Tekmar Smart Heat Pump Control Expansion 291EXP
Four-Heat-Pump Expansion Module
The Tekmar Smart Heat Pump Control Expansion 291EXP expands a Tekmar Smart Heat Pump Control 291 system by adding control for 4 additional heat pumps. Designed for larger hydronic heating and cooling systems, each 291EXP connects to the main 291 control through a wired expansion bus and can be configured for heat pump groups 5-8, 9-12, or 13-16.

Key Benefits
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System Expansion: Adds 4 additional heat pumps to a Tekmar Smart Heat Pump Control 291 system.
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Up to 16 Heat Pumps: Use multiple 291EXP modules to expand the full system up to 16 total heat pumps.
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Simple Expansion Bus: Connects to the main 291 control through a wired 3-conductor expansion connection.
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Configurable Heat Pump Groups: DIP switches assign the module to heat pumps 5-8, 9-12, or 13-16.
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Heating and Cooling Outputs: Supports compressor and reversing valve control, or separate heat and cool enable inputs.
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4-Pipe Valve Support: Includes diverting valve outputs for directing flow to hot or cold buffer tanks in 4-pipe systems.
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Service-Friendly Status LEDs: Power, communication, heating, and cooling LEDs help verify operation and simplify troubleshooting.
Specifications
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Application: Heat pump expansion module for Tekmar Smart Heat Pump Control 291 systems
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Expansion Capacity: Adds 4 heat pump stages per module
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Supported Groups: Heat pumps 5-8, 9-12, or 13-16 using DIP switch configuration
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Expansion Connection: 3-wire connection to the Smart Heat Pump Control 291; maximum bus length 100 ft using 18 AWG solid conductor cable
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Dimensions: 9 in H x 8 in W x 2 11/16 in D
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Packaged Weight: 2.4 lb
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Power Supply: 115 V(ac) +/-10%, 60 Hz, 6 W
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Staging Relays: 230 V(ac), 5 A, 1/10 hp
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Calls: 24 V(ac) or short
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Enclosure: Blue ABS plastic, NEMA type 1
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Ambient Conditions: Indoor use only, 32°F to 122°F, less than 90% RH non-condensing
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Approvals: CSA C US, FCC Part 15B, CAN ICES-3(B)/NMB-3(B)
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Warranty: Limited 3 year