Carrier F96VTN Installation Instructions Manual Download

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Specifications subject to change without notice.

match the airflow required for low-speed cooling. Select the
required airflow from Table 9 and Fig. 60.

NOTE

The airflow selected via SW2--3, 4, 5 (Low-Speed

Cooling Airflow) cannot exceed the airflow selected via SW2--6, 7,
8 (High-Speed Cooling Airflow). For other CFM per ton Setup
switch selections, see Fig. 38 and 60.

NOTE

: The airflow settings for SW2--6, 7, 8 and SW2--3, 4, 5

selections are the same, EXCEPT for the default values. See Table
9.
For a complete explanation of cooling airflow, refer to the section

titled “Sequence of Operation.”

Adjust Continuous Fan Airflow (and Low-Speed

Cooling Airflow)

Adjust continuous fan and low--stage cooling airflow using
SW2--3, 4, 5 and refer to Fig. 60. The continuous fan speed can be

further adjusted at a conventional thermostat using the continuous
fan speed select function. Changing the continuous fan speed at a

conventional thermostat DOES NOT change the low-speed
cooling airflow selected via SW2 at the control board.
Refer to the section titled “Continuous Blower Speed Selection for

Thermostat.”

Adjust Thermostat Heat Anticipator.

1. Mechanical thermostat. Set thermostat heat anticipator to

match the amp. draw of the electrical components in the
R--W/W1 circuit. Accurate amp. draw readings can be
obtained at the wires normally connected to thermostat

subbase terminals, R and W. The thermostat anticipator
should NOT be in the circuit while measuring current.

a. Set SW1--2 switch on furnace control board to ON.

b. Remove thermostat from subbase or from wall.

c. Connect an amp. meter as shown in Fig. 66 across the R

and W subbase terminals or R and W wires at wall.

R Y W G

10 TURNS

THERMOSTAT SUBBASE

TERMINALS WITH

THERMOSTAT REMOVED

(ANITICIPATOR, CLOCK, ETC.,

MUST BE OUT OF CIRCUIT.)

HOOK-AROUND

AMMETER

EXAMPLE: 5.0 AMPS ON AMMETER

10 TURNS AROUND JAWS

= 0.5 AMPS FOR THERMOSTAT

ANTICIPATOR SETTING

FROM UNIT 24-V

CONTROL TERMINALS

A96316

Fig. 66 -- Amp. Draw Check with Ammeter

d. Record amp. draw across terminals when furnace is in low

heat and after blower starts.

e. Set heat anticipator on thermostat per thermostat

instructions and install on subbase or wall.

f. Turn SW1--2 switch OFF.

g. Install blower door.

2. Electronic thermostat: Set cycle rate for 3 cycles per hr.

Check Safety Controls

The flame sensor, gas valve, and pressure switch were all checked
in the Start--up procedure section as part of normal operation.

1. Check Main Limit Switch

This control shuts off combustion system and energizes air--

circulating blower motor, if furnace overheats. By using this
method to check limit control, it can be established that lim-
it is functioning properly and will operate if there is a re-

stricted return--air supply or motor failure. If limit control
does not function during this test, cause must be determined

and corrected.

a. Run furnace for at least 5 minutes.

b. Gradually block off return air with a piece of cardboard or

sheet metal until the limit trips.

c. Unblock return air to permit normal circulation.

d. Burners will re--light when furnace cools down.

2. Check Pressure Switch(es)

This control proves operation of the draft inducer blower.

a. Turn off 115--v power to furnace.

b. Disconnect inducer motor lead wires from wire harness.

c. Turn on 115--v power to furnace.