Sel 421 - Page 82

U.2.20
SEL-421 Relay User’s Guide Date Code 20090715
Installation
Jumpers
Figure 2.20 J18 Header—Password and Breaker Jumpers
The password disable jumper, J18B, is for temporary or emergency
suspension of the relay password protection mechanisms. Under no
circumstance should you install J18B on a long-term basis. The SEL-421
ships with password disable jumper J18B OFF (passwords enabled).
For temporary unprotected access to a particular access level, use the PAS n
DISABLE command (n is the access level: n = 1, B, P, A, O, 2). For more
information on this command and setting passwords, see
Passwords on
page U.4.9.
The circuit breaker control enable jumper, Jumper J18C, supervises the
CLOSE n command, the OPEN n command, the PULSE OUTnnn
command, and front-panel local bit control. To use these functions, you must
install jumper J18C.
The relay checks the status of the circuit breaker control jumper when you
issue CLOSE n, OPEN n, PULSE OUTnnn, and when you use the front
panel to close or open circuit breakers, control a local bit, or pulse an output.
The SEL-421 ships with circuit breaker jumper J18C OFF. For commissioning
and testing of the SEL-421 contact outputs, it may be convenient to set J18C
ON, so that the PULSE OUTnnn commands can be used to check output
wiring. J18C must also be set ON if SCADA control of the circuit breaker via
Fast Operate is required, or if the
LOCAL CONTROL > BREAKER CONTROL screens
are going to be used.
Ta b l e 2 .5 M a i n B o a r d J u m p e r s
a
a
ON is the jumper shorting both pins of the jumper. Place the jumper over one pin only for OFF.
Jumper
Jumper
Location
Jumper
Position
Function
J18A Front OFF For SEL use only
J18B Front OFF Enable password protection
(normal and shipped position)
ON Disable password protection
(temporary or emergency only)
J18C Front OFF Disable circuit breaker commands (OPEN and
CLOSE) and output PULSE commands
b
(shipped position)
b
Also affects the availability of the Fast Operate Breaker Control Messages and the front-
panel
LOCAL CONTROL > BREAKER CONTROL, and front-panel LOCAL CONTROL >
OUTPUT TESTING
screens.
ON Enable circuit breaker commands (OPEN and
CLOSE) and output PULSE commands
b
J18D Front OFF For SEL use only
ON
OFF
A
B
C
D
Courtesy of NationalSwitchgear.com