
Application
These thermostats are used primarily on combination
heating and cooling air conditioning units to sense
supply media temperature and reverse the control
action of the room temperature sensing element.
Units are hermetically sealed. TC-2942 is enclosed
type and has 1/2” conduit adapter. Fast responding
bimetal element actuates snap-acting SPDT with silver
contacts. Units are supplied with three color coded 16
gauge leads 3 ft. (914 mm) long.
Dimensions: 2 in. (51 mm) diameter x 1-1/2 in. (38
mm) high.
TC-2931, TC-2942
Changeover Thermostats, Strap-On Type,
Summer/Winter
General Instructions
TC-2931
Open Type
TC-2942
Enclosed Type
Table-1 Model Chart.
Min. Hot
Part
Number
TC-2931 Strap-On
TC-2942
a. Has 1/2” conduit connector
Type
Strap-On
Enclosed
a
Setpoint
°F (°C)
Fixed
75 (24)
Approx.
Differential
°F (°C)
Fixed 15
(8)
Approx.
Water
Temp.
°F (°C)
90 (32) 60 (16)
Options
TC-2931-204 with 10 ft. (3 m) cable and plug (which cannot
be extended) for unit ventilator.
TC-2931-205 with 3 ft. (914 mm) cable (which cannot be
extended) for CP-5341.
Accessories
None.
Pre-Installation
The thermosta ts are shi pped with an att ached fl ange and two
mounting spri ngs for mounting on tubing or pipe up to 1-1/2”
(38 mm).
Before inst alling the th ermostat, inspect the un it for any signs
of damage.
Max.
Chilled
Water
Temp.
°F (°C)
Voltage
(Vac)
120
240
Switch Ratings (AC Only)
FLA
(Amps)
5.8
2.9
LRA
(Amps)
34.8
17.4
Pilot Duty
(VA)
125
Printed in U.S.A. 8-08 © Copyright 2008 TAC All Rights Reserved. F-12720-8

Requirements
Checkout
The thermostat can be mounted in any position wit h one
spring for pipe or tu bing up to 1/2” (13 mm) or 2 springs
hooked together for pipe or tubing up to 1-1/2” (38 mm).
CAUTION
Do not attempt to disassemble the thermostat as it is
hermetically sealed to prevent moisture condensation on the
electrical contact s
Procedure
On a smooth clean sec tion of th e pipe or tubing , hook one en d
of the spring in the hole on the flange. Position the thermost at,
pull the spring ar ound under the pipe, and hook the other end
in the hole on the opposite side of the flange. If installed on
insulated pipe, build up the insula ti on around and over the
thermostat only after it is installed.
Make all electrical connections in accordance with job
diagrams and in compliance with national and local elect ri cal
codes.
St andard units are suppl ied with color coded leads for direct
connection to other equipment or spliced connections in a
nearby electrical enclosure.
Expose the unit to a temperat ure below 62°F (17°C) and a
circuit must be made between yel low and red (TC-2931) or
between white and blue (TC-2942).
Expose the unit to a temperature above 88°F (31°C) and a
circuit must be made between yel low and blue (TC-2931) or
between white and black (TC-2 942).
Maintenance
If excessive corrosion develops between the sensing
elements and the pip e, remove unit, clean, and apply a
silicone lubri cant such as #6 compound from Dow Corning
Company to prevent fut ure corrosion.
Repair
Do not field repair the thermostat. If the syst em is not
operating co rrectly and the reason i s traced to the termmost at,
it should be replaced.
Blue
TC-2931
Red
Temp.
Drop
Yellow (common)
Black
TC-2942
Blue
Temp.
Drop
White(common)
Copyright 2008, TAC
All brand names, trademarks and registered
trademarks are the property of their respective
owners. Information contained within this
document is subject to change without notice.
F-12720-8
TAC
1354 Clifford Avenue
P.O. Box 2940
Loves Park, IL 61132-2940
www.tac.com