WIRING DIAGRAMS

NOTE

Polarity must be observed. If the HOT side of the second transformer is jumpered to the COMMON side of the first transformer a short will be made. Damage to equipment will occur when power is restored.

OBY2Y1G

 

 

Reversing

 

 

 

 

 

 

 

Reversing

 

Valve

 

2nd Stage

 

 

Fan

 

Energized in

 

 

 

Valve

 

 

Compressor

 

 

Relay

Energized in

 

Heat, Off,

 

 

 

 

 

 

 

Cool Mode

 

Emergency

 

 

 

Compressor

 

 

 

Mode

 

 

 

 

 

 

 

 

 

 

 

Contactor

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

E/W1

 

 

 

 

 

 

 

 

 

 

 

 

THERMOSTAT

 

 

 

 

 

 

 

 

C *

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

W2

 

 

 

 

L

R

 

 

 

 

 

 

 

SYSTEM

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Limit or

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Limit or

 

 

 

 

 

 

 

 

 

 

Safety

HOT

 

 

 

 

 

 

 

 

 

 

 

 

Safety

 

24 VAC

 

 

 

120 VAC

Switches

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Emergency

 

 

SYSTEM

 

 

 

 

Switches

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Heat

 

 

MONITOR

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NEUTRAL

 

 

Relay

 

 

SWITCH

 

 

 

 

24 VAC

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Auxiliary

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ACCESSORY

 

 

Heating

 

 

 

NOTE

 

Aux

 

 

 

 

 

 

 

 

 

 

 

RELAY N.O.

 

Transformer

The accessory relay scheme

Heat

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CONTACT

 

 

(Class II

 

is required when safety

Relay

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Current Limited)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

circuits exist in both systems.

 

 

 

 

 

 

 

 

 

 

 

 

COMMON

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TWO COMMONS MUST

 

 

 

 

 

 

Limit or

 

 

 

 

 

 

 

 

 

Limit or

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

BE JUMPERED TOGETHER!

 

 

 

Safety

 

 

 

 

 

 

 

 

 

Safety

HOT

 

 

 

 

 

 

 

 

 

 

 

Switches

24 VAC

 

 

 

 

120 VAC

Switches

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

COMMON

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NEUTRAL

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Heat Pump Transformer

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(Class II Current Limited)

 

 

 

 

 

Figure 4. Typical wiring diagram for two transformer heat pump systems with safety circuits in BOTH systems

*The 24 volt neutral connection to terminal C on the thermostat is not required if you replace the batteries once a year with fresh “AA” Energizer® alkaline batteries.

Heat Pump Terminal Outputs

Refer to equipment manufacturers' instructions for specific system wiring information.

You can configure the thermostat for use with the following heat pump system types:

HEAT PUMP TYPE 1. Single stage compressor system; gas or electric backup.

This thermostat is designed to operate a single-transformer system. If you have a two-transformer system, cut and tape off

one transformer. If transformer safety circuits are in only one of the systems, remove the transformer of the system with NO safety circuits. If required, replace remaining transformer with a 75VA Class II transformer. After disconnecting one trans- former, the two commons must be jumpered together.

Use the terminal output information below to help you wire the thermostat properly for your heat pump system. After wiring, see CONFIGURATION section for proper thermostat configuration.

 

 

 

 

THERMOSTAT TERMINALS (HEAT PUMP)

 

 

SYSTEM

L

C*

R

W2

E/W1

Y2

Y1

G

O

B

Heat

Malfunction

24 Volt

24 Volt

HP 1 and

Emergency

No

Heat and

Blower/Fan Energized

Energized

Energized

Pump 1

Light

(Common)

(Hot)

Emergency

Mode

Output

Cool mode

on call for Heat

in Cool

in Heat

 

 

 

 

2nd stage

1st stage

 

1st stage

and Cool

Mode

OFF

 

 

 

 

 

Heat

 

 

 

HP 2

 

2nd

(compressor)

Set GAS/ELEC switch

 

Emergency

Pump 2

 

 

 

3rd stage

 

stage

 

for Emergency mode

 

mode

 

 

 

 

 

 

compressor

 

 

 

 

*The 24 volt neutral connection to terminal C on the thermostat is not required if you replace the batteries once a year with fresh “AA” Energizer® alkaline batteries.

O

Reversing

Valve

Energized in

Cool Mode

B

Y1

 

Y2

G

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Compressor

 

 

 

 

 

 

 

Contactor

 

Reversing

 

 

 

 

 

 

 

 

 

Stage 2

 

Valve

 

 

 

 

 

 

 

 

 

 

 

 

 

Energized in

 

 

 

 

 

 

 

 

Heat Mode

 

Compressor

 

 

Fan

Off Emergency

 

Contactor

 

 

 

 

 

Relay

 

 

 

Stage 1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

E/W1

Heat

Relay

Stage 1

W2

Heat

Relay

Stage 2

C *

 

THERMOSTAT

R

SYSTEM

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Hot

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

24 VAC

 

 

 

 

 

 

120 VAC

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Neutral

 

 

 

 

 

 

 

 

 

TRANSFORMER

 

 

(Class II, Current Limited)

Figure 5. Typical wiring diagram for single transformer multi-stage systems

*The 24 volt neutral connection to terminal C on the thermostat is not required if you replace the batteries once a year with fresh “AA” Energizer® alkaline batteries.

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White Rodgers 1F85-277 installation instructions Wiring Diagrams, Heat Pump Terminal Outputs

1F85-277 specifications

The White Rodgers 1F85-277 is an advanced programmable thermostat known for its versatility, energy-efficiency, and user-friendly design. It stands as a reliable choice for homeowners looking to enhance their heating and cooling systems' functionality while minimizing energy consumption.

One of the key features of the 1F85-277 is its 7-day programmable capability, which allows users to set schedules for different days of the week. This flexibility ensures that the home is heated or cooled according to individual preferences, thereby optimizing energy usage and providing comfort when it’s needed the most. The thermostat can program up to four different temperature settings per day, allowing precise control over home climate conditions.

Another notable characteristic of the White Rodgers 1F85-277 is its intuitive LCD display. The backlit screen is easy to read, displaying current temperature settings, scheduled programs, and system alerts clearly. This feature is especially useful during nighttime or low-light conditions. The interface allows for straightforward navigation, making it simple for users to create and modify schedules without the need for complex instructions.

The thermostat also integrates advanced technologies, including Smart Recovery. This technology ensures that the home reaches the desired temperature at the programmed time by anticipating how long it takes to heat or cool. By learning from previous system performance, it improves efficiency while maintaining home comfort.

Additionally, the White Rodgers 1F85-277 is compatible with most heating and cooling systems, including gas, electric, and heat pump systems. It supports both single-stage and multi-stage heating and cooling, providing flexibility and compatibility for various home setups.

A significant advantage is its energy-saving features, which can lead to reduced utility bills. By allowing homeowners to schedule their HVAC systems more efficiently, the 1F85-277 plays a crucial role in energy conservation efforts.

Furthermore, installation is straightforward, as the thermostat is designed with a user-centric approach, allowing most homeowners to install it without professional help.

Overall, the White Rodgers 1F85-277 combines advanced technology with practical features, making it an ideal solution for those seeking to improve home comfort while managing energy costs effectively. Its programmable functionality, user-friendly interface, and compatibility with diverse heating and cooling systems make it a standout product in the thermostat market.