Gas Furnace Start-Up (Constant Volume & Variable Air Volume Systems); Two Stage Gas Furnace - Trane IntelliPak Installation, Operation And Maintenance Manual

Unit Start Up
7. Press theTEST START key to start the test. Remember
that the delay designated in step 6 must elapse before
the fan will begin to operate.
8. Once the system has started, verify that the electric
heat or the hydronic heat system is operating properly
by using appropriate service technics; i.e. amperage
readings, delta tees, etc.
9. Press the STOP key at the Human Interface Module in
the unit control panel to stop the system operation.
Gas Furnace Start-Up (Constant Volume &
Variable Air Volume Systems)
It is important to establish and maintain the appropriate
air/fuel mixture to assure that the gas furnace operates
safely and efficiently.
Since the proper manifold gas pressure for a particular
installation will vary due to the specific BTU content of the
local gas supply, adjust the burner based on carbon
dioxide and oxygen levels.
The volume of air supplied by the combustion blower
determines the amount of oxygen available for
combustion, while the manifold gas pressure establishes
fuel input. By measuring the percentage of carbon dioxide
produced as a by-product of combustion, the operator can
estimate the amount of oxygen used and modify the air
volume or the gas pressure to obtain the proper air/fuel
ratio. Arriving at the correct air/fuel mixture for a furnace
results in rated burner output, limited production of
carbon monoxide, and a steady flame that minimizes
nuisance shutdowns.

Two Stage Gas Furnace

WARNING
Hazardous Gases and Flammable Vapors!
Exposure to hazardous gases from fuel substances
have been shown to cause cancer, birth defects or other
reproductive harm. Improper installation, adjustment,
alteration, service or use of this product could cause
flammable mixtures. To avoid hazardous gases and
flammable vapors follow proper installation and set up
of this product and all warnings as provided in this
manual. Failure to follow all instructions could result in
death or serious injury.
When using dry nitrogen cylinders for pressurizing
units for leak testing, always provide a pressure
regulator on the cylinder to prevent excessively high
unit pressures. Never pressurize unit above the
maximum recommended unit test pressure as specified
in applicable unit literature. Failure to properly regulate
pressure could result in a violent explosion, which
could result in death or serious injury or equipment or
property-only-damage.
150
High-Fire Adjustment
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)
– RTM Occ/Unocc Output (Unoccupied)
– Heat Stages 1 & 2 (On)
– 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.
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 manifold gas pressure by using the manifold
pressure port on the gas valve. Refer to
required manifold pressure for high-fire operation. If it
needs adjusting, remove the cap covering the high-fire
adjustment screw on the gas valve. Refer to
for the adjustment screw location.Turn the screw
clockwise to increase the gas pressure or
counterclockwise to decrease the gas pressure.
6. Use a carbon dioxide analyzer and measure the
percentage of carbon dioxide in the flue gas. Refer to
the illustration in Figure
assure that an accurate reading is obtained. Refer to
Table 61 for the proper carbon dioxide levels. A carbon
dioxide level exceeding the listed range indicates
incomplete combustion due to inadequate air or
excessive gas.
Combustion Air Adjustment (O
7. Use an oxygen analyzer and measure the percentage
of oxygen in the flue gas.Take several samples to
assure an accurate reading. Compare the measured
oxygen level to the combustion curve in
p. 151.The oxygen content of the flue gas should be
4% to 5%. If the oxygen level is outside this range,
adjust the combustion air damper to increase or
Table 61 for the
Figure 120
119.Take several samples to
)
2
Figure 120,
RT-SVX36K-EN