Sel SEL-421 - Table 2.3 Main Board Jumpers

U.2.19
Date Code 20020501 User’s Guide SEL-421/SEL-421-1 Relay
Installation
Jumpers
Figure 2.14 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
Relay 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.4.10 in the User’s Guide.
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. Jumper J18C is usually installed on a long-term basis after
you have completed relay commissioning and installation tests. The SEL-421
Relay ships with circuit breaker jumper J18C OFF (control outputs disabled).
After commissioning tests, move jumper J18C to ON for proper control
output operation.
Serial Port Jumpers
Place jumpers on the main board to connect +5 Vdc to Pin 1 of each of the
three rear-panel EIA-232 serial ports. The maximum current available from
this Pin 1 source is 0.5 A. The Pin 1 source is useful for powering an external
modem. Table 2.4 on page 2.20 describes the JMP1, JMP2, and JMP3
Table 2.3 Main Board Jumpers
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 control outputs (shipped position)
ON Enable control outputs, including circuit breaker
CLOSE and OPEN (normal position)
J18D Front OFF For SEL use only
ON
OFF
A
B
C
D