CT87A,B,J ROUND® THERMOSTAT

6Wire the thermostat

1.Use the wiring cross-reference table below to match each old thermostat wire with its corresponding terminal on the CT87 wallplate or subbase. See Fig. 8 through 13 wiring diagrams.

Wiring Cross-reference

Wire Label

Connect to

Connect to

Connect to

CT87A

CT87B

CT87J

 

 

 

 

R, RH, 4, V

R

RH

R

 

 

 

 

Rc, R

 

Rc

 

W, W1, H

W

W

W

Y, Y1, M

Y

Y

Y

G, F

 

G

G

B

See Fig. 9

 

B*

O

 

 

O*

See Fig. 13

 

 

P

 

 

 

 

*Never attach wires to both the B and O terminals.

2.Strip the wire insulation as needed to fit the wires underneath the ter- minal screws (Fig. 7).

Fig. 7. Fitting wires under the terminal screws.

FOR STRAIGHT

FOR WRAPAROUND

CONNECTION—

CONNECTION—

STRIP 5/16 in. [8 mm]

STRIP 7/16 in. [11 mm]

 

 

 

 

BARRIER

M1279

3.Loosen the terminal screws and slip each wire beneath its matching terminal.

4.Securely tighten the terminal screws.

5.Push any excess wire back into the wall.

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Honeywell CT87A installation instructions Wire the thermostat, Wiring Cross-reference, Wire Label Connect to

CT87A specifications

The Honeywell CT87A is a well-regarded thermostatic control unit designed for residential and light commercial HVAC applications. Specifically known for its reliable performance and user-friendly interface, the CT87A promotes energy efficiency while ensuring a comfortable indoor environment. This model is often referred to as the "Round" thermostat, with its distinctive circular design making it a recognizable fixture in homes.

One of the main features of the CT87A is its straightforward mechanical operation. Utilizing a bimetallic strip, it provides accurate temperature readings and control without the need for complex programming. This simplicity is a significant advantage for users who prefer a manual approach over digital displays and smart technologies. The CT87A comes with an easy-to-read temperature scale, allowing users to adjust the setting effortlessly to their desired comfort level.

In terms of technology, the CT87A functions purely on mechanical principles, making it highly durable over time. The thermostat operates on a 24-volt system, which is standard in many residential heating and cooling units. It is capable of controlling both heating and cooling systems, providing versatility for year-round use. Additionally, it allows for compatibility with a variety of HVAC equipment, making it an ideal choice for homeowners looking to upgrade their system without extensive modifications.

A notable characteristic of the Honeywell CT87A is its ability to deliver consistent performance with minimal power consumption. This contributes to energy savings, making it an environmentally-friendly choice for conscientious consumers. The conventional design does not rely on batteries or complicated electrical systems, reducing maintenance costs and the risk of failure.

Furthermore, the CT87A includes a built-in anticipator that helps to prevent temperature swings, enhancing user comfort. This feature enables the thermostat to adjust its operation slightly ahead of actual heating or cooling demands, ensuring that the desired room temperature is reached more efficiently.

In summary, the Honeywell CT87A thermostat combines reliable mechanical operation, energy efficiency, and ease of use, making it an excellent choice for those who appreciate simplicity and performance in temperature control. Its time-tested design, coupled with essential features, places it among the favorites for homeowners seeking a balance between functionality and comfort. Whether for a heating or cooling system, the CT87A consistently meets the demands of everyday use, ensuring a pleasant living environment.