| Application |  |
N1 Room thermostat RDF302... M1 1- or 3-speed fan V1 Valve actuator, 2- or 3-position V1, V2 Valve actuator, 2-position E1 Electric heater C1, C2 1-stage compressor S1, S2 Switch (keycard, window contact, presence detector, etc.) B1, B2 Temperature sensor (return air temperature, external room temperature, changeover sensor, etc.) + RS485 Modbus connection - RS485 Modbus connection REF RS485 signal/common ground (Differential common) RDF302.B does not have inputs X1, X2 and M. |
| 2-pipe / heating or cooling – ON/OFF | ||
2-pipe, / heating or cooling – 3-position Y11 = Open Y21 = Close |
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2-pipe and el. heater/ Heating or cooling and el. Heater |
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4-pipe / V1 = Heating V2 = Cooling |
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1-stage compressor C1 = Heating
C2 = Cooling |
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| 1-stage compressor and electric heater |  |