Getting 47N trips when on generator but never on utility.

[CBGUY]

Device BE3-47N. tripping when set for 10%, never trips when set for 15% DRANETZ reports 1% or less. Waveform has flat spot at at zero crossing. Two devices do exact same thing. I think Specifying engineer has too tight a value. Any ideas. Load is a data center and building mechanical. Happens on primary and alternate generator. New CATS.

 

[ScottyUK]

47 is a negative sequence voltage relay, but I've not seen an 'N' designator before. Is this a conventional voltage-sensing relay?

What are you measuring with the Dranetz - voltage THD?

How well balanced is the load?

 

[CBGUY]

I am not the lead guy. They are all saying that the Basler relay should not react to 8% THDV. I saw the scope, it had weird zero crossing shifts, a flat spot between positive and negative at 180 degrees. The rest was normal switching power supply,etc along the rest of the sinewave.. Years ago this caused me big problems. I was told zero crossing shift was a big problem. I can't find info I read once, pre-internet.