KE2 Evap
OEM
Alarm Troubleshooting Guide
Q.1.61 January 2023
Page 16
© 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
LPA
LPA
LOW PRES-
SURE
Low
Pressure
Alarm
Suction pressure
below Low Pressure
Cut-out despite at-
tempts to run.
Variables
PrS – Suction Pressure
Setpoints
LPC – Low Pressure
Cut-out
• Check LPC to see if the Low Pressure Cut-out is set too high. LPC should be set to
refrigeration unit manufacturer’s recommendation.
• Check for restrictions in the liquid line.
• Confirm EEV is operating properly. See High/Low Superheat corrective actions for
troubleshooting the EEV.
KE2 Humidity Control Only
HSA
HSA
HUMIDITY
SENSOR
Humidity
Sensor
Alarm
Yellow LED is illumi-
nated. Controller will
attempt to continue
to operate system
while this alarm is
present.
Humidity sensor is
shorted or open.
Variables
HU - Humidity
• The majority of sensor alarms and inaccurate readings are caused by cut, burned,
chaffed, or otherwise damaged sensor cables. Inspect the length of the cable for any
burned, chaffed, or otherwise damaged sections. Repair or replace any damaged sec-
tions; take care not to swap colors when repairing.
• Check that the humidity sensor cable wires are inserted into the proper terminals on
the KE2 Humidity Control, and that the screw down terminals are screwed down. The
bare stranded wire of the cable should be inserted so that the wire is directly touch-
ing the gate of the connector. If the gate is contacting the insulation of the wire, it will
not allow the controller to read the sensor.
• If wires have been extended, check that colors were not swapped when extended.
Check for any bad splices, crimps, or solder joints where extended.
• Verify the voltage between the red and black humidity sensor inputs on the control-
ler is approxi14 VDC.
• Measure the voltage between the black and green inputs on the controller. Enter that
number into the following formula:
(voltage read / 5VDC) x 100 = humidity reading
HHA
HHA
HIGH
HUMIDITY
High
Humidity
Alarm
Yellow LED is illumi-
nated. Controller will
attempt to continue
to operate system
while this alarm is
present.
Humidity reading
is above Humidity
Se Humidity
Differ Humid-
ity Alarm Offset for
longer than the Hu-
midity Alarm Delay.
Variables
HU – Humidity
Setpoints
HSP – Humidity Set-
point
HdP – Humidity Dif-
ferential
UAo – Humidity Alarm
Offset
UAd – Humidity Alarm
Delay
HEt – Heater setpoint
HEd – Heater Differen-
tial setpoint
dto – Dehumidity Temp
Offset
USt – Max Superheat
• The humidity sensor should be located in an area representative of the controlled
space. Avoid large openings to the space as they have the potential to read higher
than the rest of the space. The senor must be placed with the metal cylinder in the
downward direction to read accurately.
• Confirm that any dehumidification, humidification, and/or reheat devices are operat-
ing as expected.
• Address any sources of infiltration to reduce the amount of humidity being intro-
duced to the space.
• Check drain pan and drain line for any clogs.
• Confirm Electric Expansion Valve (EEV) and refrigeration system is operating as ex-
pected. See High/Low Superheat Alarm corrective actions for troubleshooting the
EEV.
• Increase the Max Superheat setpoint to increase runtime. Do not allow superheat at
the compressor to exceed the manufacturer’s recommended maximum.
• If system is satisfying on temperature before humidity target is reached, the Dehu-
midify Offset can be decreased. Do not allow room to over-cool to the point it dam-
ages product.
• If system is satisfying on temperature before humidity target is reached, additional
reheat or dehumidifiers may be required. Defrost heaters should not be used for
reheat, as it does not allow the coil to reach dew point and extract moisture, leading
to higher humidity.
• For systems with electric defrost, increase the number of defrosts per day.
• If you believe the humidity reading may be in error, proceed to troubleshooting steps
for Humidity Sensor Alarm.
Humidity
Sensor
RED (+14VDC)
GREEN (SIG)
BLACK (0VDC)
GND
0-5
+12
EMPTY
– LPCO (Low Pressure Cut-Out control) Only