Functions
6-36 7SJ62 Manual
C53000-G1140-C121-1
The pickup of the 51N element is set at address 13,&.83. As is the case
for the 50N-1 relay element, the pickup value of the 51N relay element should be set
below the minimum anticipated ground fault current in the relay’s zone of protection.
The corresponding time dial is set at address 17,0(',$/ and should be
based on system coordination requirements.
The time dial may be set to ∞. The 51N element will then pickup and generate a mes-
sage, but will never trip. If the 51N element is not required at all, address should
be set to 'HILQLWH7LPH2QO\ during protective function configuration (Section
5.1).
Manual Close Mode When a circuit breaker is closed into a faulted line, a high speed trip by the circuit
breaker is often desired. The relay’s manual closing feature is designed to remove the
delay from one of the time-overcurrent elements when a circuit breaker is manually
closed into a fault. The time delay may be bypassed for one of the three time-overcur-
rent phase elements and one of the three time-overcurrent ground elements via an im-
pulse from the external control switch, thus resulting in high speed tripping. This im-
puls is prolonged by a period of 300 ms. Address 0$18$/&/26(02'( can be
set such that the delay is defeated for the 50N-2 element, the 50N-1 element, the 51N
element, or none of the elements (,QDFWLYH). Defeating the delay on just one of the
three elements allows control over what level of fault current is required to initiate high
speed tripping of a circuit breaker that is closed into a fault.
If the manual closing signal is not from a 7SJ62, that is, neither via the built-in operator
interface nor via a series interface, but, rather, directly from a control acknowledgment
switch, this signal must be passed to a 7SJ62 binary input, and configured accordingly
so that the element selected for high speed tripping will be effective.
Interaction with Au-
tomatic Reclosing
Equipment
At address 1DFWLYH, it can be specified whether or not the 50N-2 ele-
ments should be supervised by the status of an internal or external automatic reclosing
device. If address is set to ZLWKDFWLYH, the 50N-2 elements will not op-
erate unless automatic reclosing is enabled. If address is set to $OZD\V, the
50N-2 elements will always operate.
User-Specified
Curves
If address was set to 8VHU'HILQHG3LFNXS&XUYHor 8VHU'HILQHG
3LFNXSDQG5HVHW&XUYH during configuration of the user-specified curve option,
a maximum of 20 value pairs (current and time) may be entered at address
11 to represent the time-current characteristic curve associated with the 51N
element. This option allows point-by-point entry of any desired curve.
If address was set to 8VHU'HILQHG3LFNXSDQG5HVHW&XUYH during
configuration of the user-specified curve option, additional value pairs (current and re-
set time) may be entered at address 0RI385HV77(S to represent the reset
curve associated with the 51N element.
Current and time values are entered as multiples of the address and set-
tings. Therefore, it is recommended that addresses and be initially set to
1.00 to simplify the calculation of these ratios. Once the curve is entered, the settings
at addresses and may be modified if necessary.
Upon delivery of the device, all time values are set at ∞, preventing pickup of the de-
vice from initiating a trip signal.
When entering user-specified curve data, the same instructions apply as in Subsec-
tion 6.2.2.1 for the phase elements.
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