Mitsubishi Electric PKA-RP1.6GAL Service Technical Manual page 51

8-2. HEAT operation
Control modes
1-1. Thermoregulating function
1. Compressor
1-2. Normal control
1-3. Start-up control
1-4. Discharge temperature over-rise prevention control
1-5. Condensing temperature over-rise prevention control
The outdoor unit receives information of set temperature and intake temperature
from the indoor unit through transmission and judges the compressor ON/OFF
controlled by thermoregulating from their temperature difference. However, the
compressor does not stop when the indoor unit is in the hot adjuster mode even
though the information tells the need to turn off the compressor.
• Control timing: Once per minute after 3 minutes have passed since the
compressor started.
• Frequency changing range: -12Hz to +20Hz W1
W1. However, in the following cases, the frequency changing amount, which is different
from the normal one, will be applied to control the operating frequency.
(1) Frequency is fixed to the minimum just before the compressor is stopped
by the thermoregulating function.
Intake temperature ] Set temperature - 0.5:··· Fixed to the minimum frequency.
Intake temperature [ Set temperature - 1.0:··· Fixation is released. (Returned to normal control.)
(2) Correction of the frequency changing amount according to the estimated discharge temp.
If the estimated discharge temperature is more than 113:, the frequency
changing amount will be corrected.
• Correction amount: 0Hz to -6Hz
(3) Frequency control after the defrosting operation
After the defrosting operation is finished, the compressor will be stopped
for 1 minute and then get restarted.
Controls, which are conducted in 3 minutes after the compressor gets started,
are categorized according to the outside temperature(TH7) as shown below.
Start-up pattern
Outside temp.
Initial start-up
:
TH7 < 0 (A), (D)
[ TH7 < 12
: :
0 (A)
TH7 ] 12
:
(C)
(1) In case of pattern (A)
a. 0 min. to 1 min. after start-up: Fixed to 48Hz.
b. 1 min. to 3 min. after start-up: Fixed to the Hz which has been regulated
according to the temp. difference between intake temp. and set temp.
• Fixed frequency: minimum Hz to 48Hz.
(2) In case of pattern (B)
a. 0 min. to 1 min. after start-up: Fixed to the minimum Hz.
b. 1 min. to 3 min. after start-up: Fixed to the Hz which has been regulated
according to the temp. difference between intake temp. and set temp.
• Fixed frequency: minimum Hz or 42Hz.
(3) In case of pattern (C)
a. 0 min. to 3 min. after start-up: Fixed to the minimum Hz.
(4) In case of pattern (D)
a. 0 min. to 1 min. after start-up: Fixed to 70Hz.
b. 1 min. to 3 min. after start-up: Fixed to the 63 or 70 Hz which has been
regulated according to the temp. difference between intake temp. and set temp.
Maximum Hz will be limited to 70Hz for 10 minutes after the start-up of compressor.
The same control as that of COOL operation.
Frequency controls such as Hz-down and no more Hz-up will be conducted
according to the indoor cond./eva. temperature (TH5).
• Temperature restriction: No more Hz-up ··· When TH5 detects 53: or more
Hz-down ··· -5Hz per min. when TH5 detects 58: or more
Control details
Defrosting restore
Restart
start-up
(B), (D) (A), (D)
(B)
(C)
-10Hz per min. when TH5 detects 63: or more
51
Refer to
"INDOOR UNIT
CONTROL" for
the detailed
detection
method.
Start-up pattern
when TH7 < 0:
RP1.6, 2····(A)
(A)
RP4-6········(A)
(A)
RP2.5, 3····(D)
Remarks