12
To maintain these limit, trip settings of 130
±
5
℃
(265
±
10F) and reset of 95
±
11
℃
(205
±
20F) for C-SB, trip
setting of 135
±
5
℃
(275
±
10F) and reset of 86
±
15
℃
(187
±
27F)for C-SC should be required.
3) Low Pressure Switch
Panasonic scroll compressors require a low-pressure switch to protect against loss of refrigerant conditions.
The recommended settings are listed in Table 2-4.
Table 2-4 Low Pressure Switch Setting
Refrigerant
Cut-Off setting
R22
4.3 psig (0.03MPa G)
R407C
7.3 psig (0.05MPa G)
R410A
22 psig (0.15MPa G)
R134a
4.3 psig (0.03MPa G)
The temperature in the scroll set and motor will rise rapidly due to loss of refrigerant charge. The low-pressure
switch will react upon low pressure occurs in the system. Sometimes, the low-pressure switch will react in
priority to the action of discharge thermostat or motor protector when the large amount of refrigerant leaks in
the short time.
Do not operate the compressor in exceeding 30 seconds when running under 0.03MPa (G).
4)
Crankcase Heater
The refrigerant is usually gathering in coldest point within the system during OFF cycle
and the compressor
might become the right one where most of liquid refrigerant centralized.
The liquid refrigerant may be taken into scroll plates with refrigerant oil in foam status when compressor
restarts. It may cause the damage of the scroll plates.
Panasonic recommends crankcase heaters should be
used on all applications to ensure long lasting reliability.
A 35-Watts crankcase heater is recommended for C-SB series and an 88-Watts crankcase heater for C-SC
series. The crankcase heater must be energized for a minimum of 5 hours prior to starting compressor.
The crankcase heater should be well attached to the compressor shell, shown as Fig 2-2 and Fig 2-3.