Startup
OAU-SVX006E-EN
53
2. BEFORE OPERATING, leak test all gas piping up to
heater gas valve. Smell around the unit area for gas. If
gas is smelled, do NOT attempt to place heater in
operation until source of gas leak is identified and
corrected.
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.
Verify Indoor Fan Failure Switch (OAB, or OAG
cabinets with UC600 controls)
a. The minimum of Analog Values labelled Supply Fan
Air Flow Minimum Setpoint is Cooling Mode (AV59)
and Supply Fan Air Flow Minimum Setpoint is
Heating Mode (AV13).
b. Override Analog Output labelled Supply Fan Speed
Command (AO2) until the Supply Fan Air Flow
Active (AV41) matches the value from step 1.
c. Locate the Indoor Fan Failure Switch (IFFS) in the
control section. Labelled IFFS or two red wires
labelled IFFS/464A.
d. Slowly rotate IFFS switch clockwise (lightly tapping
the IFFS after each full turn) until IFFR relay is not lit.
e. Rotate IFFS switch ½ turn counterclockwise. IFFR
relay should then be lit.
f. Release Supply Fan Speed Command.
Verify Indoor Fan Failure Switch (OAD, OAK or
OAN cabinets with UC600 controls and all units
without UC600)
a. Set the unit at minimum air flow:
i. For OAD, OAK or OAN with UC600, override
Supply Fan Speed Command to 0%.
ii. For all Units without UC600, have the controls
contractor set the supply fan speed so that the
air flow is at minimum.
b. Locate the Indoor Fan Failure Switch (IFFS) in the
control section. Labelled IFFS or two red wires
labelled IFFS/464A.
c. Slowly rotate IFFS switch clockwise (lightly tapping
the IFFS after each full turn) until IFFR relay is not lit.
d. Rotate IFFS switch ½ turn counterclockwise. IFFR
relay should then be lit.
e. Release Supply Fan Speed Command override.
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.
