Johnson Controls A421 Temperature Controls

Temperature Controllers

  • Single Stage, NEMA 1 Digital Temp Control (120/240VAC SPDT)
    SKU: A421ABC-02C
    Brand: Johnson Controls
    (15)
    $65.95 each
    $319.75 box of 5
    $63.95 each
    87
    Thu, Dec 27
    175
    QtyArrives
    87 Thu, Dec 27
    88 Fri, Dec 28
    Questions? Call 1-888-757-4774
  • Single Stage Temp Control w/ 8' Capillary (SPDT)
    SKU: A19ABC-24C
    Brand: Johnson Controls
    (8)
    $57.95 each
    $279.75 box of 5
    $55.95 each
    39
    Thu, Dec 27
    48
    QtyArrives
    39 Thu, Dec 27
    9 Fri, Dec 28
    Questions? Call 1-888-757-4774
  • Single Stage Digital Temperature Control (24V, SPDT)
    SKU: A421GBF-02C
    Brand: Johnson Controls
    (2)
    $62.95 each
    $304.75 box of 5
    $60.95 each
    43
    Thu, Dec 27
    91
    QtyArrives
    43 Thu, Dec 27
    48 Fri, Dec 28
    Questions? Call 1-888-757-4774
  • Remote Bulb Temp Ctrl Cooling Only (-30°F to 100°F)
    SKU: A19ABA-40C
    Brand: Johnson Controls
    (4)
    $47.95 each
    $229.75 box of 5
    $45.95 each
    43
    Thu, Dec 27
    67
    QtyArrives
    43 Thu, Dec 27
    24 Fri, Dec 28
    Questions? Call 1-888-757-4774
  • Replacement PTC Sensor with 6-1/2' (2 m) Leads
    SKU: A99BB-200C
    Brand: Johnson Controls
    (5)
    $24.45 each
    $117.25 box of 5
    $23.45 each
    28
    Thu, Dec 27
    32
    QtyArrives
    28 Thu, Dec 27
    4 Fri, Dec 28
    Questions? Call 1-888-757-4774
  • Remote Bulb Temperature Control (-30° to 100°F)
    SKU: A19BBC-2C
    Brand: Johnson Controls
    (4)
    $81.95 each
    $394.75 box of 5
    $78.95 each
    30
    Thu, Dec 27
    35
    QtyArrives
    30 Thu, Dec 27
    5 Fri, Dec 28
    Questions? Call 1-888-757-4774
  • $131.95 each
    $380.85 box of 3
    $126.95 each
    12
    Thu, Dec 27
    21
    QtyArrives
    12 Thu, Dec 27
    9 Fri, Dec 28
    Questions? Call 1-888-757-4774
  • $154.95 each
    $446.85 box of 3
    $148.95 each
    Fri, Jan 25 – Fri, Feb 22
    Arrives
    Fri, Jan 25 – Fri, Feb 22
    Questions? Call 1-888-757-4774 or LiveChat Img Live Chat
  • Temperature Control 2 Inputs, 4 SPDT Relays 1 Sensor
    SKU: T775B2040
    Brand: Honeywell
    (5)
    $278.95 each
    $803.85 box of 3
    $267.95 each
    Tue, Jan 8 – Fri, Jan 11
    Arrives
    Tue, Jan 8 – Fri, Jan 11
    Questions? Call 1-888-757-4774 or LiveChat Img Live Chat
  • 1/2" Well (2-3/8"long)
    SKU: WEL11A-601R
    Brand: Johnson Controls
    (6)
    $34.95 each
    $167.75 box of 5
    $33.55 each
    21
    Thu, Dec 27
    38
    QtyArrives
    21 Thu, Dec 27
    17 Fri, Dec 28
    Questions? Call 1-888-757-4774
  • 1097 Ohm Standard Temperature Sensor
    SKU: 50021579-001
    Brand: Honeywell
    $43.95 each
    $210.75 box of 5
    $42.15 each
    44
    Thu, Dec 27
    103
    QtyArrives
    44 Thu, Dec 27
    59 Fri, Dec 28
    Questions? Call 1-888-757-4774
  • Single Stage Digital Temp Control w/ 19-1/2' Leads (120/240V SPDT)
    SKU: A421ABC-06C
    Brand: Johnson Controls
    (1)
    $71.95 each
    $344.75 box of 5
    $68.95 each
    16
    Thu, Dec 27
    18
    QtyArrives
    16 Thu, Dec 27
    2 Fri, Dec 28
    Questions? Call 1-888-757-4774
  • $258.95 each
    $746.85 box of 3
    $248.95 each
    Tue, Jan 8 – Fri, Jan 11
    Arrives
    Tue, Jan 8 – Fri, Jan 11
    Questions? Call 1-888-757-4774 or LiveChat Img Live Chat
  • $307.95 each
    $591.90 box of 2
    $295.95 each
    Tue, Jan 8 – Fri, Jan 11
    Arrives
    Tue, Jan 8 – Fri, Jan 11
    Questions? Call 1-888-757-4774 or LiveChat Img Live Chat
  • 1097 ohm Water-resistant Temperature Sensor
    SKU: T775-SENS-WR
    Brand: Honeywell
    (1)
    $53.45 each
    $205.40 box of 4
    $51.35 each
    40
    Thu, Dec 27
    61
    QtyArrives
    40 Thu, Dec 27
    21 Fri, Dec 28
    Questions? Call 1-888-757-4774
  • Remote Bulb Temperature Control (100°-240°F)
    SKU: A19DAC-1C
    Brand: Johnson Controls
    (3)
    $59.95 each
    $289.75 box of 5
    $57.95 each
    4
    Thu, Dec 27
    13
    QtyArrives
    4 Thu, Dec 27
    9 Fri, Dec 28
    Questions? Call 1-888-757-4774
  • $265.95 each
    $511.90 box of 2
    $255.95 each
    26
    Thu, Dec 27
    78
    QtyArrives
    26 Thu, Dec 27
    52 Fri, Dec 28
    Questions? Call 1-888-757-4774
  • 1097 ohm Outdoor Air Temperature Sensor
    SKU: T775-SENS-OAT
    Brand: Honeywell
    $51.45 each
    $197.40 box of 4
    $49.35 each
    18
    Thu, Dec 27
    36
    QtyArrives
    18 Thu, Dec 27
    18 Fri, Dec 28
    Questions? Call 1-888-757-4774
  • Temperature Control 2 Inputs, 2 SPDT Relays 1 Sensor
    SKU: T775B2032
    Brand: Honeywell
    (5)
    $193.95 each
    $560.85 box of 3
    $186.95 each
    4
    Thu, Dec 27
    4
    QtyArrives
    4 Thu, Dec 27
    Questions? Call 1-888-757-4774
  • $101.95 each
    $391.80 box of 4
    $97.95 each
    52
    Fri, Dec 28
    52
    QtyArrives
    52 Fri, Dec 28
    Questions? Call 1-888-757-4774
  • $119.95 each
    56
    Thu, Dec 27
    118
    QtyArrives
    56 Thu, Dec 27
    62 Fri, Dec 28
    Questions? Call 1-888-757-4774
  • 1097 ohm Water-tight Temperature Sensor
    SKU: T775-SENS-WT
    Brand: Honeywell
    (1)
    $67.95 each
    $261.00 box of 4
    $65.25 each
    22
    Thu, Dec 27
    51
    QtyArrives
    22 Thu, Dec 27
    29 Fri, Dec 28
    Questions? Call 1-888-757-4774
  • $307.95 each
    $591.90 box of 2
    $295.95 each
    Fri, Jan 25 – Fri, Feb 22
    Arrives
    Fri, Jan 25 – Fri, Feb 22
    Questions? Call 1-888-757-4774 or LiveChat Img Live Chat
  • $65.95 each
    $319.75 box of 5
    $63.95 each
    9
    Thu, Dec 27
    14
    QtyArrives
    9 Thu, Dec 27
    5 Fri, Dec 28
    Questions? Call 1-888-757-4774

Resources

Articles

  • Temperature controllers are used to regulate temperatures without extensive operator involvement. Temperature controllers can be used in a wide range of applications. Certain features should be considered before selecting a temperature controller, with the most important being the controller's temperature range. Other factors that should be considered are the application type, input sensor type, number of outputs, and the type of outputs.

    Pneumatic temperature controllers regulate air and liquid temperatures. They are designed for heating and cooling unit ventilators and fan coil units. Pneumatic temperature controllers operate in three phases. First, the pneumatic temperature controller senses the temperature being monitored. It then attempts to balance its internal lever system. Finally it adjusts its pilot pressure to counterbalance the main lever force. A pneumatic temperature controller can have direct action or reverse action. In a direct acting pneumatic controller, the output signal rises as the temperature rises. The opposite is true for a reverse acting pneumatic temperature controller. Both provide proportional control of pneumatic valves and damper actuators in heating and air conditioning systems. Direct acting and reverse acting controllers are available in one pipe or two pipe configurations. A one pipe configuration is used in low air capacity applications, while a two pipe configuration is used in high air capacity applications. Two pipe controllers are the more popular option on our website.

    Modulating temperature controllers are used to adjust water control or air temperature in ducts, tanks, and similar applications. These controllers should be selected based on the features the application requires. Models with a copper fast response element provide a response time four times faster than standard models. Modulating temperature controllers can have an analog or relay output type.

    Return-air temperature controllers are used to maintain a constant ambient temperature in farm, industrial, or commercial applications. These controls regulate temperature in ventilation, heating, or cooling systems by adjusting the temperature of the air supplied by individual cooling units. A return-air temperature controller regulates the temperature on the supply side of an air handler. This allows a facility to control and supply predictable temperatures, thereby reducing operating costs.

    Ambistat temperature controllers are used for HVAC, agricultural, and industrial applications. An ambistat temperature control regulates a wide temperature range and can be used in many applications. Common applications for these controls are beverage dispensing machines, ice cube machines, bulk milk tanks, dishwashers, crop drying, tobacco curing, and similar applications.

    Electronic temperature controls are the next generation of commercial and agricultural temperature controls. These versatile controls are economical, programmable, and simple to install. A sequencer model and a universal input model are the two unique models available. The sequencer model eliminates the need for a separate time delay device. It uses a time clock scheduler/digital input to control setback and disables output to save energy. It also controls floating actuators with floating outputs. The universal input model can control pressure, humidity, or any variable analog input. A special boiler model is available for boiler control. The staged sequencing model is the best option for applications that require relays to be staged in sequence.

    We carry a wide selection of Honeywell, Ranco, and White Rodgers temperature controllers for residential or commercial applications.
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