magicpak MGE4-12 Series, Инструкция по установке и обслуживанию, Страница: 15 / 22

508197-01 Issue 2137 Page 15 of 22
Start-Up
For Your Safety, Read Before Lighting
If you do not follow these instructions exactly, a fire
or explosion may result causing property damage,
personal injury, or loss of life.
WARNING
This furnace is equipped with a direct ignition control.
Do not attempt to manually light the burners.
CAUTION
To Light Burners
Figure 10. Gas Valve
Gas Inlet
Gas Inlet
Pressure
Test Tap
ON / OFF
Switch
Gas Manifold
Pressure
Test Tap
Regulator
Adjustment
Screw
(Under Cap)
1. Turn off electrical power to unit.
2. Turn the thermostat to lowest setting.
3. Move the gas valve switch to the “ON” position (see
Figure 10).
Operation
Operation of the unit is automatic and will provide heating
and cooling depending on the setting of the thermostat.
Heating
1. Turn on main power supply.
2.
Open manual gas shutoff valve.
3. Set thermostat system to “HEAT”.
4. Set thermostat to temperature desired.
Sequence of Operation
1. Thermostat calls for heat.
2.
Combustion air inducer starts and proper air flow is
proven by the pressure switch closing.
3. Blower continues to operate for 30 seconds prior to
the burners lighting.
4. Ignition control begins spark and opens gas valve. The
burners are lit. Ignition is proved through flame sensor.
5. Supply air blower starts 30 seconds after the burners
light.
6. When the thermostat is satisfied, the burners and
combustion air inducer shut off.
7. Supply air blower will shut off 120 seconds later.
If the burners should fail to ignite, the ignition control will
try to ignite the burners a total of three times. Should the
burners fail to ignite within the three trials for ignition, the
ignition control will lock out for 1 hour before beginning
another ignition cycle. To reset the control, turn the
thermostat down or off for 10 seconds and then set to
desired setting. At this time, the ignition sequence will try
again.
Cooling
1. Set thermostat system switch to “COOL.”
2. Set thermostat to temperature desired.
NOTE
: When Y is energized, the combustion air inducer
will operate for 10 seconds. The purpose of this action is to
deter insect nesting in the flue pipe.
Thermostat
The room thermostat should be located on an inside
wall where it will not be subject to drafts, sun exposure,
or heat from electrical fixtures or appliances. Follow
manufacturer’s instructions enclosed with the thermostat
for general installation procedures. Color-coded insulated
wires (#18 AWG) should be used to connect the thermostat
to the unit.
For **MGE4-14-361** models, a two-stage thermostat is
recommended for reaching highest efficiency and full use
of two-stage compressor.
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 after the pre-purge time expires, burners
will light.
To Shut Down Unit
1. Turn off electrical power to unit.
2. Move the gas valve switch to the “OFF” position (see
Figure 10).