Step 2: Set Low Fire Air - Eclipse RatioMatic RM Series Installation Manual

Step 2: Set Low Fire Air

1. Start combustion air blower.
2. Drive control motor to low fire position.
3. Measure air differential pressure between tap "C" and
combustion chamber. See the appropriate series 110,
datasheet.
To Chamber
Figure 4.2.
NOTE (RM0050-RM0700): The pressure tap is in the
open position when the screw inside the tap is unscrewed
approximately 1/2 turn. Do not remove screw. Be sure to
tighten pressure tap screw clockwise to the closed
position after pressure measurements have been taken.
4. Set low fire air.
a. For air control actuators that have a coupling with
set screws, as shown in Figure 4.3, loosen the set
screw  on the burner side of the coupling .
For air controlled actuators that have a keyed or
pinned coupling, as shown in Figure 4.4, please
refer to the cam adjustment section of the
actuator's installation literature for instructions on
releasing the cam's low or off start position.
• For T500 series Trilogy Actuators, see Instruction
Manual 902 or Quick Guide 902.
b. There is a slot in the end of the butterfly valve shaft
that is parallel to the air damper. This slot is used
for visual indication of the butterfly valve position.
The butterfly valve is closed when the shaft slot is
perpendicular to the direction of air flow through
the butterfly valve. See Figure 4.5
c. Rotate the air butterfly valve shaft to a fully closed
position. (Holes in the butterfly valve will supply
low fire air.)
Eclipse RatioMatic Burners, RM Series, V5, Installation Guide 110, 12/3/2014
When firing into a positive chamber pressure,
rotate the air butterfly valve from the closed position
in the direction of actuator travel to obtain a
minimum
0.3" w.c. (0,8 mbar) air differential pressure.
d. For air control actuators that have a coupling with
set screws, as shown in Figure 4.3, hold the
butterfly valve firmly in place and tighten the set
screw .
For air control actuators that have a keyed or
pinned coupling, as shown in Figure 4.4, hold the
butterfly valve firmly in place and re-engage the
cam's low or off starting position.
• For T500 series Trilogy Actuators, see Instruction
Manual 902 or Quick Guide 902.
e. High fire air adjustment is not required if the burner
is firing into a neutral pressure chamber and a 90°
travel control motor is used. It may be necessary to
limit control motor stroke to less than 90° if firing
into a large negative chamber. Contact Eclipse for
further information.
Figure 4.3. Actuator with Flexible Coupling
Figure 4.4. Actuator with Keyed Coupling
5. Verify high fire air:
a. Drive control motor to high fire, full open.
b. Compare the high fire air differential pressure
between Tap C and the combustion chamber to
the approximate datasheet chart "Air p vs. Input".
If high fire air is insufficient, refer to section 5,
"Troubleshooting & Maintenance", in this
document.
6. Return the control motor to the low fire position.
7. Close the pressure taps.
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