Honeywell Q539A User Manual

Q539A, H and J Subbases

M3375

Installation Instruction for the Trained Service Technician.

Application

Q539 Subbases provide cooling anticipators, and mounting for T87F Thermostats. Q539 Subbases also provide system

and fan switching for heating, cooling, and heating-cooling thermostats. For subbase specifications, refer to Tables 1 and 2.

TABLE 1—SUBBASE SPECIFICATIONS.

Model Description

Q539A provides system and fan switching and cooling anticipator for heating cooling systems. Includes indicator LOCKOUT LED for use in oil burner systems.

Q539H provides fan switching with Z terminal for low voltage fan switch to control fan in AUTO position.

Q539J provides system switching for control of heating and cooling for heat pump and electric heating. Auto fan operates through fan relay on both heating and cooling.

System

Switch

HEATOFFCOOL

NONE AUTO-ON R-W-Y-G-X-Z 4

HEATOFFCOOL

Fan

Switch Terminals

AUTO-ON RH

AUTO-ON R-W-Y-G-X-P-O-B 5

RC-W-Y-G-X 3

See

Fig.

TABLE 2—TERMINAL DESIGNATIONS.

Terminal Connection

R Transformer.

Cooling Transformer.

Heating Transformer. W Heating Relay or Valve Coil. Y Cooling Contactor Coil.

Heating Damper Motor or Changeover

Valve (if used).

Cooling Damper Motor or Changeover

Valve (if used). G Fan Relay Coil.

Clogged Filter Switch or Lockout Switch

(primary control). P Heat Pump Contactor Coil. Z Q539H low voltage fan switch for control

of fan relay in AUTO position for both

heating and cooling control.

Cooling transformer in systems with separate heating and cooling circuits.

Heating transformer in systems with isolated heating and cooling circuits.

Circuit only completed between R and B with system switch in HEAT position.

Circuit only completed between R and O with system switch in COOL position.

Only available on subbases with indicator LEDs.

Mercury 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 instructions regarding recycling and the proper disposal of this control, or of an old control containing mercury in a sealed tube.

Installation

WHEN INSTALLING THIS PRODUCT…

1. Read these instructions carefully. Failure to follow

instructions can damage product or cause a hazardous

condition.

2. Check ratings given in instructions and on product to

make sure product is suitable for your application.

3. Make sure installer is a trained, experienced service

technician.

4. After completing installation check out product opera-

tion as provided in these instructions.

LOCATION

Locate the subbase about 5 ft (1.5m) above the floor in an area with good air circulation at average temperature.

95-6486-9

Do not mount the subbase where it may be affected by:

)

O T W

— drafts or dead spots behind doors or in corners. — hot or cold air from ducts. — radiant heat from the sun, fireplaces, or appliances. — concealed pipes and chimneys. — unheated (uncooled) areas such as an outside wall.

CAUTION

• Disconnect power supply to prevent electrical shock or equipment damage.

• Do not short across coil terminals on relay, this can burn out the thermostat heat anticipator.

• Do not overtighten captive mounting screws because damage to subbase threads can result.

MOUNTING AND WIRING

Disconnect power supply before beginning installation to

prevent electrical shock or equipment damage.

All wiring must comply with local codes and ordinances.

1. In replacement applications, check the existing subbase wires for cracked or frayed insulation. Replace any wires in poor condition. If the wire is plastered into the wall, make a hole next to the wires and loosen the wires so that the wires can be pushed back into the wall later.

2. In new installations, run wiring (if necessary) to the subbase location.

IMPORTANT: To prevent interference with the thermostat

linkage, keep wire length to a minimum and run wires as close as possible to the subbase.

3. Connect the wires to the terminals inside the subbase. Refer to equipment manufacturer instructions for Q539 wiring diagrams. If not available, refer to Fig. 1 through 5.

4. Push excess wire back through the hole and plug any opening with insulation to prevent drafts that can affect performance.

5. Loosely fasten the thermostat subbase to the wall with a screw through the left mounting hole. Adjust the subbase so it is approximately level and start the second screw through the right mounting slot. Do not tighten.

6. Level the thermostat subbase using a spirit level as shown in Fig. 1.

7. Tighten mounting screws.

IMPORTANT: An incorrectly leveled subbase will cause

the temperature control to deviate from setpoint.

8. Mount and wire the thermostat to the thermostat subbase using the equipment manufacturer’s instructions.

Fig. 1—Level Q539 using a spirit level .

SPIRIT LEVEL

PENING FOR

HERMOSTAT

IRING

LEVELIN POSTS (2

MOUNTING SLOTS

M3319A

Fig. 2—Barrier configuration.

FOR STRAIGHT INSERTION– STRIP 5/16 in. (8 mm)

SUBBASE TERMINAL SCREW

Fig. 3—Typical hookup for Q539A in heatingcooling application with remote lockout indication.

HEAT

LOCKOUT INDICATOR LIGHT

X RH W Y G RC

SWITCH

BARRIER

Q539A/T87F INTERNAL SCHEMATIC

T87F

ADJUSTABLE HEAT ANTICIPATOR

OFF

COOL

HEAT

HEATING CONTROL

OFF

COOLING CONTROL

FOR WRAPAROUND– STRIP 7/16 in. (11 mm)

TEMP. FALL

FAN

AUTO

COOL

FAN RELAY

M8831

FIXED COOL

ANTICIPATOR

95-6486—9 2

HEATING TRANSFORMER

L2 L2

(HOT) (HOT)

POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.

COOLING TRANSFORMER

M8832

L1L1

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