User Guide

ManualsBrandsBarber Colman ManualsHVAC Replacement PartsSummer-Winter Thermostat (55-85°F)

TAC

1354 Clifford Avenue

P. O. Box 2940

Loves Park, IL 61132-2940

www.tac.com

Application

The 2218 Series Pneumatic Room Thermostats are

designed for proportional control of pneumatic valves

and damper actuators in environmental control

systems where a dual presure air main is utilized for

seasonal changeover of heating and cooling functions.

Their design incorporates a highly sensitive, bimetal,

thermostatic element, and a pilot-operated relay with

pneumatic feedback for accuracy and stability over the

entire operating range.

Indexing the thermostat from summer control (reverse

acting) to winter control (direct acting), or vice versa, is

accomplished by remotely changing the main air

pressure supply from 16 psig (summer) to 25 psig

(winter). Models are also available that operate on

slightly different pressures to replace many competitive

devices.

These thermostats have a serrated thumb wheel for

setpoint adjustment. Models are also available with

preassembled internal dial stops. Thermostat covers

are available in various styles to meet particular

requirements. Cover options include models with a

setpoint scale and a thermometer, a setpoint scale

only, a thermometer only, or blank. An external setpoint

adjustment cover is available on some models, or can

be field-installed on covers where desired.

Features

• Factory-calibrated, stainless steel ball-in-seat

provides pneumatic feedback for stable, linear

operation.

• Snap-acting (not gradual) changeover from direct

action to reverse action operation and vice versa.

• Easy-to-use throttling range adjustment and

recalibration.

• Adjustable (patented) bimetal shows actual

throttling range in both °F and °C. Adjustable 2 to

12 °F (1 to 6.7 °C).

• Leak-proof, self-closing branch gauge tap.

SPECIFICATIONS

Action: Proportional.

Setpoint Range: See Table-1 and Table-2.

Throttling Range: See Table-1 and Table-2.

Supply Air Pressure:

Below 16 psig, Operates at summer setpoint.

Above 25 psig, Operates at winter setpoint.

Maximum Air Pressure: 30 psig.

Main Air Consumption: See Table-1 and Table-2.

Calibration Point: See Table-1 and Table-2.

Summer/Winter Indexing: Remote, by change in main air

pressure.

Setpoint Adjustment: Serrated thumbwheel.

Construction:

Mechanical Components, Die cast aluminum, stainless

steel, and glass-filled nylon.

Diaphragm, Fabric-reinforced Neoprene.

Air Lines, Connect to thermostat nipples with

spring-reinforced plastic tubes.

Branch Connections, Equipped with internal fiters.

Environment

Humidity: 5 to 95% relative humidity, non-condensing.

Locations: NEMA Type 1.

2218 Series

Summer-Winter

Pneumatic Room Thermostats

General Instructions

Full Dial Cover Shown

(Covers must be ordered

separately except as noted.)

Summary of content (8 pages)

PAGE 1
2218 Series TAC 1354 Clifford Avenue P. O. Box 2940 Loves Park, IL 61132-2940 www.tac.com Summer-Winter Pneumatic Room Thermostats General Instructions Application The 2218 Series Pneumatic Room Thermostats are designed for proportional control of pneumatic valves and damper actuators in environmental control systems where a dual presure air main is utilized for seasonal changeover of heating and cooling functions.
PAGE 2
ORDERING DATA Table-1 Model Chart — Thermostats.
PAGE 3
Table-3 Covers.
PAGE 4
INSTALLATION Mounting Inspection Standard Mounting Options Inspect the package for damage. If damaged, notify the appropriate carrier immediately. If undamaged, open the package and inspect the device for obvious damage. Return damaged products.
PAGE 5
Polyethylene Tubing Air Supply Pre-plumbed Electrical Box (optional) Main Wall Plate 2 Branch 20-693 6 in. Tube Assembly with Eyelets (included with thermostat) Bracket Air Supply Tubing Branch Main 3/16 in. Tygothane Tubing with Eyelets (included with thermostat) Wall Thermostat Thermostat 1 ¡F 12 6 2 ¡C 5 2 ¡F 12 6 2 Wall Plate Cover (order separately) ¡C 5 2 3/16 in. x 1/4 in.
PAGE 6
Standard Calibration Polyethylene Tubing Air Supply 20-689 Mounting Fitting with 8 ft. Copper Lines (order separately) Branch 20-716 Insulating Back Plate (order separately) Cutouts (partially formed on underside) Main 2. Raise the main air pressure to 25 psig. 20-693 6 in. Tube Assembly with Eyelets (included with thermostat) ¡F 12 6 2 3. Turn the direct acting calibration screw until the test gauge indicates 12 psig. Clockwise rotation decreases the branch line pressure.
PAGE 7
Switch Over Point Adjustment If necessary, adjust the switch point as follows: Note: • The switch point adjustment requires changes to the main air pressure, which could affect other parts of the system. This adjustment should instead be made on a test bench at which a variable main air supply is available. 3. The winter setpoint is in calibration when the winter setpoint dial indicates the ambient temperature within ±2 °F. If not, adjust the winter setpoint as follows: a.
PAGE 8
4. Slowly increase the main air pressure until the branch tap gauge drops to 0 psig. This is the main air pressure at which the thermostat switches from summer control to winter control. 5. If the main air pressure at the switching point is less than 17 psig or greater than 21 psig, adjust the switching screw as follows, using a 20-881 thermostat wrench (1/16” hex wrench): 4. Move the setpoint adjustment to the desired temperature, using the internal setpoint indicator. 5.