Cooling High Pressure Control - Mitsubishi SCM40ZS-S Technical Manual

(c) Reset conditions
(i)
(ii)

(2) Cooling high pressure control

(a) Purpose
(b) Detector
(c) Detail of operation
(Example) Fuzzy
(3) Cooling low outdoor temperature protective control
(a) Operating conditions
When the outdoor air temperature (Tho-A) is 22°C or lower continues for 20 seconds while compressor speed is other than 0 rps.
(b) Detail of operation
(i) The lower limit of compressor speed is set to 35 or 45 rps and even if the speed becomes lower than 35 or 45 rps, the
speed is kept to 35 or 45 rps. However, when the thermostat OFF, the speed is reduced to 0 rps.
(ii) The upper limit of compressor speed is set to 75 or 60 rps, the speed is kept to 75 or 60 rps.
(c) Reset conditions
When the either of the following conditions is satisfied.
(i) When the outdoor air temperature (Tho-A) becomes 25°C or higher.
(ii) When the compressor speed is 0rps.
(4) Heating high pressure control
(a) Starting condition
When the indoor heat exchanger temperature (Th2) has risen to a specified temperature while the compressor is turned on.
(b) Operating condition
Compressor speed is controlled according to the zones of indoor heat exchanger temperature as shown by the following table.
Protection control speed (NP)
Sampling time (s)
Th2
NP
<
10 NP < 115
=
<
115 NP < 120
=
<
120 = NP
30 40
Tho-R
After lapse of 30 sec. or over
After lapse of 30 sec. or over
After lapse of 30 sec. or over
53
Outdoor heat exchanger temperature (°C)
60
Outdoor air temperature(°C)
<
Th2 < P1 P1 Th2 < P2
=
Normal Retention
Normal 20
P1 P2 P3
45 52 56
45 – 43 52 – 50 56 – 54
54
43 50
thermostat OFF, the speed is reduced to 0 rps.
(3)
(3)
(3)
58
60
< <
P2 Th2 < P3 P3 Th2 < P4
= =
NP–4rps NP–8rps
20 20
Unit: °C
P4
58
58
58
192
- -
'16 • SCM-T-199
8rps (1)
8rps (1)
Lower limit
speed 30 rps
0rps
60
8 20
<
P4 Th2
=
NP ＝ 0
Normal