U.2.13
Date Code 20020501
User’s Guide
SEL-421/SEL-421-1 Relay
Installation
Plug-In Boards
I/O Interface Board Outputs
The I/O interface boards vary by the type and amount of output capabilities.
lists the outputs of the additional I/O interface boards; the table also
shows the I/O outputs on the main board. Information about the Standard and
Hybrid (high-current interrupting) control outputs is in
.
Installing Optional I/O Interface Boards
When expanding the capability of the SEL-421 Relay with additional I/O
interface boards, perform the following steps:
Step 1. Remove the relay from service. Follow your company standard
for removing a relay from service. Disconnect power from the
SEL-421 Relay. Retain the GND connection, if possible, and
ground the equipment to an ESD mat.
Step 2. Remove the front panel from the SEL-421 Relay.
Step 3. Disconnect all cables from the main board (the top board).
Step 4. Confirm proper installation of address jumpers on the interface
board. See
Step 5. Confirm drawout tray keying. The relay chassis and the
drawout trays for the 200-addresses slot and the 300-addresses
slot are keyed (see
). The keys are two round plug-
in/plug-out discs on the bottom of the drawout tray. The 200-
addresses slot keys go to the left, and the 300-addresses slot
keys go to the right (when viewed from the top and front of the
drawout tray). Move a key on the bottom of the drawout tray to
the correct position by prying the key from the tray and
reinserting the key in the proper position. Do this for both keys.
Table 2.2
I/O Interface Boards Control Outputs
Standard
Fast
Hybrid
a
a
High-Speed/High-Current Interrupting
Hybrid
b
b
High-Current Interrupting
Board Number
Form A
Form C
Form A
Form A
Form C
INT1
13
2
INT5
8
INT6
13
2
Main Board
2
3
3
WARNING:
Have only
qualified personnel service this
equipment. If you are not qualified to
service this equipment, you can
injure yourself or others, or cause
equipment damage.
!
DANGER:
Disconnect or
de-energize all external
connections before opening this
device. Contact with hazardous
voltages and currents inside this
device can cause electrical shock
resulting in injury or death.
!
CAUTION:
Equipment
components are sensitive to
electrostatic discharge (ESD).
Undetectable permanent 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.
!
Summary of Contents for SEL-421
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