7PG2113/4/5/6 Commissioning & Maintenance
©2012 Siemens Protection Devices Limited
Chapter 6 Page 57 of 77
Where two NPS elements are being used with different settings, it is convenient to test the elements with the
highest settings first. The elements with lower settings can then be tested without disabling the lower settings.
NPS Overvoltage can be tested using a normal 3P balanced source. Two phase voltage connections should be
reversed so that the applied balanced 3P voltage is Negative Phase Sequence.
If the 47-n delay is small, gradually increased the applied balanced 3P voltage 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
Phase 27/59
setting
(Volts)
U/O DTL
(sec)
Hyst. D.O.
(calculated)
P.U.
Volts
D.O
Volts
Op. Time
2x Vs
Tolerance
NPS
Table 2.15-1
47 Test Results
2.15.1.1 Element
Blocking
The NPS Overvoltage element can be blocked by Binary Input Inhibit. This functionality should be checked.
Element BI
Inhibits
47-1
47-2
Table 2.15-2
Element Blocking
Check correct indication, trip output, alarm contacts, waveform record.