Reznor RDF Unit Installation Manual - Manual (Page 23)

I-RDF, PN148384R5, Page 23
Startup
Diagnostic
Lights
1. Prepare system for startup testing --
 Attach a slope gauge (0 to 1.0" scale) to the tubing connections in the control
compartment. The two connections are located just left of the electrical box.
Remove the caps on the 1/8" NPT test connections and attach the slope gauge.
(The recommended method for attaching the slope gauge is to use field-supplied
1/8" female NPT x 1/4" OD barbed hose connections.)
 Connect a "U"-tube manometer to the main burner pressure tap.
 Check status lights (check at each step in the Startup procedure.)
Turn ON disconnect switch; "Circuit Control Power" light is lit; Turn OFF
disconnect switch.
 Turn the disconnect switch ON and the blower service switch to TEST position.
"Control Switch Energized", "Starter Energized", and if equipped with a freeze-
stat, "Freezestat" lights are lit. After blower obtains normal speed, check for these
lights - "Outside Air Cutoff Normal"; "Low Air Pressure Normal", "Limit Con-
trols Normal"; "High Air Pressure Normal"; and if equipped with options; "Low
Gas Pressure Normal"; and/or "High Gas Pressure Normal".
 Check for blower rotation. If the blower is turning backwards (see rotation arrows),
do the following:
Turn the disconnect switch OFF
Single-phase units -- rewire motor per instructions on motor wiring plate
Three-phase units -- interchange any two motor leads at the contactor or starter
Turn disconnect switch ON and verify rotation.
If the slope gauge reading is greater than -.25" (such as
-.10" w.c.), adjust the drive to increase the blower speed.
(1) Turn disconnect switch OFF.
(2)  If equipped with a discharge damper, remove opposite
side blower door panel.
Turn disconnect switch ON.
Check that discharge damper is full open by loosening or
tightening the linkage.
Turn disconnect switch OFF.
Replace door panel.
Turn disconnect switch ON and recheck slope gauge.
Turn disconnect switch OFF.
(3) If reading is still greater than -.25" w.c., adjust drive to
increase fan RPM.
For systems with smaller than 7-1/2 HP motor
(a) Loosen belt tension and remove belt.
(b) Loosen the setscrew on the side of the pulley away from
the motor.
(c) Turn adjustable half of the pulley inward to increase
blower speed. One turn will change speed 8 to 10%.
(d) Tighten the setscrew on the flat portion of the pulley shaft.
For systems with 7-1/2 HP and larger motor
(a) Slack off all belt tension by moving the motor toward
driven shaft until the belts are free of grooves. For easiest
adjustment, remove the belts from the grooves.
(b) On the outer locking ring, locate the two locking screws
that are directly across from each other. Loosen, but do not
remove, those two screws. Do not loosen any other screws.
(c) Adjust sheave to desired pitch diameter by turning the
outer locking ring. One complete turn of the outer locking
ring will result in .233" change in pitch diameter. To increase
blower speed, decrease diameter. CAUTION: Do not adjust
sheaves in either direction to the point where moveable
and stationary flanges are in contact.
(d) Re-tighten the locking screws.
All Motor Sizes - Replace the belts and check belt tension. Be
sure that belts are aligned in the pulley grooves and are not
angled from pulley to pulley.
2. Measure burner differential air pressure on the slope gauge installed in Preparation Step 1. With the blower
operating, differential air should read between -.25" and -.75" w.c. If the slope gauge reading is not within the limits
of these numbers, do one of the following:
If the slope gauge reading is less than -.75" (such as -1.0"
w.c.), adjust the drive to decrease the blower speed.
(1) Turn disconnect switch OFF.
(2)  If equipped with a discharge damper, remove opposite
side blower door panel.
Turn disconnect switch ON.
Check that discharge damper is full open by loosening or
tightening the linkage.
Turn disconnect switch OFF.
Replace door panel.
Turn disconnect switch ON and recheck slope gauge.
Turn disconnect switch OFF.
(3) If reading is still less than -.75" w.c., adjust drive to decrease
fan RPM.
For systems with smaller than 7-1/2 HP motor
(a) Loosen belt tension and remove the belt.
(b) Loosen the setscrew on the side of the pulley away from
the motor.
(c) Turn the adjustable half of the pulley outward to decrease
blower speed. One turn will change speed 8% to 10%.
(d) Tighten the setscrew on flat portion of the pulley shaft.
For systems with 7-1/2 HP and larger motor
(a) Slack off all belt tension by moving the motor toward
driven shaft until the belts are free of grooves. For easiest
adjustment, remove the belts from the grooves.
(b) On the outer locking ring, locate the two locking screws
that are directly across from each other. Loosen, but do not
remove, those two screws. Do not loosen any other screws.
(c) Adjust sheave to desired pitch diameter by turning the
outer locking ring. One complete turn of the outer locking
ring will result in .233" change in pitch diameter. To decrease
blower speed, increase diameter. CAUTION: Do not adjust
sheaves in either direction to the point where moveable
and stationary flanges are in contact.
(d) Re-tighten the locking screws.
All Motor Sizes - Replace the belts and check belt tension. Be
sure that belts are aligned in the pulley grooves and are not
angled from pulley to pulley.