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Table of Contents
Related Manuals for Trane TTA Series
Summary of Contents for Trane TTA Series
- Page 1 Application Guide Tube Size and Component Selection for TTA and TWA Split Systems (6-20 Tons) Using Refrigerant 410A Model Numbers: TTA073D TTA090D TTA120D TTA120E TTA120F TTA150E TTA180E TTA180F TTA240E TTA240F TWA073D TWA120D TWA180E TWA240E TWA090 SS-APG008-EN October 2009...
- Page 3 CFCs such as HCFCs and HFCs. Responsible Refrigerant Practices! Trane believes that responsible refrigerant practices are important to the environment, our customers, and the air conditioning industry. All technicians who handle refrigerants must be certified. The Federal Clean Air Act (Section 608) sets forth the requirements for handling, reclaiming, recovering and recycling of certain refrigerants and the equipment that is used in these service procedures.
- Page 4 Warnings, Cautions and Notices • If there is a risk of arc or flash, technicians MUST put on all necessary Personal Protective Equipment (PPE) in accordance with NFPA70E for arc/flash protection PRIOR to servicing the unit. Failure to follow recommendations could result in death or serious injury. SS-APG008-EN...
- Page 5 R-410A high pressures which could result in death, serious injury, or equipment damage. Trademarks Trane and the Trane logo are trademarks of Trane in the United States and other countries. All trademarks referenced in this document are the trademarks of their respective owners. © 2009 Trane All rights reserved...
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Page 6: Table Of Contents
Table of Contents Introduction ............iii Overview . -
Page 7: Overview
Overview Trane’s TTA and TWA 6- through 20-ton condensing unit product line (specific model numbers are listed on the cover) has been designed for use only with R-410A and POE oil. R-410A is a higher pressure refrigerant that requires the other components of the system to be rated for the higher pressures. -
Page 8: Updated Guidelines
At the time of this writing, no known direct oil-entrainment tests have been published. Trane has used ASHRAE data to create equation-based formulas to predict the entrainment velocities of R-410A refrigerant and POE oil. These minimum velocities are reflected in the line sizes listed in the component selection summary tables (Table 2, p. -
Page 9: Equipment Placement
Interconnecting lines of 150 lineal ft (45.7 m) or less do not require Trane review, but only a limited amount may be in a riser (see... - Page 10 Overview Figure 2. Allowable elevation difference: Cooling-only TTA above indoor unit Figure 3. Allowable elevation difference: TWA heat pump above indoor unit Figure 4. Allowable elevation difference: TTA or TWA below indoor unit SS-APG008-EN...
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Page 11: Line Sizing, Routing, And Component Selection
Figure 4, p. depict the permissible rise in the liquid line (without excessive loss of subcooling). Again, system designs outside the application envelope of the TTA/TWA unit require Trane review. Insulation The liquid line is generally warmer than the surrounding air, so it does not require insulation. In fact, heat loss from the liquid line improves system capacity because it provides additional subcooling. - Page 12 Line Sizing, Routing, and Component Selection Solenoid Valve In TTA split systems, solenoid valves may be used to isolate the refrigerant from the evaporator during the off cycles. This is only done when the indoor unit is well below the outdoor unit. The solenoid valve on the TTA unit is a drop solenoid—open when the compressor is on, and off when the compressor is off.
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Page 13: Gas Line
Line Sizing, Routing, and Component Selection Gas Line Line Sizing Proper line sizing is required to guarantee that the oil returns to the compressor throughout the system’s operating envelope. At the same time, the line must be sized so that the pressure drop does not excessively affect capacity or efficiency. -
Page 14: Insulation
Line Sizing, Routing, and Component Selection Insulation Any heat that transfers from the surrounding air to the cooler gas lines increases the load on the condenser (reducing the system’s air-conditioning capacity) and promotes condensate formation. After operating the system and testing all fittings and joints to verify that the system is leak-free, insulate the gas lines to prevent heat gain and unwanted condensation. -
Page 15: Expansion Valves
Expansion Valves Expansion valves meter refrigerant into the evaporator under controlled conditions. If there is too much refrigerant, the refrigerant will not completely vaporize and the remaining liquid will slug the compressor. If there is too little refrigerant, the system won’t make capacity and there may not be enough cooling for the compressor. -
Page 16: Controls
Controls The TTA/TWA unit is available with either ReliaTel™ or thermostat control. It is important to understand that if the staging of compressors is turned over to a third party, the compressor protection, provided through system stability, is also turned over to the third party. Simply stated, this means that when a compressor turns on, it shouldn’t turn off until the expansion valve comes under control. -
Page 17: Hot Gas Bypass
Trane now has several years of successful experience with Evaporator Defrost Control (EDC). Like hot gas bypass, the EDC system protects the coil from freezing, but it does so by turning off compressors when a sensor detects the formation of frost on the evaporator coil. -
Page 18: Remodel, Retrofit, Or Replacement
R-22 refrigerant. Use ONLY R-410A rated service equipment or components with this unit. For specific handling concerns with R-410A, please contact your local Trane representative. Failure to use R-410A rated service equipment or components could result in equipment or components exploding under R-410A high pressures which could result in death, serious injury, or equipment damage. -
Page 19: Refrigerant Piping Examples
Refrigerant Piping Examples Figure 6. TTA cooling-only unit and TWE air handler Installation notes: If the total length of the liquid line exceeds 80 ft (24 m), remove the liquid-line filter drier from the TTA and install a new one (Table 2, p. - Page 20 Refrigerant Piping Examples Figure 8. TWA heat pump and TWE air handler (typical arrangement shown in cooling mode) For applications where the length of the liquid line exceeds 80 ft (24 m) and the heat pump will start in the cooling mode, remove the liquid-line filter driers from the TWA heat pump and install new filter driers and check valves at the TWE air handler..
- Page 21 Refrigerant Piping Examples Figure 9. TWA heat pump and matched indoor coil (typical arrangement shown in cooling mode) Each coil distributor requires one thermal expansion valve (TXV) and one check valve. See Table 3 Table 4, p. 21, recommendations. For applications where the length of the liquid line exceeds 80 ft (24 m) and the heat pump will start in the cooling mode, remove the liquid-line filter driers from the TWA heat pump and install...
- Page 22 Refrigerant Piping Examples Figure 10. Indoor coil (non-TWE) with one distributor (single-circuit TTA/TWA units) Pitch the liquid line 1 inch per 10 feet (1 cm per 3 m) so that the liquid refrigerant drains toward the indoor coil. Use the liquid-line size recommended in Table 2, p.
- Page 23 Refrigerant Piping Examples Figure 11. Indoor coil with two distributors (single-circuit TTA/TWA units) Pitch the liquid line 1 inch per 10 feet (1 cm per 3 m) so that the liquid refrigerant drains toward the indoor coil. Use the liquid-line size recommended in Table 2, p.
- Page 24 Refrigerant Piping Examples Figure 12. Indoor coil with two distributors (dual-circuit TTA/TWA units) Pitch the liquid line 1 inch per 10 feet (1 cm per 3 m) so that the liquid refrigerant drains toward the indoor coil. Use the liquid-line size recommended in Table 2, p.
- Page 25 Refrigerant Piping Examples Figure 13. Indoor coil with four distributors (dual-circuit TTA/TWA units) Pitch the liquid line 1 inch per 10 feet (1 cm per 3 m) so that the liquid refrigerant drains toward the indoor coil. Use the liquid-line size recommended in Table 2, p.
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Page 26: Parts
Parts Table 2. TTA component selection summary UNIT TTA073D TTA090D TTA120D TTA120E TTA120F TTA150E TTA180E TTA180F TTA240E TTA240F Refrigerant ckts 1 (Manifold) 1 (Manifold) 1 (Manifold) Minimum step (tons) 6.25 GAS LINE GAS LINE Tube diameter (in.) Horizontal (& drops) 1 1/8 1 3/8 1 3/8... - Page 27 80 ft, the included filters must be removed and filters from the table must be installed close to the air handler. See “Liquid Filter Drier,” p. Table 4. Expansion valves for TTA/TWA 6- through 20-ton applications* Model Number Refrigerant Manufacturer Tonnage Range Model Number Trane Part w/Check Valve Trane Part R-410A Sporlan ERZE-2-ZGA VAL09476 RCZE-2.0-ZGA VAL08085...
- Page 28 October 2009 Supersedes www.trane.com Trane has a policy of continuous product and product data improvement and reserves the right to change design and specifications without notice. Only qualified technicians should perform the For more information, contact your local Trane installation and servicing of equipment referred to in this literature.
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TRANE MODEL TTA120A400FA 3PH 460V - 60HZ – 23AMP SERIAL 72515X3AD