Rapid 7500 136 Installation, operation & service manual - page 121
SECTION 16: S
TART
-
UP
P
ROCEDURES
109 of 143
do not repeatedly cycle the
bu
rner. Specific
instr
u
ctions relati
v
e to component seq
u
encing are
pro
v
ided in the flame safeg
u
ard man
u
fact
u
rer's
bu
lletin
w
hich is incl
u
ded
w
ith the doc
u
mentation
shipped
w
ith the
bu
rner.
Proper test eq
u
ipment m
u
st
b
e
u
sed in order to
achie
v
e maxim
u
m system operational relia
b
ility and
f
u
el efficiencies.
All f
u
el/air adj
u
stments sho
u
ld
b
e made to achie
v
e
req
u
ired inp
u
t rate, satisfactory com
bu
stion test
v
al
u
es, flame sta
b
ility and appearance.
16.7 Gas Pressure Adjustments
All high fire adj
u
stments, for
w
hate
v
er
bu
rner type -
on/off, high/lo
w
/off and f
u
ll mod
u
lation are
accomplished
b
y adj
u
sting the main gas reg
u
lator
located in the gas manifold. Refer to the eq
u
ipment's
serial tag for proper
bu
rner manifold press
u
re at high
fire.
To adj
u
st lo
w
fire on a high/lo
w
/off
bu
rner, the control
act
u
ator contains the adj
u
stment means.
FIGURE
8
7: Low Fire Adjustment for Hi
g
h/Low/
Off Burner
A dial on the lo
w
-fire cam indicates the lo
w
-fire
setting. Beca
u
se the cam rotates as the
v
al
v
e opens,
scales are marked on the dial so the lo
w
-fire setting
can
b
e o
b
ser
v
ed
w
ith the
v
al
v
e in any position. One
scale is
v
isi
b
le
w
hen the act
u
ator is closed, and the
other is
v
isi
b
le
w
hen it is open. These scales are not
independent; the same setting applies to
b
oth. The
act
u
ator is shipped from the factory
w
ith the lo
w
-fire
setting at a
v
al
v
e gas flo
w
of approximately 40
percent,
w
hich is adeq
u
ate for safe light-off
u
ntil the
final setting can
b
e determined.
16.7.1 Recommended Procedure
To adj
u
st the lo
w
-fire setting
w
itho
u
t energizing the
act
u
ator, proceed as follo
w
s:
1. Remo
v
e the
w
iring compartment co
v
er.
2.
Man
u
ally rotate the cam and dial assem
b
ly
do
w
n
w
ard so that the setscre
w
is accessi
b
le
from the front of the act
u
ator.
3.
Loosen the setscre
w
on the lo
w
-fire cam
u
sing
the special
w
rench (s
u
pplied-taped to the
inside of the act
u
ator co
v
er).
4.
Set the cam to the predetermined lo
w
-fire set-
ting for the
bu
rner
b
eing
u
sed.
5.
Tighten the setscre
w
in the cam.
6.
Replace the
w
iring compartment co
v
er.
16.7.2 Alternate Procedure
To adj
u
st the lo
w
-fire setting after the
bu
rner is in
operation,
u
se the follo
w
ing instr
u
ctions:
1. Remo
v
e the
w
iring compartment co
v
er.
2.
Check to
b
e s
u
re the lo
w
-fire adj
u
stment is set
at 40% to ass
u
re a safe light-off. (Lo
w
-fire
adj
u
stment is preset at the factory.)
3.
Disconnect the firing rate controller lead
w
ire
from terminal 4 on the act
u
ator to keep the
v
al
v
e in the lo
w
-fire position.
4.
Start the system and esta
b
lish the main
bu
rner
flame.
5.
Loosen the setscre
w
in the cam
w
ith the spe-
cial
w
rench. Keep the
w
rench seated in the set-
scre
w
. Rotate the cam slightly do
w
n
w
ard (
b
y
mo
v
ing the
w
rench to
w
ard the act
u
ator
b
ase)
to open the
b
leed
v
al
v
e. The act
u
ator
w
ill start
to close.
6.
When the
v
al
v
e reaches the desired lo
w
-fire
position, q
u
ickly tighten the setscre
w
and
remo
v
e the
w
rench. If the desired lo
w
-fire set-
ting is missed, loosen the setscre
w
and rotate
the cam in the opposite direction to the desired
set point.
7.
Sh
u
t do
w
n the
bu
rner, and then restart. Repeat
se
v
eral times to
b
e s
u
re the lo
w
-fire setting is
s
u
ita
b
le for correct
bu
rner light off. Readj
u
st, if
necessary.
8.
Disconnect po
w
er and reconnect the controller
lead
w
ire remo
v
ed in step 3.