Why are there no fault contribution from any of the LV distribution boards even though they have motor loads?
[link Point to another website Only the registered members can access]
Junior Member
Why are there no fault contribution from any of the LV distribution boards even though they have motor loads?
[link Point to another website Only the registered members can access]
Very Active Member
check study case options.
Active Member
The motors are very small in kW size.
5.5 kW @ 400V = 8 Amps
Assuming a motor impedance of 20% the injected fault current is approximately 5 per unit.
Given the full load current of the motor is so low and the high level of fault current being supplied from the incoming supply this will dominate and you are not going to see very much contribution from the motors.
If you do a test and change the motors to 500 kW you will see 3-5 kA injected at the main bus from each motor.
Posting Permissions
Reply With Quote
Bookmarks