Q.1.61 January 2023
Page 5
KE2 Evap
OEM
Alarm Troubleshooting Guide
© 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
PSA
PSA
PRESSURE
SENSOR
Suc Pres
Sensor
Alarm
ONLY ACTIVE
WHEN AN ELECTRIC
EXPANSION VALVE IS
SELECTED.
Red LED is
illuminated.
Suction pressure
sensor is shorted,
open, or pressure is
out of range.
EEV cannot operate
while this alarm is
present.
Variables
PrS - Suction Pressure
Setpoints
rFG - Refrigerant
•Suction pressure will
read -14.6 if the green
input (signal) is open or
disconnected.
•Suction pressure will
read 150* or over if the
green input (signal)
is shorted, or if actual
pressure is higher than
the transducer is rated
for.
*150, 300, or 750
psig depending on
refrigerant selected.
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 any damaged sections; take
care not to swap colors when repairing.
• Confirm that a KE2 Therm pressure transducer and cable are being used. KE2 Therm’s
pressure transducer cable will have red, black, and green leads.
• Check that the pressure transducer cable wires are inserted into the proper position
on the board (gray connector) and that the colors are inserted into the proper screw
down terminals. The bare stranded wire of the transducer cable should be inserted so
that the wire is directly touching 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 have not been swapped when extended.
Check for any bad splices, crimps or solder joints where extended.
• Check that the pressure transducer cable is fully inserted into the pressure transducer.
The cable should click when fully inserted into the transducer.
• Confirm that the proper transducer is being used for the system. 0-150psia for most
common refrigerants, 0-300psig for R-410A and 0-750psig for R-744 (CO2). Confirm
that the proper refrigerant (rFG) is selected in the setpoints menu.
• To verify the accuracy of the transducer, remove the transducer from the system. The
controller should read suction pressure as approximately 0 psig when measuring
atmosphere. The transducer can also be checked against your manifold set.
Note: If PrS shows -15 when transducer is measuring atmosphere, the wrong pressure
transducer/refrigerant combination has been selected.
• Verify the voltage between the black and red pressure transducer inputs on the
controller is +5 VDC.
• Measure the voltage between the black and green inputs on the controller. Enter that
number into the following formula:
(voltage read - 0.5V) x 150*psia = actual pressure read
(verify with gauges)
4v
* 300 psig or 750 psig depending on pressure transducer range.