York 65075-N4U Installation Instructions Manual Download

Page: 11 / 32

Remove the screws retaining the wiring box cover. Route the
power wiring through the unit top panel with a conduit connec-
tor or other proper connection. Make wiring connections as
shown in Figure 9 or 10. Replace the wiring box cover and
screws.

An alternate wiring method is to use a field provided 2 x 4 box
and cover on the outside of the furnace. Route the furnace
leads into the box using a protective bushing where the wires
pass through the furnace panel.

ELECTRICAL CONTROL CONNECTIONS

Install the field-supplied thermostat. The thermostat instruc-
tions for wiring are packed with the thermostat. With the thermo-
stat set in the OFF position and the main electrical source
disconnected, complete the low-voltage wiring from the
thermostat to the terminal board on the ignition module. Con-
nect Class 2 control wiring as shown in Figures 11 & 12.
Electronic thermostats may require a "C" common connection
as shown dashed in Figure 12.

NOTE: Some electronic thermostats do not have adjustable

heat anticipators. They may have other type cycle rate
adjustments. Follow the thermostat manufacturer’s in-
structions.

The 24-volt, 40 VA transformer is sized for the furnace compo-
nents only, and should not be connected to power auxiliary
devices such as humidifiers, air cleaners, etc. The transformer
may provide power for an air conditioning unit contactor.

COMBUSTION AIR AND VENT SYSTEM

1. Two-pipe with a sealed combustion intake/vent system

using outdoor combustion air.

2. Single pipe vent system using combustion air from the area

surrounding the furnace.

3. Two-pipe intake/vent system using combustion air from a

ventilated attic space and a vent pipe to the outside.

Be sure to follow the appropriate venting section details, related

information and limitations for your type of installation.

COMBUSTION AIR INTAKE/VENT CONNECTIONS

This type installation requires outdoor combustion air. Two
separate, properly-sized pipes must be used. One bringing air
from the outdoors to the furnace combustion air intake collar
on the burner box, and a second pipe from the furnace vent
connection (top right of unit) back to the outdoors. See Figure
13 or 14.

The intake/vent should be located either through the wall
(horizontal or side vent) or through the roof (vertical vent). Care
should be taken to locate side vented systems where trees or
shrubs will not block or restrict supply air from entering or
combustion products from leaving the terminal.

Also, the terminal assembly should be located as far as possi-
ble from a swimming pool or a location where swimming pool
chemicals might be stored. Be sure the terminal assembly
follows the outdoor clearances listed in Table 3 for U.S. instal-
lations: In Canada, refer to CAN/CGA-B149.1 or .2 Installation
Code (latest edition -Venting Systems and Air Supply).

COMBUSTION AIR/VENT PIPE SIZING

Refer to Tables 4 or 5 to select the proper size piping for
combustion air intake and venting. The size will be determined
by a combination of furnace model, total length of run, and the
number of elbows required. The following rules must also be
observed.

ROOM

THERMOSTAT

FURNACE

CONTROL

CONDENSING

UNIT

TO AIR CONDITIONER

CONTROLS

R
W

FIGURE 11 - POWER WIRING CONNECTIONS

FIGURE 12 - TYPICAL HEATING AND COOLING

Set the heat anticipator in the room thermostat to .45
amps. Setting it lower will cause short cycles. Setting it
higher will cause the room temperature to exceed the
setpoints.

METHOD ONE: TWO

PIPE

SEALED

COMBUSTION

AIR

AND

VENT

SYSTEM

This furnace is certified to be installed with one of three
possible intake/vent configurations.

Furnace Intake / Vent Connection Size

40 - 100 MBH

120-140 MBH