TB MRD1-G 11.01 E
51
6
Relay Tests
For testing the
MRD1
the following has to be taken
into account:
The test current source must supply a current free of
harmonics. Should this not be the case, measuring er-
rors may result from this if the reference ammeter used
is an RMS instrument (which is common practice).
Test circuits for differential current I
diff
and stabilizing
current I
s
:
The rated value indication for differential current and
stabilizing current can be gathered from the following
table. Test current I should be in compliance with the
generator nominal current (or motor nominal current.
A
B
C
D
I
diff
2/3
×
I
0
1
×
In
0
I
s
0
2/3
×
I
0
1
×
In
Value indications dependent on the test circuit used
I
MRD1
B3
B4
B5
B6
B7
B8
I
MRD1
A3
A4
A5
A6
A7
A8
W1
W2
W1
W2
B3
B4
B5
B6
B7
B8
A3
A4
A5
A6
A7
A8
A
A
A)
B)
MRD1
W1
W2
I
B3
B4
B5
B6
B7
B8
A3
A4
A5
A6
A7
A8
I
I
L1
L2
L3
L1
L2
L3
LFG1
A
A
A
D)
Symmetrisches
Dreiphasensystem
symmetrical three phase
system
MRD1
W1
W2
I
B3
B4
B5
B6
B7
B8
A3
A4
A5
A6
A7
A8
I
I
L1
L2
L3
L1
L2
L3
LFG1
A
A
A
C)
Symmetrisches
Dreiphasensystem
symmetrical three phase
system
W1= Mains side, W2 = Star point side, LFG= (e.g.) |SEG Power Function Generator
NOTE for relay tests:
•
Stated accuracies apply to rated values
•
Currents must be free of harmonics
•
When a three-phase connection is used for the test, the current must form a symmetric system
•
Parameters MA CT connection and SP CT connection must be in normal position
7
Commissioning