Daikin Enfinity VFC - TROUBLESHOOTING; MicroTech III Controller LED Fault Diagnosis

troubleshooting
MicroTech III Unit Controller LED Faults
Table 14: 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 15: 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 16: 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 17: Compressor Low Suction Temp
Description* Type Yellow Green Red
CompressorLowSuctionTemp Fault Flash Flash ON
• Check water ow (heating operation)
• Check airow (cooling operation)
• Entering water and air temperatures should be within the operating limits.
Table 18: Condensate Overflow
Description* Type Yellow Green Red
CondensateOverow 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.
Table 19: Serial EEPROM Corrupted
Description* Type Yellow Green Red
SerialEEPROMCorrupted Fault ON ON ON
• Cycle power to see if problem is corrected.
• Replace main board, only if problem persists after power cycle.
Table 20: Service Test Mode Enabled
Description* Type Yellow Green Red
ServiceTestModeEnabled Mode Flash Flash Flash
• Jumper JP1 is shorted for service test mode operation. Note: Used only for testing purposes, control timing may damage actual hardware.
Table 21: Unoccupied Mode
Description* Type Yellow Green Red
Unoccupied Mode Mode ON ON OFF
• Terminal U on main control board is connected to common from external source, or the network is overriding occupancy mode.
IM 930-6 •EnnityVerticalWaterSourceHeatPumps 34 www.DaikinApplied.com