Trane Horizon OABE/F, Installation, Operation And Maintenance Manual

Page: 61 / 92

Startup
OAU-SVX004D-EN 61
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
Startup Procedure
1. Check Inlet Gas Pressure
Check to insure 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 shutoff and pressure
tap.
2. Verify Indoor Fan Failure Switch Operation
Indoor Fan Failure Switch (IFFS) is located in the unit
electrical control compartment above the heater.
Indoor fan failure switch will fail if not proven within
30 seconds of call for indoor fan—ON.
All unit air filters must be clean before proceeding to
properly complete this verification.
Important: If the unit air filters are not clean, unit
performance could be affected. Remove
and clean or replace air filters as required
prior to proceeding with the burner
pressure testing.
In the event that the pressure switch fails to operate,
check the pick-up tubes to be certain that the tubes are
not obstructed and confirm that the tube connections
to IFFS are tight and secure.
3. 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 69, p. 64 ) 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 2 and correct leak. If you don’t smell gas or have
corrected any leaks, go to Step 4 .
4. Burner Starting Sequence and Burner Ignition
Figure 69, p. 64 illustrates indirect gas-fired furnace
components.
5. Main Gas Supply
Turn manual gas cock “ON”.
6. 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
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.