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Parallel Parallel Parallel
Parallel Parallel
Compressor Compressor Compressor
Compressor Compressor
Systems Systems Systems
Systems Systems
Installation Installation Installation
Installation Installation
H-IM-72B October 1999 Part No. 25000102
Replaces H-IM-72A
Installation, Operation and
Maintenance Guide
Parallel Compressor Systems
HEATCRAFT INC. REFRIGERATION PRODUCTS DIVISION
2175 WEST PARK PLACE BLVD., STONE MOUNTAIN, GA 30087 • 770-465-5600 • FAX 770-465-6016
WWW.HEATCRAFTRPD.COM •
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Table of Contents Introduction Table 14. Oil Safety Switch Inspection Table 15. Part Load Performance Mult. Unit Designation Table 16. Required Differential Pressure Model Definition ................................................................................ 3 Three-Phase Voltage Monitor ......................................................... 22 System Warranty Sight Glass & Moisture Indicator Rigging Figure 10. Sight Glass Location of Equipment - INDOOR Safety Relief Devices Clearances F
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Model definition: HEATCRAFT INC. 1st digit - Brand (B, C, H, or L) Parallel Compressor Units 2nd digit - Compressor Type H - Hermetic INTRODUCTION R - Reciprocating Parallel Compressor systems are central refrigeration units S - Screw employing 2 to 8 parallel piped compressors, a control O - Open panel, and receiver mounted on one common base frame. Z - Scroll The system may be designed for either Indoor or Outdoor C - Compound use. The Outdoor design may include the condenser mounted and pipe
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SYSTEM WARRANTY Floor & Foundation Requirements This equipment is designed to operate properly and produce The total weight of a single unit will vary between 1200 the rated capacity when installed in accordance with good pounds and 10,000 pounds. Allowances must be made for refrigeration practice. the parallel rack and all other equipment installed in the same area as the parallel units. The location and installation The following conditions should be adhered to when of all equipment should b
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LOCATION OF EQUIPMENT - OUTDOOR COMPRESSOR SPRING VIBRATION • The mounting platform or base should be level and located ISOLATORS so as to permit free access of supply air. On units with this option, the compressors are secured rigidly • Units must not be located in the vicinity of steam, hot air or to make sure there is no transit damage. Before operating fume exhausts. the unit, it is necessary to follow these steps: • The unit should be mounted away from noise sensitive 1. Remove the upper
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UNIT ACCESS Always provide sufficient clearance for unit maintenance and service. Minimum clearances for most situations are described below (except 60 Inches of free space is required in front of the control panel). Please note that these are minimums and more clearance may be required by local codes. Vertical Clearance Overhead obstructions are not permitted. Vertical air discharge from the condenser must have no obstructions that can cause the discharge air to be recirculated back to the inl
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Ventilation Requirements Proper size refrigeration lines are essential to good refrigeration performance. Suction lines are more critical INDOOR UNITS than liquid or discharge lines. Oversized suction lines may prevent proper oil return to the compressor. Undersized lines If compressors or condensing units are located in a machine can rob refrigeration capacity and increase operating cost. room, adequate ventilation air must be provided to avoid an Consult the line sizing charts in this manu
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• In systems equipped with capacity control • When brazing refrigerant lines, an inert gas compressors, or where multiple compressors should be passed through the line at low are used with one or more compressors pressure to prevent scaling and oxidation cycled off for capacity control, double suction inside the tubing. Dry nitrogen is preferred. risers should be installed. See Figure 6 • Use long radius ell’s for lower pressure drop. below. The two lines should be sized so that the total cro
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Expansion Loops In order to compensate for the expansion of the tubing, it is Suction, liquid and remote condenser lines are subject to necessary to estimate the amount of expansion and then expansion and contraction and proper piping techniques must provide offsets or loops in the refrigerant piping. Normally the be employed (especially on hot gas lines) to prevent line area to be most concerned with is the straight line distance breakage. This is critical on long straight runs of generally f
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Table 2.Pressure Loss of Liquid Refrigerants (In Liquid Line Risers - Expressed in Pressure Drop, PSIG, and Subcooling Loss, °F) Liquid Line Rise in Feet 10’ 15’ 20’ 25’ 30’ 40’ 50’ 75’ 100’ Refrigerant PSIG °F PSIG °F PSIG °F PSIG °F PSIG °F PSIG °F PSIG °F PSIG °F PSIG °F R12 5.4 2.8 8.1 4.2 10.7 5.4 13.4 6.9 16.1 8.3 21.5 11.3 26.9 14.3 40.3 22.4 53.7 31.0 R22 4.8 1.6 7.3 2.3 9.7 3.1 12.1 3.8 14.5 4.7 19.4 6.2 24.2 8.0 36.3 12.1 48.4 16.5 R502 4.9 1.5 7.3
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Table 4. Weight of Refrigerants in Copper Lines During Operation (Pounds per 100 Lineal feet of type "L" tubing.) Line Size Suction Line at Suction Temperature O.D. Liquid Hot Gas in Inches Refrigerant Line Line -40°F -20°F0°F +20°F +40°F 12, 134a 4.0 .15 .01 .01 .02 .04 .06 3/8 22 3.9 .22 .02 .03 .04 .06 .08 R507, 502, 404A 3.4 .31 .03 .04 .06 .09 .13 12, 134a 7.4 .30 .01 .03 .04 .07 .11 1/2 22 7.4 .41 .03 .05 .07 .11 .15 R507, 502, 404A 6.4 .58 .04 .07 .13 .16 .24 12, 134a 11.9 .
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Table 5A. Recommended Line Sizes for R-404A and R507 * SUCTION LINE SIZE SUCTION TEMPERATURE SYSTEM +20˚F +10˚F-10˚F-20˚F CAPACITY Equivalent Lengths Equivalent Lengths Equivalent Lengths Equivalent BTU/H 25' 50' 75' 100' 150' 200' 25' 50' 75' 100' 150' 200' 25' 50' 75' 100' 150' 200' 25' 50' 75' 1,000 3/8 3/8 3/8 3/8 3/8 3/8 3/8 3/8 3/8 3/8 3/8 1/2 3/8 3/8 3/8 1/2 1/2 1/2 3/8 3/8 1/2 3,000 3/8 3/8 1/2 1/2 1/2 5/8 3/8 1/2 1/2 1/2 5/8 5/8 1/2 1/2 5/8 5/8 5/8 7/8 1/2 1/2 5
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Table 5B. Recommended Line Sizes for R-404A and R507 (continued) * SUCTION LINE SIZE LIQUID LINE SIZE SUCTION TEMPERATURE Receiver to -20˚F -30˚F -40˚F Expansion Valve SYSTEM Lengths Equivalent Lengths Equivalent Lengths Equivalent Lengths CAPACITY 100' 150' 200' 25' 50' 75' 100' 150' 200' 25' 50' 75' 100' 150' 200' 25' 50' 75' 100' 150' 200' BTU/H 1/2 1/2 1/2 3/8 3/8 1/2 1/2 1/2 5/8 3/8 1/2 1/2 1/2 5/8 5/8 3/8 3/8 3/8 3/8 3/8 3/8 1,000 5/8 7/8
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Table 6A. Recommended Line Sizes for R-22 * SUCTION LINE SIZE SUCTION TEMPERATURE SYSTEM +40˚F +20˚F +10˚F0˚F CAPACITY Equivalent Lengths Equivalent Lengths Equivalent Lengths Equivalent BTU/H 25' 50' 75' 100' 150' 200' 25' 50' 75' 100' 150' 200' 25' 50' 75' 100' 150' 200' 25' 50' 75' 1,000 3/8 3/8 3/8 3/8 3/8 3/8 3/8 3/8 3/8 3/8 3/8 3/8 3/8 3/8 3/8 3/8 3/8 1/2 3/8 3/8 3/8 3,000 3/8 3/8 3/8 1/2 1/2 1/2 3/8 1/2 1/2 1/2 5/8 5/8 3/8 1/2 1/2 1/2 5/8 5/8 1/2 1/2 1/2 4,000 3/8
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Table 6B. Recommended Line Sizes for R-22 (continued) * SUCTION LINE SIZE LIQUID LINE SIZE SUCTION TEMPERATURE Receiver to 0˚F -10˚F -20˚F Expansion Valve SYSTEM Lengths Equivalent Lengths Equivalent Lengths Equivalent Lengths CAPACITY 100' 150' 200' 25' 50' 75' 100' 150' 200' 25' 50' 75' 100' 150' 200' 25' 50' 75' 100' 150' 200' BTU/H 3/8 1/2 1/2 3/8 3/8 3/8 3/8 1/2 1/2 3/8 3/8 3/8 1/2 1/2 1/2 3/8 3/8 3/8 3/8 3/8 3/8 1,000 5/8 5/8 5/8 1/2 1/2 1
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Table 7. Recommended Remote Condenser Line Sizes R-12 & R-134a R-22 R-502 R507 & R-404A Liquid Line Liquid Line Liquid Line Liquid Line Net Total Discharge Cond. to Discharge Cond. to Discharge Cond. to Discharge Cond. to Evaporator Equiv. Line Receiver Line Receiver Line Receiver Line Receiver Capacity Length (O.D.) (O.D.) (O.D.) (O.D.) (O.D.) (O.D.) (O.D.) (O.D.) 50 3/8 3/8 3/8 3/8 3/8 3/8 3/8 3/8 3,000 100 1/
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Leak Checking, Evacuation, 4. With all compressor and control breakers and toggle switches turned off, apply power to the unit. If the unit is and Start-up using a phase monitor, the green light must come on before going any further. (See instructions for phase protector elsewhere in this manual.) A red light indicates incorrect phasing or voltage. Check with a volt meter to Warning: It is illegal to knowingly vent or discharge see if correct voltage is connected to the unit. Correct the
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Refrigerant Distribution Hot discharge gas is injected into the suction line at the parallel rack and flows to the evaporator being defrosted. The The distribution system is selected based upon the type of discharge gas will condense into liquid as it flows through the defrost for that particular system. For each set of liquid / cold evaporator. suction lines a distribution system must be selected. The liquid exits the coil at the distributor side-port, then flows Liquid solenoids are recommende
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Electronic control system High suction superheat will result in excessive discharge The electronic controller has become the standard on parallel temperatures that can cause a breakdown of the oil. This compressor systems. The increased capabilities of the action results in piston ring wear, piston and cylinder wall controllers magnify the efficiency of the parallel compressor damage. system making it a very attractive accessory item. Also, as the superheat increases, the suction pressure The
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Compressors reciprocating systems or as directed by the specific compressor manufacturer. A high pressure cutout and oil The majority of the Heatcraft Parallel systems incorporate the failure control are installed and wired for each compressor. Copeland compressor. Other brand compressors are available upon customer request. The compressors are solid Many compressors are available with unloading for capacity mounted to a base frame or mounted on the refrigerant control. The unloading of a co
