September 2016 AE Application Guidelines for Copeland CS**KIE Compressors in Ice Machines AE4-1421

Transcription

1 AE September 2016 Application Guidelines for Copeland CS**KIE Compressors in Ice Machines TABLE OF CONTENTS Section Page Section Page Safety Safety Instructions... 2 Safety Icon Explanation... 2 Instructions Pertaining to Risk of Electrical Shock, Fire, or Injury to Persons... 3 Safety Statements... 3 Introduction Nomenclature... 4 Operating Envelope... 4 Power Supply... 4 Electrical Connections... 4 Application Range & Approved Refrigerants... 4 Application Considerations Discharge Temperature... 4 Accumulators... 4 Superheat Requirements... 4 Crankcase Heaters... 5 Pressure Controls... 5 Pump Down Recommendations... 5 IPR Valve... 5 Internal Temperature Protection... 5 Motor Protection... 5 Oil Types... 6 Oil Charges... 6 Compressor Tubing & Mounting... 6 Starting Characteristics... 6 Shell Temperature... 6 Connection Fittings... 6 Deep Vacuum Operation... 6 Assembly Line Procedures Pulling Plugs... 6 Brazing Procedure... 6 Unbrazing System Components... 7 High Potential (Hipot) Testing... 7 Service Procedures Copeland Compressor Functional Check... 7 Compressor Replacement After Motor Burn... 7 Start-up of a New or Replacement Compressor New Installation... 8 Field Service... 8 Tables & Figures Tube Brazing... 8 CS**KIE Operating Envelope for R-404A... 9 Typical Mounting Assembly... 9 Build of Material Terminal Covers Electrical Connections Compressor Models & Approved Refrigerants Charge Limitations Crankcase Heater Kits Pressure Control Settings Recommended Oil Charges

2 Safety Instructions Copeland CS**KIE compressors are manufactured according to the latest U.S. and European Safety Standards. Particular emphasis has been placed on the user's safety. Safey icons are explained below and safety instructions applicable to the products in this bulletin are grouped on Page 3. These instructions should be retained throughout the lifetime of the compressor. You are strongly advised to follow these safety instructions. Safety Icon Explanation DANGER WARNING CAUTION NOTICE CAUTION DANGER indicates a hazardous situation which, if not avoided, will result in death or serious injury. WARNING indicates a hazardous situation which, if not avoided, could result in death or serious injury. CAUTION, used with the safety alert symbol, indicates a hazardous situation which, if not avoided, could result in minor or moderate injury. NOTICE is used to address practices not related to personal injury. CAUTION, without the safety alert symbol, is used to address practices not related to personal injury. 2

3 Instructions Pertaining to Risk of Electrical Shock, Fire, or Injury to Persons WARNING ELECTRICAL SHOCK HAZARD Disconnect and lock out power before servicing. Discharge all capacitors before servicing. Use compressor with grounded system only. Molded electrical plug must be used when required. Refer to original equipment wiring diagrams. Failure to follow these warnings could result in serious personal injury. WARNING PRESSURIZED SYSTEM HAZARD System contains refrigerant and oil under pressure. Remove refrigerant from both the high and low compressor side before removing compressor. Never install a system and leave it unattended when it has no charge, a holding charge, or with the service valves closed without electrically locking out the system. Use only approved refrigerants and refrigeration oils. Personal safety equipment must be used. Failure to follow these warnings could result in serious personal injury. WARNING BURN HAZARD Do not touch the compressor until it has cooled down. Ensure that materials and wiring do not touch high temperature areas of the compressor. Use caution when brazing system components. Personal safety equipment must be used. Failure to follow these warnings could result in serious personal injury or property damage. CAUTION COMPRESSOR HANDLING Use the appropriate lifting devices to move compressors. Personal safety equipment must be used. Failure to follow these warnings could result in personal injury or property damage. Safety Statements Refrigerant compressors must be employed only for their intended use. install, commission and maintain this equipment. All valid standards and codes for installing, servicing, and maintaining electrical and refrigeration equipment must be observed. 3

4 INTRODUCTION The Copeland CS**KIE compressor represents the latest generation of hermetic reciprocating technology for the ice machine industry. Nomenclature The refrigeration model numbers include the nominal capacity at standard 60HZ ARI rating conditions for medium temperature (20 F evap / 120 F cond / 20 F SH / 0 SC / 95 F amb). For additional information on this product, contact your Emerson representative. C = Compressor Family Series S = Medium Temperature 12K = Nominal Capacity (x 1,000 Btu/hr) I = Ice Machine Application E = POE Oil Operating Envelope The CS**KIE compressors are available in a 255 & 256 Bill of Material. The 255 build is complete with a rounded terminal cover while the 256 build is complete with a square terminal cover and is conduit ready. (See Figure 4 at the end of this bulletin). Both builds include sweat elbow up fittings. The CS**KIE ice machine compressor was designed for the use of R-404A and POE oil in ice machine applications only. The CS**KIE models are intended for medium temperature applications covering the full ice machine operating envelope. The approved operating envelopes for these models are such that they are ideally suited for ice machine applications. (See Figure 2) Power Supply All motors for the CS compressors whether single or three phase, with the exception of the PFV motor used on , 1Ø, 60 Hz power supply, are designed to operate within a voltage range of +/-10% above and below the voltages shown on the nameplate. Compressors with a PFV designated motor such as a CS14KIE-PFV, may only be operated in a range of volts, 60 Hz under maximum load conditions. Electrical Connections The orientation of the electrical connections of the CS**KIE compressors is shown in Figure 5. Compressor models can be ordered with the standard ¼ inch quick connects that come equipped with terminal box covers. Application Range & Approved Refrigerants All models are approved for use with refrigerant R-404A. All models may be operated within the entire operating envelope shown in Figure 2. CSKIE models are approved for use with R-404A. Use of refrigerants other than R-404A voids the UL listing of these models since they could affect the motor protector setting. R-404A can only be used with compressors containing Polyol Ester (POE) oil. Compressors containing POE have an 'E' just before the dash in the voltage code of the model number, e.g. CS14KIE-PFV. APPLICATION CONSIDERATIONS Discharge Temperature Figure 2 shows the operating envelope for the CS*KIE compressor. Operating beyond these limits can cause high compression ratios or excessive internal compressor temperatures. This will result in overheating the oil resulting in excessive wear or premature compressor failure. To prevent damage to the compressor the discharge temperature should never exceed 250 F. Discharge temperatures should be measured with an insulated probe 6 inches away from the discharge port of the compressor. Accumulators An accumulator is required on single compressor systems when the charge limitations exceed those values listed in Table 2. On systems with defrost/ harvest schemes or transient operations that allow prolonged uncontrolled liquid return to the compressor, an accumulator is required unless a suction header of sufficient volume to prevent liquid migration to the compressor is used. Excessive liquid flood back or repeated flooded starts will dilute the oil in the compressor causing inadequate lubrication and bearing wear. Proper system design will minimize liquid flood back, thereby ensuring maximum compressor life. Superheat Requirements In order to assure that liquid refrigerant does not return to the compressor during the running cycle, attention 4

5 must be given to maintaining proper superheat at the compressor suction inlet. Emerson recommends a minimum of 20 F (11 C) superheat, measured on the suction line 6 inches (152mm) from the suction valve, to prevent liquid refrigerant flood back. However, operation can be as low as 10 F at certain conditions. Another method to determine if liquid refrigerant is returning to the compressor is to accurately measure the temperature difference between the compressor oil crankcase and the suction line. During continuous operation we recommend that this difference be a minimum of 50 F (27 C). This 'crankcase differential temperature' requirement supersedes the minimum suction superheat requirement in the last paragraph. To measure oil temperature through the compressor shell, place a thermocouple on the bottom center (not the side) of the compressor shell and insulate from the ambient. During rapid system changes, such as during ice harvest cycles, this temperature difference may drop rapidly for a short period of time. When the crankcase temperature difference falls below the recommended 50 F (27 C), our recommendation is the duration should not exceed a maximum (continuous) time period of two minutes and should not go lower than a 25 F (14 C) difference. Contact your Emerson Climate Technologies representative regarding any exceptions to the above requirements. Crankcase Heaters Crankcase heaters are required on all CS**KIE compressors where the system charge exceeds the recommended charge limit or when ambient conditions can drop below 50 F. The listed crankcase heaters are intended for use only when there is limited access (see Table 3). Some heaters are equipped for use with electrical conduit. Where applicable, electrical safety codes require lead protection, a crankcase heater terminal box should be used. Recommended crankcase heater terminal box and cover kits numbers are listed in Table 3. Pressure Controls Both high and low-pressure controls are required on all models. See Table 4 for set points. Pump Down Recommendations If short cycling occurs please check these several factors: 1. Location of low-pressure control sensor. If it is located right at the suction inlet of the compressor, it will be more sensitive to pressure spikes. 2. Actual low-pressure setting. Refer to our recommended setting in Table 4. If the differential pressure setting is too close, this will increase the possibility of short cycling. 3. Type of Low-pressure control can have an effect on cycling. The encapsulated non-adjustable typeis more susceptible to causing excessive cycling due to tolerances. 4. If short cycling cannot be avoided, using a 5-minute time delay will limit the cycling of the compressor to an acceptable level. IPR Valve CS**KIE The internal pressure relief valve is located between the internal discharge and suction side of the compressor. It is designed to open when the dischargeto-suction pressure differential exceeds 450 to 550 psid. When the valve opens, hot discharge gas is released into the low pressure housing of the compressor. This has the effect of both increasing the suction pressure, and therefore load and current draw of the motor, as well as the temperature in the low side of the shell. Since the motor protector reacts to a combination of temperature and current it will trip and disconnect the motor once its set point is reached. Internal Temperature Protection CS**KIE ice machine compressors do not have internal discharge temperature protection. The protector opens the common connection of a single-phase motor and the center of the Y connection on three-phase motors. The three-phase protector provides primary single-phase protection. Both types of protectors react to current and motor winding temperature. In order to maintain safe discharge temperatures the compressor operation should not exceed the operating envelope. Motor Protection Conventional internal line break motor protection is 5

6 provided. The protector opens the common connection of a single-phase motor and the center of the Y connection on three-phase motors. The three-phase protector provides primary single-phase protection. Both types of protectors react to current and motor winding temperature Oil Types Polyol ester lubricants must be provided since the compressor is to be used with R-404A refrigerant. See Form for a complete list of all Emerson approved lubricants. POE must be handled carefully and the proper protective equipment (gloves, eye protection, etc.) must be used when handling POE lubricant. POE must not come into contact with any surface or material that might be harmed by POE, including without limitation, certain polymers (e.g. PVC/ CPVC and polycarbonate). Oil Charges The recommended oil charges for these compressors are shown in Table 5. Compressor Tubing and Mounting Compressor mounting must be selected based on application. See Figure 3. Consideration must be given to sound reduction and tubing reliability. Some tubing geometry or shock loops may be required to reduce vibration transferred from the compressor to external tubing. Starting Characteristics Single-phase CS**KIE compressors are designed for use with a PTC device or a start capacitor and relay. One of these start assist devices is recommended to prevent start up issues during high compression ratios or low voltage supply. Shell Temperature Since the entire shell of the CS compressor is only exposed to suction pressure it will normally be relatively cool to the touch with the exception of the compressor sump which depending on operating conditions may get as hot as 200 F. A hotter sump would indicate operation outside of approved parameters. Connection Fittings CS**KIE compressors are provided only with sweat connections. (Consult your Emerson Climate Technologies representative for details). See New Installation section for suggestions on how to properly braze these fittings. Deep Vacuum Operation Do not run any refrigeration compressor in a deep vacuum. Failure to heed this advice can result in permanent damage to the compressor. A low-pressure control is required for protection against deep vacuum operation. See the section on pressure controls for the proper set points. (See Table 4) Refrigeration compressors should never be used to evacuate refrigeration or air conditioning systems. See AE for proper system evacuation procedures. ASSEMBLY LINE PROCEDURES Pulling Plugs All hermetic compressors are pressurized with 7 to 15 psi (.5-1 kg/cm2) of dry air before they leave the factory. The plugs that seal the compressors should not be removed until the compressor has had sufficient time to reach factory temperature, if stored in an unheated space, and is ready to be brazed into the system. If a compressor contains POE oil, it should not be open to the atmosphere longer than 5 minutes. The larger suction tube plug must be pulled first to relieve most of the pressure in the compressor. Brazing Procedure Figure 1 discusses the proper procedures for brazing the suction and discharge lines to a CSKIE compressor with a copper plated steel suction fitting. It is important to flow nitrogen through the system while brazing all joints during the system assembly process. Nitrogen displaces the air and prevents the formation of copper oxides in the system. If allowed to form, the copper oxide flakes can later be swept through the system and block screens such as those protecting capillary tubes, thermal expansion valves, and accumulator oil return holes. This can lead to a blockage of oil or refrigerant which in turn can cause damage to the system and compressor. 6

7 Unbrazing System Components If the refrigerant charge is removed from a unit the high and low side of the system must be evacuated. Refrigerant will not be able to cross the valve plate inside the compressor. If one side is not evacuated and a brazing torch is then applied, the pressurized refrigerant oil mixture could ignite as it escapes and contacts the brazing flame. It is important to check both the high and low sides with manifold gauges before unbrazing. In the case of an assembly line repair, remove the refrigerant from both the high and low sides. Instructions should be provided in appropriate product literatures and assembly areas. High Potential (Hipot) Testing When Copeland compressors are Hipot tested and liquid refrigerant is in the shell, they can show higher levels of leakage current. This phenomenon can occur with any compressor when the motor is immersed in refrigerant. The level of current leakage does not present any safety issue. To lower the current leakage reading, the system should be operated for a brief period of time to redistribute the refrigerant to a more normal configuration and the system Hipot tested again. See bulletin AE for Megohm testing recommendations. Under no circumstances should the Hipot or Megohm test be performed while the compressor is under a vacuum. SERVICE PROCEDURES Copeland Compressor Functional Check The following diagnostic procedure should be used to evaluate whether a CS**KIE compressor is functioning properly: 1. Proper voltage to the unit should be verified. Determine if the internal motor overload protector has opened or if an internal motor short or ground fault has developed. If the protector has opened, the compressor must be allowed to cool sufficiently to allow it to reset. 2. Check that the compressor is correctly wired. 3. Verify that no system safety devices are keeping the compressor off. Check that the condenser fan is properly working. 4. With service gauges connected to suction and discharge pressure fittings, turn on the compressor. If suction pressure falls below normal levels the system is either low on charge or there is a flow blockage in the system. 5. To test if the compressor is pumping properly, the compressor current draw must be compared to published compressor performance curves using the operating pressures and voltage of the system. If the measured average current deviates more than ±15% from published values, a faulty compressor may be indicated. A current imbalance exceeding 15% of the average on the three phases of a threephase compressor should be investigated further. A more comprehensive trouble-shooting sequence for compressors and systems can be found in Section H of the Emerson Electrical Handbook, Form Before Replacing or Returning a Compressor Be certain that the compressor is actually defective. As a minimum, recheck a compressor for Hipot, winding resistance, and ability to start before returning to Emerson. More than one-third of compressors returned to Emerson for warranty analysis are determined to have nothing found wrong. Compressor Replacement after Motor Burn In the case of a motor burn, the majority of contaminated oil will be removed with the compressor. The rest of the oil is cleaned through use of suction and liquid line filter dryers. A 100% activated alumina suction filter drier is recommended but must be removed after 72 hours. See AE for cleanup procedures and AE for liquid line filter-drier recommendations. It is highly recommended that the suction accumulator be replaced if the system contains one. This is because the accumulator oil return orifice or screen may be plugged with debris or may become plugged shortly after a compressor failure. This will result in starvation of oil to the replacement compressor and a second failure. Start-up of a New or Replacement Compressor It is good service practice, when charging a system, to charge liquid refrigerant into the high side only and charge the low side of the system with vapor only. It is not good for any compressor to have liquid refrigerant 7

8 dumped from a refrigerant cylinder into the crankcase of the compressor. Do not start the compressor while the system is in a deep vacuum. Internal arcing may occur when a compressor is started in a vacuum. Do not operate compressor without enough system charge to maintain at least 7 psig (0.5 kg/cm2) suction pressure. Do not operate with a restricted suction. Do not operate with the low pressure cut-out disabled. Allowing suction pressure to drop below 7 psig (0.5 kg/cm2) for any length of time may overheat the compressor and cause early bearing and piston ring damage. Never install a system in the field and leave it unattended with no charge, a holding charge, or with the service valves closed without securely locking out the system. This will prevent unauthorized personnel from accidentally operating the system and potentially ruining the compressor with no refrigerant flow. New Installation The copper-coated steel suction, discharge, on CS**KIE compressors can be brazed in approximately the same manner as any copper tube. Recommended brazing material - Any Silfos material is recommended, preferably with a minimum of 5% silver. However, 0% silver is acceptable. Use of a dry nitrogen purge to eliminate possibility of carbon buildup on internal tube surfaces is recommended. Be sure process tube fitting I.D. and process tube O.D. are clean prior to assembly. Apply heat in Area 1. As tube approaches brazing temperature, move torch flame to Area 2. (See Tube Brazing figure below.) As with any brazed joint, overheating may be detrimental to the final result. Field Service To disconnect: Recover refrigerant from both the high and low side of the system. Cut tubing near compressor. To reconnect: Recommended brazing materials -Silfos with minimum 5% silver or silver braze material with flux. Reinsert tubing fitting. Heat tube uniformly in Area 1, moving slowly to Area 2. When joint reaches brazing temperature, apply brazing material. (See figure below) Heat joint uniformly around the circumference to flow braze material completely around the joint. Slowly move torch in Area 3 to draw braze material into the joint. Do not overheat joint. 3 2 }1 } } Figure 1 Tube Brazing Heat Area 2 until braze temperature is attained, moving torch up and down and rotating around tube as necessary to heat tube evenly. Add braze material to the joint while moving torch around circumference. After braze material flows around joint, move torch to heat Area 3. This will draw the braze material down into the joint. The time spent heating Area 3 should be minimal. 8

9 Condensing Temp, F Evaporating Temp, C Condensing Temp, C Evaporating Temp, F Figure 2 CS**KIE Operating Envelope for R-404A (Ice Machine Application) Spacer # Sleeve # Kit # Figure 3 Typical Mounting Assembly for Grommets Designed for Straight Through Sleeves or Studs 9

10 -255 BOM -256 BOM Figure 4 Bill of Material Terminal Covers 1 T1,C T2,S T3,R 2 3 Figure 5 Motor Winding Connections 10

11 Model CS10KIE Motor Code HP Refrigerant Lubricant 3/4 CS12KIE PFV, TF5 1 CS14KIE 1-1/4 R-404A POE Table 1 Compressor Models and Approved Refrigerants/Lubricants See Form for a complete list of all Emerson approved lubricants. Model Family CS10KIE - CS14KIE Table 2 Charge Limitations Charge Limits 6 lbs Model Part # Volts Watts Description CS10KIE, CS12KIE, CS14KIE /265 40/ /575 45/ Table 3 Crankcase Heater Kits EHP Flexible 60 SS Rigid s/conduit Box Model Pressure Control R-404A CS**KIE Low 20 PSIG Min Cut Out High Table 4 Pressure Control Settings 450 PSIG Max Cut Out Model Initial (oz) Recharge (oz) CS10KIE - CS14KIE Table 5 Recommended oil Charges The contents of this publication are presented for informational purposes only and are not to be construed as warranties or guarantees, express or implied, regarding the products or services described herein or their use or applicability. Emerson Climate Technologies, Inc. and/or its affiliates (collectively "Emerson"), as applicable, reserve the right to modify the design or specifications of such products at any time without notice. Emerson does not assume responsibility for the selection, use or maintenance of any product. Responsibility for proper selection, use and maintenance of any Emerson product remains solely with the purchaser or end user. 11