Standard formular for IDMT Relay Curve
Standard formular for IDMT Relay Curve
(OP)
Anyone know the required standard for IDMT Relay Curve? What is the Equation/Formular? Thanks.
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Standard formular for IDMT Relay Curve
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RE: Standard formular for IDMT Relay Curve
cheers Johnspark
RE: Standard formular for IDMT Relay Curve
RE: Standard formular for IDMT Relay Curve
t = (k.B)/((I/Is)^a - 1)
where t = operating time (sec)
k = TMS (time multiplier settings)
I = measured current value (A)
Is= set current value
a B
Normally Inverse 0.02 0.14
Very Inverse 1.0 13.5
Extremely Inverse 2.0 80.0
Long Time Inverse 1.0 120.0
NI = 3/10, VI = 1.2/10, EI = 0.8/10, LTI = 12/10.
You can also refer to BS142.1966 or IEC 255-4.
RE: Standard formular for IDMT Relay Curve
http://www.selinc.com/instruction_manual/551/551_4.pdf
Refer to pages 4-2 to 4-6 for different US and IEC inverse-time curves equations and graphics.
RE: Standard formular for IDMT Relay Curve
RE: Standard formular for IDMT Relay Curve
http://www.selinc.com/instruction_manual/551/551_04.pdf