Start-Up
OAU-SVX007A-EN 93
3. Use only hand force to operate the gas control lever to the
“ON” position. NEVER use tools. If lever does not operate
by hand, replace gas valve prior to staring the unit. Forcing
or attempting to repair the gas valve may result in fire or
explosion.
4. Do not attempt to operate unit, if there is indication that any
part or control has been under water. Any control or
component that has been under water must be replaced
prior to trying to start the unit.
Tools Required
• Voltage Meter (A)
• Amp Meter
• Gas Manometer (2)
• Temperature Probe
• Small Refrigeration Screwdriver
• 5/16-in. Nut Driver
• 3/16-in. Allen Wrench
• 3/32-in. Allen Wrench
• 1/8-in. NPT barbed pressure taps (3)
• 1/2-in. Open End Wrench
Start-Up Procedure
1. Check Inlet Gas Pressure
Check to ensure the gas pressure supplied to the unit is
within the pressure requirement listed on the nameplate.
DO NOT expose gas controls to pressures above 1/2 psi
(14-in. WC). The gas supply line should be installed with an
external manual shut-off and pressure tap.
2. Confirm Gas Flow at Unit
Open door to unit vestibule housing the gas heater. Move
gas control lever to “OFF” position. Remove
1/8-in. pressure taps (see Figure 144, p. 95) from both
modulating and on-off sections of the split heater manifold.
Install a barbed fitting in both 1/8-in. tapped holes for
connection to individual gas manometers.
Note: There is a third 1/8-in. gas pressure tap located in the
pipe connecting the main valve/regulator and
modulating valve. Maximum pressure into modulating
valve is 5-in. The On-Off gas valve includes a regulator
adjustment device that is located on the top of the
valve. Use this device to regulate valve output to
modulating valve as required.
Wait 5 minutes for any gas to clear. If you smell gas, see Step
1 and correct leak. If you don’t smell gas or have corrected any
leaks, go to Step 3.
3. Burner Starting Sequence and Burner Ignition
Figure 144, p. 95 illustrates indirect fired gas furnace
components.
4. Main Gas Supply
Turn manual gas cock “ON”.
5. Split Manifold High Fire and Burner Test
Open all manual gas valves. Turn power on at unit’s main
disconnect switch. Open gas supply manual shut-off valve.
using unit display (or computer with Trane Tracer TU),
proceed to system status display and override all
compressor stages OFF, disable dehumidification, disable
economizer mode, disable ERV. If two heaters are
installed, test heating with split manifold first by overriding
burner 2 OFF. Override heating output command to
100.0 percent if one heater is installed and to 49 percent if
two heaters are installed. Override heat cool mode active
to Heat. This will enable call for heat to split manifold
heater. Depending on outdoor air temperature, at time of
startup, heater high limit temperature may be exceeded
causing limit switch to trip. Limit switch is auto-reset. Limit
switch must be jumpered out of the circuit if OA
temperature dictates.
With limit switch closed, the draft inducer will run on high
speed for 10 seconds for proof of high and low airflow
switch closure, then begin a 30-second pre-purge period.
At the end of the pre-purge the direct spark will be
energized and On-Off gas valve will open for a 5-second
ignition trial. Following successful ignition, the inducer
remains on high for 10-second flame stabilization, followed
by 30-second warm up. Should the flame go out or the
burner fail to light, an ignition retry will initiate following a
15-second inter-purge period.
Following successful ignition, manifold pressure should be
1.2-in. WC during the warm-up period. The manifold
pressure will rise to 3.5-in. WC at 100 percent firing rate.
Following these sequences to check low fire gas pressure
for modulating section, reduce heating output command to
0 percent. Inducer speed will reduce to low speed. Correct
gas pressure for modulating manifold section of heater at
0 percent output signal or low fire will be 0.4-in. WC. For
WARNING
Hazardous Voltage and Gas!
Failure to turn off gas or disconnect power before
servicing could result in an explosion or electrocution
which could result in death or serious injury. Turn off
the gas supply and disconnect all electric power,
including remote disconnects, before servicing the
unit. Follow proper lockout/tagout procedures to
ensure the power can not be inadvertently energized.
AVERTISSEMENT
Tension dangereuse et présence de gaz!
Le non-respect de l’obligation de couper le gaz ou
l’alimentation électrique avant de procéder à une
opération d’entretien peut entraîner une explosion ou
une électrocution pouvant résulter en des blessures
graves, voire mortelles. Avant toute intervention sur
l’unité, couper l’approvisionnement en gaz et
l’ensemble de l’alimentation électrique, y compris les
disjoncteurs à distance. Suivez scrupuleusement les
procédures de verrouillage/mise hors service
préconisées pour empêcher tout rétablissement
accidentel de l’alimentation électrique.
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