Max-Ox MX-900B User manual

Max-Ox™ MX-900B Operators Manual, Rev. 0
Page 1 of 54
Max-Ox™ MX-900B
Commercial Wood Chip-Fired
Hydronic Boiler
Operators Manual

Max-Ox™ MX-900B Operators Manual, Rev. 0
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Max-Ox™
Model MX-900B
Commercial Wood Chip-Fired
Hydronic Boiler
Operators Manual
Please include the Manual Issue shown below when
communicating with Technical Support regarding this publication.
Publication History
Issue Date Description of Changes
Rev. 0 2/09/09 Original

Max-Ox™ MX-900B Operators Manual, Rev. 0
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Max Ox™MX-900B Operators Manual
TABLE OF CONTENTS
Section ___Page
Manual Overview
Overview of this Publication 4
Who Should Read This Manual 4
Supplemental Publications 4
Codes and Insurance Notice 5
Technical Support 6
Warranty Registration 7
Limited Warranty 8
Special Symbols 13
Specifications 14
How it Works
An Overview 16
MX-900B Control System 16
Fuel In-Feed Conveyor (by Customer) 17
Fuel In-Feed System 17
Under-fire Stoker Grate 18
Secondary Combustion Chamber 19
Fire-Tube Hydronic Boiler 19
Exhaust Fan 20
Ash Removal 20
Wood Chips as Fuel 22
Safety Information 23
Installation 26
Operation – Start-up 28
Operation – Shut-down 32
Touch Screen Controls 33
Ash Cleaning 49
Routine Lubrication 51
Boiler Water Treatment Program 52
Fuel Feed Jam Clearing 52

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MX-900B Operators Manual
Overview of this Publication
Congratulations on your decision to make very efficient use of
precious renewable fuels by using a commercial-duty automated Max-Ox™
MX-900B Wood Chip-fired Hydronic Boiler.
This MX-900B Operators Manual describes the features, installation,
operation, and maintenance of your new Max-Ox™ MX-900B Commercial
Wood-chip Fired Hydronic Boiler.
Who Should Read This Manual
This manual contains important information for those who will install,
operate, or maintain the MX-900B Wood chip-fired Hydronic Boiler.
Supplemental Publications
The National Fire Protection Association (NFPA) publishes codes,
standards, recommended practices, and guidelines for the installation and
operation of solid fuel burning appliances. To help ensure safe installation of
the Max-Ox™ MX-900B, please refer to the following NFPA publications:
•NFPA 211: Standard for Chimneys, Fireplaces, Vents, and Solid Fuel
Burning Appliances, 2006 Edition.
For information on NFPA 211, and other related NFPA publications, please
contact:
National Fire Protection Association
1 Batterymarch Park
Quincy, MA 02169-7471
www.nfpa.org
Phone: [phone]
Fax: [phone]

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MX-900B Operators Manual
Codes and Insurance Notice
The Max-Ox™ MX-900B Commercial Wood-chip Fired Hydronic Boiler is
a mechanical draft, direct-vented, NON-PRESSURIZED VESSEL, solid
fuel burning appliance. It must be installed in accordance with this Manual,
NFPA 211, Federal, State, and Local codes, and your Insurance
Underwriter’s requirements.
Local building code enforcement officials and fire inspectors are given
authority to determine if specific installations of solid fuel burning
appliances are safe. These professionals use recommended guidelines from
various nationally recognized organizations, such as the National Fire
Protection Association (NFPA), and the National Electrical Manufacturer’s
Association (NEMA).
Please be sure to follow the requirements of the Authority Having
Jurisdiction over your specific installation.
Your Insurance Underwriter may also have specific guidelines with respect
to installation and inspection requirements for your solid fuel burning
appliance.

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MX-900B Operators Manual
Max-Ox™ Technical Support
Your Sales Representative is your authorized Max-Ox™ factory -
trained Technical Support team member, and is standing-by to answer any
questions you may have with respect to your Max-Ox™ MX-900B
Commercial Wood-chip Fired Hydronic Boiler.
Please record the model number and serial number of your Max-Ox™
MX-900B in the space provided, and have this information available when
contacting your factory-authorized Sales Representative:
Model number: ________________ Serial Number: ________________
Operators Manual Revision Number: ________________
Purchase Date: ________________
Installation Date: ______________

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Max-Ox™ Warranty Registration Form
All Max-Ox™ products must be registered to activate the warranty,
and we encourage you to send this registration form back to us within 10
days of installation.
Please mail or fax the completed Max-Ox™ Warranty Registration
Form to:
Max-Ox, LLC Fax: [phone]
Mail: Max-Ox, LLC
481 Millwood Road
Willow Street, PA 17584
Customer Name: _______________________________________________
Address: _____________________________________________________
_____________________________________________________
_____________________________________________________
Phone: _________________________Fax: __________________________
E-mail: _______________________________________________________
Sales Representative Name: ______________________________________
Model Number: ___________________ Serial Number: ________________
Installation Date: _______________________________________________
Customer Signature: ____________________________________________
Date: ________________________________________________________

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Certificate of Limited Warranty
Max-Ox™ Wood Chip-Fired Hydronic Boilers
Page 1 of 5
General
This Limited Warranty is only available to the original owner of this
Max-Ox™ Wood-chip fired Hydronic Boiler (Unit). It is not transferable.
Max-Ox, LLC (Max-Ox) warrants this Max-Ox™ Wood-chip fired
Hydronic Boiler, and its component part(s), to be free from defects in
materials and workmanship, under normal use and service, for the
Applicable Warranty Periods. At its option, Max-Ox will repair or replace
defective Max-Ox™ Wood-chip fired Hydronic Boiler, or defective
component part(s), in accordance with the terms of the Limited Warranty, if
it fails in normal use and service during the Applicable Warranty Periods..
Any replacement components or replacement part(s) must be Max-Ox
authorized component or part(s). The replacement unit or part(s) will be
warranted only for the unexpired portion of the Unit’s Applicable Warranty
Periods.
Effective Date:
The Effective Date of the commencement of warranty coverage (or
the beginning of the Applicable Warranty Periods) is the date of installation
of the Unit, provided the installation, operation, and maintenance of the Unit
conforms to the instructions in the Max-Ox™ MX-900B Operators Manual,
applicable Federal, State, and Local codes, Customer’s Insurance
Underwriter requirements, and good plumbing, electrical, and HVAC
(Heating, Ventilation, Air Conditioning) trade practices. Otherwise, the
Effective Date of the commencement of warranty coverage is the date of the
manufacture of the Unit plus ninety (90) days.
Applicable Warranty Periods
Whetted hydronic heat exchanger components: Three (3) years
Cast refractory on stoker doors and combustion chamber: Three (3) years
Steel fabrications, mechanical components, thermal insulation: One (1) year
Electrical, electro-mechanical, and electronic components: One (1) year
Plumbing components (pump, valves, fittings, maifolds): One (1) year

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Certificate of Limited Warranty
Max-Ox™ Wood Chip-Fired Hydronic Boilers
Page 2 of 5
Applicable Warranty Periods (continued)
During the Applicable Warranty Periods, Max-Ox will pay a pro-rated
share of the cost of a defective item. For example, in the first year Max-Ox
will pay 100% of the cost of any failed item; in the second year Max-Ox will
pay 100% less 33.3% of the whetted hydronic heat exchanger components
and cast refractory components (3 year pro-rated); and so on until the end of
the Applicable Warranty Periods.
Warranty Exclusions
This Limited Warranty will not cover:
1. Damages to the fuel in-feed system components or fuel feed auger
train components or ash auger train components or stoker head
assembly components caused by non-wood materials present in the
fuel that are large enough to result in jams, such as metals, rocks,
masonry, fabrics, rope, stringy plant fibers.
2. Damages to the fuel in-feed system components or fuel feed auger
train components or ash auger train components or stoker head
assembly components caused by materials other than approved fuels.
Approved Fuels are specified as follows:
a. wood chips < 1.5” maximum dimension
b. wood dust briquettes < 2” maximum dimension
c. wood shavings
d. wood construction / demolition waste < 1.5” maximum dim.
3. Whetted hydronic heat exchanger component leak failure due to
contaminated or corrosive water-based heat transfer fluid or make-up
water.
4. Whetted hydronic heat exchanger component leak failures due to
Customer’s failure to follow a bi-annual (every 6 months) commercial
boiler water chemistry program for boiler water chemical analysis,
chemical treatment, boiler water blow-down, and boiler water make-

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up water addition for an open-system (non-pressurized) hydronic
heating boiler.
Certificate of Limited Warranty
Max-Ox™ Wood Chip-Fired Hydronic Boilers
Page 3 of 5
Warranty Exclusions (continued)
5. Service trips to your facility for instruction on how to install, operate,
or maintain the Unit, or to bring the Unit into compliance with local
codes or insurance underwriter requirements.
6. Units removed from the original installation location.
7. Damages, malfunctions, or failures resulting from failure to install the
Unit per applicable codes, or good plumbing, electrical, or HVAC
trade practices.
8. Damages, malfunctions, or failures resulting from failure to install,
operate, or maintain the Unit in accordance with the Max-Ox™ MX-
900B Operators Manual.
9. Damages, malfunctions, or failures resulting from over-firing the Unit
on combustible materials other than Approved Fuels.
10.Damages, malfunctions, or failures caused by abuse, accident, fire,
flood, freezing, lightning, or acts of God.
11.Damages, malfunctions, or failures resulting from failure to operate
the Unit without sufficient heat transfer fluid.
12.Cracks in the cast refractory that can be repaired with high-
temperature refractory joint compound.
13.Performance problems caused by improper sizing of the Unit,
improper sizing of the flue gas vent, or improper sizing of the
combustion make-up air opening requirements.
Labor, Shipping, and Processing Costs
This Limited Warranty does not cover any labor expenses for service,
repairs, reinstallation, permits, or removal and disposal of a failed Unit or its
defective component part(s). All such expenses are the owner’s
responsibility.

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Certificate of Limited Warranty
Max-Ox™ Wood Chip-Fired Hydronic Boilers
Page 4 of 5
Labor, Shipping, and Processing Costs (continued)
Max-Ox, LLC will pay for delivery of an “in-warranty” replacement
Unit or component part(s) to a location at or near the original point of
delivery. The Owner is responsible for any additional local delivery,
equipment rigging, and reinstallation charges. The owner is also responsible
for freight costs incurred in the return of a defective Unit or component
part(s) to the point of purchase.
Activation of Warranty
All Max-Ox™ products must be registered to activate the warranty,
and we encourage you to send this registration form back to us within 10
days of installation. The Warranty Registration Form is located on page 7 of
this manual.
Please mail or fax the completed Max-Ox™ Warranty Registration
Form to:
Max-Ox, LLC; fax: [phone]
Mail: Max-Ox, LLC
481 Millwood Road
Willow Street, PA 17584
How to Obtain Warranty Claim Assistance

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Warranty Claims must be made promptly to your factory authorized
Sales Representative. Your Sales Representative will assist you through the
claim process with costs apportioned as described elsewhere in this Limited
Warranty.
Certificate of Limited Warranty
Max-Ox™ Wood Chip-Fired Hydronic Boilers
Page 5 of 5
How to Obtain Warranty Claim Assistance (continued)
Max-Ox, LLC reserves the right to inspect, or require the return of, a
failed Unit for defective part(s). If requested items are not returned, or are
returned without all of the component parts intact, Max-Ox, LLC reserves
the right to invoice the Owner for the replacement Unit or part(s).
Exclusive Warranty – Limitation of Liability
This Limited Warranty is the only Warranty for this Unit given by
Max-Ox, LLC. No one is authorized to make any other warranties for the
Unit or its component part(s) on behalf of Max-Ox, LLC.
ANY IMPLIED WARRANTIES, INCLUDING
MERCHANTABILITY, FOR FITNESS FOR A PARTICULAR PURPOSE,
SHALL NOT EXTEND BEYOND THE APPLICABLE WARRANTY
PERIODS. THE SOLE LIABILITY OF MAX-OX, LLC, WITH RESPECT
TO ANY DEFECT, SHALL BE AS SET FORTH IN THIS LIMITED
WARANTY, AND ANY CLAIMS FOR INCIDENTAL OR
CONSEQUENTIAL DAMAGES (INCLUDING DAMAGE FROM
WATER LEAKAGE) ARE EXCLUDED. Some states do not allow
limitations on how long an implied warranty lasts, or for the exclusion of
incidental or consequential damages, so the above limitations or exclusions
may not apply to you.
This Limited Warranty gives you specific legal rights, which vary
from state to state.

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MX-900B Operators Manual
Special Symbols
Note the use of signal words: DANGER, WARNING, and
CAUTION with safety messages. The appropriate Signal Word
has been selected using the following guidelines:
DANGER: Indicates an imminently hazardous situation which, if
not avoided, will result in death or serious injury.
WARNING: Indicates a potentially hazardous situation which, if
not avoided, will result in death or serious injury.
CAUTION: Indicates a potentially hazardous situation which, if not
avoided, may result in minor or moderate injury, or serves as a reminder
to follow appropriate safety practices.

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MX-900B Operators Manual
Specifications
Your new Max-Ox™ MX-900B is classified as a fully modulated
(automatic), induced draft, under-grate stoker fed wood chip-fired hydronic
heating (hot water) boiler.
a. Nominal Output, BTU/hr: 900,000
b. Design Supply Temperature: 180°F
c. Approved Fuels:
owood chips < 1.5” maximum dimension
owood dust briquettes < 2” maximum dimension
owood shavings
owood construction / demolition waste < 1.5”
maximum dimension
d. Heat exchanger type: 2-pass fire tube type (non-condensing)
e. Material: Carbon Steel per ASTM A-36
f. Heat transfer fluid: water
g. Working pressure: 0 psig (atmospheric, NON-PRESSURIZED)
h. Design Supply temperature: 180 °F
i. Modulated (variable) speed primary loop circulator
j. Heat Transfer Fluid Capacity: 300 gallons
k. Fluid Temperature Control: PLC
l. Supply & Return connections: 3 inch female NPT
m. Draft type: Induced draft
n. Flue gas stack outlet diameter: 8 inches
o. Ash Clean-out: full-access top removable panels, (3) exhaust
plenum doors, ash cyclone container, ash auger bin, front and
rear stoker head access doors, bolted stoker grate access panel
p. Thermal insulation envelope: full coverage mineral wool
blanket on heat exchanger and combustion section, cast
refractory on stoker head doors and secondary combustion
section..
q. Enclosure: non-weather-tight primed and painted steel
r. Dimensions: 6 ft. wide x 14 ft long ( includes metering bin and
fuel auger) x 10 ft-6 inch to top of boiler
s. Weather enclosure ceiling height for boiler top panel removal:
14 feet

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MX-900B Operators Manual
Specifications (cont)
t. Electrical Requirements: 30 Amp, 240 VAC, 1 phase, 3-wire
plus safety ground
u.
Operating current: 8 Amps
v. Auxiliary control dry contacts
1. Boiler Ready signal contact
2. System Alarm signal contact
3. Fuel In-Feed conveyor control contact
4. Heat Dump control contact
w. Combustion turn-down ratio: 8:1
x. Fuel Auger Tube Fire Extinguisher Water connection: _ female
NPT, 1/2 inch minimum supply pipe diameter @ 40 psi
minimum water pressure
y. Dry (shipping & rigging) weight: 7,800 lbs

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MX-900B Operators Manual
How it Works
An Overview
Your new MX-900B Wood chip-fired Hydronic Boiler (hot water
heating boiler) is a very modern version of a very old and time-proven
method for properly burning solid fuels; called the “under-fire stoker
grate” method.
What sets your MX-900B system apart from previous older
generations of under-fire stoker grate systems is that the MX-900B
system makes use of modern advances in controls technology and
knowledge of combustion chemistry, along with advances in materials
science and modern manufacturing methods, to provide you with a
rugged, highly fuel efficient and low maintenance automatic wood
chip-fired combustion system.
This How it Works narrative is written to guide you through each
functional sub-assembly of the MX-900B Combustion System, so that
you will gain a clear understanding of the entire unit.
MX- 900B Control System:
The automatic control system of the MX-900B system is a modern
version of proven combustion control strategy. The MX-900B Control
System hardware consists of an industrial-duty programmable logic
controller (microprocessor-based PLC), touch-screen Operator
interface control / view panel, three variable speed AC motor
controllers, and a very carefully selected array of robust automation
sensors.
These industrial-duty controls components are orchestrated in unison
through a carefully designed, and extensively field tested, set of
software programs that are permanently stored in the memory of the
programmable logic controller. The control system is designed to
ensure safe operating conditions are maintained at all times, and to
initiate an automatic shut-down in the event of a fault.

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Fuel In-Feed System Conveyor ( by Customer):
You will need to provide wood chip fuel in-feed conveyor system in
order to supply fuel to your MX-900B unit. Your fuel in-feed system
should be tailored to your specific site layout requirements.
We recommend that your fuel storage bin or silo be designed to
protect your wood chips from the weather. Your wood chip transfer
conveyor should be designed to transport fuel from your storage
bin/silo to the MX-900B Fuel Metering Bin.
1. Sizing your Transfer Conveyor: Your transfer conveyor system
should be sized to convey approximately _ to 1 cubic yards of
wood chips per hour in order to support the maximum fuel
firing rate of the Max-Ox unit. This fuel flow rate criteria is a
conservative estimate that takes into account the additional fuel
volume flow needed when firing green (fresh-cut) hardwood
wood chips, as well as the variations in bulk density (fluffiness)
of the chipped or shredded wood fuel types available. Of
course, the dryer your fuel is, the less of it you will need to burn
to achieve the full power rating of renewable fuel combustion
units.
Fuel In-Feed System:
Your MX-900B mechanical hardware begins at the fuel in-feed
system. The fuel in-feed system serves to automatically receive wood
chips from your fuel storage and transfer system, and then deliver
them to the stoker grate combustion unit. The fuel in-feed system
consists of an inlet chute, an air operated knife gate, a small auxiliary
electric air compressor, a small storage chamber called the metering
bin, a fuel in-feed auger with variable speed drive motor, and a set of
automatically controlled electrical contacts to energize your fuel in-
feed conveyor motor controller.
Inlet Chute, Knife Gate, Metering Bin, and Air Compressor:
The fuel in-feed system inlet chute serves to funnel wood chips
through an open knife gate, and into the metering bin. A level sensor
in the metering bin signals your fuel transfer conveyor to stop, and

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closes the knife gate. The auxiliary air compressor provides
compressed air for actuation of the knife gate.
Fuel Feed Auger and Drive Motor: Wood chip fuel is fed by a
rotating helical auger from the metering bin and on into the stoker
grate combustion unit. The fuel feed auger is located in the bottom of
the metering bin, and extends into the stoker grate combustion unit.
The variable speed electric motor and gear reduction assembly that
drives the auger is equipped with an automatic jam clearing feature to
protect your system in the event your fuel inadvertently becomes
contaminated with unwanted metals or stones that cause the auger to
jam.
Fuel Feed Tube Fire Extinguisher: The fuel feed tube between
the metering bin and the stoker is equipped with a thermostatically
actuated water valve and thermostatic sensing element. Should the
temperature of the fuel within the fuel feed tube increase to 150 °F,
water will begin to spray into the fuel feed tube to extinguish any fire
that may be present. Below 150°F the fire extinguisher valve is fully
closed, and at a set-point of 190°F the valve is fully open.
Under-fire Stoker Grate:
An under-fire stoker grate combustion system is a simple time-proven
and robust method for conveying solid fuels into a combustion
chamber. Wood chips are conveyed by a rotating helical fuel in-feed
auger from the fuel in-feed metering bin and on into the stoker unit.
Fuel gently spills out of the mouth of the stoker cavity, and onto a
stationary ring-shaped grate. Very thin slots in the ring grate permit pre-
heated fresh combustion air to permeate the fuel bed that has spilled
onto the top of the ring grate, and thereby sustain a steady fire on the
exposed surface of the fuel.
Combustion Air Adjustment: Three manually adjustable
combustion air slide gates are mounted on the exterior face of the
stoker grate assembly. One slide gate serves to manually adjust and
set the Primary combustion air flow rate up through the thin slots in
the stoker ring grate. A second slide gate serves to manually adjust
and set the Secondary combustion air flow rate into the Secondary
Combustion Chamber lower combustion air inlets. A third slide gate

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serves to manually adjust and set the Tertiary combustion air flow rate
into the Secondary Combustion Chamber upper combustion air inlets.
Secondary Combustion Chamber:
All of the hot gases rising off of the burning surface of the fuel rise
upward into a well-insulated but extremely hot ceramic-lined secondary
combustion chamber. Carefully proportioned and highly preheated
secondary combustion air is introduced into the rising flammable fuel
gases within the secondary combustion chamber in such a way as to
promote thorough mixing with the rising fuel gasses. The resultant
mixture produces very high combustion temperatures, and therefore
very complete combustion.
Fire-Tube Hydronic Boiler:
All of the very high temperature fully combusted gasses continue to
flow upward into a modern, high efficiency, 2-pass hydronic heat
exchanger, wherein all of the available heat energy is extracted, without
permitting water vapor in the flue gas to condense. Heat energy is
transferred to circulating water for your hydronic space heating or
industrial /commercial process hot water needs.
Heat Exchangers and Water Vapor: The Hot Water Heating Boiler
system flue gas exhaust temperature and the boiler return temperature
are automatically controlled so as to prevent condensation of water
vapor within the heat exchanger. This means that just enough heat
energy deliberately remains in the exhaust gases so that the water vapor
does not cool down to the point where liquid water forms within the
heat exchangers, or your chimney. Instead, the water remains in the
vapor state, and is exhausted into the atmosphere. On cool days you
will see this water vapor form a vapor cloud plume as the exhaust rises
up into the atmosphere.