Mitsubishi Heavy Industries SCM50ZS-S1 - Cooling Low Outdoor Temperature Protective Control; Heating High Pressure Control

(4) Heating high pressure control
(a) Starting condition
Whentheindoorheatexchangertemperature(Th2)hasrisentoaspecied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.
Th2 < P1 P1
<
=
Th2 < P2 P2
<
=
Th2 < P3 P3
<
=
Th2 < P4 P4
<
=
Th2
Protection control speed (NP)
Normal Retention NP–4rps NP–8rps NP
＝
0
Sampling time (s)
Normal 20 20 20 Normal
(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
B
or
D
rps and even if the speed becomes lower than
B
or
D
rps, the
speed is kept to
B
or
D
rps. However, when the thermostat OFF, the speed is reduced to 0 rps.
(ii) The upper limit of compressor speed is set to
A
or
C
rps, the speed is kept to
A
or
C
rps.
(c) Reset conditions
Whentheeitherofthefollowingconditionsissatised.
(i) When the outdoor air temperature (Tho-A) becomes 25°C or higher.
(ii) When the compressor speed is 0rps.
(3) Cooling low outdoor temperature protective control
22 25
OFF
03
Upper limit
C
rps
Lower limit D rps
ON
ON
Upper limit A rps
Lower limit B rps
Outdoor air temperature(°C)
Model
SCM50 SCM60
A
75
rps
75
rps
B
35
rps
30
rps
C
60
rps
60
rps
D
45
rps
40
rps
・
Values of
A-D
Th2
NP
P1 P2 P3 P4
10
<
=
NP < 115
45 52 56 58
115
<
=
NP < 120
45 – 43 52 – 50 56 – 54 58
120
<
=
NP
43 50
54
58
Unit: °C
・
Model SCM50
Th2
NP
P1 P2 P3 P4
10
<
=
NP < 90
45 52 56 58
90
<
=
NP < 120
45 – 43 52 – 45 56 – 48 58
120
<
=
NP
43 45
48
58
Unit: °C
・
Model SCM60
-
187
-
'18 • SCM-T-251