going from an energized normal source to the emergency source which often creates an out of phase transfer. This would not happen should there be a loss of normal source power.
When the normal source power returns now you have both sources energizes and when you go from the the emergency source back to normal may seem to be simple but there is a very good chance the they are not in phase and their in lies the problem. By simply adding a time delay neutral (TDN) when transferring back to normal removes the emergency power briefly from the load and then transfers the load back to the normal source.
When you have an out of phase transfer you end up with a voltage spike which equates to a spike in current which is enough to trip a breaker. As such a TDN or a means to assure than an in phase transfer is necessary to prevent tripping a breaker.