The tripping comes on the Undervoltage relay. The relay currently doesn't have a time delay module. But as musaUKPN indicated, i ordered a time delay unit to add with the relay. Lets see if it works!
Yes waross. Its the voltage relay that causes tripping. It may be due to either unbalance voltage or under-voltage (coz relay doesn't have any third function :) ). I will check this tomorrow morning. Another important thing to tell here is that the old generators we has were furnace oil...
We have a cotton weaving unit with 6 gas generators at 380V output. All 6 generators are connected to 6 step up transformers (connected star-delta i.e. output 11kV side is delta and no neutral is present!). Out of all 6 transformers is connected in parallel to a common 11kV busbar. From the...