Microtech 2300 - Troubleshooting; MT2300 Unit Controller LED Faults

TROUBLESHOOTING
MICROTECH 2300 UNIT CONTROLLERDAIKIN APPLIED
18
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
• 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.
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
• 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
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
• Check water ow (heating operation).
• Check airow (cooling operation).
• Entering water and air temperatures should be within the
operating limits.
A2L Alarm – Control Board Without Power
LED Activity Type Color Description
9 Flash Fault Red
A2L Mitigation – Control Board
Without Power
• MT6210 mitigation controller is not powered up. Check
power connection to the MT6210 mitigation controller.
• If no MT6210 mitigation controller is present, 5VDC is not
detected at H1-5 and 12VDC is not detected at H1-3 12V_
A2L input. Check connection at this terminal.