Installation, Operation and Maintenance Manual - Data Aire

More documents

Recommendations

Info

2.0 PIPING 2.1 Split Air Cooled Unit Piping Refer to the attached line sizing chart on page 36 for a guideline for sizing refrigerant lines. The ultimate responsibility for line sizing selection is that of the installing contractor or the project engineer. Data Aire does not assume this responsibility. The chart covers distances up to 200 equivalent feet. For installations greater than this distance, consult ASHRAE or similar references. Standard piping practices must be used to ensure proper oil return and effi cient operation. The interconnecting lines to the remote air cooled condenser or condensing unit must be installed by a qualifi ed refrigeration mechanic. 2.1.1 Discharge Lines Discharge lines, also called hot gas lines, should be trapped at the top (inverted) and bottom, as well as every 15 to 20 feet of vertical rise. Discharge line check valves are recommended on all installations, especially those where there are long pipe runs or cold climate. Check valves should be installed 6 to 10 feet from the compressor. The discharge, suction and liquid lines need to be refrigerant grade copper and in accordance with local code. All refrigeration piping should be installed with high temperature brazed joints. When brazing, a supply of nitrogen gas needs to be fed through the refrigerant lines. Be sure to open the other end of the refrigerant line to allow the nitrogen to bleed off and not pressurize the piping. Prevailing good refrigeration practices should be employed for piping support, leak testing, dehydration and charging of the refrigerant circuits. During the installation the lines should be capped off and fi lled with dry nitrogen at the end of each day’s work or until the system is completed and sealed. Data Aire recommends a silver/phosphorus/copper alloy with 5 to 15% silver to be used to braze the refrigerant line sets to the indoor and outdoor units. Nitrogen needs to be fl owing through the lines to eliminate carbon deposit build-up of the joints. Carbon could contaminate the refrigerant and restrict the metering device. Piping must be supported within 18” of the inlet and outlet connections. The inlet connection is located on the top header of all units. The discharge outlet is located at the bottom of the header. The discharge line pressure drop should not exceed 6 PSIG for R-407C and 9 PSIG for R-410A. Recommended gas velocity for proper oil return is 1,000 FPM. Slope horizontal lines downward in the direction of refrigerant fl ow, 1/2” for every 10 feet of line length. Discharge lines do not require insulation but due to the high temperatures of the refrigerant inside the line, the pipes may be insulated to protect against burns to individuals near or around the lines. 2.1.2 Liquid Lines Liquid lines are determined by pressure drop and velocity. The liquid line pressure drop for R- 407C should not exceed 5 PSIG. For systems with R-410A, the pressure drop should not exceed 9 PSIG. The recommended velocity should be between 200 and 300 FPM. To avoid excessive 10
liquid line pressure drop, the air cooled condenser should be located above or at the same level as the evaporator. Condenser installations more than 10 feet below the evaporator are not recommended. Insulation of liquid lines is not required but can be useful in preventing condensation from forming in cold climates and to avoid fl ashing on long pipe runs. 2.1.3 Suction Lines Some applications call for the compressor to be mounted as part of the condenser, more commonly referred to as a condensing unit. Such require field piping of liquid and suction lines. Suction lines are trapped similarly to discharge lines. Common practice for suction line selection and installation should be followed. Suction lines should always be insulated. 2.1.4 Connection Sizes, Air Cooled Units MODEL HOT GAS LINE LIQUID LINE SUCTION LINE DAPA-2.5 1/2” 1/2” 3/4” DAPA-03 1/2” 1/2” 3/4” DAPA-04 1/2” 1/2” 3/4” DAPA-05 1/2” 1/2” 3/4” Note: Units will have a liquid line and either a hot gas or suction line Field connections at the indoor evaporator and remote condenser or condensing unit will not necessarily be the same as the field pipe size required. In some cases these sizes will vary significantly. 2.1.5 Field Piping, Remote Condenser 11
Page 1: Mini-Plus Installation, Operation a
Page 4 and 5: 4.0 Installation of Remote Outdoor
Page 6 and 7: 1.0 INSTALLATION WARNING: There is
Page 8 and 9: densing units have factory provided
Page 12 and 13: 2.1.6 Field Piping, Remote Condensi
Page 14 and 15: All chilled water pipes have a cap
Page 16 and 17: 3.0 ELECTRICAL CONNECTIONS WARNING:
Page 18 and 19: the panel. Although these existing
Page 20 and 21: Do not locate the heat exchanger in
Page 22 and 23: 5.0 CHARGING 5.1 Voltage Phase Chec
Page 24 and 25: NOTE: Charging to a full liquid lin
Page 26 and 27: (DRCU), the superheat should be 20
Page 28 and 29: 6.0 GLYCOL SYSTEMS 6.1 Glycol Conce
Page 30 and 31: 7.0 CONTROLS 7.1 Mini DAP-II Microp
Page 32 and 33: 8.0 REGULAR MAINTENANCE ITEMS 8.1 A
Page 34 and 35: 9.0 WARRANTY POLICY Seller warrants
Page 36 and 37: RECOMMENDED LINE SIZING for AIR COO
Page 38 and 39: Superheat and Suction Pressure Trou
Page 40 and 41: Condensers (Water-Cooled) ___ Check
Page 42: Notes _____________________________

Installation, Operation and Maintenance Manual - Data Aire

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?