Product Overview

Printed in U.S.A. 1/10 © Copyright 2010 Schneider Electric All Rights Reserved. F-25908-4
Application
2252 Series Temperature Transmitters are used in pneumatic control
systems to measure air or fluid temperatures and transmit
fixed-span, 3 to 15 psig pneumatic output signals to indicating and
controlling devices, such as receiver gauges, receiver-controllers,
sensitive pressure switches and narrow-differential snap-acting
diverting relays.
These transmitters are available with several types of sensing
elements. The transmitters are “one-pipe” devices requiring an
external source of constant pressure main air, supplied through a 1.0
scfh restrictor or restrictor-tee. Their design features pneumatic
feedback to assure accuracy and stability over a wide temperature
span.
Features
• Transmitters permit remote readout (in multiple locations, if
desired) and/or control of temperature associated with HVAC
Systems.
• Eight different temperature ranges permit proper match of
transmitter range to applications.
• Quality design and construction, with beryllium copper feedback
bellows, provides excellent linearity, response and stability.
• Field-accessible “zero” adjustment.
• Liquid-filled sensing elements in the following styles:
– 20 ft. (6.1 m) averaging, for air ducts.
– Rigid, for immersion (in well), or air duct insertion.
– 10 in. (25.4 cm) rigid coiled, for fast response in air ducts
where averaging is not required.
• Remote-bulb, for various applications.
SPECIFICATIONS
Action: Direct, proportional.
Adjustments: None required, factory calibrated. (Field
accessible zero adjustment.)
Supply air pressure: 20 psig ±0.5 psi (138 kPa ±3.4 kPa),
clean, dry air, supplied through 1.0 scfh (0.0063" dia.)
restrictor or restrictor-tee.
Maximum air pressure: 30 psig (207 kPa).
Output pressure: 3 to 15 psig (21 to 103 kPa).
Air connection: 1/8 in. FNPT.
Maximum case ambient temperature: 140°F (60°C).
Minimum case operating ambient temperature
40 °F (4.4 °C).
Construction: Liquid-Filled copper sensing element, cast
aluminum base, beryllium copper feedback bellows,
zinc-plated steel cover.
Mounting: Duct, immersion, or remote-bulb applications.
See “Model Chart”.
Weight (nominal): 0.9 lb (0.4 kg).
Case dimensions: 2-5/8 H x 3-1/16 W x 1-3/4 D in. (67 x 78 x 44
mm).
ACCESSORIES
Part Number Replaces Model Description
20-778
a
a
Use together for copper well with extended neck.
100-17
3/8 x 7-1/32 in. copper well with 1/2 in.
NPT bushing.
20-782 100-25
3/8 x 10-17/32 in. copper well with 1/2
in. NPT bushing.
20-803
a
100-47
Neck extension adaptor - converts
7-1/32 in. well to 10-17/32 in. well.
20-805 100-49
3/8 x 7-1/32 in. Stainless steel well with
1/2 in. NPT bushing (includes 20-803).
22-401 100-71
Adapter, brass, for mounting 2252
Series immersion transmitter in AT-201
or AT-203 well.
20-944 N4-32 Restrictor tee, copper tubing.
21-038 N100-0010 Restrictor tee, polyethylene tubing.
21-153 N100-2501 In-line restrictor.
2252 Series
Duct, Immersion and Outdoor-Air
Temperature Transmitters
General Instructions
Rigid Element
Remote Bulb
w/Capillary
20 Foot
Averaging Element
10 inch
Rigid (Coiled) Element