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The unit is equipped with a field makeup box. The makeup
box may be moved to the right side of the furnace to
facilitate installation. If the makeup box is moved to the right
side, clip the wire ties that bundle the wires together. The
excess wire must be pulled into the blower compartment.
Secure the excess wire to the existing harness to protect
it from damage. Seal unused openings on left side with
plugs removed from right side.
1.
The power supply wiring must meet Class I restrictions.
Protected by either a fuse or circuit breaker, select
circuit protection and wire size according to unit
nameplate.
NOTE: Unit nameplate states maximum current draw.
See Table 9 for maximum over-current protection.
Capacity
070*B12, 090*C12, 090*C16
090*C20, 110*C20, 135*D20
Table 9.
2.
Holes are on both sides of the furnace cabinet to
facilitate wiring.
3.
Install a separate (properly sized) disconnect switch
near the furnace so that power can be turned off for
servicing.
4.
Before connecting the thermostat, check to make
sure the wires will be long enough for servicing at
a later date. Make sure that the thermostat wire is
long enough to facilitate future removal of blower for
service.
5.
Complete the wiring connections to the equipment.
Use the provided unit wiring diagram and the field
wiring information shown in Figure 46 and Table 18.
Use 18 gauge wire or larger that is suitable for Class II
rating for thermostat connections.
6.
Electrically ground the unit according to local codes or,
in the absence of local codes, according to the current
National Electric Code (ANSI/HFPA No. 70) for the
USA and current Canadian Electric Code Part 1 (CSA
standard C22.1) for Canada. A green ground wire is
provided in the field makeup box.
7.
One line voltage "AAC" 1/4" spade terminal is provided
on the furnace integrated control. Any electronic air
cleaner or other 120V accessory rated up to one amp
can be connected to this terminal with the neutral leg
of the circuit being connected to one of the provided
neutral terminals. See Figure 56 for location of
terminal. This terminal is energized when the indoor
blower is operating.
8.
One line voltage "HUM" 1/4" spade terminal is provided
on the furnace integrated control. Any humidifier or
other 120V accessory rated up to one amp can be
connected to this terminal with the neutral leg of the
circuit being connected to one of the provided neutral
508364-01
Maximum Over-Current
Protection (Amps)
15
20
terminals. See Figure 56 for location of terminal. This
terminal is energized in the heating mode when the
indoor blower is operating.
9.
One 24V "H" terminal is provided on the furnace
integrated control terminal block. Any humidifier rated
up to 0.5 amp can be connected to this terminal with
the ground leg of the circuit being connected to either
ground or the "C" terminal. See Figure 56 for location
of terminal.
10. Install the room thermostat according to the
instructions provided with the thermostat. See Table
18 for thermostat connections. If the furnace is being
matched with a heat pump, refer to the instruction
packaged with the dual fuel thermostat.
Wire Run Length
Less than 100'
(30 m)
More than 100'
(30 m)
Table 10. Run Length - Non-Communicating
Thermostat Selection
A Comfort Sync thermostat must be used in communicating
applications. Refer to the instructions provided with the
thermostat for installation, set-up and operation.
This unit is designed to operate in a variable rate
capacity mode using a two-stage thermostat. This unit
will automatically adjust firing rate based upon thermostat
cycle times.
For optimal performance, use a high quality electronic
digital thermostat or any other with adjustable settings for
1st stage / 2nd stage on / off differentials and adjustable
stage timers.
The following is a two-stage thermostat setup for optimal
variable rate capacity mode:
First heat stage differential set to 1/2 to 1° F; second heat
stage differential set to 1/2 or 1° F; second heat stage
upstage timer disabled, or set to maximum (1 hr. minimum).
Indoor Blower Speeds
1. When the thermostat is set to "FAN ON", the indoor
blower will run continuously at a percentage of the
second stage cooling speed when there is no cooling
or heating demand. See Table 20 for allowable
continuous circulation speeds.
2.
When the unit is running in the heating mode, the
integrated control will automatically adjust the blower
speed to match the furnace firing rate. This speed can
be adjusted up or down by 7.5% or 15% using DIP
switches 14 through 16 for the low heat speed and 17
through 19 for the high heat speed. See Table 19 for
allowable heating speeds.
Issue 2346
AWG#
Insulation / Core Typs
Color coded, temperature
18
rating 95°F (35°C) minimum,
solid core. (Class II Rated
16
Wiring)
Page 31 of 74
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