Siemens SIPROTEC 4 7SJ61 User Manual

Current Input Function
Ι
N
or Ι
Nsdlich
Ground fault detection (sensitive / not sensitive) (Section 2.9 Ground Fault Protection
64, 67N(s), 50N(s), 51N(s))
Single-phase time overcurrent protection (Section 2.4 Single-Phase Overcurrent Protec-
tion)
Intermittent ground fault protection (Section 2.10 Intermittent Ground Fault Protec-
tion)
The settings for address 251 are only possible with DIGSI under Additional Settings.
i
i
NOTE
The settings under address 251 CT Connect. affect the time overcurrent protection with regard to the
evaluation of phase currents only if address 250 50/51 2-ph prot has been set to OFF.
ATEX100 (Power System)
Parameter 235 ATEX100 enables meeting the requirements for protecting explosion-protected motors for
thermal replicas. Set this parameter to YES to save all thermal replicas of the 7SJ61 devices in the event of a
power supply failure. After the supply voltage is restored, the thermal replicas will resume operation using the
stored values. Set the parameter to NO, to reset the calculated overtemperature values of all thermal replicas
to zero if the power supply fails.
Nominal Values of Current Transformers (CTs)
At addresses 204 CT PRIMARY and 205 CT SECONDARY, information is entered regarding the primary and
secondary ampere ratings of the current transformers. It is important to ensure that the rated secondary
current of the current transformer matches the rated current of the device, otherwise the device will calculate
incorrect primary data. At addresses 217 Ignd-CT PRIM and 218 Ignd-CT SEC, information is entered
regarding the primary and secondary ampere rating of the current transformer. In case of a normal connection
(neutral point current connected to Ι
N
transformer), 217 Ignd-CT PRIM and 204 CT PRIMARY must be set
to the same value.
If the device features a sensitive ground current input, parameter 218 Ignd-CT SEC is set to 1 A by default.
In this case, the setting cannot be changed.
If address 251 has been set so that ground currents are measured by two inputs (setting options A,G2,C,G;
G->B or A,G2,C,G; G2->B), you have to set the primary rated current of the second ground transformer
connected to Ι
N2
at address 238. secondary ampere rating must conform with the phase current transformer.
To calculated the phase current Ι
B
correctly, the primary rated current of the ground current transformer,
which is used to calculate Ι
B
(address 217 or address 238), must be smaller than the primary rated current of
the phase current transformer (address 204).
Trip and Close Command Duration (Breaker)
In address 210 the minimum trip command duration TMin TRIP CMD is set. This setting applies to all protec-
tion functions that can initiate tripping.
In address 211 the maximum close command duration TMax CLOSE CMD is set. It applies to the integrated
reclosing function. It must be set long enough to ensure that the circuit breaker has securely closed. An exces-
sive duration causes no problem since the closing command is interrupted in the event another trip is initiated
by a protection function.
Current Flow Monitoring (Breaker)
Address 212 BkrClosed I MIN corresponds to the threshold value of the integrated current flow moni-
toring system. This parameter is used by several protection functions (e.g. overload protection and auto-reclo-
sure for motors). If the set threshold current is exceeded, the circuit breaker is considered closed and the
power system is considered to be in operation.
Functions
2.1 General
38 SIPROTEC 4, 7SJ61, Manual
C53000-G1140-C210-6, Edition 05.2016

Siemens SIPROTEC 4 7SJ61 Specifications

General

Brand	Siemens
Model	SIPROTEC 4 7SJ61
Category	Relays
Language	English