Burnham V8 Series - Manual (Page 17)

17
Disconnect the fl ared fi tting to the oil line
and remove the aluminum thumb-nut from
the nozzle line. Remove the combustion
head assembly from the air tube. Rotating
the assembly upside down will ease
removal. Inspect the nozzle for size and
type, refer to Table 6 of this manual.
ii. To change a nozzle, loosen the clamp screw
on the retention ring assembly and slide the
retention ring off the adaptor.
Install and tighten the proper nozzle in
the adaptor. See Table 6 of this manual.
Be careful not to damage the electrode
insulators or to bend the wires.
iii. Replace the retention ring assembly, slipping
one of the riveted arms through the 1/8-inch
gap between the electrode tips. This arm
should be straight up. Also, be sure that the
retention ring clamp is tight against the
shoulder on the adaptor. Then tighten the
clamping screw.
iv. Check the electrode settings specifi ed as
follows and shown in Figure 27B. 1/8-inch
gap, 1/4-inch above the nozzle centerline,
and 3/16-inch ahead of the nozzle tip.
v. Re-install the combustion head assembly
into the air tube. It may be necessary to turn
nozzle line assembly upside down to ease
insertion into the air tube. Then the threaded
adapter on the end of the nozzle line is
passed through the opening in the left side of
the housing.
vi. Run the aluminum (knurled) thumb-nut onto
the nozzle line and tighten hand-tight.
vii. Connect the fl ared fi tting on the copper oil
line to the nozzle line and tighten.
viii. Swing the transformer to the closed position,
rotate latches and tighten screws.
b. Combustion Head Setting/Adjustment
i. Verify combustion head setting, refer to
Table 6 of this supplement. Read the scale
embossed in the housing, which is calibrated
in 1/16-inch divisions (dimension ‘A’)
the position of the fl ame retention ring in
relation to the air cone can be determined at
a glance. Refer to Figure X.
ii. By moving the electrode and combustion
head assembly forward or backward, the
location of the fl ame retention ring relative
to the throttle ring can be controlled. Refer
to Figure 7A.
By loosening the locking screw and thumb-
nut and turning the adjusting screw using a
5/32-inch allen wrench, the assembly can be
moved to the required position.
Turn the adjusting crew clockwise to move
the combustion head forward, increasing the
‘A’ dimension, counterclockwise will pull
the head back, decreasing the ‘A dimension.
To lock in place, fi rst tighten the thumb-nut
and then the locking screw.
c. Initial Air Shutter/Band Setting
i. The air shutter has a pointer which indicated
the percent of opening against a calibrated
scale (9 = 90%, fully open = 100%). The
setting is locked in place by a screw just
above the fuel unit.
ii. The air band is adjusted by loosening the
screw, rotating the air band and then locked
in place after fi nal adjustment. Refer to
Table 6 of this manual for initial settings.
iii. The burner is now set at the approximate
air band setting for the gallonage indicated.
During fi nal adjustment, using combustion
testing equipment, the air band may need
minor adjustment to achieve the desired
effi ciency.
Water Boilers Only
Knockdown V87 - V89 boilers are provided
with one nozzle, installed in the burner, that
provides the same fi ring rate as the steam
boiler of the same size.
Inspect the installed nozzle and assure that
the nozzle is the correct size and type as
specifi ed in Table 6 of this manual. The
nozzle input is stamped on the hex fl at of the
nozzle.
Refer to Paragraph K, 7, a for burner drawer
assembly removal.
Figure 7A: Combustion Head Adjustment