Normal Inverse Curve Formula of BBC ICM Overcurrent Relay
Normal Inverse Curve Formula of BBC ICM Overcurrent Relay
(OP)
Hello everyone!
What is the formula of a Normal Inverse Curve of BBC ICM overcurrent relays?
Thanks.
What is the formula of a Normal Inverse Curve of BBC ICM overcurrent relays?
Thanks.






RE: Normal Inverse Curve Formula of BBC ICM Overcurrent Relay
The equation is t = TMS(((k/((I/Is)^a) -1))+ C))))
Where:
t = operating time for a constant current
I = energising current
Is = overcurrent setting
TMS = time multiplying setting
k, a and c = constants defining the curve
For nor4mal Inverse, defined by the IEC, K = 0.14, a = 0.02 and c = 0.
RE: Normal Inverse Curve Formula of BBC ICM Overcurrent Relay
RE: Normal Inverse Curve Formula of BBC ICM Overcurrent Relay
Thanks for the information. The relay that im referring is the old one, the BBC ICM2.
Thanks very much.
GRAEE