Graco Therm-O-Flow 20 Instructions - Parts Manual page 44

Troubleshooting
Code Description
T3 _ High Temp. Unit _
Zone _
T4C# AWB Temperature
Runaway
Transformer
T4M# AWB High
Transformer Temp
T4 _ High Temp. Unit _
Zone _
T6 _ Sensor Err. Unit _
Zone _
T6C# AWB Invalid
Thermistor Reading
T8V_ No Temp. Rise Unit _
Zone _
V1|# Low CAN Voltage,
MZLP _
V1M# Low Voltage Line
AWB, Unit _
V4|# High CAN Voltage,
MZLP _
V6M# Wiring Error Line
MZLP _
44
Type Cause
Deviation Temperature
reading has
risen too high
Alarm Cooling fan
not working or
inlet is
blocked/dirty
Alarm Transformer
Temperature is
too High
Alarm Temperature
reading has
risen too high
Alarm Bad RTD
Reading
Alarm Transformer
thermistor
temperature is
incorrect
Alarm Temperature
reading does
not change.
Alarm Bad or
overloaded
Power Supply
Deviation The voltage to
the AWB is
below
threshold
Alarm Bad or
overloaded
Power Supply
Alarm Incoming
power is wired
incorrectly
Solution
Change High Temp Deviation Offset.
Verify setpoint upstream is not hotter than this
zone's setpoint.
Ensure inlet and outlets are not obstructed.
Verify fan is plugged in.
Ensure inlet and outlets are not obstructed.
Verify fan is plugged in.
Change High Temp Alarm Offset.
Verify setpoint upstream is not hotter than this
zone's setpoint.
Check RTD wiring and harness/connector
integrity.
Replace RTD.
Verify thermister is securely connected to J7 of
the AWB. Replace transformer if necessary.
Check fuses on MZLP connected to that Zone.
Check wiring to device.
Check heater resistance on device.
Verify Power Supply voltage is 24 VDC. If
voltage is low, disconnect the power lines and
re-check voltage reading. If voltage is still low,
replace Power Supply. If voltage is correct
after disconnecting the power lines.
Connect items one at a time until the voltage
drops to isolate the bad module.
Verify Transformer voltage top matches
incoming voltage. Verify incoming voltage is
correct.
Verify Power Supply voltage is 24 VDC. If
voltage is high, replace Power Supply unit.
Correct the Wiring.
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