CHAPTERS
NOTE:
On
an initial starting attempt, por-
tions
of
the fuel lines may be
empty and require
"bleeding"
time. It is better to accomplish
this
with repeated short lighting
trial periods
with
intervening
purge
periods
than
to
risk
prolonged fuel introduction.
If
the
pilot
does
not
light
after
several attempts, check all com-
ponents
of
the pilot system.
(5) When the pilot flame
is
established,
and with the pilot adjusting cock wide
open, remove the flame detector from the
burner plate. The pilot flame then can be
observed through this opening.
!WARNING
Wear
a
protective
shield
or
suitable glasses and keep eyes
sufficiently away from the sight
tube
opening
to
avoid serious
personal Injury or death. Never
remove the
flame detector while
the main burner is firing.
(6) To make the fmal adjustment, slowly
close the gas pilot adjusting cock until the
flame no longer can be seen through the
sight tube. Then slowly open the cock
until a flame providing full sight tube
coverage
is
observed.
This adjustment must
be accomplished
within the time limit
of
the safety switch
or approximately
30 seconds after the
detector
is
removed.
If
the control shuts
down, manually reset it. Replace the
detector and repeat from step 5.
750-150
ADJUSTMENT PROCEDURES
(7) When a suitable flame as indicated
in
number 6
is
obtained, replace the detec-
tor. Observe the reading on the micro-
ammeter. The reading should be between
2-1/4 and
S microam.ps when using a lead
sulfide detector and a standard amplifier.
See
the
flame
signal
table
in
the
manufacturer's bulletin for values
of
other combinations.
The flame signal indicated on the annun-
ciator type relay should not
be less than
10 volts D.C. and many be
as
high as
20
or greater.
The reading must be steady.
If the reading
fluctuates, recheck the adjustment. Make
sure that the flame detector
is
properly
seated and that the lens
is
clean.
(8) Return the
·test switch to the RUN
position.
(9)
If
the main flame previously has not
been established, proceed
to
do so
in
accordance with instructions elsewhere
in
the manual.
(10) The reading
of
the main flame signal
should also be checked. Observe the
flame signal for pilot alone, pilot and
main burner flame together and the main
burner flame at high, low, and inter-
mediate firing rate positions. Readings
should
be steady and
in
the range indi-
CHAPTER
5-11
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