A-Control Error Codes (U) - Mitsubishi Electric PAR-21MAA Manual

2.3 A-Control Error Codes (U)

Displayed on Outdoor control board
remote controller LED1 "Green" LED2 "Red"
U2
Flash
1 time
U7
U1
Flashes
UE
2 times
UL
Flashes
Ud
3 times
U6
Flashes
3 times
UC
Flashes
UF
4 times
UP
UH
U3
Flashes
U4 5 times
Flashes
U5
6 times
Flashes
U6
7 times
Error details
Abnormal discharge temperature / 49C
activated (inner thermostat)
Insufficient refrigerant
Abnormality of low discharge super heat
63H activated due to abnormally high
pressure
63H activated due to abnormally high
pressure
63L activated due to abnormally low
pressure
Overheat protection (overloaded opera-
tion protection / fan error)
Shutoff due to overcurrent in compres-
sor (overload)
Power module error
Compressor self-protection function activated
Compressor overcurrent (lock)
Shutoff due to overcurrent in compres-
sor
Current sensor error
Discharging thermistor (TH4) open/short-circuit
Pipe thermistor (TH3) open/short-circuit
2-phase pipe thermistor (TH6) open/short-circuit
Outside air temperature thermistor (TH7) open/short-circuit
Heat sink thermistor (TH8) open/short-circuit
Abnormal heat sink temperature
Abnormal voltage
Location
Non INV Power INV
of error
1 Check filter for dirt → Clean if dirty.
G
—
2 Gas leakage/insufficient gas
3 Check for indoor/outdoor short cycle.
1 Check if discharging thermistor is disconnected.
G
—
2 Check electronic expansion valve for breakdown.
3 Check CNLEV connector on outdoor control board.
1 Check if ball valve is open.
G G
2 Check for indoor/outdoor short cycle.
1 Check if ball valve is open.
G G
2 Check for indoor/outdoor short cycle.
3 Check if there is too much gas.
1 Check if ball valve is open.
G
—
2 Gas leakage/insufficient gas
1 Check if outdoor unit's heat exchanger is dirty. → Clean if dirty.
G
—
2 Check for indoor/outdoor short cycle.
1 Check if 12 hours or more have passed since crank-
G G
Outdoor
G
—
(Replace outdoor control board.)
G
—
1 Check if ball valve is open.
1 Check if ball valve is open.
G G
2 Check if power capacity is sufficient.
1 Check if ball valve is open.
G G
2 Check if power capacity is sufficient.
1 If outdoor control board has been replaced:
G G
G G
1 Outdoor control board connector (TH4) disconnected
G G
1 Outdoor control board connector (TH3/TH32) disconnected
G
—
1 Outdoor control board connector (TH6) disconnected
G
—
1 Outdoor control board connector (TH7) disconnected
G
—
1 Outdoor control board connector (TH8) disconnected
1 Check if there are obstructions in intake/discharge
G
—
1 Check power line for open phase.
G
—
2 Check if power voltage is high enough.
Location of inspection
case heater was turned ON.
Check wiring and board design.
ports of outdoor unit.
49