Generator set with ATS and UPS

[spidersparks]

Hi guys, been wiring up a 3ph 20kva generator set and auto transfer switch, mains supply is 3ph TN-C-S 80a cut outs, the set is a Perkins with deep sea electronics 6120 controller. The set runs ok until I turn on the circuit (ring final) that has the ups's in the server room on, the load is 13-14a in total over all three phases which is nothing for this set, then the controller says over voltage and shuts the set off the circuit tested out text book so no problems with that, has any one had this problem or knows anything that might be my problem
Many thanks
David

 

[cossie400]

What size UPS's do you have? Has the generator been matched to the UPS's?

 

[Lucien Nunes]

Is the voltage actually rising when the UPSs are connected? What other load was connected at the time? If they are presenting a heavy leading pf to an otherwise unloaded genny, they could be defeating the AVR because leading pf load is self exciting.