Mastervolt ALPHA ALTERNATOR 12/90 User manual

USERS MANUAL / GEBRUIKERSHANDLEIDING
BETRIEBSANLEITUNG / MANUEL UTILISATEURS
ALPHA ALTERNATOR
12/90, 12/130, 24/75, 24/110 & 24/150
HIGH OUTPUT ALTERNATORS WITH ALPHA PRO II REGULATOR
MASTERVOLT
Snijdersbergweg 93,
11 5 AN Amsterdam
The Netherlands
Tel.: [phone]
Fax.: [phone]
www.mastervolt.com
1 2887/ 2

CONTENTS
2 January 2 13/ Alpha alternator - Alpha Pro II regulator / EN
THIS MANUAL HAS TO BE READ IN COMBINATION
WITH THE “APPENDIX ALPHA ALTERNATOR”
CONTENTS: 1 2887/ 2
1 GENERAL INFORMATION............................................................................................................................. 4
1.1 Use of this manual .............................................................................................................................. 4
1.2 Guarantee specifications .................................................................................................................... 4
1.3 Quality ................................................................................................................................................. 4
1.4 Validity of this manual ......................................................................................................................... 4
1.5 Liability ................................................................................................................................................ 4
1.6 Changes to the Alpha alternator / Alpha Pro II regulator.................................................................... 4
2 SAFETY GUI ELINES AN MEASURES ..................................................................................................... 5
2.1 Warnings and symbols ....................................................................................................................... 5
2.2 Use for intended purpose ................................................................................................................... 5
2.3 Organizational measures .................................................................................................................... 5
2.4 Maintenance & repair.......................................................................................................................... 5
2.5 General safety and installation precautions ....................................................................................... 6
2.6 Warning regarding life support applications ....................................................................................... 6
2.7 Warning regarding the use of batteries. ............................................................................................. 6
3 HOW IT WORKS ............................................................................................................................................. 7
3.1 Alpha alternator .................................................................................................................................. 7
3.2 Alpha Pro II regulator .......................................................................................................................... 7
3.2.1 Three step charging system ................................................................................................ 7
3.2.2 Temperature compensated charging .................................................................................. 8
3.2.3 MasterBus ........................................................................................................................... 8
4 INSTALLATION .............................................................................................................................................. 9
4.1 Unpacking ........................................................................................................................................... 9
4.2 Important to know ............................................................................................................................... 9
4.3 Environment ........................................................................................................................................ 9
4.4 Mounting of the alternator ................................................................................................................. 1
4.4.1 General .............................................................................................................................. 1
4.4.2 Rotating direction .............................................................................................................. 1
4.4.3 Mounting step-by-step ....................................................................................................... 1
4.5 Electrical connections ....................................................................................................................... 11
4.5.1 Battery capacity ................................................................................................................. 11
4.5.2 Installation drawings .......................................................................................................... 11
4.5.3 Wiring instructions ............................................................................................................. 12
4.5.4 Connection of a tachometer (optional) .............................................................................. 13
4.5.5 Connection of an alternator indication lamp (optional) ...................................................... 13
4.5.6 Use of a battery isolator (optional) .................................................................................... 14

CONTENTS
EN / Alpha alternator - Alpha Pro II regulator / January 2 13 3
5 COMMISSIONING ......................................................................................................................................... 15
5.1 Selecting the charging mode ............................................................................................................ 15
5.1.1 Commissioning when selecting MasterBus ...................................................................... 15
5.2 Testing .............................................................................................................................................. 15
5.2.1 Test prior to starting engine .............................................................................................. 15
5.2.2 In operation test ................................................................................................................. 16
5.2.3 Voltage Settings ................................................................................................................ 18
5.2.4 Absorption voltage adjustment .......................................................................................... 18
5.2.5 Float voltage adjustment ................................................................................................... 18
5.2.6 Absorption time adjustment ............................................................................................... 18
5.2.7 Temperature compensation .............................................................................................. 18
5.3 Operation .......................................................................................................................................... 18
6 MASTERBUS ................................................................................................................................................ 19
6.1 What is MasterBus?.......................................................................................................................... 19
6.2 How to set up a MasterBus network ................................................................................................. 19
6.3 MasterBus functions ......................................................................................................................... 2
6.3.1 Monitoring .......................................................................................................................... 2
6.3.2 Alarms ............................................................................................................................... 2
6.3.3 History ............................................................................................................................... 2
6.3.4 Configuration ..................................................................................................................... 21
6.3.5 Alpha Pro II event source list (Alpha Pro II as event source) ........................................... 22
6.3.6 Alpha Pro II event target list (Alpha Pro II as event target) ............................................... 22
6.3.7 Keep alive function ............................................................................................................ 23
6.3.8 Small engine function ........................................................................................................ 23
6.3.9 Unlocking configuration ..................................................................................................... 23
6.3.1 MasterShunt connected .................................................................................................... 23
6.3.11 Start Float SOC ................................................................................................................. 23
7 MAINTENANCE ............................................................................................................................................ 24
7.1 Electrical connections ....................................................................................................................... 24
7.2 Cleaning of the alternator ................................................................................................................. 24
7.3 Mounting of the alternator ................................................................................................................. 24
7.4 Tension and condition of V-belts. ..................................................................................................... 24
8 TROUBLE SHOOTING ................................................................................................................................. 25
9 TECHNICAL ATA ....................................................................................................................................... 27
9.1 Specifications Alpha alternator ......................................................................................................... 27
9.2 Specifications Alpha Pro II regulator ................................................................................................ 28

GENERAL INFORMATION
4 January 2 13/ Alpha alternator - Alpha Pro II regulator / EN
1 GENERAL INFORMATION
1.1 USE OF THIS MANUAL
This manual serves as a guideline for the safe and
effective operation, maintenance and possible
correction of minor malfunctions of the Alpha
alternator and the Alpha Pro II regulator.
This manual is valid for the following models:
Part
number
escription
48512 9 Alpha alternator 12/9 , incl 3-stage
Alpha Pro II regulator MasterBus
4851213 Alpha alternator 12/13 , incl 3-stage
Alpha Pro II regulator MasterBus
48512131 Alpha alternator 12/13 MG + 3-stage
Alpha Pro II regulator MasterBus
48524 75 Alpha alternator 24/75, incl 3-stage
Alpha Pro II regulator MasterBus
48524 76 Alpha alternator 24/75 MG + 3-stage
Alpha Pro II regulator MasterBus
4852411 Alpha alternator 24/11 , incl 3-stage
Alpha Pro II regulator MasterBus
4852415 Alpha alternator 24/15 , incl 3-stage
Alpha Pro II regulator MasterBus
45512 Alpha Pro II regulator for Mastervolt
and Bosch alternator
Every person who works on or with the Alpha
alternator / Alpha Pro II regulator must be completely
familiar with the contents of this manual and must
follow its instructions. Installation of, and work on the
Alpha alternator / Alpha Pro II regulator, must be
carried out by qualified, authorised and trained
personnel, consistent with the locally applicable
standards and taking into consideration the safety
guidelines and measures (section 2 of this manual).
Keep this manual at a secure place!
1.2 GUARANTEE SPECIFICATIONS
Mastervolt guarantees that this unit has been built
according to the legally applicable standards and
specifications. Should work take place, which is not
in accordance with the guidelines, instructions and
specifications contained in this users manual, then
damage may occur and/or the unit may not fulfil its
specifications. All of these matters may mean that
the guarantee becomes invalid.
1.3 QUALITY
During their production and prior to their delivery, all
of our units are exhaustively tested and inspected.
The standard guarantee period is two years.
1.4 VALI ITY OF THIS MANUAL
All of the specifications, provisions and instructions
contained in this manual apply solely to standard
versions of the Alpha alternator / Alpha Pro II
regulator delivered by Mastervolt.
1.5 LIABILITY
Mastervolt can accept no liability for:
• consequential damage due to use of the
Alpha alternator / Alpha Pro II regulator;
• possible errors in the manuals and the
results thereof.
CAREFUL!
Never remove the type number plate.
Important technical information required for service,
maintenance & secondary delivery of parts can be
derived from the type number plate.
1.6 CHANGES TO THE ALPHA ALTERNATOR /
ALPHA PRO II REGULATOR
Changes to the Alpha alternator / Alpha Pro II
regulator may be carried out only after obtaining the
written permission of Mastervolt.

SAFETY GUIDELINES AND MEASURES
EN / Alpha alternator - Alpha Pro II regulator / January 2 13 5
2 SAFETY GUI ELINES AN MEASURES
2.1 WARNINGS AN SYMBOLS
Safety instructions and warnings are marked in this
manual by the following pictograms:
A procedure, circumstance, etc which
deserves extra attention.
CAREFUL!
Special data, restrictions and rules with
regard to preventing damage.
WARNING
A WARNING refers to possible injury to
the user or significant material damage to
the Alpha alternator / Alpha Pro II
regulator if the user does not (carefully)
follow the procedures.
WARNING
Moving machinery. This symbol indicates
that a potential hazard exists caused by
moving parts.
2.2 USE FOR INTEN E PURPOSE
1 The Alpha alternator / Alpha Pro II regulator is
constructed as per the applicable safety-
technical guidelines.
2 Use the Alpha alternator / Alpha Pro II regulator
only:
• for the charging of lead acid or li-ion
batteries and the supply of loads connected
to these batteries, in permanent systems;
• with fuses, protecting the wiring between
Alpha alternator / Alpha Pro II regulator
output and battery;
• in a technical correct condition;
• in a closed, well-ventilated room, protected
against rain, moist, dust and condensation;
• observing the instructions in the users
manual.
WARNING
Never use the Alpha alternator / Alpha
Pro II regulator in locations where there is
danger of gas or dust explosion or
potentially flammable products!
3 Use of the Alpha alternator / Alpha Pro II
regulator other than mentioned in point 2 is not
considered to be consistent with the intended
purpose. Mastervolt is not liable for any damage
resulting from the above.
2.3 ORGANIZATIONAL MEASURES
The user must always:
• have access to the user's manual;
• be familiar with the contents of this manual.
This applies in particular to section 2, Safety
Guidelines and Measures.
2.4 MAINTENANCE & REPAIR
1 If the Alpha alternator, Alpha Pro II regulator and
engine are switched off during maintenance
and/or repair activities, they should be secured
against unexpected and unintentional switching
on:
• remove the key from the engine ignition
switch
• switch off the connection with the batteries
or remove the DC fuse(s);
• be sure that third parties cannot reverse the
measures taken.
WARNING
When service has to be carried out while
the engine is running, be aware of
moving parts like V-belts.
2 If maintenance and/or repairs are required, only
use original spare parts.

SAFETY GUIDELINES AND MEASURES
6 January 2 13/ Alpha alternator - Alpha Pro II regulator / EN
2.5 GENERAL SAFETY AN INSTALLATION
PRECAUTIONS
• Before using the Alpha alternator / Alpha Pro II
regulator, read all instructions and cautionary
markings on the Alpha alternator / Alpha Pro II
regulator, the batteries, and all appropriate
sections of the manual. If you do not follow these
instructions danger may occur or the unit could
be damaged.
• The Alpha alternator / Alpha Pro II regulator is
designed to be permanently connected to your
DC electrical systems. Mastervolt recommends
that all wiring be done by a certified technician or
electrician to ensure adherence to proper
electrical wiring regulations.
• Wrong use of the mode selector will lead to
serious damage to batteries, the Alpha alternator,
the Alpha Pro II regulator and the cabling.
• Wrong MasterBus settings will lead to serious
damage to batteries, the Alpha alternator, the
Alpha Pro II regulator and the cabling.
• Selection of a MasterShunt connected to a
battery with a different nominal voltage will lead
to serious damage to batteries, the Alpha
alternator, the Alpha Pro II regulator and the
cabling.
• Be aware of parts that can be hot: not only
engine parts, but the alternator as well.
• In case of fire, you must use the fire extinguisher
which is appropriate for electrical equipment.
• Short circuiting or reversing polarity will lead to
serious damage to batteries, the Alpha alternator,
the Alpha Pro II regulator and the cabling. Fuses
between the batteries and the electrical
installation can not prevent damage caused by
reversed polarity and the warranty will be void.
• Secure the DC wiring with a fuse, according to
the guidelines in this manual. Connection and
protection must be done in accordance with local
standards.
• Do not work on the Alpha alternator, Alpha Pro II
regulator or parts of the electrical system if it is
still connected to a current source. Only allow
changes in your electrical system to be carried
out by qualified electricians.
2.6 WARNING REGAR ING LIFE SUPPORT
APPLICATIONS
Mastervolt products are not sold for applications in
any medical equipment intended for use as a
component of any life support system unless a
specific written agreement pertaining to such
intended use is executed between the manufacturer
and Mastervolt. Such agreement will require the
equipment manufacturer either to contract for
additional reliability testing of the Mastervolt parts
and/or to commit to undertake such testing as a part
of the manufacturing process. In addition such
manufacturer must agree to indemnify and hold
Mastervolt non responsible from any claims arising
out of the use of the Mastervolt parts in the life
support equipment.
2.7 WARNING REGAR ING THE USE OF
BATTERIES.
Excessive battery discharge and/or high charging
voltages will cause serious damage to batteries. Do
not exceed the recommended limits of discharge
level of your batteries. Avoid short circuiting
batteries, as this may result in explosion and fire
hazard. Installation of the batteries and adjustments
of the Alpha alternator / Alpha Pro II regulator should
only be undertaken by authorised personnel!

TECHNOLOGY
EN / Alpha alternator - Alpha Pro II regulator / January 2 13 7
3 HOW IT WORKS
This user’s manual describes the installation and
operation of the Alpha Alternator together with the
Alpha Pro II regulator from Mastervolt. This charging
system is designed to provide a high output power at
low RPM, which is typical for marine applications. It
consists of the following main components (See
figure 1):
1 Alpha alternator (included)
2 Alpha Pro II charge regulator (included)
3 Battery fuses (1 A fuse included)
4 Batteries (not included)
5 Temperature sensor (included)*
*The picture shows an installation without
MasterShunt. If you have a MasterShunt installed,
the Alpha Pro II temperature sensor is better
mounted on the alternator.
Fig.1: Basic charging system consisting of the
Alpha Alternator and the Alpha Pro II regulator
3.1 ALPHA ALTERNATOR
Mastervolt Alpha alternators are specially designed
to provide high power even at low RPM. A pulley
ratio of 1:2 – 1:3 and an engine idle speed of around
7 -8 rpm will generate substantial current for
charging the battery sets and powering the
connected equipment.
Mastervolt alternators are resistant to the high
temperature of the engine room, allowing the engine
to serve as the energy source for onboard
consumers and as a quick charger for the service
and starter batteries.
3.2 ALPHA PRO II REGULATOR
The Alpha Pro II voltage regulator controls the
alternator’s output voltage. It is designed for optimal
recharging of both wet, gel, AGM and li-ion batteries.
Battery charging is accomplished in three automatic
stages: BULK, ABSORPTION and FLOAT. Simple,
automatic operation is made possible by the
microprocessor that is the brain of the Alpha Pro II
regulator.
3.2.1 Three step charging system
Figure 2: Three step plus charge system
See figure 2. The first step of the three step plus
charge system is the BULK phase (A), in which the
output current of the charging system is limited by
the maximum output current of the alternator and the
engine RPM. At this stage the major part of the
battery capacity is rapidly charged. The current
charges the batteries and the voltage will rise to the
absorption voltage. Refer to the specifications for the
charging voltages for different batteries.
The duration of this phase depends on the ratio of
charging capacity to battery capacity and on the
degree to which the batteries were discharged to
begin with.
The bulk phase is followed by the absorption phase.
(B). The absorption charge starts when the voltage
on the batteries has reached the absorption voltage,
and ends when the battery is fully charged. Battery
voltage remains constant throughout this stage, and
the charge current depends on the state of charge of
the battery, the battery type, the ambient
temperature, and so on. With a wet cell battery this
stage lasts about four hours, with gel, AGM and li-
ion batteries around three.
1
3
45
2
CHARGE CURRENT
BATTERY VOLTAGE
BULK ABSORPTION FLOAT
TIME

TECHNOLOGY
8 January 2 13/ Alpha alternator - Alpha Pro II regulator / EN
Once the battery is fully charged, the Alpha Pro II
regulator automatically switches over to the float
phase.
After Absorption phase (C) the Alpha Pro II regulator
switches to Float voltage and stabilises this voltage
to maintain the batteries in an optimum condition.
Connected loads are powered directly by the
charging system. If the load is higher than capacity
of the charging system, the required additional
power comes from the battery, which will be
progressively discharged. The Alpha Pro II regulator
will start a new cycle when the engine is started
again.
3.2.2 Temperature compensated charging
A battery temperature sensor is not included in the
delivery of the Alpha Pro II regulator. By installing
this battery temperature sensor the charge voltages
are automatically adapted for deviating
temperatures.
Figure 3: Temperature compensated charging
See figure 3. When the battery temperature is low,
the charge voltage increases. On the other hand,
when the battery temperature is high, the charge
voltage is decreased. Over charge and gassing are
prevented this way. This will extend the life of your
batteries. Consult your battery manufacturer for
recommended charging voltages.
3.2.3 MasterBus
The Alpha Pro II regulator features MasterBus,
enabling communication with a MasterShunt for
instance. This MasterShunt can be selected in the
configuration menu after which it transmits battery
state data to the Alpha Pro II. More MasterBus
devices can be connected.
12V 24V
battery temperature (°C)
charge voltage (V)

INSTALLATION
EN / Alpha alternator - Alpha Pro II regulator / January 2 13 9
4 INSTALLATION
During installation and commissioning of the Alpha
Alternator and Alpha Pro II regulator, the Safety
Guidelines & Measures are applicable at all times.
See section 2 of this manual.
4.1 UNPACKING
In addition to the Alpha Pro II alternator the delivery
includes:
• The Alpha Pro II regulator
• A cable assembly for Mastervolt and Bosch
alternators
• A Bosch adapter
• Battery temperature sensor
• MasterBus terminator
• This user’s manual + appendix
After unpacking, check the contents for possible
damage. Do not use the product if it is damaged. If
in doubt, contact your supplier.
4.2 IMPORTANT TO KNOW
Mastervolt alternators offer a much higher output
than alternators usually supplied with engines. As a
result, a single V-belt is insufficient to transfer the
power from the engine to the alternator. Therefore
Mastervolt alternators are standard equipped with a
pulley for two V-belts.
Before installing the pulley ratio between alternator
and main engine need to be checked.
Alternator model Maximum speed:
12/9 , 12/13 ,
24/75, 24/11 , 24/15
8 RPM
Your engine supplier can help you choose an
appropriate double pulley and advise on the bracket
for the alternator.
Note that the alternator support has to be
made suitable for handling the high
forces as well
CAREFUL!
Any changes to the alternator, including
the alternator’s wiring, pulley and/or
mounting points, will make the guarantee
void!
The (remaining) capacity of the engine should be
large enough to drive the alternator. Take into
consideration that the efficiency of a typical
alternator (including transmission V-belt) is
approximately 5 %.
Example:
At full output power, the required engine power to
drive Alpha Alternator model 24/75 is:
75 Amps x 28.5V / 5 % = 4.3kW
4.3 ENVIRONMENT
Keep the Alpha Pro II alternator away from:
• Excessive heat. The maximum alternator
temperature should not exceed 1 5°C/22 °F. An
alternator can become damaged if it operates too
long at excessive temperatures. Damaging heat
levels are generated in two ways:
1. when the alternator becomes dirty either
externally or internally restricting its ability to
dissipate heat from its external surface or
2. when fresh airflow through the alternator is
restricted.
• irt and dust. The alternator operates less
efficiently when buildup of dirt particles forms
around wire and cable connections. Dirty
connections impair the flow of electrical current.
• Vibration. If the alternator is poorly or loosely
mounted, the resulting vibration can damage
internal components. A loosely mounted
alternator will also diminish the performance of
the belt drives.

INSTALLATION
1 January 2 13/ Alpha alternator - Alpha Pro II regulator / EN
4.4 MOUNTING OF THE ALTERNATOR
4.4.1 General
Consult your engine supplier for the availability of a
mounting bracket and other necessary mounting
hardware to mount the alternator on the engine.
Mastervolt Alpha alternators require two A-type V-
belts of equal length (measured pair) for
transmission.
As every engine differs from the other, Mastervolt
can not give any specific mounting instructions for
any particular engine.
4.4.2 Rotating direction
The Alpha alternator is equipped with a bidirectional
fan. Therefore it may rotate in either a clockwise or
counter clockwise direction.
4.4.3 Mounting step-by-step
1 Determine the alternator mounting location.
2 Loosely attach the mounting bracket to the
engine with the mounting engine bolts. Position
the alternator mounting foot between the two
ears (figure 5, references A and B) on the
mounting bracket with the alternator mounting
bolts. Note that the ear at the rear side of the
alternator housing should be fixed in such way
that it can freely move in the direction of the
arrow (see figure 5, reference A). This is to avoid
mechanical stress due to possible high
temperatures of the alternator.
Figure 5
3 See figure 6. Align the alternator pulley (3) with
the engine (1) drive pulley (2) and tighten the
bracket mounting bolts, securing the mounting
bracket (4) to the engine.
Figure : Alignment
90°
1
2
3
D
D
C
B
A

INSTALLATION
EN / Alpha alternator - Alpha Pro II regulator / January 2 13 11
4 Loosely attach the alternator adjustment strap
(Figure 5 and 6: reference D) to the alternator
adjustment ear (figure 5, reference C) with the
bolt, lockwasher and flat washer.
5 Tighten the V-belt by applying pressure to the
alternator front housing only and tighten the bolt
to the adjustment ear (figure 5, reference C). Set
belt tension per belt manufacturer's
recommended specifications. If manufacturer's
specifications are not readily available, set V-belt
tension tight enough so that the V-belt on
alternator fan pulley will not slip when attempting
to rotate alternator by hand.
CAREFUL!
Alternator will be permanently damaged if
pressure is applied to rear housing.
Tighten the V-belt by pressing against
front casing near alternator fan.
6 Tighten all remaining alternator mounting bolts
and check all other bolts to secure the
installation.
4.5 ELECTRICAL CONNECTIONS
WARNING
Let installation work be done by a
licensed electrician. Before beginning
with the connection of the wiring, make
the DC distribution voltage free.
CAUTION!
Short circuiting or reversing polarity may
lead to serious damage to the batteries,
the alternator, the Alpha Pro II regulator,
the cabling and/or the terminal
connections. Fuses can not prevent
damage caused by reversed polarity. The
damage as a result of reverse polarity is
not covered by the warranty.
CAUTION!
Too-thin cables and/or loose connections
can cause dangerous overheating of the
cables and/or terminals. Therefore
tighten all connections well, in order to
limit transition resistance as far as
possible. Use cables of the correct size.
See specifications (section 9) for
recommended wire sizes.
• Use the supplied cable assembly for connection
of the Alpha Pro II regulator
• DC Cables to connect the Battery to the
alternator are not included in the delivery.
• The alternator wiring is electrically isolated from
ground.
4.5.1 Battery capacity
Make sure that the alternator has the right capacity
to charge the batteries and to supply the load that is
connected to the batteries while charging. Failure to
do so may result in extended charging times,
increased alternator temperatures, and finally a
reduced lifetime of your alternator and your
batteries. The ratio between alternator capacity and
battery capacity should be for a wet battery:
Type of vessel Ratio between alternator
capacity and battery capacity
Motor boat 2 – 4 %
Sailing boat 3 – 5 %
For example: on a sailing boat an alternator type
24/75 is suitable for charging a 24V battery bank of
15 -25 Ah (with no load connected).
Note that all above recommendations are given as
example only. Choosing the correct alternator /
battery capacity depends on many factors such as
daily engine running hours, load connected to the
batteries during charging, other charging equipment,
etcetera. Therefore Mastervolt strongly advises to
make an energy balance for the entire electrical
installation.
4.5.2 Installation drawings
NOTE!
From the text below is often referred to a
reference. These references are shown
in the installation drawings of the loose
supplied APPENDIX. Keep the
APPENDIX on hand during installation
• For Alpha alternator model 12/9 : see
APPENDIX figure A-6
• For Alpha alternator models 12/13 , 24/75 and
24/11 : see APPENDIX figure A-7
• For Alpha alternator model 24/15 : see
APPENDIX figure A-8

INSTALLATION
12 January 2 13/ Alpha alternator - Alpha Pro II regulator / EN
4.5.3 Wiring instructions
1 See reference 1. Run the DC-cables between
the battery set and the alternator. A DC-fuse
must be integrated in the positive cable (see
section 9 for specifications). Do not install the
DC-fuse of the DC-distribution before the entire
installation is completed. Connect the red cable
between the B+ terminal of the alternator and
the positive (+) pole of the battery. Connect the
black cable between the B– terminal of the
alternator and the negative (–) pole of the
battery.
2 See reference . Connect the black wire of the
cable assembly between the [gnd] terminal of
the Alpha Pro II regulator and the B– terminal of
the alternator.
3 Insert the two pole connector of the cable
assembly into the field connector of the
alternator See reference . Take adequate
measures to assure a strain relief for this
connector.
4 See reference . Connect the red wire of the
cable assembly between the [+bat] terminal of
the Alpha Pro II regulator and the positive (+)
pole of the battery or the B+ terminal of the
alternator.
NOTE!
If a battery isolator is used to charge
more than one battery, the red wire of the
cable assembly should not be connected
to the B+ terminal of the alternator but to
the positive (+) pole of the battery
instead.
5 See reference . The brown cable of the cable
assembly must be connected to the [reg on]
terminal of the Alpha Pro II regulator. Connect
the other wire end through a switch (“S1”) with
normally open contacts to the positive (+) pole of
the battery as indicated. You can use the ignition
switch (figure 7) or preferably an independent
(ungrounded) oil pressure switch (figure 8). Use
a 2.5mm² cable. This cable must also be
secured by a 2 Amp fuse. As the [reg on]
terminal is also used for voltage measurement,
this cable should not be shared with other loads.
CAUTION!
If the engine is not running switch “S1”
must be open, otherwise the field
windings of the alternator will be
damaged due to overheating.
NOTE!
An additional toggle switch may be added
in series with switch “S1” to shut down
the alternator manually when increased
propulsion is needed.
Figure 7: Connection of the ignition switch (left) and
an independent (ungrounded) oil pressure switch
with normally open contact (right)
1. Brown wire
2. Ignition switch
3. Relay
4. Normally open oil pressure switch
5. Positive battery pole
6 See reference . The blue wire of the cable
assembly is the field connection of the
alternator. Connect this wire to the [field]
terminal of the Alpha Pro II regulator.
NOTE, only applicable for non-Mastervolt
alternators: With most other brands there
is an internal connection between the
negative field terminal of the alternator
(D–) and the alternator housing (GND).
Be sure to remove this connection before
installation. See APPENDIX section 2.5.
7 See reference . Attach the temperature sensor
to the battery and connect the RJ12 connecter to
the Alpha Pro II regulator as indicated.
reg on
reg on
2A
2A
S1
S1
11
3
5
4
5
2

INSTALLATION
EN / Alpha alternator - Alpha Pro II regulator / January 2 13 13
4.5.4 Connection of a tachometer (optional)
If a tachometer is used, it should be connected
between the W terminal of the alternator (see
reference ) and the B– terminal of the alternator
(or the NEG pole of the battery). See figure 9.
NOTE!
With some alternators the W terminal is
marked by an “R” instead of a “W”
NOTE!
The operation of the tachometer can not
be guaranteed when the Alpha Pro II
regulator switches from absorption mode
to float mode. Switching on some loads
during operation will solve this problem.
Figure 9: Connection of a tachometer (position of the
terminals may differ; see APPENDIX figures A- till
A-9)
The Alpha Pro II regulator has the same function
integrated in its MasterBus functionality, so the
number of revs can be shown on a MasterBus
connected display too.
4.5.5 Connection of an alternator indication
lamp (optional)
To check the correct operation of the alternator often
an indication lamp is used. This lamp will go off
when the alternator is charging.
The Alpha Pro II regulator has this function
integrated in MasterBus so at an alternator failure a
MasterBus alarm is shown, refer to section 6.3.2.
Tachometer
“W”
“B–”

INSTALLATION
14 January 2 13/ Alpha alternator - Alpha Pro II regulator / EN
4.5.6 Use of a battery isolator (optional)
When two or more battery banks need to be charged simultaneously, using a battery isolator is recommended.
See figure 12 for installation details. See APPENDIX figures A-11, A-13 and A-14 for installation examples.
CAUTION!
If there is a battery isolator between the B+ terminal of the alternator and the positive (+) pole of the
battery, both the red [+bat] wire and the brown [reg on] lines must be connected to the positive (+) pole
of the battery. Do not connect these wires to the input of the battery isolator.
NOTE!
As battery voltage sensing is performed by the Alpha Pro II regulator, you can use a battery isolator
that has no voltage sense connection.
Figure 12: Installation of the Alpha Pro II
1. Alternator
2. Alpha Pro II regulator
3. Battery isolator
4. Auxiliary battery fuse
5. Auxiliary batteries
6. Main battery fuse
7. Main batteries
8. Minus bus bar
9. Battery sensor on main battery
1 . 1 A replaceable fuse between battery positive pole and alternator Field connector
11. Ignition relay or oil pressure switch, to be connected to Regulator On connection, number 1 in cable
assembly
+_+_
10A 2A
B+
B-
Field
conn.
1
3
4
5
6
7
11
9
2
8
10

COMMISSIONING
EN / Alpha alternator - Alpha Pro II regulator / January 2 13 15
5 COMMISSIONING
CAUTION!
Check all wiring before commissioning:
positive connected to positive (red
cables), negative connected to negative
(black cables)
Commissioning of the Alpha alternator and the Alpha
Pro II regulator involves two major parts:
• Selecting the charging mode
• Testing and adjusting
5.1 SELECTING THE CHARGING MO E
Both the Alpha alternator and the Alpha Pro II
regulator are preset from the factory with settings
that will work fine for most batteries.
Figure 13: Three positions selector
The Alpha Pro II regulator has a three positions
selector featuring standard settings for a 12V or 24V
(lead acid) system and advanced settings via
MasterBus. See figure 13. The default setting is
MasterBus.
5.1.1 Commissioning when selecting
MasterBus
In case the MasterBus setting is selected by default
the product’s configuration will be unlocked resulting
in an Alpha Pro II that remains inactive (shown by
LEDs blinking twice alternately). Two parameters
need to be selected via MasterBus before the
configuration can be locked and the Alpha Pro II
made operational (see Chapter 6 for more extensive
explanation on using MasterBus).
1. Go to Configuration page
2. Go to group ‘System’ and select the
‘Alternator type’ present in your system
Figure 14:
Selecting
‘Alternator type’
through
MasterAdjust
3. Go to group ‘Battery’ and select the ‘Battery
type’ present in your system
Figure 15: Selecting ‘Battery type’ through
MasterAdjust
4. Go to group ‘Alpha Pro setup’ and select
‘Lock setup’
Figure 1 : Selecting ‘Lock setup’ via MasterAdjust
After this has been done the Alpha Pro II is ready for
testing.
CAUTION!
Invalid settings can cause serious
damage to your batteries. Adjustments of
settings may be undertaken by
authorised personnel only! Keep a record
of setting changes in this manual.
CAUTION!
Use a .4 x 2.5mm flat blade screwdriver
to adjust the selector. Do not attempt to
rotate the selector past the limit. You will
damage the selector.
5.2 TESTING
5.2.1 Test prior to starting engine
Before starting the engine, follow all steps in order of
succession as described below:
1 Place the DC-fuse(s) to connect the batteries to
the wiring of the Alpha alternator and the Alpha
Pro II regulator.
2 Check whether all indication lights on the Alpha
Pro II regulator are off.

COMMISSIONING
16 January 2 13/ Alpha alternator - Alpha Pro II regulator / EN
3 Energize the [reg on] terminal by either turning
on the ignition switch (DO NOT START THE
ENGINE) or by putting a jumper across switch
S1 (see figure 14). Check whether the 3 yellow
LED’s start to blink. After approx. 1 seconds
the yellow bulk led will illuminate.
Figure 14: Jumper across switch S1
4 Check whether the alternator field is energized
by touching the shaft of the alternator with a
screwdriver. It should be strongly magnetic.
5 De-energize the [reg on] terminal by turning off
the ignition switch or by removing the jumper
across switch S1 again. All LED’s should go off
and the field should no longer be strongly
magnetic.
CAUTION!
After performing this test, be sure to turn
de-energize the [reg on] terminal,
otherwise the field windings of the
alternator will be damaged due to
overheating
If you cannot pass the tests mentioned above,
remove the DC-fuses and double check the wiring.
Refer to the Trouble shooting section (section 8).
6 Check whether all bolts are securely mounted.
Check both the aligning and tension of the V-
belts.
5.2.2 In operation test
To check for proper operation you will need a hand
held digital meter. If you have installed a battery
monitor such as the MasterShunt or any other digital
voltage measuring device, you can use this as well.
WARNING
When the engine is running, be aware of
moving parts like V-belts.
NOTE!
See section 3.2.1 for explanation of the
bulk, absorption and float mode.
• Be sure no loads or any other charging sources
are on!
• Be sure the battery is (almost) fully charged
Follow all steps in order of succession as described
below:
1 Measure and record the battery voltage at idle.
2 Start the engine. The three LEDs on the Alpha
Pro II blink together to indicate the start up
mode.
3 Check for abnormal noise or vibration.
4 The yellow [bulk] LED on the Alpha Pro II
regulator (see figure 15) illuminates, indicating
that the charge-cycle begins.
5 Measure and record the battery voltage. The
battery voltage should be higher than measured
before at step 1. The battery voltage rises until
the yellow [abs] LED illuminates.
6 When the yellow [abs] LED illuminates, the
absorption mode commences. Measure and
record the voltage at which the battery stabilizes
(@ 25°C / 77°F).
7 An absorption timer starts to keep the Alpha Pro
II regulator in the absorption mode. The factory
setting of this timer is 4 hours.
NOTE!
For testing you might want to reduce the
absorption time temporarily.
8 When absorption time has elapsed, the green
[float] LED will illuminate. This means that the
float mode has started.
If you have passed the above mentioned tests, the
charging system is ready for operation. Else check
trouble shooting.
Depending on your settings the regulator can switch
to Float before a 1 % SOC has been reached,
refer to section 6.3.4
reg on
Positive
battery pole
2 Amp
Oil pressure switch
Ignition relay
Jumper
S1

COMMISSIONING
EN / Alpha alternator - Alpha Pro II regulator / January 2 13 17
Figure 15: Overview of the Alpha Pro II regulator
1. Settings selector 12/24V, MasterBus
2. Yellow LED to indicate Bulk phase
3. Yellow LED tot indicate Absorption phase
4. Yellow LED to indicate Float phase
5. Green LED to indicate MasterBus traffic
Figure 1 : Connections of the Alpha Pro II regulator
1 2 3 4 5
6 7 8 9 10 11 12
12
4 3
Temperature
sensor
4. Reg on (brown)
3. D+ lamp (yellow)
2. W (white)
1. Not used
+_
MasterBus
+
_
Field coil
Field coil
Battery
Cable assembly
Reg on
D+
W

COMMISSIONING
18 January 2 13/ Alpha alternator - Alpha Pro II regulator / EN
5.2.3 Voltage Settings
The Alpha Pro II regulator uses the [reg on] terminal
(figure 16, connection 4) and the [gnd] terminal for
measurement of the battery voltage.
As the field current flows through the [gnd] terminal
as well, a voltage drop may occur on the black cable
which is connected to the [gnd] terminal. This will
affect the charge voltage. To minimize this voltage
drop, a 4mm² black cable is used. Under all
circumstances the voltage-drop may not exceed
. 1 Volts.
5.2.4 Absorption voltage adjustment
The factory-settings for the absorption voltage are
14.25V for 12V battery and 28.5 V for 24V batteries
(@ 25°C / 77°F). These settings can be changed
with the mode selector in MasterBus position and
the configuration unlocked. Refer to section 6.3.4.
Do not adjust the charge voltage above the
recommended limits of the battery manufacturer.
Also note that too high voltages may damage
sensitive equipment that is connected to the
batteries.
5.2.5 Float voltage adjustment
The factory-settings for the float voltage are 13.25V
for 12V battery and 26.5 V for 24V batteries.
These settings can be changed with the mode
selector in MasterBus position and the configuration
unlocked. Refer to section 6.3.4.
If the float voltage is set near 13. V you may have to
switch on some DC loads to get the alternator to turn
on because it takes some time +for the voltage to
settle from the higher absorption voltage.
5.2.6 Absorption time adjustment
Factory setting of the absorption timer: 4 hours. This
is appropriate for most systems. Exceptions might
be:
• Extension of the absorption time to do some
intentional overcharging to regain lost capacity.
• Shorten the time if you stop and start the engine
often each day.
• Temporary time reduction for testing purposes
Changing absorption time is possible with the mode
selector in MasterBus (9 o’clock) position and the
configuration unlocked. Refer to section 6.3.4.
Adjustable range: minutes up to 1 hours.
NOTE!
The new setting will only be activated
after the Alpha Pro II was powered up
again.
5.2.7 Temperature compensation
The battery temperature sensor included,
compensates the charge voltage for deviating
battery temperatures. See section 3.2.2 for details.
When the temperature-sensor is not connected, the
25°C settings are taken.
High temperatures are destructive to batteries. If
your batteries are regularly subjected to
temperatures above 3 °C / 1 °F, you should
relocate them or supply forced fresh air ventilation.
5.3 OPERATION
After starting the engine the Alpha alternator and the
Alpha Pro II regulator will switch on automatically.
The regulator will wait for the engine to rev up before
it starts charging the battery. Refer to section 5.2.2
Start Up mode. There is no need for adjustment or
operation. If the engine is stopped the Alpha
alternator and the Alpha Pro II regulator will switch
off again. When switched off, all LED’s of the Alpha
Pro II regulator are off. An exception is when the
Alpha Pro II is set to power the MasterBus network.
It will then stay switched on, even after switching off
the engine.
CAUTION!
Never disconnect any wiring during
operation of engine.
NOTE!
If a heavy load is switched on during the
absorption or float mode the alternator
will compensate this by increasing its
output power, given the engine number of
revs is sufficiently high. Note that the
regulator will not change back to bulk
mode to start a new charging cycle. A
new charging cycle will only commence
when the engine is started again.
See section 3.2.1 for explanation of the three step
PLUS charging cycle.
Although the Alpha alternator is almost
maintenance-free, still moving parts are involved that
need regular service and maintenance. This should
be done according to the directions in section 1.

MASTERBUS
EN / Alpha alternator - Alpha Pro II regulator / January 2 13 19
6 MASTERBUS
6.1 WHAT IS MASTERBUS?
All devices that are suitable for
MasterBus are marked by the MasterBus
symbol.
MasterBus is a fully decentralized data network for
communication between the different Mastervolt
system devices. It is CAN-bus based which has
proven itself as a reliable bus-system in automotive
applications. MasterBus is used as power
management system for all connected devices, such
as the inverter, battery charger, generator and many
more. This enables communication between the
connected devices, for instance to start the
generator when the batteries are low.
MasterBus reduces complexity of electrical systems
by using UTP patch cables. All system components
are simply chained together. Therefore each device
is equipped with two MasterBus data ports. As only
a few MasterBus cables are needed, installation and
material costs are reduced importantly. New devices
can be added to the existing network easily.
Consequently the MasterBus network is highly
flexible for extended system configuration.
Mastervolt also offers several interfaces like the
Modbus interface, making even non-MasterBus
devices suitable to operate in the MasterBus
network. For central monitoring and control of the
connected devices Mastervolt offers four different
panels, from the small Mastervision compatible 12
x 65 mm LCD screen up to the full colour
MasterView System panel. All monitoring panels can
be used for monitoring, control and configuration of
all connected MasterBus equipment.
CAUTION: Never connect a non-
MasterBus device to the MasterBus
network directly! This will void warranty of
all MasterBus devices connected.
6.2 HOW TO SET UP A MASTERBUS
NETWORK
Every MasterBus device is equipped with two data
ports. When two or more devices are connected via
these ports, a local data network called the
MasterBus is formed. Keep the following rules in
mind:
Terminating
device
Terminating
device
OK
Do not make T-connections in the network.
Do not make ring networks.
OK
Connections between the devices are made by
standard straight UTP patch cables.
OK
Place a terminating device on both network
ends.
At least one device in the network must be
MasterBus powering (see specifications). As all
powering devices are galvanically isolated,
multiple powering devices are allowed.

MASTERBUS
2 January 2 13/ Alpha alternator - Alpha Pro II regulator / EN
6.3 MASTERBUS FUNCTIONS
Adjustment of the settings of the Alpha Pro II can be
made via the MasterBus network (by means of a
remote control panel or a MasterBus - USB interface
connected to a PC with MasterView System
software).
CAUTION!
Invalid settings of the Alpha Pro II can
cause serious damage to your batteries
and/or the connected load! Adjustments
of settings may be undertaken by
authorised personnel only.
6.3.1 Monitoring
Value
Meaning
General
Device state Shows the state of the Alpha Pro II: Standby/ Charging/ Alarm
Charger state Shows the state of the internal charger: Off/ Bulk/ Absorption/ Float
Battery
Battery voltage Battery voltage measured by the MasterShunt or, if no Mastershunt has been selected, the
battery voltage is measured by the Alpha Pro II [V]
Battery temp. Battery temperature measured by the MasterShunt or, if no Mastershunt has been
selected, the battery temperature is measured by the Alpha Pro II [°C]
Alternator
Alternator shaft Number of revolutions alternator [rpm]
Engine shaft Number of revolutions engine [rpm]
Sense voltage Battery voltage measured by the Alpha Pro II [V]
Field current Current through the alternator field coil [A]
Alternator volt. Voltage measured between +Bat and GND [V]
Alternator temp. Alternator temperature, mount the sensor on the alternator. Also refer to section 6.3.4
Shunt
Status Not selected/ Connected/ Connection lost
State of charge Battery state of charge calculated by the shunt [%]
Battery voltage Battery voltage [V] measured by the MasterShunt
Battery current Battery current [A] measured by the MasterShunt
Battery temp. Battery temperature measured by the MasterShunt temperature sensor [°C]
6.3.2 Alarms
Value
Meaning
TS error Temperature Compensation error
Bat. Temp. high The battery temperature sensor measures a high temperature
Dev. Temp. high Alpha Pro device temperature too high
+D overload Overload of the lamp connection (current too high)
Invalid system Selector on a blank spot. The selector has two blank spots to separate 12V,MasterBus,24V.
The yellow LEDs are blinking twice alternately.
Battery high Battery high voltage warning, generated by the Alpha Pro II
Battery low Battery low voltage warning, generated by the Alpha Pro II
High field current Field current too high, Alpha Pro II stops regulating and retries after 5 seconds repeatedly
Low field current Field current too low, there is a disconnection in the field wiring
Cable losses Cable between alternator and battery is too thin, causing voltage drop
Shunt mismatch Different voltage settings of MasterShunt and Alpha Pro II
6.3.3 History
Value
Meaning
Factory setting
Adjustable range
Completed cycles Total number of completed charging cycles -2 x
Restarted cycles Total number of aborted charging cycles -2 x
Total charge time Total regulator charge time since commissioning min -2 min
# Temp. alarms Total number of temperature alarms -65535
# High DC alarms Total number of high DC voltage alarms -65535
# Low DC alarms Total number of low DC voltage alarms -65535