(4)
Frequency control
• Depending on capacity required, capacity control change and frequency change are performed to keep constant
evaporation temperature in cooling operations, and high pressure saturation temperature in heating operation.
• Frequency change is performed at the rate of 3Hz/second as follows.
1)
Frequency control starting
• 60Hz is the upper limit for 3 minutes after starting.
2)
Pressure control
<PU(H)Y-(P)200·250·315, PURY-P200·250>
3)
Discharge temperature control
Discharge temperature (Td) of compressor is detected during operation. If the upper limit is exceeded, the frequency
is reduced. (Change rate : 5Hz of the present v alue)
• 30 seconds after starting compressor, control is performed every minute.
• Operation temperature is 110˚C : Td.
4)
Periodical frequency control
Frequency controll is periodically performed except for the frequency controls at operation start, status change, and
protection.
1
Cycle of periodical frequency control
Periodical frequency control is performed every minute after the time specified below has passed.
• 60 sec after star
• 30 sec after frequency control by discharge temperature or pressure limit
2
Amount of frequency change
The amount of frequency change is controlled corresponding to evaporation temperature and high pressure
saturation temperature.
3
-1 Back up of frequency control by bypass valve (PUHY-(P)200·250·315/PURY-P200·250)
During low frequency operation, frequency is backed up by turning on (opening) bypass valve (SV1).
• Cooling
3 minutes after starting compressor, bypass valve is turned on when Discharge Pressure(Pd) is higher than
2.5 MPa , and turned off when Pd is less than 2.25MPa.
• Heating
During low frequency operation, 3 minutes after starting compressor, SV1 turned on when high pressure (Pd)
exceeds pressure limit of 2.5MPa and turned off when Pd falls to 2.25MPa or less .
ON
OFF
2.25MPa
2.5MPa
The upper limit value for the high pressure (Pd) has been set for each
frequency, when this value is exceeded, the frequency is reduced every
30 seconds.
ting compressor or 30 seconds after finishing defrostoing operations
Cooling
Heating
Unit
Minimum
❇
❇
20Hz...TH6 20
°
C or TdSH 10deg.
❇
28Hz...TH6
≤
20
°
C and TdSH
≤
10deg.
–
–
Maximum
Unit
Minimum
Maximum
(P)200YEM-A
20Hz (28Hz)
(P)200YEM
(C)-A
20Hz
61Hz
61Hz
69Hz
74Hz
66Hz
(P)250YEM(C)-A
20Hz (28Hz)
79Hz
200YEMC-A
20Hz (28Hz)
250YEMK-A
20Hz (28Hz)
(P)250YEM
(K,C)-A
20Hz
(P)315YEM(K,C)-A 20Hz (28Hz)
100Hz
100Hz
86Hz
P315YEM-A
20Hz
120Hz
112Hz
3
°
C
37
°
C
40
°
C
5
°
C
3
°
C
5
°
C
3
°
C
5
°
C
315YEM
(K,C)-A
20Hz
120Hz
91Hz
3
°
C
5
°
C
Pressure limit
Compressor Frequency (Hz)
Pd
2.65MPa
2.45MPa
Max
30
79Hz
92Hz
37
°
C
40
°
C
- 55 -
Summary of Contents for CITY MULTI CMB-P1016V-F
Page 18: ... 17 RELAY 10 board RELAY 4 board ...
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