7SR224 Argus Commissioning & Maintenance Guide
©2010 Siemens Protection Devices Limited
Chapter 6 Page 50 of 73
2.12.7 Inverse Time (59NIT)
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 voltage until Pickup LED operates.
Apply 2x setting voltage and record operating time,
Apply a higher multiple of setting voltage and record operating time.
Compare to calculated values for operating times from:
(
)
[ ]
⎥
⎦
⎤
⎢
⎣
⎡
−
=
1
1
)
sec
Vs
Vn
op
M
onds
t
Where M = Time multiplier and Vn/Vs = multiple of setting.
Operate Voltage
Operate Time
Ph. Vs
(V)
TM
P.U.
(Volts)
D.O.
(Volts)
2 x Vs
(sec)
x Vs
(sec)
NOTES
P.U.
D.O.
&
TIMING
TESTS
E
2.12.7.1
Element Blocking
The Neutral Overvoltage elements can be blocked by Binary Input Inhibit. This functionality should be checked.
Element BI
Inhibits
59NIT
59NDT
Check correct indication, trip output, alarm contacts, waveform record.
When testing is complete reinstate any of the disabled functions.