CleaverBrooks WB Installation guide

Table Of Contents
Model WB
Electric Boilers
Hot Water
Operation and Maintenance Manual
750-136
07/2018

Please direct purchase orders for replacement manuals to your local Cleaver-Brooks authorized representative
Manual Part No. 750-136
07/2018 Printed in U.S.A.
Cleaver-Brooks 2018
CLEAVER-BROOKS
Model WB
Electric Boilers - Hot Water
Operation and Maintenance Manual

This instruction and maintenance 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.
Cleaver-Brooks boilers are designed and engineered to give long life and excellent service on the job. The
electrical and mechanical devices supplied 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 the equipment is not to be considered
free from the hazards inherent in handling electricity, pressurized hot water, and steam.
It is solely the operator’s responsibility to properly operate and maintain the equipment. No amount of writ-
ten instructions can replace intelligent thinking and reasoning and this manual is not intended to relieve the
operating personnel of the responsibility for proper operation or the application of timely preventive mainte-
nance.
It is recommended that a boiler room log or other permanent record be maintained. Recordings of daily,
weekly, monthly, and yearly maintenance activities and recording of may unusual operation will serve as a
valuable guide to any necessary investigation.
It is customary to engage the services of a qualified water treatment company or a water consultant to rec-
ommend the proper water treating practices. Contact your local Cleaver-Brooks authorized representative for
details about Cleaver-Brooks water treatment services.
The operation of this equipment must comply with all requirements or regulations of the insurance company
and/or any other authority having jurisdiction. These legal requirements take precedence over anything con-
tained herein.
DO NOT OPERATE, SERVICE, OR REPAIR THIS EQUIPMENT UNLESS YOU FULLY UNDERSTAND ALL
APPLICABLE SECTIONS OF THIS MANUAL.
DO NOTALLOW OTHERS TO OPERATE, SERVICE, OR REPAIR THIS EQUIPMENT UNLESS THEY FULLY
UNDERSTAND ALL APPLICABLE SECTIONS OF THIS MANUAL.
FAILURE TO FOLLOW ALL APPLICABLE WARNINGS AND INSTRUCTIONS MAY RESULT IN SEVERE
PERSONAL INJURY OR DEATH.
!DANGER
WARNING

CONTENTS
CHAPTER 1 General Description 1-1
1.1 — Introduction 1-1
1.2 — Application 1-2
1.3 — Description 1-2
1.4 — Principles of Operation 1-4
CHAPTER 2 Installation Instructions 2-1
2.1 — Receiving Inspection 2-1
2.2 — Location 2-1
2.3 — Piping 2-2
2.4 — Heat Pump Systems with High Flow Rates 2-2
2.5 — Electrical 2-3
CHAPTER 3 Pre-Start Preparation 3-1
3.1 — Inspection 3-1
3.2 — Boiler and System Cleaning 3-2
3.3 — Boiler Water Treatment 3-4
CHAPTER 4 Operating Instructions 4-1
4.1 — Initial Startup 4-1
4.2 — Maintenance Schedule 4-4
4.3 — Element Replacement Procedure 4-5
CHAPTER 5 Troubleshooting 5-1
5.1 — Problems, Causes, and Actions 5-1
CHAPTER 6 Parts 6-1
6.1 — Ordering Parts 6-1

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Model WB Electric Boiler Manual 1-1
CHAPTER 1 General Description
1.1 — Introduction
1.1.1 — Safety Precautions
A complete understanding of this manual is required before attempting to operate or maintain the equipment.
It is essential to read and understand all safety precautions before attempting to operate the equipment.
Failure to follow these precautions may result in damage to equipment, serious personal injury, or death.
The equipment should be operated and maintained only by personnel who have read this manual and who have
a working knowledge and understanding of the equipment.
Warning indicates a potentially hazardous situation which, if not avoided, could result in serious injury or death.
Caution indicates a potentially hazardous situation which, if not avoided, could result in damage to the equipment.
NOTE: ”NOTE:” indicates information that is vital to the operation of the equipment.
!Warning
!Caution

General Description
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Model WB Electric Boiler Manual
1.1.2 — Abbreviations
Following is an explanation of the abbreviations, acronyms, and symbols used in this manual.
1.2 — Application
The Cleaver-Brooks Models WB boilers come equipped with 75 wsi Incoloy elements. The boilers are designed
to operate in hot water heating systems, and to deliver maximum kilowatts in minimum space requirements. The
WB is ideal for new boiler applications or as a replacement unit to upgrade existing installations.
These boilers are also designed for use as supplemental heat for heat pump systems operating between 55º F
and 175º F, or standard hot water systems up to 250º F. (Higher temperature boilers are available on special
order.)
1.3 — Description
A typical Model WB hot water boiler system includes operating controls, elements, fuses, contactors, relief valve,
drain valve, etc.; wired, tested, and ready for installation.
The vessel construction complies with the ASME Boiler & Pressure Vessel Code, Section IV, and is suitable for
operation at pressures to 160 psig and temperatures to 250º F. All WB boilers carry the “H” stamp.
An 11” x 15” manhole is provided on the WB models 361 through 422, smaller boilers are supplied with hand-
holes as required by ASME Code, Section IV.
Abbreviation Explanation Abbreviation Explanation
ASME American Society of Mechani-
cal Engineers
LWCO Low Water Cut Off
AR Automatic Reset MR Manual Reset
BHP Boiler Horsepower pH Measure of the degree of acid-
ity or basicity of a solution
BTU British Thermal Unit P/N Part Number
C Degree Celsius PPB Parts Per Billion
F Degree Fahrenheit PPM Parts Per Million
Ft Feet PSI Pounds Per Square Inch
GPM Gallons Per Minute T Temperature
Ht Height TC Temperature Control
Hz Hertz TI Temperature Gauge
KW Kilowatt wsi Watts Per Square Inch
Lb Pound

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Model WB Electric Boiler Manual 1-3
1.3 — Description
The following items are standard on all Cleaver-Brooks Electric Hot Water Boilers:.
Component Description
1. Main Lugs for Supply Circuit Standard boilers are designed for top entry to main power terminals and
are supplied with solderless wire connectors suitable for copper supply
wires. These main lugs are mounted on distribution buses which provide
individual connections for each heating element circuit.
2. Supplemental Internal Protection
Fuses
Boilers are provided with supplemental internal protection fuses rated at
approximately 125% of the element circuit load. These current-limiting
cartridge fuses have a minimum 200,000 ampere interrupting capacity to
provide protection for the element circuit wiring.
3. Built-In Magnetic Contactors All boilers use definite purpose magnetic contactors designed for use with
resistance heating loads. Minimum contactor rating is 50 amps resistive
duty rated for 500,000 duty cycles.
4. Heating Elements Standard heating elements are Incoloy sheathed and rated at 75 watts
per square inch (model WB). These elements are individually replaceable
hairpin type.
5. 120 Volt Control Circuit All boilers have 120 volt control circuits. Control circuit transformers with
primary fusing and grounded secondary are provided on all models.
6. Customer Control Interlock Con-
nection
A terminal strip is provided on all boilers for connection of the customer’s
external control devices, interlocks, and switches to enable/disable the
boiler, from remote locations.
7. High Temperature Cutoff All standard boilers are supplied with one automatic-resetting, and man-
ual-resetting high temperature cutoff. These are normally set at 235º F
and 240º F respectively, unless otherwise specified. On smaller boilers,
one auto-resetting temperature cutoff is standard as a backup to the limit
duty rated temperature control.
8. Low Water Cutoff (Model WB only) Each boiler is equipped with an automatic resetting electrical low water
cutoff of the probe type.
9. Temperature Control and Tempera-
ture Sensor
Boilers with 1 to 4 stages of control are standardly provided with on-off
controls. Larger boilers are provided with a solid state, proportional, mod-
ulating, step-type temperature control system. The temperature control
system controls the input power to the boiler by increasing (or decreasing)
the number of heating element groups (steps) in use as the temperature of
the water returning from the system varies due to system load. The con-
troller switches on or off banks of elements in order to maintain a constant
outlet temperature. Both control systems (on-off and proportional) have
adjustable temperature ranges. The on-off control has a fixed differential
of approximately 5º F. The proportioning control has an adjustable differ-
ential or proportioning range from 3º F to 30º F.
The proportional solid state electronic sequencers also have adjustable
time delay between steps varying from 5 seconds up to 10 minutes.
These adjustable controls enable the boiler to be tuned to the system it
regulates in order to optimize boiler responsiveness and system operation.
The proportional controller also prevents serious electrical damage in the
event of a power interruption. As power is restored to a cool system, the
controller turns on each step in timed sequence until full load is achieved.
This avoids the high current surges that would result if the steps were all
energized at once.

General Description
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Model WB Electric Boiler Manual
The following optional equipment may be added and supplemental descriptive information (suppliers’ literature)
may be included with your manual for these options:
1. Manual reset low water cutoff
2. Auxiliary low water cutoff (manual or auto reset)
3. High or low pressure cutoff
4. Pilot lights for individual steps
5. Toggle switches to enable/disable individual steps
6. Solid state progressive sequencing step control
7. Outdoor reset controls
8. Proportional outdoor load limiter
9. Demand limiting controls or interface
10. Door interlock
11. Boiler disconnect switch or circuit breaker (with or without shunt trip)
12. Ground fault detection
13. Metering (ammeter, voltmeter or KWH meter)
14. Alarm circuit (with or without horn/silencer push button)
15. Flow switch (with or without time delay)
16. Preheat switch
17. Local/remote modulation switch
18. SCR controller
19. Feedwater valve
20. Other misc. options
Your Dimension Drawings (DD) and Wiring Diagrams (WD) will show the optional equipment on your boiler.
1.4 — Principles of Operation
An electric hot water boiler is a simple device. Water passes through a steel drum (vessel) containing resistance
type heating elements. As the water circulates, it absorbs heat from the heating elements. The heated water is
then circulated through the external system to heat buildings, to provide heat for manufacturing processes, or for
use wherever it is required.
10. Pilot Switch and Pilot Lights Pilot lights are standardly provided to indicate “power on,” “high tempera-
ture,” and “low water.”
11. Pressure/Temperature Combina-
tion Gauge
NOTE: Model WB 121 is supplied with individual pressure and tempera-
ture gauges. Larger models include a separate pressure gauge and digital
temperature read-out.
12. Pressure Relief Valve This valve is sized according to the boiler’s electrical rating (3500 Btu/
KW) per the ASME Code and National Board.
Component Description

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Model WB Electric Boiler Manual 1-5
1.4 — Principles of Operation
Cleaver-Brooks boilers are designed to keep water volume as low as possible to provide close control and rapid
response to the heating needs. Close temperature control of the water is maintained by turning off or on, groups
of resistance elements. Controls in the boiler automatically select the number of heating element groups (or
steps) needed to maintain the water temperature, while supplying the system’s heat demands.
NOTE: Although circulation pumps are not supplied with these boilers, they should, however, be sized to provide a
flow rate adequate to deliver the boiler’s full output to the system, without high boiler temperature rise (100º F).
Pumps should operate continuously and, for the best control, the flow through the boiler should be constant.

General Description
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Model WB Electric Boiler Manual

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Model WB Electric Boiler Manual 2-1
CHAPTER 2 Installation Instructions
2.1 — Receiving Inspection
Every Model WB boiler is completely inspected at the factory and carefully crated for shipment. Inspect the pack-
ing for signs of exterior damage. After placing the unit as close as possible to the point of actual installation,
uncrate carefully and check all boxes and cartons against the packing slip. In case of damage or shortage, notify
the carrier immediately.
2.2 — Location
Consult local codes for specific requirements. Refer to the Dimensional Drawings (DD) and Wiring Diagrams
(WD) prepared by Cleaver-Brooks for your specific installation. Position the boiler to provide adequate clearance
on all sides for necessary access when operating and servicing the boiler.
Installation should be performed only by qualified personnel who are familiar with this equipment. Failure to heed
this warning may result in serious personal injury or death.
Before proceeding, make sure you read and understand the contents of this manual. Failure to do so may result in
serious personal injury or death.
To avoid damage to the equipment, be sure to:
1. Check your local electrical code for minimum clearances required around electrical equipment.
2. For installation in a closet, provide ventilation openings of 200 square inches per 100KW of boiler rating.
3. Observe local codes, which may specify greater clearances over top of boiler and must take precedent.
4. Install indoors only.
!Warning
!Caution

Installation Instructions
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Model WB Electric Boiler Manual
2.3 — Piping
This boiler is intended for use on forced circulation systems with a pump of adequate capacity to overcome the
system head loss (pressure drop at required flow rate), and to provide a flow rate adequate to permit the boiler to
generate its full heat output. Radiators and convectors in the system must have adequate capacity to dissipate
the boiler output at system design operating water temperature.
The pressure drop through the boiler is equivalent to the pressure drop through 30 feet of pipe equal to the
diameter of the inlet and outlet fittings.
Failure to provide adequate radiator capacity may create a low flow rate through the boiler, raising the tempera-
ture too high, and will result in “short cycling” of the boiler due to operation at the limiting or maximum tempera-
ture. This also will prevent the boiler from supplying its rated output to the system.
Tight-closing valves should be installed on the inlet and outlet piping to facilitate isolating the boiler from the sys-
tem for annual boiler internal inspection and/or repair that requires the boiler to be drained.
An expansion tank should be provided with a volume equal to 1/16 of the total water volume of the system,
inclusive of the boiler vessel, radiators, coils, and all piping. The expansion tank may be connected to the fitting
provided on top of the boiler vessel. If another location for the expansion tank connection is used, the boiler
opening must be plugged.
Water for make-up during operation should be added manually or automatically directly to the expansion tank.
The boiler drain valve should be piped to the drain.
2.4 — Heat Pump Systems with High Flow Rates
The Model WB will accept flow rates that will give a minimum temperature rise across the boiler as low as 3º F
when supplied with optional inlet baffle or oversized connections. Minimum temperature rise can also be
obtained by installing a bypass piping arrangement to adjust the flow through the boiler.
Use the following formula to determine the maximum and minimum flow rates of a given boiler:
FLOW (GPM) = KW x 6.816
T
where T is equal to any temperature rise between 3º F and 30º F, as indicated by TI1 and TI2 in Figure 2-1.
If the system flow rate is greater, a bypass around the boiler with a balancing cock or globe valve will be required
to bypass the appropriate portion of the system flow.
The relief valve outlet should be piped to a safe point of discharge where no serious personal injury or death to per-
sons, or impaired access to the boiler controls, would result from unexpected discharge of hot water from the relief
valve.
!Warning

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Model WB Electric Boiler Manual 2-3
2.5 — Electrical
FIGURE 2-1. Typical Piping Arrangement for Bypass System
For optimum temperature control without cycling, the flow rate through the boiler must be kept constant.
2.5 — Electrical
The following procedures are based on requirements of the National Electrical Code. Local electrical codes and/or
boiler codes may require slightly different procedures, and it is therefore recommended that the electrical instal-
lation be performed under the supervision of a qualified and licensed electrical contractor familiar with local
codes and inspection procedures.
Electric hot water boilers are typically designed for top connection to the main supply lugs and are supplied with
solderless wire connectors suitable for copper supply wires.
Disconnect and lock out the main power before proceeding with the electrical installation in order to avoid the hazard
of electrical shock, which can cause serious personal injury or death.
* If the hot water boiler cannot handle the full system GPM, substitute the balancing valve, which will be partially
opened, to bypass the appropriate portion of flow. The flow must be constant.
** The boiler temperature control is to be located so as to sense temperature of the system water after the boiler
water and bypassed water have blended (TI3).
!Warning

Installation Instructions
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If aluminum supply wires are selected by the customer, Cleaver-Brooks strongly recommends that the installing
electrical contractor splice a short length of copper wire to the aluminum supply conductors and terminate this
copper wire in the main supply lugs on the heater. If copper splices are not used and the customer chooses to
terminate the aluminum supply wires directly in the main supply lugs, an oxide inhibitor paste should be applied
liberally to the conductors.
Power wiring should be selected for high temperature use (minimum wire rating, 75º C, per National electrical
Code) and/or per local electrical codes.
2.5.1 — Electrical Installation Checklist
The following procedures are recommended:
1. Check the boiler nameplate for the boiler kilowatt rating, voltage, amperage, and whether it is single or three
phase.
2. Check the electrical supply voltage to verify that it conforms to the boiler requirements, and that sufficient cir-
cuit capacity is available for the boiler.
3. Refer to the boiler Wiring Diagram (WD), included with the boiler, for the number and rating of supply circuits
required by the boiler.
4. Refer to your local electrical code for proper wire and conduit sizes for these ratings.
5. Install wiring from the feeder switch or circuit breaker to the boiler, and connect to the bus assembly as indi-
cated on the boiler Wiring Diagram (WD).
6. All Cleaver-Brooks Electric Boilers are supplied with factory-mounted magnetic contactors, and all internal cir-
cuits are factory installed and tested.
7. Check all electrical connections for tightness. Vibration during transit sometimes loosens connections.
Before tightening the main supply lugs, disconnect and lockout main power to avoid the hazard of electrical shock,
which can cause serious personal injury or death.
Main supply lugs should be tightened every 24 hours during the first week of operation. After the first week, the main
supply lugs should be tightened once every 30 days. After the first 30 days of operation, all electrical power connec-
tions should be tightened (with power off).
To avoid the hazard of electrical shock: On boilers requiring more than one supply circuit, be sure that phasing is cor-
rect and circuits are not “mixed” before energizing. Failure to observe this warning could result in serious personal
injury or death.
!Warning
!Caution
!Warning

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Model WB Electric Boiler Manual 2-5
2.5 — Electrical
2.5.2 — Recommended Torque Settings
The following table notes typical torque settings only, as recommended by Cleaver-Brooks. Specific components
may differ between boilers. ALWAYS adhere to each component’s recommended torque setting for specific wire
size and type (often located on component’s factory label).
Recommended torque settings
Electric boilers - main control panel
Power distribution blocks (6AWG - load side) 45 in lbs
Fuse blocks for contactors (6AWG) 45 in lbs
Contactor, 50A res. (6AWG - line side) 45 in lbs
Contactor, 50A res. (8AWG - load side) 40 in lbs
Specific components may differ between boilers. ALWAYS adhere to each component’s recommended
torque setting for specific wire size and type (often located on component’s factory label).
!Caution

Installation Instructions
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CHAPTER 3 Pre-Start Preparation
3.1 — Inspection
Boilers which have been exposed to dust, wet and/or humid conditions must be thoroughly cleaned and dried
out. Otherwise, the buildup of dust and rust on the contactors, or moisture at the terminal end of the elements,
may result in severe damage.
The following precautions must be undertaken:
1. Make certain all electrical connections and element terminals are thoroughly cleaned, dried, and checked for
loose connections.
2. Inspect all contactors, fuse bases, and wire bundles for stray or loose metal objects (screws, bolts, metal
shavings, knockout slugs, etc.) that may lodge there. All such material must be removed before startup.
Make certain that you have read and understand Chapters 1 and 2 before proceeding.
Pre-startup should be performed by a qualified technician who is familiar with this equipment.
Failure to heed this warning may result in serious personal injury or death.
Disconnect and lockout the main power to avoid the hazard of electrical shock, which could cause serious personal
injury or death.
!Warning
!Warning

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3. There is a very high probability that, during shipment or storage prior to operation, the elements will accumu-
late moisture. The moisture will turn to steam when the elements are energized, rupturing the element casing.
To check for this condition, take a reading with an ohmmeter between one of the contactor terminals (load side)
to ground for each contactor. If the reading is less than 17,000 ohms for standard 3-phase connection, or
50,000 ohms for a single element, remove the fuses going to that contactor so that, during the first day’s opera-
tion, the low reading elements will not be energized, but will be heated by other dry elements and the moisture
driven out at a controlled rate.
There are alternate heating methods. Direct a heat lamp at the offending elements or remove the element assem-
bly, bake it in a 200º F oven for 8 hours, then reinstall and rewire. Following any of these procedures, the sup-
port element then may be put in operation by replacing the fuses after the elements have been rechecked with
an ohmmeter.
3.2 — Boiler and System Cleaning
One important phase in completing hot water heating installations and boiler startup is cleaning the system.
No matter how carefully a system is constructed, certain extraneous materials could find their way into the
boiler. Pipe dope, thread cutting oils, soldering flux, rust preventatives, soldering compounds, core sand, welding
slag, and dirt, sand or clays from the jobsite usually are found.
Cleaning a hot water system (either steel or copper piping) is neither difficult nor expensive. The three most com-
mon materials used for cleaning are:
a. Trisodium Phosphate (TSP)
b. Sodium Carbonate
c. Sodium Hydroxide (Lye)
Their preference is in the order shown. Prepare the cleaning solutions as follows, do not mix different types of
cleaners.
a. Trisodium Phosphate: one lb. for each fifty gallons in the system.
Moisture in the element may result in damage to the element.
Disconnect and lockout the main power to avoid the hazard of electrical shock, which could cause serious personal
injury or death.
!Caution
!Warning