Service manual

F35425 (February 2006)Page 13 of 40
C24GA SERIES CONVECTION STEAMERS - SERVICE PROCEDURES AND ADJUSTMENTS
SERVICE PROCEDURES AND ADJUSTMENTS
WARNING: CERTAIN PROCEDURES IN THIS SECTION REQUIRE ELECTRICAL TEST OR MEASURE-
MENTS WHILE POWER IS APPLIED TO THE MACHINE. EXERCISE EXTREME CAUTION AT ALL TIMES.
IF TEST POINTS ARE NOT EASILY ACCESSIBLE, DISCONNECT POWER AND FOLLOW LOCKOUT /
TAGOUT PROCEDURES, ATTACH TEST EQUIPMENT AND REAPPLY POWER TO TEST.
BLOWER AIR PRESSURE
ADJUSTMENT
Adjust the blower air pressure at the gas combination
manifold pressure tap. Turn the gas valve off. Remove
pipe plug from pressure tap on the outlet side of the
gas combination valve and install a gas manometer.
The air pressure should be 0.35"W.C. (0.09 kPa) to
0.4"W.C. (1 kPa). If the reading is not correct adjust
blower speed control adjustment screw clockwise to
increase and counter-clockwise to decrease.
AIR PRESSURE SWITCH
ADJUSTMENT
Blower air pressure adjustment must be performed
before proceeding with this procedure.
The air pressure switch senses the pressure level
produced by the blower for combustion. When the
pressure is sufficient, the switch closes and supplies
power to the ignition control module. The gas ignition
sequence starts to light the gas pilot and then main
burner. If gas pilot is not lighting (valve not energized),
the ignition control module may not be receiving
power, assuming the minimum water level is satisfied.
Check the air pressure switch operation then adjust if
necessary as outlined in the procedure below.
1. Turn the power switch off.
2. Remove the front panel from the cabinet base.
A. Inspect the air intake to the blower for
debris build up and clogging.
1) If debris is found, clean it away from
the air intake.
B. Turn the power switch on and verify main
burner ignition.
1) If burner ignites no adjustment to the
pressure switch setting is necessary.
2) If burner does not ignite, proceed to
step 3.
3. Turn the main gas valve to off.
4. Adjust the air pressure switch setting as follows:
A. Turn the adjustment screw fully clockwise
to the highest setting.
B. Slowly turn the adjustment screw counter-
clockwise until main gas valve energizes
then add 1/2 turn to the adjustment.