Troubleshooting; Microtech Iii Unit Controller Led Faults - Daikin MicroTech III Installation And Maintenance Manual

MicroTech III Unit Controller LED Faults

Troubleshooting I/O Expansion Communication Fail
Description
I/O Expansion Fail
• Verify connection of 12 wire cable between H5 on the main board and H1 on the I/O expansion board is fully engaged in the connector.
• Verify run program jumper on the I/O expansion board is installed in the run position.
• Replace the run jumper with a spare jumper.
• Replace I/O expansion board.
Invalid Configuration
Description
Invalid Configuration
• Verify jumper selection on both the main board and I/O expansion board. Jumper selections must be verified using the jumper configuration
setting outlined in this document, main board and I/O expansion board software must be compatible.
Table 11: Low Voltage Brownout / Emergency Shutdown
Description*
Low Voltage Brownout
Emergency Shutdown
* Same LED display for both conditions.
• Verify the E terminal is not connected to common. Remove wire, if connected, and LED should change to solid green only (Occ, Bypass,
Standby modes).
• Confirm the low voltage supply is between 19-32VAC at the H1 terminal of the main board. If the low voltage supply is out of range, verify the
unit supply voltage matches the nameplate voltage and the correct transformer primary wire has been selected.
Compressor High Pressure
Description
Compressor High Pressure
• Verify high pressure switch is connected to terminal H3 on the main board.
• Check for continuity of the high pressure switch.
If the high pressure fault resets when power is recycled:
• Check water flow (cooling operation)
• Check airflow (heating operation)
• Entering water and air temperatures should be within the operating limits.
Compressor Low Pressure
Description
Compressor Low Pressure
• Loose wire connection on low pressure circuit.
• Failed low pressure switch.
• Unit is low on charge.
Compressor Suction Temp Sensor Fail / Room or Return Temp Sensor Fail (Room Sensor or HGRH
Control Only) / Leaving Water Temp Sensor Fail or Room/Return Air Sensor On Units With HGRH
Description
Compressor Suction Temp Sensor
Fail
Room Temp Sensor Fail
(Room Sensor or HGRH Control Only)
Leaving Water Temp Sensor Fail
(Freeze Fault Protection Only)
• Check connection of low suction temperature sensor on terminal H6 pins 2 and 3.
• Check resistance of low suction temperature sensor, leaving water temperature sensor, and room sensor or return air sensor. All sensors are
10kohm thermistor @77°F.
• Return air sensor and room sensor shall not be connected simultaneously.
Compressor Low Suction Temp
Description
Compressor Low Suction Temp
• Check water flow (heating operation).
• Check airflow (cooling operation).
• Entering water and air temperatures should be within the operating limits.
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Type Yellow
Fault ON
Type Yellow
Fault Flash
Type Yellow
Fault OFF
Mode OFF
Type Yellow
Fault OFF
Type Yellow
Fault OFF
Type Yellow
Fault Flash
Fault Flash
Fault Flash
Type Yellow
Fault Flash
17
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Green Red
Flash OFF
Green Red
Flash OFF
Green Red
Flash OFF
Flash OFF
Green Red
OFF Flash
Green Red
OFF ON
Green Red
Flash ON
Flash ON
Flash ON
Green Red
OFF OFF
OM 1149-5