SM Split AH/AV Air Handler Document Conventions | 3 DOCUMENT CONVENTIONS Key to Symbols WARNING: When working on equipment, always observe precautions described in Warnings the literature, tags, and labels attached to Warnings in this document are identified by the unit. Follow all safety codes. Wear a warning triangle printed against a gray safety glasses and work gloves.
4 | Model Nomenclature SM Split AH/AV Air Handler MODEL NOMENCLATURE Fig. 1 Model Nomenclature Subject to change without prior notice 8733826256 (2020/06) SM Split AH/AV Air Handler...
6 | SM Split AH/AV Standard Package SM Split AH/AV Air Handler SM SPLIT AH/AV STANDARD PACKAGE The Water-to-Air Heat Pumps are designed to operate with entering fluid temperature between 20°F to 80°F in the heating mode and between 50°F to 110°F in the cooling mode. Antifreeze solution is required for entering fluid temperatures below 50°F.
SM Split AH/AV Air Handler Unit Installation | 7 UNIT INSTALLATION NOTICE: These units are not approved for This section contains information on the following: outdoor installation; therefore, they must be installed inside a structure in a Subject Page conditioned space. Do not locate in areas that are subject to freezing.
8 | Installation SM Split AH/AV Air Handler Air Handler Section Installation Hanging Bracket Kit The air handler section may be installed on any All horizontal air handler units come with a level surface strong enough to support its weight. Hanging Bracket Kit to facilitate suspended unit When installed in a closet or on a base stand, it mounting using threaded rods.
SM Split AH/AV Air Handler Installation | 9 2. Mount the four Brackets to unit’s four corner posts using the screws provided in the kit. Refer to Fig. 6 and Fig. 7. WARNING: Do not re-use screws removed from the unit on step 1 to mount the Hanging brackets to the unit.
10 | Duct System SM Split AH/AV Air Handler The air handler should be pitched approximately duct work should be installed. Also, check for 1/4" towards the drain in both directions, to existing leaks and repair. facilitate condensate removal. See Fig. 10. NOTICE: Do not connect discharge ducts directly to the blower outlet.
SM Split AH/AV Air Handler Electrical | 11 The unit is provided with a concentric knock-out in the front-left corner post for attaching common trade sizes of conduit, route power supply wiring through this opening. Always connect the ground lead to the grounding lug provided in the control box and power leads to the power supply terminal block as indicated on the wiring diagram.
12 | Electrical SM Split AH/AV Air Handler Low-Voltage Connection Points Function From To Air Handler From Air Thermostat Handler Condensing Section 24 VAC Common 24 VAC Power Fan Operation — — Reversing Valve Compressor 1 Stage Compressor 2 Stage —...
SM Split AH/AV Air Handler Electrical | 13 ECM Interface Board The thermostat connections and their functions are as follows: In addition to providing a connection point for thermostat wiring, the interface board also translates thermostat inputs into control Connection Function commands for the Electronic Commutated Motor (ECM) fan motor and provides thermostat signals...
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14 | Electrical SM Split AH/AV Air Handler Bosch recommends the use of 18 AWG thermostat Just above the connector block is a single-red LED conductive cable for up to 60 foot, 16 AWG up to labeled CFM that will blink intermittently when the 100 ft, and 14 AWG up to 140 ft.
SM Split AH/AV Air Handler Refrigerant Lines | 15 select the proper program in the ECM motor for Some points to consider are: the unit. Refer to Fig. 13 for the proper jumper • Pressure drop (friction losses) in refrigerant placement.
16 | Refrigerant Lines SM Split AH/AV Air Handler Connecting Refrigerant Lines • Use only ACR grade copper tubing and keep ends sealed until joints are made. • For best performance, select routing of refrigerant lines for minimum distance and fewest number of bends.
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SM Split AH/AV Air Handler Refrigerant Lines | 17 Refrigerant Charge, Line Sizing, and Capacity Multiplier Chart Refrigerant Line O.D. Size (Based on Equivalent Line Length) Suction Factory Line System R410A 25 FT. 36 FT. 45 FT. 50 FT. 75 FT. Riser Models Charge...
18 | Typical System Setup SM Split AH/AV Air Handler TYPICAL SYSTEM SETUP For Reference Only. A typical setup is shown for illustration purposes only. Fig. 14 Typical Setup [1] Flex Duct Connection [2] Low Voltage Control Connection [3] Vibration Pad [4] Ball Valves [5] Solenoid Valve Slow Closing [6] Condensate Drain Connection...
SM Split AH/AV Air Handler Specific Application Considerations | 19 SPECIFIC APPLICATION CONSIDERATIONS Thread sealant tape should be used when connecting to the unit to insure against Well Water Systems leaks and possible heat exchanger fouling. (Refer to Fig. 14) In well water applications water pressure must Do not overtighten the connections.
• Bosch recommends the following guidelines for wiring between a thermostat and the unit: 18 AWG up to 60 foot, 16 When the thermostat calls for first-stage cooling AWG up to 100 ft and 14 AWG up to 140 ft.
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SM Split AH/AV Air Handler Sequence of Operation | 21 Some options will have a built-in delay, and When using a 2-cool, 3-heat thermostat hence, compressor operation is not both the W1 & W2 on the Heat Pump and immediate. W2 &...
22 | Options SM Split AH/AV Air Handler OPTIONS continue to operate along with the blower motor in the case of unit compressor and/or compressor Electric Heat power supply failure. Refer to the SM Split Air Factory-installed internal electric heater packages Handler with Electric Heat option wiring diagram are available for all unit sizes.
SM Split AH/AV Air Handler Troubleshooting | 23 TROUBLESHOOTING A possible fault may be one or a combination of causes and solutions. Check each cause and adopt “process of elimination” and or verification of each before making any conclusion. Unit Troubleshooting Problem Possible Cause Checks and Corrections...
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24 | Troubleshooting SM Split AH/AV Air Handler Unit Troubleshooting Problem Possible Cause Checks and Corrections Unit Oversized Recalculate heating and or cooling loads. If the thermostat is installed near a supply air grill, UNIT SHORT Thermostat relocate thermostat. Adjust the heat anticipator. CYCLES Check for defective or improperly calibrated low- Wiring and Controls...
SM Split AH/AV Air Handler Troubleshooting | 25 Unit Lockouts Periodic lockouts almost always are caused by air or water flow problems. The lockout (shutdown) of the unit is a normal protective measure in the design of the equipment. If continual lockouts occur call a mechanic immediately and have them check for: water flow problems, water temperature problems, airflow problems or air...
26 | Maintenance SM Split AH/AV Air Handler MAINTENANCE Lubrication of the blower motor is not required; however, it may be performed on some motors to extend motor life. Use a SAE-20 non-detergent WARNING: Installation and servicing of this electric motor oil. equipment can be hazardous due to system pressure and electrical components.
SM Split AH/AV Air Handler Decommissioning Information | 27 Components DECOMMISSIONING INFORMATION Only trained and qualified technicians are allowed Many parts in the Heat Pump can be fully to decommission and dispose of equipment recycled at the end of the product life. following the requirements of the Local Authority Contact your...
28 | Check-Out Sheet SM Split AH/AV Air Handler CHECK-OUT SHEET Customer Data Customer Name Date Address Phone Unit Number Unit Nameplate Data Unit Make Model Number Serial Number Refrigerant Charge (oz) Compressor: RLA Blower Motor: FLA (or NPA) Maximum Fuse Size (Amps) Maximum Circuit Ampacity Operating Conditions Heating Mode...
SM Split AH/AV Air Handler Wiring Diagrams | 29 WIRING DIAGRAMS Fig. 15 SM — Wiring Diagram (without Electric Heat) FOR REFERENCE ONLY Actual unit wiring may vary from this example. Always refer to the wiring diagram attached to the unit. Subject to change without prior notice SM Split AH/AV Air Handler 8733826256 (2020/06)
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30 | Wiring Diagrams SM Split AH/AV Air Handler Fig. 16 SM — Wiring Diagram (with Electric Heat) FOR REFERENCE ONLY Actual unit wiring may vary from this example. Always refer to the wiring diagram attached to the unit. Subject to change without prior notice 8733826256 (2020/06) SM Split AH/AV Air Handler...
SM Split AH/AV Air Handler Dimensional Drawings | 31 DIMENSIONAL DRAWINGS Fig. 17 SM HZ Air Handling Section Subject to change without prior notice SM Split AH/AV Air Handler 8733826256 (2020/06)
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32 | Dimensional Drawings SM Split AH/AV Air Handler Fig. 18 SM VT Air Handling Section Subject to change without prior notice 8733826256 (2020/06) SM Split AH/AV Air Handler...
SM Split AH/AV Air Handler Terminology | 33 TERMINOLOGY Recycling — Referring to the reuse of a recovered fluorinated-greenhouse gas following a basic cleaning Acronyms process. AHJ — Authority Having Jurisdiction Repair — Referring to the restoration of damaged or AWG —...