Coleman P*HU Installation Instruction page 19

035-17405-000 Rev. B (0801)
6. Turn the electrical and gas supplies back on, and, with
the burners in operation, check for gas leakage around
the plug with a soap and water solution.
CAUTION
Be sure that the gas valve pressure regulator cap
is replaced.
ADJUSTMENT OF TEMPERATURE RISE
The temperature rise, or temperature difference between the
return air and the heated air from the furnace, must be within
the range shown on the furnace rating plate and within the
application limitations shown in Tables 3 or 4. After the tem-
perature rise has been determined, the airflow (cfm) can be
calculated.
After about 20 minutes of operation, determine the furnace
temperature rise. Take readings of both the return air and the
supply (heated) air in the ducts, about six feet from the fur-
nace where they will not be affected by radiant heat.
Increase the blower speed to decrease the temperature rise;
decrease the blower speed to increase the rise.
All direct-drive blowers have multi-speed motors. The blower
motor speed taps are located on the control module in the
blower compartment. Refer to Figure 15, and the unit wiring
label to change the blower speed.
You may select a heating speed and a cooling speed. They
may be the same speed or a different speed.
To use the same speed tap for heating and cooling, the heat
terminal and cool terminal must be connected using a jumper
Unitary Products Group
wire and connected to the desired motor lead. Place all
unused motor leads on Park terminals. Two are provided.
CAUTION
Do not energize more than one motor speed at a
time or damage will result.
ADJUSTMENT OF FAN-OFF CONTROL SETTINGS
This furnace is equipped with a time-on/time-off heating fan
control. The fan on delay is fixed at 30 seconds. The fan off
delay is field adjustable from 60 to 180 seconds. The fan off
delay is factory set to 120 seconds.
The fan-off setting must be long enough to adequately cool
the furnace, but not so long that cold air is blown into the
heated space.
The fan-off timing may be adjusted by positioning the jumper
located on the control board. Refer to Figure 15.
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