Schweitzer Engineering Laboratories SEL-351 - Troubleshooting Procedure; All Front-Panel Leds Dark; Cannot See Characters on Relay LCD Screen; Relay Does Not Respond to Commands from Device Connected to Serial Port

Date Code 20001006 Testing and Troubleshooting 13-9
SEL-351 Instruction Manual
Troubleshooting Procedure
All Front-Panel LEDs Dark
1. Input power not present or fuse is blown.
2. Self-test failure.
Cannot See Characters on Relay LCD Screen
1. Relay is deenergized. Check to see if the ALARM contact is closed.
2. LCD contrast is out of adjustment. Use the steps below to adjust the contrast.
a) Remove the relay front panel by removing the six front-panel screws.
b) Press any front-panel button. The relay should turn on the LCD back lighting.
c) Locate the contrast adjust potentiometer adjacent to the serial port connector.
d) Use a small screwdriver to adjust the potentiometer.
e) Replace the relay front panel.
Relay Does Not Respond to Commands From Device Connected to Serial Port
1. Communications device not connected to relay.
2. Relay or communications device at incorrect baud rate or other communication parameter
incompatibility, including cabling error.
3. Relay serial port has received an XOFF, halting communications. Type <CTRL>Q to send
relay an XON and restart communications.
Relay Does Not Respond to Faults
1. Relay improperly set.
2. Improper test source settings.
3. CT or PT input wiring error.
4. Analog input cable between transformer secondary and main board loose or defective.
5. Failed relay self-test.
RELAY CALIBRATION
The SEL-351 Relay is factory-calibrated. If you suspect that the relay is out of calibration,
please contact the factory.
Courtesy of NationalSwitchgear.com