Bryant R-22 Copeland Scroll Compressor I. Features, Compressoroil Recharge, Ii. Troubleshooting

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 CR-6 and scroll compressors have copper-plated, steel-suction ports. Excess heat during brazing will burn off copper plating. See Brazing section for additional informa- tion.

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
		Syn-O-Ad
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
*ZR49K1-PFV	56
*ZR49K2-TF5, ZR49K2-TFD	56
*ZR61K2-PFV	56
*ZR61K2-TF5, ZR61K2-TFD	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

—28—

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