Venting; Start-Up, Adjustment, And Safety Check; General; Sequence Of Operation - Carrier 58UHV Installation, Start-Up, And Operating Instructions Manual

2. Humidifier (HUM)
Screw terminals (HUM and C
humidifier connection. The terminals are energized with 24v,
0.5-amp maximum when the gas valve is energized.
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Do not connect furnace control HUM terminal to HUM
(humidifier) terminal on Thermidistat™, Zone Controller, or
similar device. See Thermidistat, Zone Controller, thermostat,
or controller manufacturer's instructions for proper connec-
tion. A failure to follow this warning could result in fire.
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NOTE: A field-supplied, 115-v controlled relay connected to
EAC terminals may be added, if humidifier operation is desired
during blower operation.
Step 7—Venting
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Refer to the enclosed Installation Instructions, (Vent Tables For 1-
and 2-Stage Category I Fan-Assisted Furnaces) for quick, easy
reference and national or local code such as NFGC in the United
States, or NSCNGPIC in Canada, for proper vent sizing and
installation requirements.
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After fully assembling the vent connector to the furnace flue collar,
securely fasten the vent connector to the collar with 2 field-
supplied, corrosion-resistant, sheet metal screws located 180
degrees apart and midway up the collar.
The horizontal portion of the venting system shall maintain a
minimum of 1/4-in. upward slope per linear ft and it shall be
rigidly supported every 5 ft or less with hangers or straps to ensure
that there will be no movement after installation.
'
Step 8—Start-Up, Adjustment, and Safety Check

GENERAL

The furnace must have a 115-v power supply properly connected
and grounded. Correct polarity must be maintained to enable gas
heating operation.
The gas service pressure must not exceed 0.5 psig (14-in. wc), and
no less than 0.16 psig (4.5-in. wc).
Thermostat wire connections at R and W/W1 are the minimum
required for gas heating operation. W2 must be connected for
2-stage heating thermostats. Y/Y2 and G are required to be
connected to the furnace for cooling and heat pumps. G is required
for continuous-fan. C 24v is required for some clock thermo-
OM
stats. These connections must be made at the 24-v terminal block
on furnace control. (See Fig. 12.) O is required for heat pumps
only. Y1 is required for 2-stage cooling and 2-stage heat pumps.
The O and Y1 connectors must be made to the ICM2+ furnace's
orange and blue leads, flagged "O" and "Y1," respectively.
This furnace can be installed with either a single-stage heating or
a 2-stage heating thermostat.
For single-stage thermostats, connect thermostat R to W/W1 at the
furnace control terminal block. (See Fig. 13.) For single-stage
thermostats, the control will determine, based on length of previ-
ous heating on and off cycles, when to operate in low- and
high-stage for optimum comfort. Setup switch-2 (SW-2) must be
in the factory-shipped OFF position. See Fig. 15 and Tables 6 and
7 for setup switch information.
If a 2-stage heating thermostat is to be used, move SW-2 to the ON
position at end of furnace installation. This overrides built-in
control process for selecting high- and low-stage and allows the
2-stage thermostat to select gas heating modes. The W2 from
thermostat must be connected to W2 on control terminal block.
(See Fig. 14.)
24V) are provided for 24-v
OM
4 3
BLOWER-
OFF
DELAY
Fig. 15—Setup Switches on Furnace Control
(Factory Settings)
This furnace is equipped with a manual reset limit switch in
the gas control area. The switch will open and shut off power
to the gas valve if a flame rollout or overheating condition
occurs in the gas control area. DO NOT bypass the switch.
Correct inadequate combustion-air supply, component fail-
ure, or restricted flue gas passageway before resetting the
switch.
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Before operating furnace, check each manual reset switch for
continuity. If necessary, press and release the button to reset
switch. The blower compartment door must be in place to
complete the 115-v circuit to furnace.

SEQUENCE OF OPERATION

Using schematic diagram in Fig. 16, follow the sequence of
operation through the different modes. Read and follow diagram
very carefully.
NOTE: The GE ICM2+ BLWM speeds are infinitely variable
from 300 to 1400 rpm and are dynamically controlled to precisely
control airflow rate (CFM). The ICM2+ motor ramps to speed at
a controlled rate to reduce start-up noise perception (4 to 11 sec,
depending on the target CFM). The ICM2+ motor ramps down
slowly to a stop in the same time as ramp-up time. ICM2+ ramp-up
and ramp-down times are additive to blower-on and -off delays,
respectively. The ICM2+ is 115-v energized whenever power is
available at furnace control, but operates only when 24-v motor
control input(s) are on.
NOTE: If a power interruption occurs during a call for heat
(W/W1 or W/W1 and W2) and if the thermostat is still calling for
gas heating, the control will start a 90-sec blower only on period
2 sec after power is restored. The red LED will flash code 12
during the 90-sec period, after which the LED will be on
continuously as long as no faults are detected. The ICM2+ motor
will operate at low-gas heat CFM after a power interruption in
either low- or high-heat. After 90-sec period, furnace will respond
to the thermostat normally.
The blower door must be installed for power to be conducted
through blower door interlock switch (ILK) to furnace control
(CPU), transformer (TRAN), inducer motor (IDM), blower motor
(BLWM), hot surface ignitor (HSI), and gas valve (GV).
12
2 1
OFF
ON
LOW
HIGH
HEAT
HEAT
(ADAPTIVE
ONLY
ALGORITHM)
A96402