Carrier Programmable Dual Fuel Thermostats Operations Instructions download pdf

Programmable Dual Fuel Thermostats

Installation, Start-Up, and Operating Instructions

NOTE: Read the entire instruction manual before starting the

installation.

This symbol → indicates a change since the last issue.

SAFETY CONSIDERATIONS

Read and follow manufacturer instructions carefully. Follow all

local electrical codes during installation. All wiring must conform

to local and national electrical codes. Improper wiring or installa-

tion may damage thermostat.

Recognize safety information. This is the safety-alert symbol

When you see this symbol on the equipment and in the instruction

manual, be alert to the potential for personal injury.

Understand the signal words DANGER, WARNING, and CAU-

TION. These words are used with the safety-alert symbol. DAN-

GER identifies the most serious hazards which will result in severe

personal injury or death. WARNING signifies a hazard which

could result in personal injury or death. CAUTION is used to

identify unsafe practices which would result in minor personal

injury or product and property damage.

INTRODUCTION

Carrier’s 7-day programmable dual fuel thermostat is a wall-

mounted, low-voltage thermostat which provides proper control of

a heat pump (HP) and furnace combination without using a

HP/furnace interface kit. Separate heating and cooling setpoints,

plus auto changeover allow setback programming for maximum

energy savings. Up to 4 time/temperature settings per 24 hour

period for 7 independent days may be programmed. Batteries are

not required; during a power interruption, the internal memory

stores programs for an unlimited time and the clock continues to

run for at least 72 hrs.

SYSTEM CONSIDERATIONS

The dual fuel thermostat is designed to be used only in HP/furnace

installations. It replaces a conventional 2-stage HP thermostat and

a HP/furnace interface kit. An outdoor temperature sensor, Part

No. TSTATCCSEN01 MUST be used with this thermostat. It is

not supplied with thermostat.

If HP is not already equipped with a high-pressure switch, one

must be added for dual fuel applications. It protects HP from

overpressure which would occur if a failure resulted in both

HP and furnace operating at same time. Kit No.

KSAHI0201HPS includes required switch and instructions

for its proper installation.

A HP/furnace installation has several special requirements. Fore-

most is that furnace and HP must not be allowed to operate at same

time, except during HP defrost. A second is to have furnace

complete a heating cycle once it is turned on. A third is the need

to have HP not operate at all when outdoor temperatures are below

a certain value. Finally, HP and furnace must work together

properly to provide an efficient and comfortable defrost. These

requirements are addressed by the dual fuel thermostat itself and

an interface kit is NOT required.

APPLICATION

The dual fuel thermostat is designed for the following applications:

1-stage cool, 2-stage heat: 1-speed HP with 1-stage furnace

1-stage cool, 3-stage heat: 1-speed HP with 2-stage furnace

2-stage cool, 3-stage heat: 2-speed HP with 1-stage furnace

2-stage cool, 4-stage heat: 2-speed HP with 2-stage furnace*

*This combination must use furnace algorithm to control furnace

staging.

As outdoor temperature decreases, heat loss increases and HP

capacity decreases. There is a temperature below which HP will

not be able to ″keep up″ and furnace will be required to maintain

temperature. This is the thermal balance point.

There is also an economic balance point, determined by relative

costs of fuel and electricity, below which the furnace is the most

cost effective and above which the HP is the most cost effective.

Finally there may be a comfort balance point below which leaving

air temperature of HP is not comfortable, even if HP has sufficient

capacity to keep structure warm.

Any of these balance points may be the determining factor in the

selection of an outdoor temperature below which HP will be turned

off and only furnace allowed to operate. This balance point

temperature is entered into thermostat by installer. Outdoor tem-

peratures from 15˚F to 55˚F may be selected. Instructions for

entering this selection is covered in the section: Balance

Point—Value Selection.

When outdoor temperature is below selected balance point tem-

perature, furnace is used exclusively to supply heat.

Fig. 1—Carrier Programmable Thermostat

A94134

HEIGHT (IN.) WIDTH (IN.) DEPTH (IN.)

4-1/4 7-1/2 1-3/8

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.

Book 1 4

Tab misc. misc.

PC 101 Catalog No. 92-33TS-TA35C Printed in U.S.A. Form TSTAT-9SI Pg 1 2-96 Replaces: TSTAT-6SI

1 2 3 4 5 6 7 8

Summary of Contents

Page 1 - 4-1/4 7-1/2 1-3/8

Programmable Dual Fuel ThermostatsInstallation, Start-Up, and Operating InstructionsNOTE: Read the entire instruction manual before starting theinstal

Page 2

When outdoor temperature is above both selected balance pointtemperature and thermal balance point, HP will be used exclu-sively, because it will have

Page 3 - Table 1—Heating Stages

Table 1—Heating StagesWIRINGDIAGRAMSYSTEMTYPEOUTDOOR TEMP/BAL. PT. TEMPSTAGE 1 STAGE 2 STAGE 3Fig. 21-speed HP1-stage furnaceAbove HP Furnace —Below F

Page 4

Improper wiring or installation may damage the thermostat.Check to make sure wiring is correct before proceeding withinstallation or turning on unit.9

Page 5 - Single-Speed Heat Pump

HEATING OPERATION1. Press MODE button until HEAT is displayed under the modeannunciator.2. Make sure outdoor temperature is above balance point settin

Page 6 - 2-Speed Heat Pump

A95217Fig. 4—Single-Stage Furnace with2-Speed Heat PumpY/Y2W/W1R24 VAC HOTFANFURNACECOMPRESSOR HIRVS COOLINGCOMPRESSOR LODUAL FUELTHERMOSTATTWO-SPEEDH

Page 7 - Thermostat Troubleshooting

OPERATIONAL INFORMATIONFive-minute Compressor TimeguardThis timer prevents the compressor from starting unless it has been off for at least 5 minutes.

Page 8 - Tab misc. misc