Daikin Enfinity CCH - MicroTech III Controller LED Fault Diagnosis

troubleshooting
MicroTech III Unit Controller LED Faults
Table 11: Low Voltage Brownout or Emergency Shutdown
Description Type Yellow Green Red
Low Voltage Brownout Fault OFF Flash OFF
Emergency Shutdown Mode OFF Flash OFF
* 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
• Conrm 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
Table 12: Compressor High Pressure
Description Type Yellow Green Red
Compressor High Pressure Fault OFF OFF Flash
• 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 cycled
• Check water ow (cooling operation)
• Check airow (heating operation)
• Entering water and air temperatures should be within the operating limits
Table 13: Compressor Low Pressure
Description Type Yellow Green Red
Compressor Low Pressure Fault OFF OFF ON
• Loose wire connection on low pressure circuit
• Failed low pressure switch
• Unit is low on charge
Table 14: Compressor Suction Temp Fail, Room Temp Sensor Fail, Leaving Water Temp Sensor Fail
Description Type Yellow Green Red
Compressor Suction Temp Sensor Fail Fault Flash Flash ON
Room Temp Sensor Fail (Room Sensor Control Only) Fault Flash Flash ON
Leaving Water Temp Sensor Fail Fault Flash Flash ON
• 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
Table 15: Compressor Low Suction Temp
Description Type Yellow Green Red
Compressor Low Suction Temp Fault Flash OFF OFF
• Check water ow (heating operation)
• Check airow (cooling operation)
• Entering water and air temperatures should be within the operating limits
Table 16: Low Entering Water Temp
Description Type Yellow Green Red
Low Entering Water Temp
(No Display with Boilerless EH)
Fault Flash OFF Flash
• Low entering water temperature (below 35°F standard range or 13.5°F extended range)
Table 17: Condensate Overflow
Description Type Yellow Green Red
CondensateOverow(Cooling&
DehumidicationModesOnly)
Fault ON OFF OFF
• Poor condensate drain
• Check the resistance to ground on condensate wire. This should be open if there is no water in the pan
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