Sunday, February 13, 2011

Temperature Controls - Mechanical




Fenwal controls and Barksdale manufacture mechanical temperature control devices. The switches are bi-metal or liquid filled switches that use expansion and contraction to cause the switching. This type of mechanism can be extremely accurate but lacks in displaying the temperature. In todays computerized/automated world this type of control tends to be used for over temperature control or alarm as opposed to the process control point.


Barksdale manufactures liquid filled switches, both for Hazardous areas and normal areas. The switches can be either local or remote mount. They can sense temperatures up to 600 degrees F.

Local mount type temperature switches are installed in the pipe or vessel. In this type of sensor, the filling fluid surrounds the bellows. A negative temperature change forces the fluid to contract - expanding the bellows to actuate the switch.
Remote bulb and capillary type temperature switches allow the switch enclosure to be placed up to 25 feet from the media. These models use a bulb and capillary sensing device which may be ordered in standard six and 12 foot lengths. Extra lengths up to 25 feet are available. Six and 12 foot sensors can be copper or stainless steel with or without protective spiral-wound armor. The 25 foot lengths are armored stainless steel only.
Barksdale's MT1H & T2H Series Temperature Switches provide unmatched performance, quality & reliability in a mechanical thermostat. The single set point MT1H and dual set point T2H, can switch, measure & control temperatures from -50° to 650°F (-45° to 343°C), The optional adjustable differential provides precise control while ambient compensation maintains 1/2% accuracy with external temperatures from -65° to 165°F. The MT1H & T2H Series are electrically rated for 10 amps @ 125/250 VAC & 3 amps @ 480 VAC. Standard 3- & 6-pin terminal strips simplify installation. The MT1H & T2H Series are rated NEMA 4 & 13; the optional NEMA 4X construction protects the rugged die-cast aluminum enclosure from corrosive environments. A remote bulb and capillary sensor is available in copper or stainless steel allowing the switch to be mounted up to 25 feet from the temperature source. Optional thermowells allow the sensor to work in pressurized vessels to 5000 psi. UL listed & CSA approved, MT1H & T2H Series Temperature Switches are perfect for your temperature sensing needs.

Barksdale's L1X, T1X & T2X Series Temperature Switches provide unmatched performance, quality & reliability in a mechanical thermostat - a safe solution for hazardous locations. The single set point L1X & T1X and dual set point T2X, can switch, measure & control temperatures from 50° to 650°F (-45° to 343°C), and meets Class 1, Div. 1 & 2 hazardous location requirements. The optional adjustable differential provides precise control. These switches can be mounted locally for control directly at the source or remotely up to 25 feet. The L1X, T1X & T2X Series are electrically rated for 10 amps @ 125/250 VAC & 3 amps @ 480 VAC. Standard 3 & 6 pin terminal strips simplify installation. The L1X, T1X & T2X Series are rated NEMA 4, 7 & 9 and incorporate stainless steel temperature sensors to handle a wide range of media. Optional thermowells allow the sensor to work in pressurized vessels to 5000 psi. The L1X, T1X & T2X Series are UL listed & CSA approved & ATEX Certified for hazardous zones within the European Community.

Barksdale's ML1H & L2H Series Temperature Switches provide unmatched performance, quality & reliability in a mechanical thermostat. The single set point ML1H and dual set point L2H, can switch, measure & control temperatures from -50° to 450°F (-45° to 232°C), while the optional adjustable differential provides precise control. These locally mounted switches provide fast response and accurate measurements at the temperature source. Both the ML1H & L2H Series are electrically rated for 10 amps @ 125/250 VAC & 3 amps @ 480 VAC. Standard 3- & 6-pin terminal strips simplify installation. The ML1H & L2H Series are rated NEMA 4 & 13; the optional NEMA 4X construction protects the rugged die-cast aluminum enclosure from corrosive environments. Copper or stainless steel temperature sensors are available to handle a wide range of media. Optional thermowells allow the sensor to work in pressurized vessels to 5000 psi. UL listed & CSA approved, ML1H & L2H Series Temperature Switches are perfect for your temperature sensing needs.




The FENWAL THERMOSWITCH was invented in the 1930's to control fish tanks, irons and other simple applications, but it was soon realied that they could be used for industrial, commercial and process applications. They're durability, reliability and accuracy are the strong points for THERMOSWITCHES.


THERMOSWITCH® Temperature Controllers are tubular devices featuring an outer shell made of high-expanding metal and internal struts made of low-expanding metal, with a pair of electrical contacts between them.
When the temperature of the media being measured changes, a corresponding change in the spacing of the contacts provides instant on/of
f control with a small differential, resulting in +1°F precision, depending upon the application.

Series 17000, 18000


PROBE TYPE, SPDT

Series Features:

  • Fast Response - outer shell is the active sensing member
  • Precise Control - substantially reduces overshoot & undershoot
  • Extreme Sensitivity - slow make and break contacts, resolution 0.1°F (0.05°C)
  • Vibration Resistance - best possible control under difficult physical conditions
  • Cost-effective, Compact, Simple-In-Operation
  • Numerous Mounting Configurations
  • Specifications:

  • Overlapping ranges from -100°F to 600°F (-73° to 316°C)
  • 1200 Watt resistive load at 120/240 VAC
  • 5/8" diameter THERMOSWITCH® models available
  • Agency Approvals:

  • UL and CSA

    Applications:

  • Food service equipment
  • Packaging equipment
  • Laminating presses
  • Agricultural equipment

    Fenwal's snap action liquid filled THERMOSWITCH® controllers, the expandable liquid surrounding the bellows is in direct contact with the temperature sensing outer shell providing a fast response for accurate temp- erature sensing.


    Series 20000, 21000, 22000 - OBSOLETE

    Fenwal Thermoswitch 20000

    PROBE TYPE, SPST

    Series Features:

  • Individually field adjustable micro-switches
  • One or two micro-switches
  • Specifications:

  • Overlapping ranges from 0° to 300°F (-18° to 148°C)
  • Ratings to 15 A at 120/250 VAC
  • Factory preset temperatures available
  • NEMA 4 enclosure available

  • Agency Approvals:

  • UL, CSA

    Applications:

  • Food service equipment
  • Medical vaporizers
  • Commercial dishwashers


    Based on the differential expansion of metals principle, an increase in temperature causes the stainless steel outer case of the Surface Mounting THERMOSWITCH® controller to expand at a greater rate than the internal bridge assembly.
    Because the case is in direct contact with the heated surface, a temperature change is sensed almost instantaneously.
    Call for availability, most of the part numbers are obsolete as of July 2012.

    Series 30000

    Fenwal Thermoswitch 30000

    SURFACE MOUNT TYPE, SPST

    Click below to buy.

    Series Features:

  • Fully adjustable
  • Narrow temperature differential
  • Compact size
  • Economical
  • Factory preset temperatures
  • NEMA 4 enclosure

  • Specifications:


  • Overlapping ranges from 50° to 600°F (10° to 315°C)
  • 1200 Watt resistive load at 120/240 VAC
  • Minimum contact rating of 100,000 cycle
  • Options:

  • Cross mounting bracket
  • Slotted and extended adjusting screw lengths
  • Factory preset temperature
  • Special range calibration
  • Agency Approvals:

  • UL

    Applications:

  • Plastic laminating presses
  • Food warming trays
  • Popcorn machines
  • Domestic appliances
  • Industrial steam cleaners
  • Anderson-Bolds can supply all of your temperature control needs.



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