CleaverBrooks CB burner 100 Series User manual

OPERATING
INSTRUCTIONS
$30.00 U.S.
CB
burner
model CN
FUEL: LIGHT OIL, HEAVY OIL, GAS
OR COMBINATION
SERIES 100-200-400-600-700
Cleave'*Rrooks®
DIVISION OF AQUA·CHEM, INC.
Milwaukee, Wisconsin 53201
Service and Parts Coast to Coast
Boilers and Accessories for the Complete Boiler Room
Manual Part No. 750-308

TO: Owners, Operators or Maintenance Personnel
This operating manual presents information that will help to properly operate and care for the equipment.
Study its contents carefully . The unit will provide good service and continued operation if proper
operating and maintenance instructions are followed . No attempt should be made to operate the unit until
the principles of operation and all of the components are thoroughly understood . Only trained and
authorized personnel should be allowed to operate , adjust or repair this equipment .
Cleaver-Brooks products are designed and engineered to give long life and excellent service on the job .
The
electrical and mechanical devi ces supplied as part of the unit were chosen because of their
known ability to perform : however, proper operating techniques and maintenance procedures must be
followed at all times . Although these components afford a high degree of protection and safety,
operation of equipment is not to be considered free from all dangers and hazards inherent in handling and
firing of fuel.
Any "automatic " features included in the design do not relieve the attendant of any responsibility .
Such features merely free him of certain repetitive chores and give him more time to devote to the proper
upkeep of equipment .
It is solely the operator 's responsibility to properly operate and maintain the equipment. No amount of written
instructions can replace intelligent thinking and reasoning and this manual is not intended to relieve the
operating personnel of the responsibility for proper operation .
Because of state, loca l or other applicable codes there are a variety of electrical controls and safety
devices which vary considerably from one installation to another . This manual contains information
designed to show how a standardly equipped burner operates .
Operating controls will normally function for long periods of time and we have found that some
operators become lax in their daily or monthly testing assuming that normal operation will continue
indefinitely . Malfunctions of controls leads to uneconomical operation and damage and in most
cases these conditions can be traced directly to carelessness and deficiencies in testing and maintenance .
It is recommended that a boiler room log or record be maintained . Recording of daily , weekly, monthly
and yearly maintenance activities and recording of any unusual operation will serve as a valuable
guide to any necessary investigation .
Most instances of major boiler damage are the result of operation with low water. We cannot emphasize
too strongly the need for the operator to periodically check his low water controls and to follow good
maintenance and testing practices . Cross connecting piping to low water devices must be internally
inspected periodically to guard against any stoppages which could obstruct the free flow of water to
the low water devices . Float bow Is of these controls must be i nspected frequently to check for the
presence of foreign substances that would impede the float ball movement .
The waterside condition of the pressure vessel is of extreme importance . Waterside surfaces should be
i nspected frequently to check for the presence of any mud , sludge , scale or corrosion .
It is customary to engage the services of a qualified water treating company or a water consultant to
recommend the proper boiler water treating practices .
The operation of this equipment by the owner and his operating personnel must comply with all requirements
or regulations of his insurance company and/ or any other authority having jurisdiction . These legal
requirements take precedence over anything contained herein .
Cleaver-Brooks Service Engineers . or Cleaver-Brooks authorized service representatives , present
for start-up or service are present only in an advisory capacity . The operation of the burner or bo iler is
under the scope of work to be performed by the owner 's operating personnel at the owner's risk, and under the
owner's insurance protection . Recommendation for proper adjustments required to make the equipment
perform can be made by these Service Engineers .

CONTENTS
Page
CHAPTER I - GENERAL DESCRIPTION . .. .. ... .... .. . ... .. . .. . ..... . .. . . ... . 1-1
A. The Burner and Control System .. .. ...... . ... . ._ ... .... . ......... 1-1
B. Controls and Functions ... .... ... ...... .. .............. . ..... . ... 1-2
C. Controls Common To All Burners . ... . .. .. ... . .. ......... . .. . . . . 1-2
D. Controls For Gas Firing ...... . ..... . .... ...... . .. ... . . . .. . .. . ... 1-7
E. Controls For Oil Firing .... .. . .. . . .. . .. . . ..... . .. . ...... . .. .... . 1-8
F. Additional Controls For Heavy Oil . .. . . .. . . ... . .. .. .......... ... 1-11
G. Automatic Ignition ..... . .......... .. .. .. .. . . . .. .... .......... .. . 1-11
H. Combustion Air .... . . ... . ... . . .. ... .. . ...... . ..... . ........... . . 1-13
I. Atomizing Air ..... . ... . .... . .. . .. . .... . .... .. .. .. ............. . 1-13
J. Modulating Firing ... . .... . .. . . .. ....... ... . . .. . .... . ... . ....... . 1-13
K. Gas Fuel Flow .. . ...... . . .... . .... . . .. . .......... . . . .. .... ...... 1-15
L. Oil Fuel Flow -Light Oil ..... . . . ..... . . . .. . . . ..... . .. ...... .. . 1- 15
M. Oil Fuel Flow- Heavy Oil ............................ .. ....... 1-16
N. Steam Atomizing . . . .. . .... ... .. . . . . . . . ....... . ..... . .. ... ..... . . 1-17
CHAPTER 2 - SEQUENCE OF OPERATION . ... . . . .. . . .. ... .. . .... . ........... 2-1
A. General . ..... ... .. . ..... . .. . ......... . . . .. . ............... . .... . 2-1
B. Circuit and Interlock Controls ..... .. . .. .. . ... . . ... ..... . . ... .... 2-1
C. Water Level Indicating System ..... . . . .... . . . ....... . .. . .... . .... 2-4
D. Sequence
Of Operation (Electric Positioning) ... ... .. . ... . . .. .. . .. 2-4
E. Sequence Of Operation (Pneumatic Positioning) . ... .. ... . . ........ 2-8
F. Flame Loss Sequence ........ . ... . .. . ... . .. .. . ...... . . ... ........ 2-10
CHAPTER 3- STARTING AND OPERATING INSTRUCTIONS ......... .. ..... 3-1
A. General Preparation For Start-Up -All Fuels ...... . . .. . .... . . .. 3-1
B. Control Settings . . .......................... . ....... . ........ . . . . 3-1
C. Gas Pilot ... .. . ... .... . .. . .... . .. . ..... . ..... .... . ..... ........ .3-2
D. Atomizing Air .
.... . .. .. .... . .......... . ... . . ....... .. .... ... .. .3-2
E. Firing Preparations
For No. 2 Oil Series 100-200 ... .. .... . .... .. .3-2
F. Firing Preparations
For No. 6 Oil Series 400-600 . . ... . . .. ... .. . . .. 3-3
G. Firing Preparations For Gas Series 200-400-700 ... . ... . . ... .. . ... . 3-5
H. Start-Up, Operating and Shutdown -All Fuels . . . . .. . . ... .. . . .... 3-6
I. Control Operational Tests and Checks ... . .. . .... . .. ...... ....... 3-7
CHAPTER 4- ADJUSTMENT- MAINTENANCE- SERVICE ... . .... . ...... .4-1
A. General
... . .. ... ....... ... . . ... ... ... . ......... . ... .. .... .. ..... 4-1
B. Burner Operating Controls . . .. . . .. .. .. . .. .... ... . ... ... ....... . .. 4-2
a. General . . .... .......... ..... .. . . . .. ... ................. .. . .. 4-2
b. Modulating Pressure Control . .
.... .. . . . .. .. .. ....... . ... ... .. 4-4
c. Operating Limit Pressure Control ,
.... . . ............. . ...... . .4-4
d. High Limit Pressure Control
........ . .... . . .. .... . ...... . . . .. 4-4
e. Low
Fire Pressure Switch ... .. .. .. ... . .. . .. .. . .... .. .. ..... .. 4-4
f. Programming
Control . ..... . .... .... . .... .. . .. . . .. .. ... . . .... 4-4
g. Combustion Air Proving Switch
.... .. . . .. .. . . ... . . .. .. ... .. .. 4-5
h. Atomizing Air Proving Switch . .
.. . ... . ...... . ... ... ... . .. . .. .4-5
i. Modulating Motor ... ..... . . ... . . .... . .... . . .. .... .. .. .. .... .4-5
J. Modulating Motor Switches -Low Fire and High Fire .. .. .. .4-6
k. Linkage .
.. .. . . .. .... ... . . .... . . . .. .. . .... . ..... . .... . ... .. .. 4-6
I. Cam Spring ... . .. ... ....... . .. .. ........ . ...... .. . . . .... .... 4-6
m.
Control Maintenance . ..... . .. .... ........ . .. . ....... . .. . .... .4-6
'Aqua-Chem Inc. 1978

CONTENTS <continued>
C. Gas Pilot Flame Adjustment ..................................... 4-7
D.
The Gas Burner ................................................. 4-7
a. Combustion Adjustment . ................... : ................. 4-7
b. Gas Pressure and Flow ...................................... 4-10
c. Gas Burner Maintenance ..................................... 4-12
d. Low Gas Pressure Switch
.................................... 4-12
e. High Gas Pressure Switch
..... ............ ......... ..... ..... 4-12
f. Motorized Gas Valve ........................................ 4-12
E. The Oil Burner ............. .. .......................... ... ..... 4-13
a. General ..................................................... 4-13
b. Oil Burner Adjustments .................................... .. 4-13
c. Combustion Adjustment
...................................... 4-14
d. Cleaning
The Oil Nozzle ..................................... 4-15
e. Back Pressure Orifice Nozzle (
100 & 200 Series) .. .. .......... 4-16
f. Low Oil Pressure Switch ..................................... 4-16
g. Electric Oil Heater Thermostat ............................... 4-16
h. Steam Oil Heater Thermostat.
................ .. . .... ... ...... .4-16
i. Low Oil Temperature Switch ................................. 4-16
j. High Oil Temperature Switch
................................. 4-16
k. Oil Drawer Switch ...... . .......................... .. ... .... .4-17
I. Oil Strainers ............................ . .................... 4-17
m. Fuel Oil Treatment
.............. . .. .......... . .. ........... .4-17
n. Oil Control Valves ............. .............. ............... 4-17
o. Oil Heaters- Steam, Electric ................... ............. 4-17
p. Steam Heater Pressure Regulator ............................. 4-18
r. Air Pump and Lubricating System ............................ 4-18
F. Solenoid Valves
........................................... . ..... 4-20
G. Lubrication ..................................................... 4-21
CHAPTER 5 - TROUBLE SHOOTING ......................................... 5-l
A Burner Does Not Start .......................................... 5-l
B. No Ignition
............... . ............... ........... ... ........ 5-l
C. Gas Pilot Flame, But No Main Flame ............................ 5-2
D. Low Fire Flame, But No High Fire Flame
....................... 5-2
E. Loss
Of Flame ............... ................ ................... 5-2
F. Modulating
Motor ................... . . . .... . ................... 5-2
CHAPTER 6- PARTS ORDERING INSTRUCTIONS ... .... ..... ... ............ 6-1
Parts List ....................................................... 6-2

CHAPTER 1
CHAPTER DESCRIPTION
A. THE BURNER AND CONTROL SYSTEM
B. CONTROLS AND FUNCTIONS
C. CONTROLS COMMON TO ALL BURNERS
D. CONTROLS FOR GAS FIRING
E. CONTROLS FOR OIL FIRING
F. ADDITIONAL CONTROLS FOR HEAVY OIL
G. AUTOMATIC IGNITION
H. COMBUSTION AIR
I . ATOMIZING AIR
J. MODULATING FIRING
K. GAS FUEL FLOW
L. OIL FUEL FLOW -LIGHT OIL
M. OIL FUEL FLOW -HEAVY OIL
N. STEAM ATOMIZING
A. THE BURNER AND CONTROL
SYSTEM
The information in this manual applies to the
Cleaver-Brooks Model CN burner whether it is
mounted on a Cleaver-Brooks watertube boiler
or installed as a conversion burner on a water-
tube boiler manufactured by others. In either in-
stance the burner is functionally the same al-
though slight modifications or piping arrange-
ment may be required in some conversion instal-
lations.
When provided as a part of a Cleaver-Brooks wa-
tertube boiler, and on some conversions, the
burner is fired into a boiler having a positive fur-
nace pressure. The conversion burner may be in-
stalled on a boiler with a negative furnace pres-
sure. The basic difference is in the BTU input
·which is somewhat greater on a negative pressure
furnace.
The burner is made in seven sizes with the fol-
lowing input capacities:
BTU MAXIMUM INPUT
CB Watertube
Boiler
Negative
Burner Pressurized Pressure
Model Furnace Furnace
CN-1 52,000,000 58,000,000
CN-2 58,000,000 65,000,000
CN-3 65,000,000 72,000,000
CN-4 69,000,000 79,000,000
CN-5 76,000,000 N.A.
CN-6 82,000,000 90,000,000
CN-7 90,000,000 100,000,000
The type of fuel determines the series classifica-
tion.
Series 100- equipped to burn No. 2 oil only
Series 200 -equipped to burn No. 2 oil or gas
Series 400- equipped to burn No.6 oil or gas
Series 600 -equipped to burn No. 6 oil only
Series 700 -equipped to burn gas only
NOTE: Although the Series 400 or 600 burner is
designed and designated to burn No. 6
oil (CS12-48) it must be recognized that
the burner will handle grades 4 and 5
equally well. While this manual contains
pertinent information on No. 6 fuel oil,
all references to this fuel should be con-
sidered equally applicable to all grades
of heavy oil.
The oil burner is of the low pressure, air atomiz -
ing (nozzle) type. The gas burner is of the non-
premix orifice type. The burners are ignited by
spark ignited gas pilot. The pilot is of the inter-
rupted type and is extinguished after main flame
is established .
The burners equipped to burn oil and gas include
equipment for each distinct fuel. Since the
burner uses only one type of fuel at a time, a
gas/oil selector switch is incorporated in a com-
bination burner .
It is important that the burner model and serial
number, shown on the nameplate, be included in
any correspondence or parts order.
Regardless of which fuel is used, the burner oper-
ates with full modulation thru potentiometer
type positioning controls. The standard control
system utilizes electric positioning controls. A
switch is provided to permit changeover from
automatic fully modulated firing to continuous
firing at any desired rate between minimum and
maximum . In either case, additional safeguards
1-1

Chapter 1 - General Description
assure that the burner always returns to the
minimum firing position for ignition.
The flame safeguard and programming control
includes an infra-red sensitive flame detector to
supervise both oil and gas flames and to shut the
burner down in the event of loss of flame signal.
The programming portion of the control provides
a pre-purging period, proving of the pilot and
main flame, and a period of continued blower
operation to purge boiler of all unburned fuel va-
por. Other safety controls shut down the burner
under low water conditions or excess steam pres-
sure.
Safety interlock controls include combustion and
atomizing air proving switches and, depending
upon the fuel and insurance carrier requirements,
controls that prove the presence of adequate fuel
pressure plus temperature proving controls when
heated fuel oil is used.
The low fire pressure switch holds the burner in
the low fire position until the boiler is properly
warmed up.
Combustion air is provided by a centrifugal blow-
er mounted in the wind box of the burner . Com-
bustion air delivery to the burner is under the
control of a damper motor . This same motor
regulates the flow of gas fuel thru a linkage sys-
tem connected to a gas butterfly valve and the
flow of oil thru a cam operated metering valve.
Fuel input and air are thus properly propor-
tioned for most efficient combustion.
For an oil fired boiler, filtered primary air for
atomizing the fuel oil is furnished independently
of the combustion air by a motor driven air com-
pressor. The fuel oil pump may be mounted near
the burner or at some remote location.
Indicator lights signaling load demand, fuel
valve, low water, and flame failure conditions are
standard equipment.
The sequence of burner operation from start up
thru shut down is governed by the programming
control in conjunction with the operating, limit
and interlock devices which are wired into the
circuitry to provide safe operation and protect
against incorrect operating techniques.
The function of individual components is out-
lined in this chapter and the electrical sequence
is covered in chapter 2.
B. CONTROLS AND FUNCTIONS
The term "control" as used here covers the more
important valves and components including but
not limited to electrical controls or those mon-
1-2
itored by the programming control. The operator
must become familiar with the individual func-
tion of all controls, whether or not outlined, be-
fore he can understand the burner's operation or
follow the procedures outlined in this manual.
Identify and locate each item using the figure
callout. A non-standard burner or one having
specially ordered features may have components
not listed here.
The actual controls furnished will depend upon
the type of fuel for which the burner is equipped.
Refer to the following applicable group or groups
listed below that apply to your burner.
C. Controls common to all burners.
D. Controls for gas firing (including combina-
tion)
E. Controls for oil firing (No. 2, No. 6 oil and
combination)
F. Additional controls for heavy oil
C. CONTROLS COMMON TO
ALL BURNERS
(1) Forced Draft Fan (figure 1-1 ): Furnishes all
air, under pressure, for combustion of pilot fuel
and main fuel and provides purge air.
(2) Forced Draft Fan Motor (figure 1-1 ): Drives
forced draft fan directly to provide combustion
air. Also referred to as a blower motor .
(3) Forced Draft Fan Motor Starter (figure 1-4):
Energizes forced draft fan (blower) motor .
(4) Ignition Transformer (figure 1-2): Provides
high voltage spark for ignition of gas pilot .
(5) Modulating Motor (figure 1-2): Operates the
rotary air damper and fuel valves through a cam
and linkage system to provide proper air-fuel ra-
tions under all boiler load conditions.
(6) Low Fire Switch (figure 1-2): Actuated by ro-
tation of the modulating damper motor shaft. In
order for the burner to start firing in a low fire
position, this switch must be closed. This is a fea-
ture which prevents burner ignition unless the
modulating motor has returned the rotary air
damper and modulating fuel valve to the low fire
position. This switch is an integral part of the
motor .
(7) Burner Switch (figure 1-4): A manually oper-
ated start-stop switch for directly starting and
stopping operation of burner.
(8) Manual-Automatic Switch (figure 1-4): When
set at "automatic," subsequent operation is at

the command of the modulating control which
governs
the position of the modulating motor in
accordance
with load demand. When set at
"manual" the modulating motor, through the
manual flame control, can be positioned at a de-
sired burner firing rate. The primary purpose of
FORCED DRAFT
FAN MOTOR
AIR DAM'ER
ATOMIZING AIR
PRESSURE GAUGE
GAS METERING
OIL HEATER
STEAM VALVE
Chapter 1 - General Description
the manual position is for testing and setting the
air-fuel ration through the entire firing range.
(9) Manual Flame Control (figure 1-4): A man-
ually operated potentiometer that permits the
FUEL OIL CONTROLLER
FIGURE 1-1 TYPICAL MODEL CN BURNER - NO. 6 OIL AND GAS FIRED
1-3

Chapter 1-General Description
AIR DAMPER
OIL B URN ER GUN
FIGURE 1-2 OIL BURNER COMPONENTS - NO. 2 OIL
positioning of the modulating motor to a desired
burner firing rate when the manual-automatic
switch is set on manual. It is used primarily for
initial or subsequent setting of fuel input
throughout the firing range. It has no control
over the firing rate when the manual-automatic
switch is set on "automatic."
1-4
(10) Modulating Motor Transformer (not
shown): Reduces control circuit voltage
(115VAC) to required voltage (24VAC) for opera-
tion of the modulating motor.
(11) Indicat0r Lights (figure 1-4): Provide visual
information on operation of boiler as follows:

Chapter 1 - General Description
FUEL 0 IL CONTROLLER
OIL HEATER
THERMOSTAT
LOW OIL TEMPERATURE
SWITCH
FIGURE 1-2 (A) OIL BURNER COMPONENTS - NO. 6 OIL
Flame Failure
Steam Demand
Low Water
High Water
(12) Combustion Air Proving Switch (figure 1-2):
A
pressure sensitive switch actuated by
air pressure from the forced draft fan. Its con-
tacts close to prove presence of combustion air .
(13) Operating
Limit Pressure Control (figure 1-
8): Breaks a circuit to stop burner operation on a
rise of boiler pressure above a selected setting.
It
is adjusted to stop or start the burner at a
preselected pressure setting.
(14) High
Limit Pressure Control (Optional)
(figure 1-8): Breaks a circuit
to stop burner oper-
ation on a rise of pressure above a selected set-
ting. It is adjusted to stop the burner at a prese-
lected pressure above
the operating limit control
setting.
The high limit pressure control is
equipped
with a manual reset.
(15)
Modulating Pressure Control (figure 1-8):
Senses changing boiler pressures and transmits
this information to the modulating motor to
change the burner's firing rate when the manual-
automatic switch is set on automatic.
(16) Low Fire Pressure Switch (figure 1-8):
Senses boiler pressure and limits the burner to
low fire operation until boiler and casing is prop-
erly warmed and pressure reaches a pre-set point.
(17)
Alarm Horn (not shown): Sounds to notify
the operator of a cqndition requiring attention.
(18) Alarm Test Switch (figure 1-4) Used to
check alarm wiring system during normal oper-
ation.
(19)
Rotary Air Damper (figure 1-1}: This damp-
er provides accurate control of combustion air in
proportion
to fuel input for various load de-
mands .
(20) Diffuser (figure 1-3): This is a circular plate
located at the furnace end of the burner drawer
to impart a rotary swirling motion to combustion
air immediately prior to its entering the flame,
thus providing a thorough and efficient mixture
with the fuel.
(21) Gas-Oil Switch (figure 1-4): To manually se-
lect circuitry for either oil firing or gas firing.
(combination
burner only)
1-S

Chapter 1 - General Description
FIGURE 1-3 REAR VIEW -MODEL CN BURNER
(22) Programming and Flame Safe Guard Con-
trol (figure 1-4): Automatically programs each
starting , operating and shutdown period in con-
junction with operating , limit, and interlock de-
vices. This includes in a timed and proper se-
quence the operation of the blower motor , igni-
tion system, fuel valve(s) and the damper motor .
The sequence includes air purge periods prior to
ignition and upon burner shutdown.
The flame detector portion of this control super-
vises
both oil and gas flames and provides igni-
tion and flame failure protection in the ev~nt of
loss of a flame.
The control re-cycles automatically during nor-
mal operation , or following a power interruption .
It must be manually reset following a safety
shutdown caused by a loss of flame.
Incorporated
is an internal checking circuit effective on every
start which causes a safety lockout in the event
anything causes the flame relay to hold in during
this period.
This control contains the following major inte-
1-6
gral components
that are referred to in the oper-
ating sequence text:
(a) Master Relay (RLl): Energized when all the
limit and operating controls and lock-out
switches
are closed to start program sequenc-
ing
and to energize the forced draft fan motor
starter.
(b) Flame Relay (RL2): Energized when the
flame detector senses a suitable burner
flame. When de-energized by a loss of flame
it routes control circuit through the safety
switch.
(c ) Non-recycling Relay (RL3): Held in by the
airflow switch(es) which must be closed dur-
ing the prepurge and firing cycle. A safety
lockout will occur if a control in
this circuit
opens during operation.
(d) Lockout
Switch (LS): Trips following a loss
of flame, ignition failure, or failure of
the
flame relay to remain in its de-energized po-
sition during the programmer's checking peri-
od. A short cooling period is required before