Voltage Settings; Absorption Voltage Adjustment; Float Voltage Adjustment; Absorption Time Adjustment - Mastervolt ALPHA ALTERNATOR 12/90 User Manual

COMMISSIONING
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
0.01 Volts.
5.2.4

Absorption voltage adjustment

The factory-settings for the absorption voltage are
14.25V for 12V battery and 28.50V 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 26.50V 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 13.0V 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: 0 minutes up to 10 hours.
NOTE!
The new setting will only be activated
after the Alpha Pro II was powered up
again.
18
5.2.7

Temperature compensation

The battery temperature
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
temperatures above 30°C / 100°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
maintenance-free, still moving parts are involved that
need regular service and maintenance. This should
be done according to the directions in section 1.
January 2013/ Alpha alternator - Alpha Pro II regulator / EN
sensor included,
regularly subjected to
alternator is almost