Slant/Fin Prodigy 21 KC-45, Instruction Manual

Page: 13 / 24

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STEP 2: CALIBRATE BLOWER SPEED
• Connect tubing to differential pressure gage as fol-
lows:
1.From Blower Outlet Pressure Fitting on MIXING
ELBOW to GAGE HI side.
2.From BURNER ENCLOSURE Pressure Fitting to
GAGE LO side.
FOR HIGH FIRE OPERATION:
• Set the Operation Selector Switches as follows:
Switch 1 (left) UP MAN
Switch 2 (center) DOWN CAL
Switch 3 (right) UP HI
• Turn power ON. (Red power light and amber full rate
light will come on. Blower will start.)
• Allow about 30 seconds for pressure to stabilize.
• Read gage.
Reading should be 1.00" w.c.
• Adjust as necessary. Using HI Blower Speed
Adjustment Pot, turn in small increments (clockwise to
increase reading or counterclockwise to decrease the
reading). Allow to stabilize between adjustments.
FOR LOW FIRE OPERATION:
• Set the Operation Selector Switch 3 to DOWN, LO
position. (Amber light goes off, green reduced rate
light comes on.)
• Allow about 30 seconds for pressure to stabilize.
• Read gage.
Pressure reading should be 0.25" w.c..
• Adjust as necessary. Using LO Blower Speed
Adjustment Pot, turn in small increments (clockwise to
increase reading or counterclockwise to decrease the
reading). Allow to stabilize between adjustments.
STEP 4: CHECK BOILER INPUT RATE
NOTICE: DO NOT USE GAS VALVE TO ADJUST
INPUT RATE. FOLLOW DIRECTIONS BELOW.
• Consult gas supplier for heating value of gas (usually
1000 Btu/cu.ft. for NG; 2500 Btu/cu.ft. for LP).
• Place the jumper across the T1-T2 terminals and
allow the boiler to operate 10 minutes.
• Shut off all other appliances served by gas meter dur-
ing timing of input rate.
FOR HIGH FIRE OPERATION : Set the Operation
Selector Switches to MAN, OP and HI.
• At meter, observe number of cubic feet of gas the boil-
er uses in 3 minutes.
• Verify input using following formula:
Cu.Ft. in 3 mins. x Heating Value x 20 = Btu/hr Input
Example: 4.5 cu.ft. x 1000 x 20 = 90,000 Input
FOR LOW FIRE OPERATION : Set Operation Selector
Switch 3 to LO position.
• Allow operation to stabilize.
• At meter, observe number of cubic feet of gas boiler
uses in 3 minutes. Verify input using same formula.
Example: 2.25 cu.ft. x 1000 x 20 = 45,000 Input
IF ADJUSTMENTS NECESSARY : Turn Blower Speed
Adjustment Pot (HI for high-fire or LO for low-fire) in
small increments, clockwise to increase input or coun-
terclockwise to decrease input. Allow for stabilization of
operation between adjustments.
STEP 3: CALIBRATE GAS VALVE (First Light-Off)
PURPOSE OF GAS VALVE CALIBRATION IS TO
ADJUST AIR-GAS RATIO ONLY - NOT INPUT.
• Connect tubing to differential pressure gage as fol-
lows:
1. From Blower Outlet Pressure Fitting on MIXING
ELBOW to GAGE HI side.
2. From GAS VALVE OUTLET Pressure Fitting to
GAGE LO side.
• Disconnect any wires from T1, T2 and A1-A2 termi-
nals and set up a jumper wire across T1-T2 terminals
to control operation at boiler. Open zone valves.
FOR LOW FIRE OPERATION:
• Set the Operation Selector Switches as follows:
Switch 1 (left) UP MAN
Switch 2 (center) UP OP
Switch 3 (right) DOWN LO
• Open manual main gas shutoff valve and turn boiler
gas valve ON.
• Place the jumper across the T1 and T2 terminals.
• After about 20 seconds, boiler will start. (Green
reduced rate light on.)
• Allow about 30 seconds for pressure to stabilize.
• Read gage.
Reading should be 0" w.c. ±0.01".
• Adjust as necessary. Remove round screw cap cover-
ing gas valve adjustment. Position screwdriver into
adjustment screw slot carefully. Observe gage while
adjusting and turn screw slowly. Turn adjustment
screw clockwise to decrease reading if over 0 set-
point. Turn adjustment screw counterclockwise to
increase reading if under 0 setpoint.
Note: Remember that the gas pressure is on the low
side of the gage. Consequently, decreasing the differen-
tial reading actually is INCREASING the gas pressure
reading, since the blower outlet pressure is on the high
side of the gage and not changing.
FOR HIGH FIRE OPERATION:
• Set Operation Selector Switch 3 (right) to the UP, HI
position. (Green light goes off. Amber full rate light
comes on.)
• Allow about 30 seconds for pressure to stabilize.
• Read gage.
Pressure reading should be about 0"
w.c. ±0.05". If reading slightly off “zero”, DO NOT re-
adjust gas valve. This would alter the more critical low
setting. This step is done only to check boiler rate
switching ability.
• REPLACE SCREW COVER ON GAS VALVE
ADJUSTMENT. Double check gage reading with
cover on.
• Disconnect gage adapters and replace service fitting
caps hand tight.
• If gas meter available, proceed to Step 4.