Energy Recovery Wheel - Carrier AERO 39MN Installation, Start-Up And Service Instructions Manual

6. Install a tapped fitting for attachment to a manometer, or
other gauge suitable for 14.0 in. wg in the inlet pressure
tap, and for 10.0 in. wg in the manifold pressure tap.
7. Wait 5 minutes for any gas to clear out. If you smell gas,
see Step 2 and correct leak. If there is no odor or leaks have
been corrected, go to the next step.
8. Turn gas control knob to "ON" position.
9. Open all manual gas valves.
10. Turn power on at disconnect switch.
11. Set thermostat or controller to its highest position to initiate
call for heat and maintain operation of unit.
The draft inducer will run for a 15 to 30 second pre-purge
period. At the end of the pre-purge period, the direct spark will
be energized and the gas valve will open. The burners ignite.
Failure to Ignite (Duct Furnace) — On the initial start-up, or
after the unit has been off for long periods of time, the first igni-
tion trial may be unsuccessful due to the need to purge air from
the manifold at start-up. If ignition does not occur on the first
trial, the gas and spark are shut off by the ignition control and
the control enters an inter-purge period of 15 seconds, during
which the draft inducer continues to run. At the end of the inter-
purge period, another trial for ignition will be initiated.
Control will initiate up to three ignition trials on a call for heat
before lockout of control occurs. Control can be brought out of
lockout by turning thermostat or controller to its lowest position,
waiting 5 seconds, and then turning back up to call for heat. Con-
trols will automatically reset after one hour and initiate a call for
heat.
Start-Up (Rack System) — Multiple heater systems are con-
trolled by a Vernier stage controller. This control provides modu-
lation of the lead gas furnace and staging control of additional
furnaces in the assembly. The stage controller requires a Heat
Enable signal and a 0-10VDC analog input to operate the sys-
tem. Refer to the wiring diagrams provided for electrical connec-
tions included in the furnace section. A Control Instruction Sheet
is provided in the instruction package with the Sequence of Op-
eration for the system under the supervision of the stage control-
ler are also available in the information packet, or contact your
Carrier service representative.
Place system in operation and verify inlet gas pressure, mani-
fold pressure to each individual heater and proper modulating
operation and sequencing of slave heaters.
Manifold Pressure Adjustment — A pressure tap is provided
in each furnace manifold for measuring the gas manifold pres-
sure. Manifold pressure must be checked at start-up and during
any service or maintenance. All control systems require a mani-
fold pressure of 3.40 to 3.50 in. wg at maximum input rating on
natural gas, and 10.0 in. wg on propane gas at maximum input
rating. See Fig. 102A-102C on page 117 for gas valve adjust-
ment locations.
NOTE: For two stage and modulating control applications, ver-
ify proper low fire adjustments as outlined in the Sequence of
Operation document provided in the instruction package. Check
the furnace section for this document or contact your Carrier ser-
vice representative.
Burner Flames — Prior to completing the start-up, check the
appearance of the main burner flame.
1. The burner flame should be predominately blue in color,
and well-defined and centered at the tube entry as shown in
Fig. 110. Distorted flame or yellow tipping of natural gas
flame, or a long yellow flame on propane, may be caused
by lint and dirt accumulation inside burner or at burner
ports, at air inlet between burner and manifold pipe, or de-
bris in the main burner orifice. Soft brush or vacuum clean
affected areas.
2. Poorly defined, unfocused, substantially yellow flames, or
flames that appear weak or wavering, indicate poor air
supply to burners or excessive burner input. Verify gas sup-
ply type and manifold pressure with rating plate.
Poor air supply can be caused by obstructions or blockage in
heat exchanger tubes or vent discharge pipe. Inspect and clean as
necessary to eliminate blockage. Vacuum any dirt or loose de-
bris. Clean heat exchanger tubes with stiff brush.
Poor flame characteristics can also be caused by undersized
combustion air openings or flue gas recirculation into combus-
tion air supply. Increase air opening size or re-direct flue prod-
ucts to prevent re-circulation.
Reduced air delivery can also be the result of fan blade slip-
page, dirt accumulation on the fan blade, or low voltage to draft
inducer motor. Inspect draft fan assembly and be sure fan blade
is secure to motor shaft. Check line voltage to heater.
Fig. 110 — Proper Flame Appearance
Normal Operation
1. Turn on electrical supply to unit at disconnect switch.
2. Turn on manual gas supply.
3. Set thermostat or temperature controller to desired temper-
ature.
Information outlining the normal sequence of operation and
wiring diagram for the control system supplied with the furnace
model is located in the furnace section, or contact your Carrier
service representative.
Shutdown
1. Set thermostat or controller to lowest setting.
2. Turn off electrical supply to unit at disconnect switch.
3. Turn off manual gas supply.
4. Disconnect manifold and inlet pressure taps and re-install
pipe plugs.
5. Replace vestibule access panel or close door.

Energy Recovery Wheel

Keep hands away from rotating wheel. Contact with rotat-
ing wheel can cause physical injury.
1. By hand, turn the wheel clockwise (as viewed from the
pulley side), to verify that the wheel turns freely through
a full 360-degree rotation.
2. Before applying power to the drive motor, confirm that
the wheel segments are fully engaged in the wheel
frame and that the segment retainers are completely fas-
tened. (See Fig. 111.)
3. With hands and objects away from moving parts, acti-
vate the unit and confirm wheel rotation. The wheel ro-
tates clockwise (as viewed from the pulley side).
4. If the wheel has difficulty starting, turn the power off
and inspect for excessive interference between the
wheel surface and each of the four (4) diameter seals. To
correct, loosen the diameter seal adjusting screws and
back adjustable diameter seals away from the surface of
125
CAUTION
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