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lines, a coil of tubing may provide adequate protectionagainst vibration. On larger compressors, flexible metallichose is most frequently used.STRAINERSThe moisture indicator provides a warning signal forthe serviceman in the event moisture has entered thesystem, indicating that the dehydrator should be changedor that other action should be taken to effectively drythe system.DISCHARGE MUFFLERSStrainers, as the name implies, are mounted in refrigerantlines to strain any dirt, metal chips, etc. out of therefrigerant which might cause a malfunction in eitherthe refrigerant control devices or the compressor. Whilethe configuration of the strainer will vary, basically it iscomprised of a shell with a fine mesh screen. Becauseof the small orifice in expansion and solenoid valves,strainers are normally mounted just upstream from themin the refrigerant liquid line.SIGHT GLASS AND MOISTURE INDICATORSA sight glass in the liquid line allows the operator orserviceman to observe the flow of liquid refrigerant.Bubbles or foaming in the sight glass indicate a shortageof refrigerant, or a restriction in the liquid line that isadversely affecting system operation. Sight glasses arewidely used as a means of determining if the system isadequately charged when adding refrigerant.Moisture indicators have been incorporated in sightglasses as shown in Figure 65.On systems where noise transmission must be reduced toa minimum, or where compressor pulsation might createvibration problems, a discharge muffler is frequently usedto dampen and reduce compressor discharge noise.The muffler is basically a shell with baffle plates, withthe internal volume required primarily dependent onthe compressor displacement, although the frequencyand intensity of the sound waves are also factors inmuffler design.CRANKCASE HEATERSWhen the compressor is installed in a location whereit will be exposed to ambient temperatures colder thanthe evaporator, refrigerant migration to the crankcasecan be aggravated by the resulting pressure differencebetween the evaporator and compressor during offcycles. To protect against the possibility of migration,crankcase heaters are often employed to keep the oil inthe crankcase at a temperature high enough so that anyliquid refrigerant entering the crankcase will evaporateand create a pressure sufficient to prevent large scalemigration.Crankcase heaters may be of the insert type or can bemounted externally on the crankcase. The heater is alow wattage resistance element, normally energizedcontinuously, and must be carefully selected to avoidoverheating of the oil in the compressor.© 1967 Emerson Climate Technologies, Inc.All rights reserved.11-3
REFRIGERATION GAUGESPressure gauges, especially calibrated for refrigerationusage, are the primary tool of the serviceman in checkingsystem performance. Gauges for the high pressure sideof the system have scales reading from 0 psig to 300psig (or for usage on higher pressures, from 0 psig to 400psig). Gauges for the low pressure part of the system aretermed compound gauges, since the scale is graduatedfor pressures above atmospheric pressure in psig, andfor pressures below atmospheric pressure in vacuum ininches of mercury. The compound gauge is calibratedfrom 30 inches of vacuum to pressures ranging from 60psig to 150 psig depending on gauge design.In addition to the pressure scales, equivalent saturationtemperatures for commonly used refrigerants are usuallyshown on the gauge dial.11-4© 1967 Emerson Climate Technologies, Inc.All rights reserved.
Page 3 and 4:
Part IIREFRIGERATION SYSTEM COMPONE
Page 5 and 6:
Section 4COMPRESSORSThe compressor
Page 7 and 8:
CROSS-SECTIONAL VIEW OF COPELAMETIC
Page 9 and 10: When the piston starts down on the
Page 11 and 12: COMPRESSORS WITH UNLOADERSIn order
Page 13 and 14: flow by means of louvers is also an
Page 15 and 16: Figure No.20 shows parallel circuit
Page 17 and 18: and the total pressure existing in
Page 19 and 20: if the evaporator temperature is to
Page 21 and 22: In modern refrigeration practice, a
Page 23 and 24: CAPILLARY TUBE SELECTION R-22HIGH T
Page 25 and 26: CAPILLARY TUBE SELECTION R-12MEDIUM
Page 27 and 28: CAPILLARY TUBE SELECTION R-502LOW T
Page 29 and 30: multiple evaporators are used. On l
Page 31 and 32: which may be caused by pulsations i
Page 33 and 34: WATER REGULATING VALVESOn water coo
Page 35 and 36: CONDENSER FAN CYCLING CONTROLIn ord
Page 37 and 38: 1. The continuous VA (volt-amperes)
Page 39 and 40: A. Continuous VA requirement2 Conta
Page 41 and 42: The desired pulley size or the resu
Page 43 and 44: un winding is wound with relatively
Page 45 and 46: TWO PHASE MOTORSTwo phase power is
Page 47 and 48: 1 = 1 + 1MFD total MFD1 MFD2For exa
Page 49 and 50: voltage torque, and star-delta star
Page 51 and 52: 10-6© 1967 Emerson Climate Technol
Page 53 and 54: Regular Copeland® brand motor prot
Page 55 and 56: contact prematurely due to shock or
Page 57 and 58: The effect of an open phase in the
Page 59: vulnerable to liquid damage such as
Page 63 and 64: © 1967 Emerson Climate Technologie
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