Honeywell Thermostat T874/Q674 Bedienungsanleitung PDF herunterladen

S. M. • Rev. 5-93 • • ©Honeywell Inc. 1993 • Form Number 60-1147—4

T874/Q674

Thermostat/Subbase Combinations

Installation Instructions for the Trained Service Technician.

Application

The T874/Q674 Thermostat/Subbase combinations provide 24 to 30 Vac control for heat pump systems. See Table 1.

TABLE 1—T874/Q674 THERMOSTAT/SUBBASE COMBINATIONS.

Thermostat/ Number Changeover

Subbase

of Stages Stage Type of Switching

Model Heating Cooling Heating Cooling System Fan See Fig.

T874N/Q674C 2 1 1 — OFF-AUTO AUTO-ON 5

T874N/Q674F 2 1 — 1 OFF-EM. HT.- AUTO-ON 6

HEAT-AUTO-COOL

T874R/Q674L 2 1 — 2

EM. HT.-HEAT- AUTO-ON 7

OFF-COOL

Q674 Subbase provides the wiring terminals, system switch and fan switch for system operation.

Provides manual changeover with the subbase system switch in COOL position.

Installation

WHEN INSTALLING THIS PRODUCT…

1. Read these instructions carefully. Failure to follow

them could cause a hazardous condition.

2. Check the ratings given in the instructions and on the

product to make sure the product is suitable for your applica-

tion.

3. Installer must be a trained, experienced service tech-

nician.

4. After installation is complete, check out product opera-

tion as provided in these instructions.

CAUTION

1. Disconnect power supply to prevent electrical

shock and equipment damage.

2. To prevent interference with the thermostat link-

age, keep wire length to a minimum and run

wires as close as possible to the subbase. Push

excess wire back into the hole and plug hole to

prevent drafts from affecting thermostat opera-

tion.

3. Do not overtighten thermostat captive mounting

screws because damage to subbase threads may

result.

4. Do not short across coil terminals on the relay.

This may burn out the thermostat heat

anticipator.

IMPORTANT: Thermostats are calibrated at the factory

using subbases mounted at true level. An inaccurately

leveled subbase will cause thermostat control devia-

tion.

Operation

On a two-heat thermostat, the two stages of heat make

sequentially as the temperature drops. Make refers to the

mercury switch initiating a call for heat or cool.

There are about 2° F [1° C] between stages so that the

second stage makes only when the first stage cannot handle

the load. This is the interstage differential.

One or two LEDs (light emitting diodes) are included on

your subbase. Refer to the list below for specific meaning.

The CHECK LED lights when something needs to be

checked or done to maintain efficient operation of the system.

See your heating system instructions for the specific mean-

ing.

The EM. HT. LED lights when the system switch is placed

in the EM. HT. position. Emergency heat is operating; in

most systems, the compressor has failed and the heat pump

is not operating.

The AUX. HT. LED lights when the auxiliary heat stage

is operating. The weather is cold enough that the first stage

cannot handle the load alone.

LEDs are not field replaceable or addable.

M3375

Recycling Notice

This control contains mercury in a sealed tube. Do not

place control in the trash at the end of its useful life.

If this control is replacing a control that contains mercury in

a sealed tube, do not place your old control in the trash.

Contact your local waste management authority for in-

structions regarding recycling and the proper disposal of this

control, or of an old control containing mercury in a sealed

tube.

If you have questions, call Honeywell at 1-800-468-1502.

1 2 3 4 5 6 7 8

Inhaltsverzeichnis

Seite 1 - T874/Q674

S. M. • Rev. 5-93 • • ©Honeywell Inc. 1993 • Form Number 60-1147—4T874/Q674Thermostat/Subbase CombinationsInstallation Instructions fo

Seite 2 - 60-1147-4

60-1147-42Fig. 1—Installation of Q674 Subbase on outlet box.M925VERTICAL OUTLETBOXADAPTERRINGSUBBASECOVER PLATEMOUNTINGSCREWS (2)MOUNTINGSCREWS (2)1SU

Seite 3 - Fig. 4—Wiring connections

60-1147-43Fig. 4—Wiring connections.2. Carefully remove and discard the polystyrene packinginsert that protects the mercury switches during shipment.3

Seite 4

60-1147-44Fig. 6—Internal schematic and typical wiring diagram for T874N and Q674F.L1 HOTL21W1W2EM. HEATLED (RED)CHECKLED (GREEN)FAN RELAYGEM. HEAT RE

Seite 5 - 60-1147-45

60-1147-45Fig. 7—Internal schematic and typical wiring diagram for T874R and Q674L.L1 HOTL21X2W2EM. HEATLED (RED)AUX. HEATLED (GREEN)HIGH LIMIT SWITCH

Seite 6

60-1147-46Fig. 9—Mounting thermostat on subbase.THERMOSTATMOUNTING POST (2)M93650 60 70 8050 60 70 80HEATCOOLTHERMOSTATMOUNTING SLOT

Seite 7 - Calibration

60-1147-47CheckoutHEATINGMove the system switch on the Q674 to HEAT or AUTO(if used) and the fan switch to AUTO. Move the heating setpoint lever on th

Seite 8 - 60-1147 –4 S.M. Rev. 5-93

60-1147-48Honeywell Limited-Honeywell Limitée35 Dynamic DriveScarborough, Ontario M1V 4Z960-1147 –4 S.M. Rev. 5-93Automation and Control Solution