7PG2113/4/5/6 Commissioning & Maintenance
©2012 Siemens Protection Devices Limited
Chapter 6 Page 34 of 77
2.7.1 Directional
Polarity
See section Directional Earth Fault Polarity Check above for testing details.
Forward Reverse
Lag (point C)
Lead (point A)
Lead(point B)
Lag (point D)
MTA
Pick-up Drop-off Pick-up Drop-off Pick-up Drop-off Pick-up Drop-off
………….
MTA-85
………..
MTA+85
…………
MTA-85
…………
MTA-85
………...
Derived EF
Table 2.7-1
Directional Limits Test Results
2.7.2 Definite Time Overcurrent (50N)
If DTL setting is small, gradually increase current until element operates.
If DTL is large apply 0.9x setting, check for no operation, apply 1.1x setting, check operation
Apply 2x setting current if possible and record operating time
Check correct indication, trip output, alarm contacts, waveform record.
Note that these elements can be set to directional.
Phase Dir
.
Is
(Amps)
DTL
(sec)
P.U. Current
Amps
Operate Time
2 x Is
NOTES
E
Table 2.7-2
50N Results
If VTS action is set to BLOCK, this option should be tested. Apply balanced voltage and current. Reduce a-phase
voltage to cause a VTS condition. Increase 3P current and check that the element does not operate.
If VTS action is set to Non-Directional, this option should be tested. Apply balanced voltage and current. Reduce
a-phase voltage to cause a VTS condition. Increase a-phase current and check that the element operates at its
normal setting. Reverse the voltage phase direction whilst checking that the element does not reset.
2.7.3 Inverse Time Overcurrent (51N)
It will be advantageous to map the function being tested to temporarily drive the relevant Pickup output in the
Pickup Config
sub-menu in the
Output Config
menu as this will allow the Pick-up led to operate for the function.
Gradually increase current until Pickup LED operates.
Apply 2x setting current and record operating time,
Apply 5x setting current and record operating time.
Compare to calculated values for operating times.
Operate Current
Operate Time
Ph.
P.U.
(Amps)
D.O.
(Amps)
Tol
2 x Is
(sec)
5 x Is
(sec)
Tol
P.U.
D.O.
&
TIMING
TESTS
E
Dir
Char.
(NI EI VI LTI,
DTL)
Is
(A)
TM
Table 2.7-3
51N Results