REG 316*4 1MRB520049-Uen / Rev. C ABB Switzerland Ltd
2-27
2.10. Testing without the generator
In order to test the operation of the injection unit Type REX 010
plus injection transformer block Type REX 011 or REX 011-1/-2
and the Stator-EFP and Rotor-EFP protection functions without
them being connected to the protected unit, set up the test circuit
shown in Fig. 2.9 or Fig. 2.10.
The two grounding resistors RE and RP are used for both stator
and rotor protection schemes to simplify the circuit.
The injection voltage of 50 V is also common to both.
The ground fault resistance is simulated by the variable resistor
Rf.
Stator ground fault protection:
To test the stator ground fault protection, switch S1 must be kept
closed all the time.
The grounding resistor RE comprises two resistors of 1 kW and
22 W.
This is a simple method of simulating the ratio of the v.t.
Settings for MTR and REs:
The theoretical value of MTR is determined as follows:
MTR x
V
V
=
+
=
22 1000
22
110
50
102
WW
W
The low injection voltage of 50 V increases the value of MTR
by a factor 110 V/50 V.
REs = 1022 W.
The settings can also be determined using the setting func-
tions ‘MTR-Adjust’ and ‘REs-Adjust’ according to Section
3.5.24. which is to be preferred to the above calculation.
Rotor ground fault protection:
To test the rotor ground fault protection, the switch S1 must be
kept open all the time with the exception of when the coupling
capacitor is bridged for setting mode ‘AdjRErInp'.
Settings:
The theoretical settings are:
REr = 1022 W
Ck = 4 µF.
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