Mitsubishi Electric Mr.SLIM PEH Series Technical & Service Manual page 29

(1) Compressor control
13-minute time delay
To prevent overload, the compressor will not start within 3, minutes after stop.
2The compressor runs when the room temperature is lower than the set temperature.
The compressor stops when the room temperature is equal to or higher than the set temperature.
3The compressor stops in check mode or during protective functions.
4Overheat protection
<Start condition>
When the indoor coil thermistor reads 70°C or above, the overheat protection will start.
<Overheat protection>
The compressor stops for 6 minutes, and then restarts.
If the start condition is satisfied again within 10 minutes of compressor operation, both the indoor and outdoor units stop,
displaying a check code of "P6" on the remote controller.
<Termination conditions>
Overheat protection is terminated when the start condition is not satisfied again during the allowance (10-minute compres-
sor operation), when operation mode changes to other mode, or when thermostat turns OFF.
(2) Indoor fan control
(a) Normal control
( i )The indoor fan runs on EXTRA-LOW speed during the thermostat OFF.
EXTRA-LOW speed can be changed to LOW or HIGH speed by setting the dipswitch SW1-7 and SW1-8.
If the indoor coil temperature becomes more than 5 degrees below the room temperature during the thermostat
OFF, the indoor fan will stop. After, when the indoor coil temperature becomes within 5 degrees of room tempera-
ture, the indoor fan will run on EXTRA-LOW speed.
( ii )Hot adjustment
Hot adjustment is a warm-up for HEAT operation
<Start conditions>
The hot adjustment works under any of the follwing conditions.
HEAT operation starts.
Defrosting ends.
Thermostat turns ON.
[Hot adjustment]
Initially, the indoor fan runs on EXTRA-LOW speed. When 5 minutes have passed or the indoor coil temperature
exceeds 35°C, the fan speed changes to LOW. Two minutes later, the hot adjustment ends. Then, the fan speed
depends on the remote controller setting.
(iii)The indoor fan stops when the indoor coil temperature is within 5 degrees either way of room temperature.
(iv)To eliminate the remaining heat, the indoor fan runs for the first 1 minute after the booster heater is turned OFF.
(3) Booster heater control
When the room temperature is 3 degrees below the set temperature, the booster heater will turn ON.
When the room temperature is equal to the set temperature, booster heater will turn OFF.
During the hot adjustment, the booster heater will not work.
<Overheat prevention>
When the indoor coil thermistor rises to 60°C or above, the booster heater cannot work.
When the indoor coil thermistor falls to 55°C or below, the booster heater can work.
(4) Detecting abnormalities in the outdoor unit
When the outdoor unit is determined to be abnormal by the following causes, the compressor will stop and the check code
" P8 " will appear on the remote controller display.
1 During compressor ON after hot adjustment
1 If the difference between the indoor coil temperature and room temperature is in the RANGE B, the indoor fan will stop.
2 Within 20 minutes after entering RANGE B (except for the first 10 seconds),
a) If the temperature difference enters RANGE A, the hot adjustment stasrts,
b) If the temperature difference is still in RANGE B, the outdoor unit is deemed abnormal.
c) If the temperature difference enters RANGE C, defrosting starts.
Within 20 minutes after entering RANGE C,
If the temperature difference does not return to RANGE B,the outdoor unit is deemed abnormal.
If the temperature difference returns to RANGE B, the next 20 minutes is an allowance period. If the difference enter
RANGE A during the allowance, defrosting ends and the hot adjustment starts. If the difference does not enter
RANGE A during the allowance, the outdoor unit is deemed abnormal.
2 During compressor ON in hot adjustment
After 20 minutes of defrosting in hot adjustment, if the temperature difference is still in RANGE C, the outdoor unit is
determined to be abnormal.
3 During compressor OFF
After 20 minutes of thermostat OFF, if the indoor coil thermistor reads -25°C or below, the outdoor unit is determined to
be abnormal.
w1(See the next page.)
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