1F57-312 TWO-STAGE

low voltage – two stage

This multi-stage heating/cooling thermostat provides low voltage control of up to two stages of heating and two stages of cooling, switches on the sub-base provide convenient selection of heating, cooling and blower operation on cooling air conditioning systems using electric heat where thermostat cycles the fan relay on both heating and cooling.

First stage heat is equipped with an adjustable heat anticipator while 2nd stage in non-anticipated. First stage cooling is equipped with cooling anticipation while 2nd stage is not.

Anticipators provide narrow differential control of room temperature. With sealed mercury cells to provide long life and reliability.

  • Controls Up to 2 Stages of Heat & 2 Stages of Cooling.
  • Single Bimetal Construction.
  • Sub-base has System & Fan Switches to Select System Function & Blower Operation.
  • First Stage is Equipped with an Adjustable Heat Anticipator While 2nd Stage in Non-Anticipated.
  • Vertical Profile
  • 24 Volt Control Circuits
  • 50° to 90°F (10°C – 32°C)
  • Sealed Mercury Cell for Reliable Operation.
  • Imported to King Specifications

Available Models

Ordering Information

MODELUPCVOLTSTYPETEMP. RANGE
1E30-9101900024Mercury Free, Vertical Mount - beige50°F to 90°F
1F56W-4441901024Mercury Free, Heat / Cool / Fan, Horizontal - white50°F to 90°F
1F57-3121901524Two Stage Heat Plus Fan Only50°F to 90°F

Engineering Specs

Temperature Range: 50°F to 90°F (10°C to 32°C)

Temperature Default: 55°F or 68°F (13°C or 20°C)

Display: 5° increments

Rate: 2 cycles per hour

Accuracy: ±3°F

Power Source: 24 VAC

  • Three wire installation
  • Snap action switch
  • Flexible wire leads
  • 50° to 90°F (10°C – 32°C)
  • Anticipated (resistor style)
  • Large bi-metal sensor
  • Meets most energy codes
  • For use on all types of electric heater relays; fan-forced, baseboard, radiant with 24 Volt control circuits

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