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Q.1.61 January 2023
Page 10
KE2 EvapOEM
Alarm Troubleshooting Guide
Troubleshooting Tables
Alarm & Alarm Name
Basic
Combo
Web-
Display
Display
pages
HtA
HIGH AIR
High Air
TEMP
Temp
HtA
Alarm
LtA
LOW AIR
Low Air
TEMP
Temp
LtA
Alarm
© Copyright 2023 KE2 Therm Solutions, Inc., Washington, Missouri 63090
Description
Variables & Setpoints Corrective Action
Variables
Yellow LED is
illuminated.
rtP - Room (Air) Temp
Controller will
Setpoints
attempt to continue
tS - Room Temp Set-
to operate system
point
while this alarm is
HAo - High Temp Alarm
present.
Offset
Return air temp is
HAd - High Temp Alarm
above Room Temp
Delay
setpoint + Air Temp
Diff + High Temp
Alarm Offset for
longer than High
Temp Alarm Delay.
Example
Room Temp
20°F
setpoint
Air Temp
1°F
Diff
High Temp
10°F
Alarm Offset
Alarm
threshold
31°F
temp
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
Yellow LED is
illuminated.
rtP - Room (Air) Temp
Controller will
Setpoints
attempt to continue
tS - Room Temp Set-
to operate system
point
while this alarm is
LAo - Low Temp Alarm
present.
Offset
Return air temp is
LAd - Low Temp Alarm
below Room Temp
Delay
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.
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.
• 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
(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.
and
until ddF
21214V3.0
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