44
Technical Information
Service Manual
6. Function and Control
mode.
b. Fan mode is in conflict with heating mode and the heating
mode is the basic mode. No matter which indoor unit operates
first, the unit will run in heating mode.
2.2 Overload protection function
When the tube temperature is a little low, the compressor raises
the operation frequency; when the tube temperature is a little
high, the compressor frequency is restricted or lows down the
operation frequency; when the tube temperature is too high, the
compressor protection stops running.
If the discharge temperature protection continuously appears for
6 times, the compressor can’t resume running. The compressor
can resume running after cutting off the power and then putting
through the power. (if the running time of the compressor is
longer than 7min, the protection times record will be cleared)
2.3 Discharge Protection Function
When the discharge temperature is a little low, the compressor
raises the operation frequency; when the discharge temperature
is a little high, the compressor frequency is restricted or lows
down the operation frequency; when the discharge temperature
is too high, the compressor protection stops running.
If the discharge temperature protection continuously appears for
6 times, the compressor can’t resume running. The compressor
can resume running after cutting off the power and then putting
through the power. (if the running time of the compressor is
longer than 7min, the protection times record will be cleared.)
2.4 Communication malfunction
Detection of the quantity of installed indoor units:
After 3min of energizing, if the outdoor unit does not receive the
communication data of certain indoor unit, the outdoor unit will
judge that indoor unit is not installed and will treat it as it is not
installed. If the outdoor unit receives the communication data of
that indoor unit later, the outdoor unit will treat that unit as it is
installed.
2.5 Overcurrent Protection
a. Overcurrent protection of complete unit; b. phase wire current
protection; c. compressor phase current protection
2.6 Compressor high-pressure protection
2.6.1 When the high-pressure switch is detected cut off for 3s
continuously, the compressor will enter high-pressure protection
as it stops when reaching set temperature. Meanwhile, the
outdoor unit will send the signal of “high-pressure protection” to
the indoor units;
2.6.2 After the appearance of high-pressure protection, when the
high-pressure switch is detected closed for 6s continuously, the
compressor can resume running only after cutting off the power
and then putting through the power.
2.7 Compressor overload protection
If the compressor overload switch is detected having movement,
the indoor unit will display the corresponding malfunction as it
stops when the indoor temperature reaching set temperature.
When the compressor stops for more than 3min and the
compressor overload switch is reset, the unit will resume
operation status automatically. If the protection appears for more
than 6 times (if the running time of the compressor is longer
than 30min, the protection times record will be cleared), the unit
can not resume operation status automatically, but can resume
running only after cutting off the power and then putting through
the power.
2.8 Compressor Phase-lacking Protection
When the compressor starts, if one of the three phases is
detected open, the compressor will enter phase-lacking
protection. The malfunction will be cleared after 1min, the unit
will restart and then detect if there is still has phase-lacking
protection. If the phase-lacking protection is detected for 6 times
continuously, the compressor will not restart but can resume
running only after cutting off the power and then putting through
the power. If the running time of the compressor is longer than
7min, the protection times record will be cleared.
2.9 IPM Protection
2.9.1 When the IPM module protection is detected, the unit
will stop as the indoor temperature reaching set temperature,
PFC is closed, display IPM protection malfunction. After the
compressor stops for 3min, the unit will resume operation status
automatically; if the IPM protection is detected for more than 6
times continuously (If the running time of the compressor is longer
than 7min, the protection times record will be cleared), the system
will stop and send the signal of module protection to indoor unit.
The unit can not resume operation status automatically, but can
resume running only after cutting off the power and then putting
through the power.
2.9.2 IPM module overheating protection
2.9.2.1 When TIPM>85
o
C, prohibit to raise frequency;
2.9.2.2 When TIPM>=90
o
C, the operation frequency of
compressor lows down by 15% every 90s according to the
present capacity requirement of the complete unit. It will keep 90s
after lowing down the frequency. After lowing down the frequency,
if TIPM>=90
o
C, the unit will circulate the above movement until
reaching the minimum frequency; if 85
o
C<TIPM<90
o
C, the unit
will run at this frequency; when TIPM 85
o
C, the unit will run at the
frequency according to the capacity requirement;
2.9.2.3 When TIPM>=95
o
C, the compressor stops. After the
compressor stops for 3min, if TIPM<85
o
C, the compressor and
the outdoor fan will resume operation.
