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EN
SYMBOLS AND TERMINALS
Fuse
See ”CABLE AND FUSE REQUIREMENTS”
Flashing lamp
Continuously lit lamp
Alternator
Non critical consumer
Earth connection
Critical consumer
Connection
D250T
Connected to
Equalization
EQU
Mid point of starter battery
Input Alternator
+IN
• Starter battery
• Input Alternator SMARTPASS 120T via
connector plate or cable
Output Service battery
+OUT
• Service battery
• Output Service battery SMARTPASS 120T
Earth Connection
• Chassis/Earth
• Solar panel (-)
• SMARTPASS 120T (-)
Connection
SMARTPASS 120T
Connected to
Input Alternator
+IN
• Starter battery
• Input Alternator D250T via connector plate
or cable
Output Service battery
+OUT
Output Service battery D250T
Output Consumers
+OUT
Non-critical consumers
Smart generator (red cable)
See "SETTINGS SMARTPASS 120T"
DEFINITIONS AND DESCRIPTIONS
STARTER BATTERY
A battery intended for the engine’s electric starter motor in automotive applications.
A starter battery should never be deeply discharged.
SERVICE BATTERY
Service battery is an auxiliary battery that will provide power to electrical equipment when the
vehicle motor is not running. This additional battery will prevent the starter battery to be being
drained and protect against a flat battery. Suitable deep cycle batteries should be used.
TEMPERATURE SENSOR
The D250T optimises the charge voltage by increasing the charge voltage at temperatures below
25°C/77°F and reducing it at temperatures higher than 25°C/77°F.
TEMPERATURE COMPENSATED CHARGE VOLTAGE
The charger will adjust the charge voltage according to service battery temperature. This can be
done by attaching the temperature sensor to the starter battery or somewhere close to the battery.
BATTERY TEMPERATURE PROTECTION
Protects the battery by switching off charging if the temperature rises too high.
FUSES
Fuses must be used for overload protection. Mount the fuses as close to each battery as
possible. Please see this instruction manual for recommended fuse sizes - see “CABLE AND FUSE
REQUIREMENTS” table.
WIRING
Please see this instruction manual for recommended cable length and sizes - see “CABLE AND FUSE
REQUIREMENTS” table.
CONSUMERS
Consumers should normally be connected to the consumer output terminal on the SMARTPASS 120T.
If battery voltage reaches a critically low level, the consumer output terminal is deactivated to protect
the service battery from being deeply discharged.
When the vehicle motor is running, non-critical consumers receive current from the alternator instead
of the service battery, for faster charging of the service battery.
If there are some consumers with low power consumption that must be prioritized (critical consu-
mers), they can be connected directly to battery. This will ensure they are always is connected to the
service battery. Please note: by connecting consumers directly to the service battery, the SMARTPASS
120T can no longer protect against deep discharge. A critical consumer could be a ticket system, life
support equipment, communication radio etc.
EQUALIZING (EQU)
In a 24V system where we have two 12V batteries in series the voltage in the two batteries can be
unbalanced, especially if there are 12V consumers connected to one of the batteries. The Equalizing
process is balancing the voltage level in the two batteries and ensures battery performance and
extends battery life.
