Carrier 42QHF009DS Service Manual page 45

Note: if the low voltage protection occurs and not resumes within 3min, it will keep the protection always
after restart the machine.
11.6.4 Compressor current limit protection
If the compressor current exceeds the current limit value for 10 seconds, the compressor frequency will be
limited as below table.
Cooling mode:
Current frequency（Hz） Current limit value（A）
COOL_F16
COOL_F15
COOL_F14
COOL_F13
COOL_F12
COOL_F11
COOL_F10
COOL_F9
COOL_F8
COOL_F7
COOL_F6
COOL_F5
If the current frequency is lower than COOL_F4, the frequency will not be limited.
After 10s of the compressor start, if the current>ICOOL, the AC will display the failure for 30 seconds and stop. The AC
will restart 3 minutes later.
Heating mode:
Current frequency（Hz） Current limit value（A）
HEAT_F16
HEAT_F15
HEAT_F14
HEAT_F13
HEAT_F12
HEAT_F11
VOLTAGE
VOLT_RST1_ADD
VOLT_LTM1_ADD
VOLT_RST2_ADD
VOLT_LTM2_ADD
ICOOLLMT12
ICOOLLMT11
ICOOLLMT10
ICOOLLMT9
ICOOLLMT8
ICOOLLMT7
ICOOLLMT6
ICOOLLMT5
ICOOLLMT4
ICOOLLMT3
ICOOLLMT2
ICOOLLMT1
IHEATLMT12
IHEATLMT11
IHEATLMT10
IHEATLMT9
IHEATLMT8
IHEATLMT7
No limit
VOLT_LTM_FREQ1_ADD
VOLT_LTM_FREQ2_ADD
Frequency limit
Decrease the frequency to COOL_F4 and run at COOL_F4 for
3 minutes.
After that, the frequency will be adjusted according to the
capacity demand and rise to the upper level every 3 minutes
(When the frequency>COOL_F4 via capacity demand).
Frequency limit
Decrease the frequency to HEAT_F4 and run at HEAT_F4 for
3 minutes.
After that, the frequency will be adjusted according to the
capacity demand and rise to the upper level every 3 minutes
(When the frequency>Heat_F4 via capacity demand).
45 / 78