Dual electronic expansion valve module, Diagnostics – Orion System Dual Electronic Expansion Valve Module User Manual
Page 10

Dual Electronic Expansion Valve Module
Technical Guide
10
LED Descriptions
The Dual Electronic Expansion Valve Module is equipped with LEDs
that can be used to verify operation and perform troubleshooting. There
are LEDs for communication, operation modes, and diagnostic codes.
The module has 11 LEDs—1 used for E-BUS communications, 8 used
for operation & status, and 2 used for alarms.
See Figure 4 for the LED locations. The LEDs associated with these
inputs and outputs allow you to see what is active without using a volt-
meter. The LEDs and their uses are as follows:
Operation LEDs
POWER - This green LED will light up to indicate that 24 VAC power
has been applied to the module.
STATUS - This green LED will light up and blink the board address
at startup.
Diagnostic LEDs
ALARM - This red LED will light up to indicate an alarm. The type of
alarm will display on the LCD display. The ALARM LED also blinks
when the expansion valve is initializing at startup.
Alarms
The controller may have the following alarms for each refrigerant circuit:
•
Low Suction Pressure
This alarm will be activated when the suction pressure
drops below 70 PSIG for longer than 10 seconds.Valve
will modulate by 10% one time when alarm occurs to
try to get suction pressure back up. This alarm will
cease when Suction Pressure is above 70 PSIG.
•
High Superheat
This alarm will be activated when the Superheat
reaches 25 degrees for longer than 60 seconds. This
alarm will not affect valve operation. This alarm will
cease when the Superheat drops below 25 degrees.
•
Low Superheat
This alarm will be activated when the Superheat
is 0 degrees for longer than 60 seconds. This alarm
will not affect valve operation. This alarm will cease
when the Superheat rises above 0 degrees.
Alarm LED’s will blink and the specifi c alarm can be accessed on the
LCD display. Also, the Relay will activate for the specifi c valve that
has the alarm.
Diagnostics