Manual 37138C
ESDR 4T - Current Differential Protection Relay
© Woodward
Page 29/46
Nominal Data
≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡
General Data
Nominal current
0000A
Rated current of the protected object
10 to 9,999 A
This value is used as reference value for the calculation and display of restraint cur-
rent and differential current. The entered value of the generator current must be at
least 60% of the nominal current of the CT and must not exceed the entered value
of CT nominal current. You must enter the rated current of the low-voltage side
when implementing transformer or block differential protection.
Example: ...... CT ratio
500/5 A
Range of rated current
300 A to 500 A
Data for Differential Protection
Curr. transf. Id
high vol. 0000A
Primary value (high-voltage side) of the current transformer
10 to 9,990 A
Entry of the current transformer ratio is necessary. The ratio must be selected so
that during normal operations, the secondary side of the CT is operating at least at
60% of the transformer’s capacity when at maximum current. A smaller current
transformer ratio would cause inaccuracies in the monitoring functions.
Curr. transf. Id
low vol. 0000A
Primary value (low-voltage side) of the current transformer
10 to 9,990 A
Entry of the current transformer ratio is necessary. The ratio must be selected so
that during normal operations, the secondary side of the CT is operating at least at
60% of the transformer’s capacity when at maximum current. A smaller current
transformer ratio would cause inaccuracies in the monitoring functions.
Nominal voltage
high vol 000,0kV
Rated voltage primary value (high-voltage side)
0.4 to 750.0 kV
The transformer conversion ratio is calculated using this value. This value is the
same as the rated voltage on the low-voltage side when the device is being used for
generator differential protection.
Nominal voltage
low vol 000,0kV
Rated voltage primary value (low-voltage side)
0.4 to 750.0 kV
The transformer conversion ratio is calculated using this value. This value is the
same as the rated voltage on the high-voltage side when the device is being used
for generator differential protection.