Gree GVC24AMXF-K3NTC7A - How to Check Simply the Main Part of Outdoor

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Installation and Maintenance
Service Manual
9.3 How to Check Simply the Main Part of Outdoor
1. E1: High pressure protection
Malfunction description: The pressure of ODU high pressure side
is too high.
Main check points:
a. Is the system pressure is normal;
b. Is the pressure switch is normal;
c. If above two issues are normal, the mainboard circuit is with
malfunction, please replace mainboard.
2. E2: Freeze protection
Malfunction description: Too low tube temperature of IDU under
cooling mode.
Main check point:
a. Check if the IDU fan speed is normal, if the air inlet/outlet is
smooth;
b. Check if the IDU, ODU heat exchanger is too dirty that affect the
heat exchanging effect.
3. E3: Low pressure protection
Malfunction description: The pressure of ODU low pressure side is
too low
Main check points:
a. Is the system pressure is normal;
b. Is the pressure switch is normal;
c. If above two issues are normal, the mainboard circuit is with
malfunction, please replace mainboard.
4. E4: The air discharging temperature is too high
Main check points:
a. Pull off the ODU air discharging temp. sensor, check if the temp.
sensor resistance value match with present temperature;
b. Check if the refrigerant is too much or too little;
c. Check if the IDU, ODU heat exchanger is too dirty that affect the
heat exchanging effect.
5. E6: IDU, ODU communication malfunction
Main check points:
a. Check if the wiring connection if IDU and ODU is correct;
b. Check if the communication power supply voltage is normal,
if the DC voltage is more than 56±15%, please replace the ODU
mainboard.
6. F4: Outdoor condenser temperature sensor open or short circuit
Malfunction description: The ODU condenser temp. sensor
temperature value is too high or too low that out of the normal
range.
Main check points:
a. Pull off the ODU condenser temp. sensor, check if the temp.
sensor resistance value match with present temperature;
b. If the temp. sensor resistance is normal, please replace ODU
mainboard;
7. F3: ODU ambient temp. sensor open/short circuit
Malfunction description: The ODU ambient temp. sensor
temperature value is too high or too low that out of the normal
range.
Main check points:
a. Pull off the ODU ambient temp. sensor, check if the temp.
sensor resistance value match with present temperature;
b. If the temp. sensor resistance is normal, please replace ODU
mainboard;
8. F5:ODU air discharging temp. sensor open, short circuit
Malfunction description: The ODU air discharging temp. sensor
temperature value is too high or too low that out of the normal
range.
Main check points:
a. Pull off the ODU air discharging temp. sensor, check if the temp.
sensor resistance value match with present temperature;
b. If the temp. sensor resistance is normal, please replace ODU
mainboard;
9. H3: Compressor overload protection
Malfunction description: Temperature of top compressor is over
than the limit value
Main check points:
a. Normally the compressor overload protection switch is always
on, check if the switch is normal.
10. H5: IPM module protection
Main check points:
a. Check if the compressor wiring connection is well connected,
if the compressor wiring sequence is correct. The correct wiring
sequence is yellow, blue, red in anticlockwise direction.
b. Pull off the compressor connection wire, measure the
impedance between phase U/V/W and P/N, if any of them is short
circuit, please replace the ODU mainboard;
c. Check if the compressor is damaged, measure the resistance
between any two phases of the compressor three phases.
They should be almost the same, if they’re with big difference, the
compressor is damaged, please check the insulation
condition of three phases to the case.
11. HC: PFC protection
Main check points:
a. Check if the unit voltage input is normal;
b. Check if the inductance wire is well connected;
9. Maintenance