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10.24
SEL-400 Series Relays
Instruction Manual
Date Code 20171006
Testing, Troubleshooting, and Maintenance
Maintenance
CAUTION
Step 23. Reconnect any serial cables that you removed from the
EIA-232 PORTS
in the disassembly process.
Step 24. Follow your company standard procedure to return the relay to service.
NOTE:
Some versions of this relay
will have the PS50 power supply. The
fuse is located in the same location as
the PS30, but it is rotated 90 degrees.
Installing Optional I/O Interface Boards
Perform the following steps to install SEL-400 series relay I/O interface boards.
Equipment components are sensitive
to electrostatic discharge (ESD). Per-
manent damage can result if you do
not use proper ESD procedures.
Ground yourself, your work surface,
and this equipment before removing
any cover from this equipment. If your
facility is not equipped to work with
these components, contact SEL about
returning this device and related SEL
equipment for service.
Step 1. Follow your company standard to remove the relay from service. It
will be necessary to remove power from the relay as part of this pro-
cess.
Step 2. Disconnect power from the relay. Isolate any contact inputs or out-
puts that will be affected by the installation of the I/O interface
board.
Step 3. Retain the
GND
connection, located to the right of the power supply
terminals to the relay, and ground the equipment to an ESD mat, or
other grounding point.
Step 4. Remove the communications cable connected to the front-panel
serial port, if applicable.
Step 5. Remove the rear-terminal block connectors for the I/O board that is
being installed. Two screws are used to retain each connector. Once
these screws are loosened, pull the connector firmly to remove it
from the rear of the relay. Note that these connectors are keyed to
their mating connectors in the relay.
Figure 10.11
PS30 Power Supply Fuse Location
J1
F1
J2
J3
Fuse
F1
Summary of Contents for SEL-421-4
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