Start- -Up, Adjustment, And Safety Check; Prime Condensate Trap - Carrier 59MN7A Installation, Start-Up, Operating And Service And Maintenance Instructions

START- -UP, ADJUSTMENT, AND SAFETY
CHECK
General
1. Furnace must have a 115-v power supply properly connec-
ted and grounded.
NOTE: Proper polarity must be maintained for 115-v wiring.
Control status indicator light flashes rapidly and furnace does not
operate if polarity is incorrect or if furnace is not grounded.
2. Thermostat wire connections at terminals R, W/W1, G, and
Y/Y2 must be made at 24-v terminal block on furnace con-
trol. See communicating wall control instructions for proper
wiring of communicating controls.
3. Natural gas service pressure must not exceed 0.5 psig (14-
in. w.c., 350 Pa), but must be no less than 0.16 psig (4.5-in.
w.c., 1125 Pa).
4. Blower door must be in place to complete 115-v electrical
circuit and supply power to the furnace components.
CAUTION
!
UNIT OPERATION HAZARD
Failure to follow this caution may result in intermittent unit
operation or performance dissatisfaction.
These furnaces are equipped with a manual reset limit
switch in burner assembly. This switch opens and shuts off
power to the gas valve if an overheat condition (flame
rollout) occurs in the burner assembly/enclosure. Correct
inadequate combustion- -air supply, improper gas pressure
setting, improper burner or gas orifice positioning, or
improper venting condition before resetting switch. DO
NOT jumper this switch.
Before operating furnace, check flame rollout manual reset switch
for continuity. If necessary, press button to reset switch.
EAC-1 terminal is energized whenever blower operates, HUM
terminal is only energized when blower is energized in heating.
Setup Switches
There are 4 sets of setup switches on the furnace control board.
These switches configure the furnace for correct application
requirement. They also select the airflow settings for Air
Conditioning and Continuous Fan airflows.
The Setup Switch locations are shown and described on Fig. 56.
The setup switches are also shown on the unit wiring label.
Setup Switches (SW1)
The furnace control has 8 setup switches that may be set to meet
the application requirements. Refer to Fig. 56 and the Adjustments
section for setup switch configurations. To set these setup switches
for the appropriate requirement:
1. Remove blower door.
2. Locate setup switches on furnace control.
3. Configure the set-up switches as necessary for the
application.
4. Replace blower door.
NOTE: If a bypass humidifier is used, setup switch SW1-3
(Min/Int Heat Rise Adjust) should be in ON position. This
compensates for the increased temperature in return air resulting
from bypass.
NOTE: If modulating dampers are used, blower motor
automatically compensates for modulating dampers.
Air Conditioning (A/C) Setup Switches (SW2)
The air conditioning setup switches are used to match furnace
airflow to required cooling airflow or high stage cooling airflow
when a two- -stage outdoor unit is used. Refer to Fig. 56 and the
Adjustments section for setup switch configurations.
To set the desired cooling airflow:
1. Remove blower door.
2. Locate A/C setup switches on furnace control.
3. Determine air conditioning tonnage used.
4. Configure the switches for the required cooling airflow.
NOTE: Incorrect airflow caused by improper A/C switch setup
may cause condensate blow-off or a frozen indoor coil in the
cooling mode.
5. Replace blower door.
Continuous Fan (CF) Setup Switches (SW3)
The CF setup switches are used to select desired airflow when
thermostat is in continuous fan mode or to select low-cooling
airflow for two-speed cooling units. Refer to Fig. 56 and the
Adjustments section for setup switch configurations. This setup
feature allows continuous fan airflow or low-cooling airflow to be
adjusted. To set desired continuous fan airflow or low-cooling
airflow:
1. Remove blower door.
2. Locate CF setup switches on furnace control.
3. Determine desired continuous fan airflow or low-cooling
airflow.
4. Configure the switches for the required continuous fan or
low- -cooling airflow.
5. Replace blower door.
Additional Setup Switches (SW4)
The furnace control has 3 additional setup switches labeled SW4.
Setup switch SW4-2 can be used to lock the furnace into
intermediate heat. When setup switch SW4-2 is ON it will over
ride setup switch SW1-2 if it is ON. SW4- -3 is used to adjust
airflow. Refer to Fig. 56 and the Adjustments section for setup
switch configurations. To activate setup switch SW4-2 and
SW4- -3:
1. Remove blower door.
2. Locate setup switch SW4 on furnace control.
3. Configure the switches for the required heat stages and
airflow if necessary.
4. Replace blower door.
Prime Condensate Trap with Water
WARNING
!
CARBON MONOXIDE POISONING HAZARD
Failure to follow these warnings could result in personal injury
or death.
Failure to use a properly configured trap or NOT
water- -priming trap before operating furnace may allow
positive pressure vent gases to enter the structure through drain
tube. Vent gases contain carbon monoxide which is tasteless
and odorless.
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