20T / 25T Series Temperature Switchgage®

The 20 Series (2 inch/51 mm dial) and the 25 Series (2- 1/2 inch/64 mm dial) Swichgage models are diaphragm actuated, temperature-indicating gages with built-in electrical switches for tripping alarms and/or shut-down devices. Ranges are available from 32°-120°F (0°-45°C) through 300°-440°F (160°-220°C).

Swichgage® instruments are built in the USA and have protected engines and equipment in applications such as oil and gas, marine, irrigation, construction and trucking applications to monitor engine coolant, crankcase oil, transmission oil and others for more than 80 years.

Base Models Diagrams Specifications Downloads How To Order

The gage mechanism is enclosed in a steel case coated to resist corrosion. A polycarbonate, breakresistant lens and a polished, stainless steel bezel help protect this rugged, built-to-last instrument. These vapor-actuated gages feature a sealed capillary tube and a sensing bulb. When subjected to heat, the liquid in the sensing bulb changes to vapor creating pressure against the diaphragm mechanism. The diaphragm translates this vapor pressure into a mechanical gage reading.

Coolant or Oil Temperature

  • 20T and 25T Series Swichgage
    For these models the gage pointer acts as a temperature indicator and as one switch pole which completes a circuit when it touches the adjustable limit contact. Contact(s) are grounded through the Swichgage case. They have a self-cleaning motion to enhance electrical continuity.
  • 20TL and 25TL Swichgage instrument
    For use on Ford Worldwide engines. Supplied with special sensing bulb.
  • 20TE (was 20ESR) and 25TE (was 25ESR) Swichgage instrument internal snap-switch
    Models with internal SPDT snap-switches instead of the single pole/pointer contact(s). When the switch closes on rising temperature, it becomes set. As temperature decreases, the switch resets.
  • 20TABS and 25TABS Swichgage instrument
    Same as 20/25T with internal SPDT snap-switch for pre-alarm.

Cylinder Head Temperature

  • 20TH (was 20TL8133) and 25TH (was 25TL8133) Swichgage instrument
    For use on air-cooled engines.

Direct Mount Models

  • 20TD Swichgage instrument
    Same as 20T. Available ranges: 220°F (104°C) or 250°F (121°C). Includes 1/4 x 4 in. (6 x 102 mm) sensing bulb.
  • 20SD Swichgage instrument
    Same as 20T. Available ranges: 220°F (104°C) or 250°F (121°C). Includes 11/32 x 1-1/2 in. (9 x 38 mm) sensing bulb.

Gage–Only Models

  • 20TG and 25TG MurphyGage
    Gauges without contact(s).

  • Dial: White on black, dual scale °F/°C (others available)
  • Case: Plated steel; mounting clamp included (except direct mount models)
  • Bezel: Polished stainless steel, standard; others available
  • Pointer: Tempered nickel silver
  • Lens: Polycarbonate, high-impact
  • Sensing Element: Beryllium copper diaphragm.
  • Capillary*: PVC armored copper; 4 ft. (1.2 m). Stainless steel armor optional
  • Sensing Bulb*: Copper
  • Gauge Accuracy: See technical sales bulletin
  • Maximum Temptature: See technical sales bulletin
  • Maximum Ambient Temperature Range: -40°F (-40°C) thru 150°F (66°C)
  • Adjustable Limit Contact (20T and 25T): SPST contact; pilot duty only, 2 A @ 30 VAC/ VDC; Ground path through encasement. Normally Closed (NC) when the high limit is met. Normally Open (NO) when pointer is in normal operating range. Contacts are gold flashed silver.
  • Limit Contact Adjustment: By a 1/16 in. hex wrench through 100% of the scale
  • Limit Contact Wire Leads: 18 AWG (1.0 mm) 2 x 12 in. (305 mm)
  • Snap-Switch Rating (20TE and 25TE): SPDT, 3 A @ 30 VDC inductive; 4 A @ 125 VAC inductive
  • Snap-Switch Wire Leads: 20 AWG (0.75 mm2) x 12 in. (305 mm)
  • Unit Weight:
    • 20 Series: 12.7 oz. (0.39 kg)
    • 25 Series Models: 13.8 oz. (0.43 kg)
  • Unit Dimensions:
    • 20 Series: 4-3/4 x 4-3/4 x 2-3/4 in. (121 x 121 x 70 mm)
    • 25 Series Models: 4-3/4 x 4-3/4 x 3 in. (121 x 121 x 76 mm)

*For optional capillary lengths, engine adapters, sensing bulbs and range combinations, see bulletin 8428.

 WARNING: This product may expose you to chemicals which are known to the State of California to cause cancer, birth defects or other reproductive harm. For more information about California Propsition 65, go to www.P65Warnings.ca.gov or visit our California Proposition 65 page.

Additional product documentation can be found on our product support website or by clicking the Help Center button above.

All configurations may not be available. Call your sales representative or Enovation Controls for more information.

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