5.Scratch matching marks on stubs in old compressor. Make corresponding marks on replacement compressor.
6.Use torch to remove stubs from old compressor and to reinstall them in replacement compressor.
7.Use copper couplings to tie compressor back into system.
8.Evacuate system, recharge, and check for normal system operation.
9.Copeland
COPELAND SCROLL COMPRESSOR
I. FEATURES
The scroll compressor pumps refrigerant through the system by the interaction of a stationary and an orbiting scroll. (See Fig. 29.) The
Scroll Gas Flow
Compression in the scroll is |
|
created by the interaction of |
|
an orbiting spiral and a |
|
stationary spiral. Gas enters |
|
an outer opening as one of the |
|
spirals orbits. | 1 |
|
2 | 3 |
scroll compressor has no dynamic suction or discharge valves, and it is more tolerant of stresses caused by debris, liquid slugging, and flooded starts. Due to the design of the scroll compressor, the internal compression components unload (equalize pressure) on shutdown. The white oil (Sontex 200LT) used in the scroll is compatible with 3GS oil, which can be used if additional oil is required. (See Table 13 for oil recharge requirements.)
TABLE 13—COMPRESSOR OIL RECHARGE
COMPRESSOR MODEL | RECHARGE | OIL TYPE | |
(FL. OZ.) | |||
|
| ||
Carlyle/Scroll |
| ||
″ J″ Type | 44 | Suniso 3GS | |
SC, SRD450AC | 34 | Zerol 150 | |
SR | 52 | ||
|
The open passage is sealed off as gas is drawn into the spiral.
4
By the time the gas arrives at the center port, discharge pressure has been reached.
As the spiral continues to orbit, the gas is compressed into an increasingly smaller pocket.
5
Actually, during operation, all six gas passages are in various stages of compression at all times, resulting in nearly con- tinuous suction and discharge.
|
|
| w/3 percent | |
SRH482, SRY482 | 68 | |||
SRH602, SRY602 | 70 | |||
| ||||
Copeland |
|
| ||
CRG3, CRH3, CRJ3, CRK3, CRL3 |
| 51 |
| |
CRN5, CRP5, CRT5, CTH1, CTL1 |
| 66 |
| |
CRC4, CRZ4 |
| 36 |
| |
CR16K6 THROUGH CR42K6 |
| 42 |
| |
*ZR18K1 |
| 19 |
| |
*ZR23K1, ZR28K1 |
| 24 | Suniso 3GS | |
*ZR34K1 |
| 30 | ||
|
| |||
*ZR40K1 |
| 34 |
| |
| 56 |
| ||
| 56 |
| ||
| 56 |
| ||
| 66 |
| ||
Tecumseh |
|
| ||
AV55 |
| 50 |
| |
AW55 |
| 30 | Suniso 3GS | |
AG |
| 60 |
| |
Bristol |
|
| ||
H23A |
| 52 |
| |
H23B |
| 37 |
| |
H24A3, H24A4 |
| 47 | Suniso 3GS | |
H24A5 |
| 52 | ||
|
| |||
H25A, H26A |
| 62 |
| |
H25B, H26B, H29B |
| 32 |
| |
|
|
|
|
*Copeland scrolls are charged initially with Sontex 200LT white oil. Since this oil is not commercially available, use 3GS.
II. TROUBLESHOOTING
Troubleshooting mechanical or electrical problems in a scroll compressor is the same as for a reciprocating compressor, except that a scroll compressor should never be allowed to pump into a
A90198
Fig. 29—Scroll Compressor Refrigerant Flow
vacuum. If a pumpdown procedure is used, the scroll compressor is capable of pumping into a vacuum very quickly, which could cause fusite arcing and compressor failure. See Step IV of Reciprocating Compressor section for removal and replacement.
III. DISCHARGE THERMOSTAT
Some scroll compressors have a discharge thermostat that recip- rocating compressors do not have. This thermostat is mounted in a well in the top of the compressor shell to sense if the discharge temperature reaches 290°F and shuts down the compressor to prevent damage to it. When the temperature of the thermostat reaches 140°F, power is restored to the compressor.
To determine if the thermostat is operating properly, either attach the thermocouple of an electronic thermometer to the dome of the compressor near the thermostat, or remove the thermostat and place the thermocouple inside the well. The electronic thermom- eter must be capable of reading at least 300°F. Start the unit and let it run for at least 15 minutes to obtain normal operating conditions. Watch the thermometer to see if it is approaching 270°F. If the thermocouple is located on the dome near the discharge thermo- stat, there could be a 20° difference between well and dome temperatures. If the temperature approaches 270°F, repair system problem, such as low charge, blocked condenser coil, and so forth. If the temperature does not approach 270°F, replace discharge thermostat.
Replacing Discharge Thermostat
To replace the discharge thermostat, refer to the Installation Instructions packaged with the replacement discharge thermostat kit. (See Fig. 30.)
IV. DISCHARGE SOLENOID VALVE
Some larger units equipped with scroll compressors contain a solenoid valve that is piped between the discharge tube and suction tube of the compressor. The purpose of the solenoid valve is to