U.2.46
SEL-421 Relay User’s Guide Date Code 20090715
Installation
Connection
Obsolete TIME Input Connection
Previous SEL-421 relays had a TIME 1k PPS input BNC connector. When relay
firmware version R112 was released, the rear-panel TIME inputs were
reconfigured. If you have upgraded the firmware in a previous SEL-421, see
Using New SEL-421 Firmware in an Existing Relay on page U.4.73 for retrofit
information.
The previous 1k PPS BNC connector is the new IRIG-B connector. The previous
IRIG-B BNC connector is not used. See 1k PPS Connection Not Required on
page U.4.72 for details.
Replacing the Lithium
Battery
You can replace a bad lithium battery in the SEL-421. Perform the following
steps to replace the lithium battery.
Step 1. Follow your company standard procedure to remove a relay
from service.
Step 2. Disconnect power from the SEL-421.
Step 3. Remove the relay from the rack or panel.
Step 4. Retain the GND connection, if possible, and ground the
equipment to an ESD mat.
Step 5. Remove the communications cable connected to the front-panel
serial port, if applicable.
Step 6. Remove the rear-panel EIA-232 PORTS mating connectors.
Step 7. Unscrew the keeper screws and disconnect any serial cables
connected to the PORT 1, PORT 2, and PORT 3 rear-panel
receptacles.
Step 8. Loosen the four front-panel screws (they remain attached to the
front panel), and remove the relay front panel.
Step 9. Remove the 34-pin ribbon cable from the front panel by
pushing the extraction ears away from the connector.
Step 10. Disconnect the power, the interface board, and the analog input
board cables from the main board.
Step 11. Pull out the drawout tray containing the main board.
Step 12. Locate the lithium battery.
The lithium battery is at the front of the main board (see
Figure 2.19).
Step 13. Remove the spent battery from beneath the clip of the battery
holder.
Step 14. Replace the battery with an exact replacement.
Use a 3 V lithium coin cell, Ray-O-Vac
®
No. BR2335 or
equivalent. The positive side (+) of the battery faces up.
Step 15. Reinstall the SEL-421 main board, and reconnect the power,
the interface board, and the analog input board cables.
Step 16. Reconnect the cable removed in Step 9 and reinstall the relay
front-panel cover.
Step 17. Reconnect any serial cables that you removed from the EIA-232
PORTS in the disassembly process.
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.
!
DANGER
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.
!
WARNING
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.
!
CAUTION
There is danger of explosion if the
battery is incorrectly replaced.
Replace only with Ray-O-Vac
®
no.
BR2335 or equivalent recommended
by manufacturer. Dispose of used
batteries according to the
manufacturer’s instructions.
!
CAUTION
Courtesy of NationalSwitchgear.com
To Next Page
Loading...
