Daikin MicroTech MT2300 - Troubleshooting; MT2300 Unit Controller LED Faults

TROUBLESHOOTINg
MICROTECH 2300 UNIT CONTROLLERDAIKIN APPLIED
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Troubleshooting
MT2300 Unit Controller LED Faults
Microcontroller Not Programmed or Hardware
Failure
LED Activity Type Color Description
Steady ON Fault Red Hardware Failure
Steady ON Fault Yellow MCU Not Programmed
• Replace the controller.
Invalid Conguration
LED Activity Type Color Description
1 Flash Fault R-Y-G Invalid Conguration
• Verify conguration switch settings on both the main board
and I/O expansion board. Conguration switch setting must
be veried using the conguration switch setting outlined
in this document, main board and I/O expansion board
software must be compatible.
Incompatible Software
LED Activity Type Color Description
2 Flash Fault R–Y–G Incompatible Software
• Replace the controller.
I/O Expansion Board Communication Fail
LED Activity Type Color Description
1 Flash Fault R–Y I/O Exp Board Communications Fail
• Verify connection of 5 wire cable between H3 on the
MT2300 main board and H3 on the MT2310 I/O expansion
board is fully engaged in the connector.
• Conrm the low voltage supply is between 19-32VAC at the
H1 terminal of the MT2310 I/O expansion board.
• Replace I/O expansion board.
Service Test Mode Enabled
LED Activity Type Color Description
1 Flash Mode G–Y Service / Test Mode Active
• Conguration switch SW1 is ON for test mode operation.
A2L Alarm – Refrigerant Leak
LED Activity Type Color Description
Rapid Flash Fault Red A2L Mitigation – Refrigerant Leak
• MT6210 mitigation controller has detected a A2L refrigerant
leak.
• If no MT6210 mitigation controller is present, 5VDC is
detected at H1-5 but 12VDC is not detected at H1-3 12V_
A2L input. Check connection at this terminal.
• Compressor and electric heat will be disabled and the fan
will be forced to high speed during this alarm and for a
minimum of 5 minutes after it has been resolved.
Compressor High Pressure
LED Activity Type Color Description
1 Flash Fault Red Compressor 1 High Pressure
5 Flash Fault Red Compressor 2 High Pressure
Compressor 1
• Verify high pressure switch is connected to terminal H7,
pins 3 and 4 on the main board.
• Check for continuity of the high pressure switch.
Compressor 2
• Verify high pressure switch is connected to terminal H2,
pins 5 and 6 on the expansion board.
• Check for continuity of the high pressure switch.
Both Compressors
If the high pressure fault resets when power is recycled:
• Check water ow (cooling operation)
• Check airow (heating operation)
• Entering water and air temperatures should be within the
operating limits.
Compressor Low Pressure
LED Activity Type Color Description
2 Flash Fault Red Compressor 1 Low Pressure
6 Flash Fault Red Compressor 2 Low Pressure
• Loose wire connection on low pressure circuit.
• Failed low pressure switch.
• Unit is low on charge.
Compressor Suction Temp Sensor Fail / Room
Temp Sensor Fail (Room Sensor Control Only) /
Leaving Water Temp Sensor Fail (FFD Units Only)
/ Return Air Sensor Failure (HGRH Units Only)
LED Activity Type Color Description
3 Flash Fault Red Compressor 1 Suction Temp Sensor Fail
5 Flash Fault Yellow Leaving Water Temp Sensor Fail
7 Flash Fault Yellow Compressor 2 Suction Temp Sensor Fail
8 Flash Fault Yellow Space Temp Sensor Fail
9 Flash Fault Yellow Return Air Temp Sensor Fail
• Check connection of low suction temperature sensor on
terminal H2 pins 3 and 4.
• Check resistance of low suction temperature sensor,
leaving water temperature sensor, room sensor, and return
air sensor. All sensors are 10kohm thermistor at 77°F.
Compressor Low Suction Temp
LED Activity Type Color Description
4 Flash Fault Red Compressor 1 Low Suction Temp
8 Flash Fault Red Compressor 2 Low Suction Temp
• Check water ow (heating operation).
• Check airow (cooling operation).
• Entering water and air temperatures should be within the
operating limits.