Full Modulating Gas Furnace - Trane IntelliPak Installation, Operation And Maintenance Manual

Unit Start Up
Figure 121. Gas valve adjustment screw locations

Full Modulating Gas Furnace

Full Modulating gas heaters are available for the 500, 850
and 1000 MBH heater sizes.These heaters are available in
the same cabinet sizes as the current heaters.
The firing rate of the unit can vary from the pilot rate of 125
MBH up to the nameplate rating of the unit.The turn down
ratios, therefore, vary from 4:1 for the 500 MBH to 8:1 for
the 1000 MBH heater.
Heat Exchanger
The heat exchanger drum, tubes and front and rear
headers are constructed from stainless steel alloys.
Unit control
The unit is controlled by a supply air temperature sensor
located in the supply air stream for DischargeTemperature
Control units. ZoneTemperature Control units have two
sensors, one located in the supply air stream and the zone
sensor.The temperature sensor signal is sent to the Heat
module of the IntelliPak Unit Control.The control signal
from the Heat Module is an inverse proportional 5 -10VDC.
The higher the voltage signal, the lower the call for heat.
The 5 -10 VDC. signal controls the angular position of the
combustion air damper through a direct coupled damper
actuator motor.The position of the air damper in turn
controls the combustion air pressure that is sensed by the
modulating gas valve.The greater the combustion air
pressure, the greater the call for gas and the higher the
firing rate of the heater. As the temperature setpoint is
reached, the Modulating Heat control will cause the
combustion air actuator to change the damper position to
a lower firing rate that matches the heat load of the space.
1. Use Table 42, p. 96 to program the following system
components for operation by scrolling through the
Human Interface displays;
• Gas Heat
– Supply Fan (On)
– Variable Frequency Drive (100% Output, if
applicable)
152
– RTM Occ/Unocc Output (Unoccupied)
– High Fire (90%)
– Turn the 115 volt control circuit switch 4S24 located
in the heater control panel to the "On" position.
– Open the manual gas valve, located in the gas heat
section.
2. Once the configuration for the appropriate heating
system is complete, press the NEXT key until the LCD
displays the "Start test in __Sec. " screen. Press the +
key to designate the delay before the test is to start.
This service test will begin after theTEST START key is
pressed and the delay designated in this step has
elapsed. Press the ENTER key to confirm this choice.
3. Press theTEST START key to start the test. Remember
that the delay designated in step 2 must elapse before
the system will begin to operate.
WARNING
Rotating Components!
During installation, testing, servicing and
troubleshooting of this product it may be necessary to
measure the speed of rotating components. Have a
qualified or licensed service individual who has been
properly trained in handling exposed rotating
components, perform these tasks. Failure to follow all
safety precautions could result in rotating components
cutting and slashing technician which could result in
death or serious injury.
4. Once the system has started, check the appearance of
the flame through the sight glass provided on the front
of the heat exchanger. In appearance, a normal flame
has a clearly defined shape, and is primarily (75%) blue
in color with an orange tip.
5. Check the inlet gas pressure at the modulating gas
valve.The inlet pressure should be 6" to 8" w.c.
6. Use a carbon dioxide analyzer and measure the
percentage of carbon dioxide in the flue gas. Refer to
the illustration in Figure 119, p.
samples to assure that an accurate reading is obtained.
151.Take several
RT-SVX36K-EN