Hussmann KRACK MK Series, Installation And Operation Manual, Page: 60 / 70

MK/MV – Medium Profile Series Unit Coolers (E206993_M) 57
KE2 Evap OEM
Alarm Troubleshooting Guide
Q.1.61 November 2018
Page 4
© Copyright 2018 KE2 Therm Solutions, Inc. . Washington, Missouri 63090
Alarm Alarm
Name
Description
Parameter in VARIABLES menu to
diagnose further.
Corrective Action
SSA Suction
Tem-
perature
Sensor
ONLY ACTIVE WHEN
AN ELECTRONIC
EXPANSION VALVE IS
SELECTED:
Red LED is illuminated.
System cannot operate
while this alarm is
present.
Temperature sensor is
shorted or open (not
connected).
SUt - T1 SUCTION TEMP
• If SUt reads -88 the sensor is open, or not
connected.
• If SUt reads 180+ the sensor is shorted.
•
The majority of sensor alarms and inaccurate readings are caused by cut,
burned, cha ff ed or otherwise damaged sensor cable. Inspect the length of
the cable for any cut, burned, cha ff ed or otherwise damaged sections. Repair
any damaged sections
• Check that the sensor is inserted into the proper position on the board. The
sensor is not polarized; black and white wires can be inserted in either posi-
tion on the connector:
Suction Temp: black connector labeled TSUC .
Air Temp: blue connector labeled TAIR .
Coil Temp: yellow connector labeled TCOIL .
2nd Coil Temp/Aux 1 Temp: green connector labeled AUX1 .
Aux 2 Temp: black connector labeled AUX2 .
Aux 3 Temp: black connector labeled AUX3 .
• The bare stranded wire of the temperature sensor should be inserted so that
the wire is directly touching the gate of the connector. If the gate is con-
tacting the insulation of the wire, it will not allow the controller to read the
sensor.
• If wires have been extended, check for any bad splices, crimps or solder joints
where extended.
• Check the sensor probe. If the sensor cable has been pulled, the sensor
probe may have been damaged, and needs to be replaced.
• To verify accuracy of the sensor, the preferred method is to place the sensor
in a proper ice bath while connected to the controller. View SUt on variables
menu, temperature should read around 32.0°F. If adjustment is necessary, an
o ff set can be applied via the browser interface.
• Sensor accuracy can also be veri fi ed using a third party thermometer, how-
ever, it must be calibrated and rated to measure low temperatures.
• Unplug the connector and check that the resistance reading of the sensor
matches the temperature vs. resistance table.
Temperature
°
F Ohms
-22 19480
-4 12110
14 7763
32 5114
50 3454
68 2387
77 2000
86 1684
104 1231
122 885
• If temperature appears to be within the proper operating range, swap a non-
alarming sensor with the sensor being diagnosed.
• If the new sensor is read properly by the controller, the sensor being diag-
nosed will need to be replaced.
• If the sensor was disconnected for diagnostic purposes, return the sensor
to the appropriate location on the controller once diagnostics are complete.
ASA Air Tem-
perature
Sensor
Alarm
Yellow LED is illumi-
nated.
Controller will attempt
to continue to operate
system while this alarm
is present.
Temperature sensor is
shorted or open (not
connected).
rtP - ROOM TEMP
• If rtP reads -88 the sensor is open, or not
connected.
• If rtPt reads 180+ the sensor is shorted.
CSA Coil Tem-
perature
Sensor
Alarm
CLt - COIL TEMP
• If CLt reads -88 the sensor is open, or not
connected.
• If CLt reads 180+ the sensor is shorted.
A1A Auxiliary 1
Tempera-
ture Sen-
sor Alarm
AU1 - AUX TEMP 1
• If AU1 reads -88 the sensor is open, or
not connected.
• If AU1 reads 180+ the sensor is shorted.
A2A Auxiliary 2
Tempera-
ture Sen-
sor Alarm
AU2 - AUX TEMP 2
• If AU2 reads -88 the sensor is open, or
not connected.
• If AU2 reads 180+ the sensor is shorted.
A3A Auxiliary 3
Tempera-
ture Sen-
sor Alarm
AU3 - AUX TEMP 3
• If AU3 reads -88 the sensor is open, or
not connected.
• If AU3 reads 180+ the sensor is shorted.