A20 and A25 Series Temperature SWICHGAGE®
Revised
Catalog Section 10
**
A20T Series shown
2 and 2-1/2 in. (51 and 64 mm) Dial
■Corrosion Resistant Polycarbonate Case
■Indicating Gage and Limit Switch
■Switch Can Activate Alarms and/or Shut Down Equipment
■Critical/High Temperature Limit Switch Is Visible and Adjustable (Most Models)
■Contact(s) Isolated From Ground
The A20 Series (2 inch/51 mm dial) and the A25 Series
Ranges are available from
All models of these rugged,
These vapor/pressure 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 a diaphragm mechanism.
The diaphragm translates this vapor pressure into a mechanical gage reading.
For series A20T and A25T, 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 isolated from ground. They have
Applications for A20 and A25 Series temperature SWICHGAGE® instruments include: engines and equipment in Oil Field, Marine, Irrigation, Construction and Trucking industries. Monitoring Engine Coolant temperature, Crankcase Oil, Transmission Oil.
SpecificationsDial: White on black; U.S.A. standard scale is dual scale °F/°C; others available.
Case: Glass filled/Polycarbonate,
are available.
Pointer: Tempered nickel silver; red tip.
Lens: Polycarbonate,
Sensing Element: Beryllium copper diaphragm.
Capillary: PVC armored copper; 4 ft. (1.2 m)*. Stainless steel armor optional.
Sensing Bulb: Copper*.Gage Accuracy: See accuracy chart, on page 2.
Maximum Temperature: See Temperature Ranges and Factory Settings table on page 2.
Adjustable Limit Contact (A20T and A25T):SPST contact;
Limit Contact Adjustment: by a 1/16 in. hex wrench thru 100% of the scale.
Wiring: A20T: Number 4 screw terminals; A25T: Number 6 screw terminals.
SPDT, 3 A@ 30 VDC inductive; 4 A @ 125 VAC inductive.
Wiring: A20TE: Number 4 screw terminals; A25TE: Number 6 screw terminals.
Unit Weight: A20 Series: 11.9 oz. (0.370 kg). A25 Series Models: 13.3 oz. (0.413 kg).
Unit Dimensions: A20 Series:
Coolant or Oil Temperature
A20T and A25T Series SWICHGAGE® For these models the gage pointer makes with an adjustable contact to complete a
A20TL and A25TL SWICHGAGE®
For use on Ford Worldwide engines. Supplied with special sensing bulb.
A20TE and A25TE SWICHGAGE®
A20TE (was A20ESR) and A25TE (was A25ESR). Models with internal SPDT
C & D hazardous areas.
A20TABS and A25TABS SWICHGAGE® Same as 20 and 25T with internal SPDT snap- switch for
Cylinder Head Temperature
A20TH and A25TH SWICHGAGE® A20TH (was A20TL8133) and A25TH (was A25TL8133). For use on Air Cooled engines.
Gage–Only Models
A20TG and A25TG MURPHYGAGE®
Gage without contact(s).
*For optional capillary lengths, engine adapters, sensing bulbs and range combinations, see Murphy bulletin
**Products covered by this bulletin comply with EMC Council directive 89/336/EEC regarding electromagnetic compatibility except as noted.
Bulletin