Application Bulletin 140. H20J/H21J and H70J/H71J Series OVAL HOUSING ROUND HOUSING. BENCHMARK Compressor with Refrigerants R22 and R407C

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1 H20J/H21J and H70J/H71J Series OVAL HOUSING (14,000 ~25,000 BTU/Hr.) ROUND HOUSING (~25,000 44,000 BTU/Hr.) Application Bulletin 140 BENCHMARK Compressor with Refrigerants R22 and R407C Page

2 Application Bulletin Number: 140 Release EN: M02108 Date: 3/12/04 Revision EN: Z27301 Date: 10/2/15 Subject: H20J/H21J and H70J/H71J Series Compressor Applications with Refrigerant R22 and R407C This Application Bulletin is for air-to-air air conditioning and heat pump applications only. For other applications or deviations from this Bulletin, please call Bristol s Applications Engineering Department at (276) The BENCHMARK R22 reciprocating compressor can be recognized by the number 2 in the second character and with the letter J in the fourth character of the compressor model number (example: H20J or H21J223ABCA). The BENCHMARK R407C compressor can be recognized by the number 7 in the second character of the compressor model number (example: H71J223ABCA). Innovative mechanical design and gas management make the BENCHMARK compressor very efficient. Not only is the sound level (db) lower than previous products but the sound content (frequency) delivers exceptional acoustical characteristics. The following guidelines were developed for the BENCHMARK H20/21J/71J series compressors through system testing as well as laboratory testing with model specifics highlighted where applicable. For the purpose of explaining the features of the two Benchmark configurations, this bulletin uses two distinct product differentiators/. OVAL HOUSING Smaller capacity Internal muffler ROUND HOUSING Larger capacity Requires External muffler Note: Non-compliance with this document does not necessarily void the compressor warranty. Its primary purpose is to provide the system designer with guidelines that help assure the integrity of the final product. 1.0 Crankcase Heat The refrigerant charge limit is published on the individual compressor specification sheet. Total charge includes the allowance for the tube size and length plus the tolerance of the charging equipment. A crankcase heater is not required on systems when the total system charge is below the compressor charge limit. For applications that require a crankcase heater, insertion type PTCR (Positive Temperature Coefficient Resistance) crankcase heaters are available. Refer to the individual compressor specification sheet for the heater part number and wattage rating. To increase the longevity of the compressor bearings, a crankcase heater is recommended to prevent liquid refrigerant from migrating into the compressor. Liquid refrigerant can dilute the oil causing excessive bearing wear. Refer to Application Bulletin 135, Crankcase Heaters. 2.0 Motor Overload Protection The BENCHMARK compressors are protected by internal line break overload protectors that sense motor winding temperature and current. These protectors are automatic reset devices containing a snap action bimetal switch. They are designed to interrupt motor current under a variety of fault conditions such as: failure to start, running overload, fan failure and loss of charge. In three-phase compressors, these devices provide protection during transformer primary and secondary single-phase conditions. Page 2

3 3.0 High Pressure Protection BENCHMARK compressors are equipped with an internal pressure relief valve (IPRV) sensitive to excessive discharge pressure. High pressure gas is by-passed internally if the differential open setting is reached. The valve will open between 450 and 550 psig (32-39 kg/cm 2 ) pressure differential, (Example: With a suction pressure of 84 psig (6 kg/cm 2 ), the internal relief will open at 534 to 634 psig (38-45 kg/cm 2 ). The IPRV resets automatically when the fault condition is corrected. Such fault conditions are: condenser fan failure, dirty or restricted condenser coils, refrigerant overcharge and discharge restriction. If the IPRV is the primary system protection, the following test must be performed: (1) Operate the system at the highest outdoor and indoor ambient that the system will experience, (2) Simulate a failed condenser fan motor by disconnecting the fan motor. Heat pumps will require simulating the outdoor unit motor failure in cooling and the indoor unit motor failure in the heating mode. It is recommended that all commercial installations incorporate low and high pressure manual reset safety switches. 4.0 Accumulators All heat pump systems require an accumulator. Other systems should be evaluated per Application Bulletin 101, to determine if an accumulator will be required. Cooling-only systems with a total charge less than the compressor charge limitation normally will not require an accumulator. A double-sided seethrough sight glass installed in the suction line of a test compressor, will assist the system designer in observing liquid refrigerant flowing into the compressor during system testing. Large volumes of liquid refrigerant repeatedly returning to the compressor during the off-cycle, defrost cycle or excessive floodback during steady operation can dilute the oil to the point that the bearings are inadequately lubricated. These conditions cause excessive bearing wear. 5.0 Excessive Continuous Liquid Floodback Tests The following tests are for all systems including those designed with an accumulator. These tests are used to determine if the system needs design change. Bristol testing has indicated that adding an accumulator as the only solution to excessive flooding, in most cases, is inadequate. Two excessive liquid floodback tests are required on heat pumps: one for the heating mode and one for the cooling mode. Air conditioners will require the cooling test. Non-reversing heat pumps will require only the heating test. The test set up is the same for heat pumps and air conditioners. Before starting the test, thermocouples (TC s) should be attached to the suction and discharge tubes approximately 6 to 8 inches (15 to 20 cm) from the compressor. A TC should also be attached to the sump of the compressor (as close to bottom center as possible, all TC s must be insulated). The system charge for this test should be adjusted to represent the equipment s worst-case flood-back field condition. This test should simulate the affect of refrigerant overcharge, or other variables that could result in inadequate suction superheat at the compressor. Bristol recommendations: Add 10% greater charge than design specifications for non-txv metering devices and 20% greater charge for TXV metering. The evaporator should be elevated 5 feet (1.5 m) above the condensing unit with a 25- foot (7.6 m) line set to verify the evaporator out tubing configuration does not allow liquid to flow out of the coil and down the suction line into the compressor under these flooded coil conditions (again, use of a suction sight glass is highly recommended). If the sump T or discharge superheat values are below the following guidelines, the system design must be changed. Minimum Sump T Sump temperature should be 30 F (16.7 K) warmer than the saturated temperature equivalent of the suction pressure. Minimum Discharge Superheat Discharge temperature should be 50 F (27.7 K) warmer than the saturated temperature equivalent of the discharge pressure. Note: Discharge superheat may run as low as 10 F (5.6 K) during start-up operation, as long as the temperature increases steadily and exceeds the minimum value before the compressor cycles off. The sump over saturated suction temperature should also be above the minimum value before cycling off. Extended operation is normally required to heat up the oil sump adequately, especially with low discharge superheat. Page 3

4 Heating Mode Excessive Continuous Liquid Floodback Test Set up the test unit to operate under a worst case set of conditions that will produce an outdoor coil frost condition. This scenario should take into account high humidity, low temperature conditions and reduced airflow across the outdoor coil in order to evaluate the affect of blocked outdoor coils. Bristol recommendations: The defrost control must be disconnected to prevent unit from defrosting. Outdoor ambient should be 17 F DB (-8.3 C), 15 F WB (-9.4 C) and indoor ambient 70 F DB (21.1 C), 60 F WB (15.5 C) maximum. Outdoor unit fan motor should be disconnected to simulate a blocked evaporator coil. Operate unit until pressures and temperatures are stabilized and verify the Sump T and Discharge Superheat, as noted above, exceed the minimum values. Cooling Model Excessive Continuous Liquid Floodback Test This test should simulate the affect of reduced airflow over the indoor coil (i.e., dirty filter, obstructed coils, faulty duct work, etc.) and the resulting decreased suction superheat at the compressor. The evaporator airflow should be reduced to levels the system might experience in a worst case field scenario. Bristol recommendations: Operate the system for 1 hour; outdoor unit should be in 95 F (35 C) DB, 75 F (23.9 C) WB ambient and indoor unit at 67 F (19.4 C) DB, 57 F (13.9 C) WB with evaporator airflow reduced to 50% to simulate dirty return air filter. Verify the sump T and discharge superheat, as noted above, exceed the minimum values. 6.0 Excessive Liquid Floodback Cycling Test The purpose of this test is to determine how much liquid actually gets into the compressor during system on/off cycles. This test should simulate the affect of refrigerant overcharge, or other variables that could result in inadequate suction superheat at the compressor and cause slugging. To complete this test, a sample compressor must be obtained with a sight tube to measure the liquid level in the compressor or set the compressor on calibrated scales to measure the weight. The refrigerant charge should be adjusted to represent the amount that the system might experience in a worst case field overcharge scenario. Bristol recommendations: 10% greater charge than design specifications for non-txv metering devices and 20% greater charge for TXV metering. The evaporator should be elevated 5 feet (1.5 m) above the condensing unit with a 25-foot (7.6 m) line set. Operate the system in the cooling mode for 1 hour before testing at each of the ambient temperatures indicated in Table 1 below. Shut the outdoor unit off (compressor and fan). Keep evaporator blower running. System on/off time and number of cycles are different for each of the 3 tests shown in Table 1. Observe and record the amount of liquid refrigerant (height or weight) at the start of each on cycle. If the compressor slugs or makes a metallic sound on start-up, system design change is required. TABLE 1 EXCESSIVE LIQUID FLOODBACK CYCLING TESTS Test No. 1 No. 2 No. 3 Indoor Ambient ( F) 70 (21.1 C) 70 (21.1 C) 70 (21.1 C) Outdoor Ambient ( F) 85 (29.4 C) 95 (35 C) 105 (40.6 C) System On-time (Minutes) System Off-time (Minutes) Number of On/Off Cycles Page 4

5 7.0 Starting Characteristics The BENCHMARK models do not require start components on systems where the pressure equalizes completely in the off-cycle. For single-phase applications, a low torque PTCR can be used if only a light assist is needed, as in the case of a low voltage condition. If a non-bleed expansion valve is used, or other reasons exist that will not allow pressure equalization prior to compressor start-up, then a start capacitor and potential relay are required (Exception: see Section 8 for an option to eliminate starting components). High torque start components are available for the BENCHMARK model. The PTCR and starting components are listed under the Electrical Accessory Components section of the individual compressor specification sheet. This information can be obtained via Bristol s web site or directly from Bristol Compressors. Recommended sources for the electrical components are: Source for the PTCR 305 Series Source for the GE Relays Source for the Electrica Relays Ceramite Corporation th Avenue P. O. Box 166 Grafton, WI Phone: (414) Web: General Electric Appliance Control Division West Wall Street Morrison, IL Phone: (815) Web: Manitowoc Relay & Protectors, Inc. 1429B Wentker Court P.O. Box 146 Two Rivers, WI Phone: (920) afond@lakefield.net 8.0 Start Components Elimination An innovative starting concept has been developed by Bristol Compressors that eliminates the compressor start components (start capacitor/relay) required for systems using non-bleed type expansion valves. This optional feature is available on select BENCHMARK models. They are identified by the letter B in the seventh character of the model number (H2*J**B). These Bleed compressors are designed to internally equalize by utilizing an external check valve in conjunction with a non-bleed type TXV. Bristol recommends the check valve to be installed on the compressor s discharge connector tube (or as close as possible) in order to minimize pressure equalization time across the compressor valves. It is recommended that each OEM perform start tests at their worst case condition to assure no issues with their placement of the check valve. It is also important to determine if the equalization time is acceptable with the check valve moved downstream of the compressor discharge connector. This technique will help maintain system operating pressures during the off-cycle, thus improving the SEER performance by decreasing C D. The internal equalization is transparent to the customer and requires no special attention. Bleed Compressors with Oval Housing Only an external check valve is required since these models employ an internal discharge muffler. Again, the check valve may be installed at any point in the hot gas line, preferably as close to the compressor discharge connector as possible. See Table 2 for recommended check valves. TABLE 2 CHECK VALVES FOR BLEED COMPRESSORS Bristol Part Number Manufacturer Material Manufacturer s Part Number Muffler Diameter Length (inch/ cm) Inlet/Outlet ID or OD Internal Free Volume (inches 3 /cc) NA Mueller Refrigeration Copper A / / Inlet/Outlet:.50 / 1.3 ID 2.5 / Henry Technologies Copper MS / / 9.52 Inlet:.50 / 1.3 ID Outlet:.50 / 1.3 OD 1.5 / 24 NA Henry Technologies Copper MS / / 9.52 Inlet/Out:.50 / 1.3 ID 1.5 / 24 Note: The above check valves may be used with products that employ an external muffler (see details below). Note: See recommended sources on page 11 for all external components shown in Tables 2, 3 and 4. Page 5

6 Bleed Compressors with Round Housing These models do not employ an internal discharge muffler; therefore they require one of the following options: 1) An external discharge muffler with integral check valve installed per Section 9. See Table 4 for a listing of these mufflers and check valve assemblies which integrate the individual components into one compact part thus reducing the number of braze joints. Properly installed, this method is effective for reliable starting without a start capacitor/relay at all expected differentials. The required time for internal compressor equalization depends on the specific pressure differential when the compressor cycles off. To assure pressure equalization, a minimum five minute delay is recommended to avoid shortcycling. However, if mufflers (with integral check valve) that have larger volumes than noted in Table 4 are employed, a longer time delay may be needed to assure equalized pressure at start up. This is important since the muffler volume is on the compressor side of the check valve with this integrated design. 2) A check valve installed as close to the compressor discharge connector as possible, along with a separate discharge muffler installed downstream (muffler must be installed as illustrated in Section 9). System designers must perform system evaluations to assure the pressures are equalized across the compressor before each compressor start-up and to set their time delay accordingly. 9.0 External Discharge Muffler Requirement Round Housing Bristol Compressors research has proven that the use of an external discharge muffler is far superior to the internal style. This is due to the space limitation and fixed location within the hermetic shell. The external muffler approach gives the system designer the opportunity to utilize the most effective muffler type and location. The round housing BENCHMARK models do not employ an internal discharge muffler and require that an external muffler be precisely placed in the discharge line as illustrated in Figure 1. The noted dimension A is to be used for the following tubing placements: For 60 Hz applications, install assembly with 13 inches (±2 in.) or 33 cm (±5cm) of tubing between the discharge tube outlet and the muffler. For 50 Hz applications, install assembly with 20 inches (±2 inches) or 50.8 cm (±5 cm) of tubing between the discharge tube outlet and the muffler. The muffler must be UL/CSA certified for use as a high-side component for the intended refrigerant application. IMPORTANT NOTES: 1) It is preferable that the muffler be installed as shown in Figure 1 with use of the mufflers shown in Table 3. However, if it is necessary that bends be placed in the tube between the compressor and the muffler, both indoor and outdoor sound evaluations must be performed to confirm acceptance of the final configuration. Bristol field testing indicates any bends prior to the muffler can result in increased sound and tubing vibration, primarily with copper mufflers. 2) If the Sporlan muffler Part No. M-16E32 (see Table 3) is used, the DIM A tube may be reduced to a minimum length of 9 inches. No bends would be allowed in the tube between the compressor and the muffler. 3) The tubing design between the compressor and the condensing unit coil is very important in regard to both sound performance and reliability. The length, number of bends, geometry, and method of attachment can have a significant impact on acoustic performance of the muffler and tube vibration levels. The system tubing vibration should be thoroughly evaluated using accelerometers. Discharge tube total displacement (peak-to-peak) needs to be kept below inches (as measured 3.5 inches from the top of the compressor discharge elbow) to avoid premature tubing failure due to excessive vibration. Page 6

7 4) Use of only an external discharge muffler (i.e. no check valve) applies only to models that do not have a B in the seventh character of the model number, refer to Section 8. Oval Housing The oval housing models do not require an external discharge muffler for 50 or 60 Hz. The Table 3 generic muffler recommendations are based on Bristol sound test evaluations with various systems. The Sporlan M-16E32 yielded the best overall field results. Operational characteristics can vary between different system types and applications. The OEM system designer must perform sound tests to determine the best muffler configuration and optimize its location in the discharge line to satisfy their particular design requirements. All available options should be thoroughly evaluated and the following considered: A heat sink is required to prevent internal check valve damage during brazing Do not use ball type check valve A filter-drier in the discharge line may be substituted for the external muffler, if system testing confirms that the filter-drier provides acceptable discharge pulse and sound attenuation. If components other than those recommended in Tables 2, 3 and 4 are utilized, Bristol advises the use of a high quality, non-positional check valve designed for near-zero leak rates. The muffler and check valve must be UL/CSA certified for use as high side components for the intended refrigerant application. Increased internal free volume or multi-chamber style discharge mufflers may provide superior results. Discharge Muffler or Muffler/Check Valve DIM A FIGURE 1 Page 7

8 H20J/H21J Series Compressor Applications with Refrigerant R22 H71J Series Compressor Applications with Refrigerant R407C PRODUCT GUIDE FOR TABLE 3 Application Cooling Only Heat Pumps Voltage Frequency Round Compressor Housing Oval Compressor Housing Muffler* 60 Hz 50 Hz 60 Hz 50 Hz Tube Length* Dim - A Muffler* Tube Length* Dim - A A 13 ± 2 B 20 ± 2 External Muffler Not Required External Muffler Not Required Muffler* B C (optional) Tube Length* Dim - A 13 ± 2 External Muffler Not Required Note: Use above Product Guide Letter designation in choosing muffler in Table 3 below. *See Section 9.0 for further details on muffler and tube length. Muffler* B C (optional) Tube Length* Dim - A 20 ± 2 External Muffler Not Required TABLE 3 EXTERNAL MUFFLER ONLY Product Guide Letter Bristol Part Number Manufacturer Material Manufacturer Part Number Muffler OD Length Inlet and Outlet ID Internal Free Volume (inches 3 /cc) A Parker Copper / / / / 88.5 A Kraftube Steel EM / / / / B Parker Copper / / / / B Kraftube Steel EM / / / / C Sporlan Steel M-164-S or M-16E / / / / C Kraftube Steel EM / / / / Note: Direct muffler orders to manufacturers should reference the manufacturer s part number. TABLE 4 EXTERNAL MUFFLER WITH INTEGRAL CHECK VALVE (for use only with round housing compressors with bleed) Bristol Part Number Manufacturer Material Manufacturer Part Number Muffler OD Length Inlet and Outlet ID Internal Free Volume (inches 3 /cc) Superior Copper 900RGN-8S 1.63 / / / / Mueller Copper A / / / / Henry Technologies Copper MSM / / / / 162 Page 8

9 10.0 Operation Envelope BENCHMARK compressors are designed to operate within a specific range of operation or envelope. Systems must be designed so that the compressor does not operate outside the envelope or continuously at its boundary. Reference the individual compressor model specification sheet for the operational envelope, which is available at or may be obtained directly from Bristol Compressors. Any deviation from the published limits must be evaluated and approved by Bristol Compressors 11.0 Power Terminal Cover Only the Bristol Compressors approved power terminal cover/retainer should be used unless written approval is provided by Bristol Compressors for an alternative Mounting Isolators Although the BENCHMARK model compressors are internally isolated and the vibrations transmitted to the shell are exceptionally low, external mounting isolators (grommets) are required. These resilient type mounts have been specially developed to isolate the compressor from the system chassis and increase reliability. Refer to Application Bulletin 112 for guidance on selection of isolators. Customers preferring alternative mounting isolator designs should thoroughly test to ensure satisfactory performance Field Replacement The BENCHMARK model compressors are excellent choices for field replacements and efficiency upgrades. The larger capacity models are specifically designed with the external discharge muffler concept to achieve exceptionally quiet operation while maintaining high efficiency. When used as a replacement for compressor models in systems not equipped with an external discharge muffler, the proper external discharge muffler and mounting components should be supplied with the compressor and accompanied with detailed installation instructions. Page 9

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11 Recommended sources for check valves, mufflers, and muffler/check combinations: CHECK VALVE ONLY Henry Technologies 701 S. Main Street Chatham, IL (217) Mueller Refrigeration Company, Inc. 121 Rogers Street Hartsville, TN (800) MUFFLER ONLY Parker Hannifin Euclid Avenue Cleveland, OH (800) Sporlan Valve Company 206 Lang Drive Washington, MO (636) Kraftube 925 E. Church Avenue Reedy City, MI (231) , Extension MUFFLER + CHECK VALVE COMBINATION Mueller Refrigeration Company, Inc. 121 Rogers Street Hartsville, TN (800) refrig@muellerindustries.com Superior Sherwood Valves 2111 Liberty Drive Niagara Falls, NY (716) Henry Technologies 701 S. Main Street Chatham, IL (217) Page 11

12 Release EN Number M02108 Release Date 3/12/04 REVISIONS M /12/04 U /30/10 V /3/12 X /29/14 Z /2/15 Page 12