Cleaver-Brooks CBH 40 - Page 40

Chapter 4-Starting and Operating Instructions
above the operating limit temperature control set-
ting.
Inspect the high-low flame control for proper set-
ting which should be slightly lower than that of the
operating limit control.
Adjustment procedures for these controls is
covered
in Chapter 5.
Inspect the low water cut-off. Check for freedom of
float and verify that control is functioning
properly.
In the event the boiler is equipped with optional
control devices not listed here, ascertain that their
settings are correct. If additional information is
required see your local Cleaver-Brooks representa-
tive or contact Cleaver-Brooks.
Set damper positioning switch at "low". Leave
burner switch "off' but close all other power en-
trance switches (supplied by others).
C. Oil BURNER START -UP
(100 and 200 Series)
PREPARATION FOR INITIAL FIRING
Verify that the driving belt for the oil pump is in
place.
Temporarily close the oil shut-off valve
(Figure 1-1).
On a 200 series boiler, set the gas/oil selector
switch to "Oil". Close main gas cock and open
pilot gas cock.
Open all valves in the oil suction line and oil
return line. The line from the storage tank to the
pump should be filled with fuel. Short suction lines
may be filled by use of the fuel pump. Long suction
lines and those of large diamet-er pipe should be
filled by priming or other means.
Manually hold in the blower motor starter until
the oil pump picks up and circulates oil. The oil
flow
may be verified when the pressure gauge in-
dicates a steady pressure reading of 175 psi (ap-
proximately). If no pressure ·shows on the gauge af-
ter a few moments stop the pump and prime the
suction line. Continue this procedure until the oil
flow is
established.
A vacuum (or compound pressure -vacuum) gauge
installed in the oil suction line will reveal the
tightness of the system. Its readings should be ob-
served and recorded for future guidance. Refer to
Chapter 5 for further information on the oil piping
system.
Check that damper positioning switch is set at
"low". Turn burner switch to "on". The blower
motor will start and oil pressure will be indicated
on the gauge. The timer in the programming con-
trol will begin rotating.
The damper will open for the pre-purge period and
allow a flow of air through the fireside area of the
4-2
pressure vessel. The damper motor will return to
the low fire position after this pre-purge is com-
pleted. The low fire switch must be closed for ac-
tion to continue.
Now check for ignition spark. When the "pilot
ignition" legend appears on the timer dial, the
ignition transformer is energized. An electric spark
should be visible when viewed through the rear
door sight glass. If the unit has a gas pilot, its
flame can be seen.
The main burner will not light since the oil shut-
off valve is closed.
With evidence of a good spark (or gas pilot) and
proper oil pressure, the unit is ready to be fired.
Turn burner switch to "off'. The programmer will
complete its cycle and stop. Reset the safety switch
in the event programmer locked out prior to the
burner switch being turned off.
Review the sequence of operation given in Chapter
3 for a complete description of the action that
takes place during a starting and operating cycle.
INITIAL START-UP AND FIRING
Set damper position switch to "low". Open the
manual fuel oil valve (Figure 1-1). Turn burner
switch "on". After the pre-purge period the burner
will light and operate at its low fire rate.
In some instances on initial firing, air may be trap-
ped in the fuel lines preventing ignition until it is
completely expelled and replaced by fuel oil. It
may be possible for the burner to go through
several cycles until all lines are filled with oil. If
ignition does not then occur, do not repeat un-
successful lighting attempts without re-checking
burner and pilot adjustments.
On an ignition failure the blower will continue
running to purge the boiler of any unburned fuel
vapors before stopping. After ignition failure wait
a few moments before re-setting safety switch.
CAUTION: The burner and control system is de-
signed to provide a pre-purge period
of fan operation prior to establishing
ignition spark and pilot flame. Do not
attempt to alter the system in any way
that might circumvent this feature.
When flame is established leave the burner in low
fire
position for approximately 30 minutes or until
boiler is properly warmed, unless it reaches its nor-
mal operating pressure or temperature sooner.
A
hot water boiler must have a continuous flow of
system water through the vessel during the warm-
up period. If conditions permit, the entire water
content of the system and boiler must be warmed
prior to increasing fuel input.
As normal pressure or temperature is approached
at low fire, turn the damper positioning switch to
"high". Observe the burner as it progresses to high