UPS over load

[Eng Majed]

Hi every body,

I face probelm during comissioning of one project , and I hope that I will find answer here.

My system is like this:


I have 200Kva UPS feeding 100Kva Step-Up Trnasformer.

this step up tr feeding 3 s/dawn transformers


step/up is y-delta connection


from UPS DP I connect 3-Phase to my LV side of the Tx.

then I connect the Neutral in the Y side of Tx to Ground.

what I 'm facinf now is Inverter Overload



it shows 230 Amp L1,, L2 L3 in UPS Reading 120% over load




then the UPS switch to ByPass.


when it switch to Bypass the reading of the current is view Amps .

the load drawn for the 3-step-dawn Tx is working well (which is cameras)

I calcualted my load which will not exeed 30 Kva.


I don't know why when I switch the operattion of the UPS to the Normal (through Inverter) it shows over load !!??


I did one thing.

I switch off the load of one of the 3 step-dawn Tx. but still the load same 120% over !!


finally you may need to know


UPS Output voltage is 380V

while my Step up Tx input is 400V (suppose to be) 400v/13.8Kv


can some body advice me?

 

[thepurple1]

This unit needs to be commissioned by the manufacturer.

 

[Eng Majed]

Thanks


any body can advice?

 

[sparks1234]

Thanks


any body can advice?

I think the best advice came from purple1