KE2 Evap
OEM
Alarm Troubleshooting Guide
Q.1.61 January 2023
Page 10
© Copyright 2023 KE2 Therm Solutions, Inc., Washington, Missouri 63090
21214V3.0
Troubleshooting Tables
Alarm & Alarm Name
Description
Variables & Setpoints Corrective Action
Basic
Display
Combo
Display
Web-
pages
HtA
HtA
HIGH AIR
TEMP
High Air
Temp
Alarm
Yellow LED is
illuminated.
Controller will
attempt to continue
to operate system
while this alarm is
present.
Return air temp is
above Room Temp
se Air Temp
Diff + High Temp
Alarm Offset for
longer than High
Temp Alarm Delay.
Example
Room Temp
setpoint
20°F
Air Temp
Diff
1°F
High Temp
Alarm Offset
10°F
Alarm
threshold
temp
31°F
These setpoints can
be adjusted by the
user. The High Temp
Alarm Offset factory
default is 10.0°F for
electric defrost and
3.0°F for air defrost.
Variables
rtP - Room (Air) Temp
Setpoints
tS - Room Temp Set-
point
HAo - High Temp Alarm
Offset
HAd - High Temp Alarm
Delay
Investigate condition. The majority of high temperature alarms are not related to the
controller. To resolve the High Air Temp Alarm will require basic refrigeration trouble-
shooting.
• Ask staff if the door has been propped open for an extended period of time due to
loading, unloading, inventory, etc. If this is not the case, begin to troubleshoot the
system.
• Check air sensor.
• Check the evaporator coil to verify the coil is free from excessive frost.
• Check the fans to ensure all fans are rotating properly.
• Check compressor operation.
• Check for proper refrigerant charge.
• Make sure the system has sufficient capacity.
• If pressure transducer and suction temperature sensor are installed, check superheat
and investigate if superheat is abnormally high.
• Troubleshoot TEV or EEV (if installed, see high superheat corrective actions on the
previous pages).
Note: High Temp Alarm is not triggered during defrost.
LtA
LtA
LOW AIR
TEMP
Low Air
Temp
Alarm
Yellow LED is
illuminated.
Controller will
attempt to continue
to operate system
while this alarm is
present.
Return air temp is
below Room Temp
setpoint - Low Temp
Alarm Offset for
longer than Low
Temp Alarm Delay.
The default alarm
condition is 4°F
below the Room
Temp setpoint for
10 minutes, but
can be adjusted as
necessary.
Variables
rtP - Room (Air) Temp
Setpoints
tS - Room Temp Set-
point
LAo - Low Temp Alarm
Offset
LAd - Low Temp Alarm
Delay
• Verify the system will pumpdown. This can be done in multiple ways; the easiest is
to initiate a defrost from the Basic Display. Press and hold the
and
until ddF
(defrost delay fan) or dEF (defrost) is displayed. Liquid line solenoid should close im-
mediately, if not, troubleshoot the solenoid and the wiring controlling the solenoid.
Solenoid should shut tightly and not allow liquid refrigerant through. If the system
only has an EEV, the EEV should also shut tightly during the defrost.
• Check that the low pressure control is set, and operating properly.
• Check the tS (room temperature setpoint), LAo (low alarm offset), and LAd (low
temp alarm delay) settings.
• If there are multiple systems in the room, check the room temperature setpoint of
the other systems.
• Check for outside air infiltration. Example: Infiltration from freezer into cooler.