186CNV / 284ANV: Service Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
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Code 39-13 Fan Start Failure
Code 39-53 Fan Start Failure Lockout
When a demand startup begins a fan speed is commanded to VFD. After
25 seconds of FG (fan speed feedback signal) = 0, the PCM will reset the
VFD and try to start fan again. After 3 VFD resets Code 39-13 will be
set. PCM will continue to reset VFD a total of 6 times before declaring
code 39-53 and locking out for 1 hour. A successful fan start will reset
the fan start failed counter.
Inspect all wiring and connectors for damage and loose connections.
Check for fan blade blockage and free spin. Check external fan fuse. If
no physical blockage is present and fuse is not open, ohm motor and
replace if necessary.
Code 39-14 Fan Speed Error
A code 39-14 is declared when the commanded speed is greater than
200rpm and differs from actual speed (as reported from fan to VFD) by
more than 20%. This fault is also declared when the commanded speed
is 0 and the VFD is receiving greater than 80rpm feedback from fan
motor. The most likely scenario for this fault is a partial physical
blockage of blade, ice buildup on fan blade, extreme coil blockage that
loads blade heavily, or bearings with high resistance to spinning.
Code 39-15 Unexpected Fan Shutdown
Code 39-55 Unexpected Fan Lockout
A code 39-15 is declared when VFD commanded speed is above 200rpm
and actual speed is reduced to less than 80rpm as reported via VFD for
10 seconds consecutively after starting. The fault triggers compressor
and fan shutdown, then VFD reset. If demand is still present the system
will attempt to restart normally and run. An intermittent open connection
on fan FG wire or a failing fan motor may create these faults.
Code 39-58 VFD System Lockout - Fan Motor Fail
Code 39-58 originates in the VFD control when fan motor feedback
signal (FG) is not received while a Vsp value has been sent to fan motor
for 30 seconds. The fault can also be set when speed error between
feedback and command is greater than 100rpm. This fault should never
occur because code 39-15 will be declared after 10 seconds. When fault
is active, compressor and fan are shut down and lockout time is 30
minutes. Internal electrical damage is likely causing FG feedback to not
be received by VFD. Replace fan motor 1st, then VFD.
Code 41-13 Defrost Timeout
This system operates using both a time and temperature requirement.
After a predetermined length of time at a possible coil frosting condition
(OCT below 35F) defrost will be initiated. OCT is monitored and will
complete defrost cycle once it reaches a target value dependent on model
and OAT value. Code 41-13 is triggered when defrost is terminated on
maximum time and the target coil temperature has not been reached.
This may indicate an extreme amount of ice formed on coil or the OCT
sensor not being securely attached to butterfly tube. This fault may also
trigger if high winds are present and are cooling the coil, not allowing
heat to build and melt frost or ice.
Code 44-13 PEV Timeout
The PEV is used to equalize suction and discharge pressures and lessen
the starting torque required from compressor and VFD. The PEV will
open 2.5 minutes after compressor shutdown if pressure differential is
between 200-300psi or if pressure differential is greater than 50psi and
demand is present. In both cases PEV will open until differential
pressure is less than 40psi. Code 44-13 will be set if PEV is open for 10
minutes and does not reduce pressure differential below 40psi. If this
occurs it is likely the valve or coil has failed. Replace PEV coil and
harness first and if fault persists open refrigeration system and replace
PEV valve itself. This fault will not prevent system from starting, but
will likely be accompanied by another fault.
Code 51-01 OAT Open
The outdoor air thermistor determines operating range of compressor
and fan speeds in cooling and heating operating modes. When "OAT
Open" fault is active, the OCT will be substituted in its place and
compressor operating speed will be limited to 2700rpm. Fan speeds will
be limited based on OCT value. The sensor is monitored continuously
and if resistance is above 465kohm for 1 second this fault will occur.
Once sensor value drops below 465kohm for 1 second the fault will
clear. This fault does not escalate to a malfunction.
If the resistance value of OAT thermistor is higher than the electrical
circuit is capable of measuring, this fault will be generated. Measure
resistance value of thermistor at the PCM connector. If value is above
465kohm, look for a break in the wiring or at the connector itself. If no
breaks are observed, replace sensor. If measured resistance is within
allowable range, replace PCM.
Code 51-02 OAT Shorted
The outdoor air thermistor determines operating range of compressor
and fan speeds in cooling and heating operating modes. When "OAT
Shorted" fault is active the OCT value will be substituted in its place,
and compressor operating speed will be limited to 2700rpm. Fan speeds
will be limited based on OCT value. The sensor is monitored
continuously and if resistance is below 1kohm for 1 second this fault will
occur. Once sensor value increases above 1kohm for 1 second the fault
will clear. This fault does not escalate to a malfunction.
If the resistance value of OAT thermistor is lower than the electrical
circuit is capable of measuring, this fault will be generated. Measure
resistance value of thermistor at the PCM connector. If value is below
1kohm, look for bare wire, short in the wiring, or at the connector itself.
If no bare wires or shorts are observed, replace sensor. If measured
resistance is within allowable range, replace PCM.
Code 52-01 OCT Open
The outdoor coil thermistor is used to determine when the outdoor coil is
completely cleared during defrost. For this reason all defrosts performed
when this fault is active will occur for the maximum time length allowed
by software. The sensor is monitored continuously and if resistance is
above 465kohm for 1 second this fault will occur. Once sensor value
drops below 465kohm for 1 second the fault will clear. This fault does
not escalate to a malfunction.
Measure resistance value of thermistor at the PCM connector. If value is
above 465kohm, look for a break in the wiring or at the connector itself.
If no breaks are observed, replace sensor. If measured resistance is
within allowable range, replace PCM.
*Note if any combination of OAT and OCT shorted/open are present the
system will limit operation based on each individual fault.
