streetfix
Electrical
- Jan 22, 2024
- 3
Hi, for my RMU switchboard of 12kV rated voltage and busbar rating of 630A consists of three panels. Two got CT ratings of 150/1A 15VA 5P10 and remining got a surge arrestor. I have received a comment saying "One of these two CTs should be connected to the generator protection relay so the cable lenght would be 25 meters but according to cable length it seems that 5VA is not suffiecient for both CTs." but we have allowed 120 meters in our calculation with 0.2VA for relay burden and 1.2 VA as safety factor.
Distance from RMU to ERF Generators = 20 meters
Distance from RMU to HV Switchboards = 120 meters
What should advice my design team regarding the above comment?
The total calculated burden Va is 2.61 as shown below. Should I increase the cable size to 10mm2 to allow signal losses?
Distance from RMU to ERF Generators = 20 meters
Distance from RMU to HV Switchboards = 120 meters
What should advice my design team regarding the above comment?
The total calculated burden Va is 2.61 as shown below. Should I increase the cable size to 10mm2 to allow signal losses?