Magic-Pak HWC8-12 - START-UP Procedure; Lighting Main Burners

Page 9 of 18507388-01 Issue 1504
Blower
The unit contains a direct-drive, mulspeed blower. The proper
speeds have been preset at the factory for heang and cooling.
Refer to the wiring diagram for recommended
heang/cooling speeds for specic models. Direct-drive blower
motors are permanently lubricated and do not require oiling.
Limit Control
A xed temperature limit control is provided which will shut
o the gas to the main burners if the unit is overheated for any
reason. The control must not be adjusted or relocated.
High Altude Adjustments (U.S. Installaons)
Rangs shown on the rang plate are for elevaons up to 2000
feet. For elevaons above 2000 feet, rangs should be reduced at
a rate of 4% for each 1000’ above sea level. Refer to the Naonal
Fuel Gas Code Z223.1 (latest edion) for further explanaon.
High Altude Adjustments (Canadian Installaons)
High altude conversions may be made by the manufacturer’s
authorized representave, in accordance with the requirement
of the manufacturer, provincial, or territorial authories having
jurisdicon, and in accordance with the requirements of CAN/CGA
B149.1 or B149.2 Installaon Code. A high altude conversion kit,
available from the manufacturer and approved for this purpose,
must be used.
Installaon and Operaon in Extremely Cold Weather Areas
In areas where extremely cold (below – 20°F) outdoor temperatures
can be expected, some additional installation and operating
precauons should be taken. The following precauons are taken
to prevent possible vent system ice blockage that could result in
safety shutdown of the burners:
1. Adjust to the highest achievable temperature rise within
the rise and stac pressure ranges specied on the rang
plate. Depending on specic model, it may be possible to
change to a lower heang blower speed tap to get a higher
temperature rise. This also increases comfort.
2. Make sure there are no leaks of outside air into the return
air system.
3. Keep the outside louver grille as free as possible of any ice
that may form and obstruct the ue outlet.
START-UP
For Your Safety Read Before Lighng
If you do not follow these instrucons exactly, a re or
explosion may result causing property damage, personal
injury, or loss of life.
WARNING
This furnace is equipped with a direct ignion control. Do
not aempt to manually light the burners.
CAUTION
To Shut Down Main Burners
1. Turn o electrical power to unit.
2. Move the ON/OFF switch to the “OFF” posion
(see Figure 4).
To Light Main Burners
1. Turn o electrical power to unit.
2. Turn the thermostat to lowest seng.
3. Move the gas valve ON/OFF switch to the “ON” posion (see
Figure 4).
4. Turn on electrical power to the unit.
5. Set the room thermostat to the desired temperature.
(If the thermostat “set” temperature is above room
temperature aer the pre-purge me expires, main burners
will light.)
Gas Valve
Figure 4
Gas Inlet
ON/OFF
SWITCH
Gas Inlet
Pressure
test tap
Regulator
adjustment
Screw
(Under Cap)
Gas manifold
Pressure test
tap