351-7 formula
351-7 formula
(OP)
I am looking for a formula how to calculate the relay settings reverse power on SEL 377-1. I found some other formulas but I am not sure if they are applicable to this relay. I couldn't find anything in SEL manuals.
I have 25kW system, CT ratio 200:5, PT ration 36:1. I know I need some Generator info also to get the calculations but I would like to know what the formula for calculating out the settings is.
I have 25kW system, CT ratio 200:5, PT ration 36:1. I know I need some Generator info also to get the calculations but I would like to know what the formula for calculating out the settings is.






RE: 351-7 formula
RE: 351-7 formula
RE: 351-7 formula
RE: 351-7 formula
RE: 351-7 formula
Im = secondary current to the relay
Im = (Primary kw at motoring x 1000) / (generator terminal volts x ct ratio x Sqrt(3))
You will need to set a time delay to prevent tripping during synchronizing and stable system swings.
RE: 351-7 formula
RE: 351-7 formula