For a motor circuit were you install a a breaker for short circuit protection in series with a thermal overload. How do you come up with the SCCR Short circuit Current rating of the breaker.
In other words how do you calculate the expected short circuit current for the circuit. eg for 40hp...
At what minimum voltage do we use the fomula (3VL + 1)Megaohms to calculate the minimum IR value which is acceptable.
How was the 1 Megaohm minimum derived. Is it universal for fractional horse power motors to multiple MVA motors.
Running a 250KW separately excited DC motor with a 3 phase supply 6 Thyristors module coupled with a DC drive controller. On starting the motor sounds like a single phasing 3 phase motor. At full speed 1000rpm if you change the button from motoring to generation that is breaking it burns...
