Close Transition between Main Power Supply and Generator

A standard ATS will always give a voltage dip because it disconnects the one supply from the load before transfering to the other supply. if you want bumpless tranfer you need to sychronise the supplies together before switching one of them off.

If you are using generator as mains failure only you will always get a dip

I presume what you observed was your standby generator being reverse powered by the grid..

The next time you transition observe your KW meter on standby genset, and look for power flow in the negative direction, also observe your reactive power (VARS) in the same fashion.. A couple of questions..

How long is your closed transition timer set for? Normally this can be very short..

How big is you standby gen set?

Has the DG source tripped ?.If it is tripped then there is a problem which has to be probed thoroughly.

If it is only dip, it is bound to happen, as the Mains supply will be cut off and DG supply will be switched On in a fraction of second.

If you do not want any dip in voltage, you should first synchronise the DG supply to the Mains , transfer the loads to the DG source and trip the Mains supply.

Hi everybody, thanx to All for ur respon. After some troubleshooting, we found that no problem actually on our existing genset, the problem was caused by the new ACTTS installed. some setting on that equipment. problem eliminated already.tq once again

Owh...so the conclusion is setting on that equipment....

Well done.

Just curious, ainahamd,..but what was that "some setting"...it would be great if you can share that info with the forum members once you find it...

Cheers