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Specifications
Input Voltage:
9.5 to 35 VDC (external battery
voltage sensing).
Operating temperature:
0 to 50 deg Celsius ( 32
to 122 deg Fahrenheit).
Size:
100 x 60 x 30 mm (4 x 2.4 x 1.2 inch).
Drive Current:
8 Amps maximum (Automatic
cut-back for non-hot rated alternators). Ramps
current up from 0% to 100% in 30 seconds to
prevent belt slip after waiting 60 seconds for
engine to warm up.
Steps:
Bulk, Absorption, Float and Equalization.
Temperature compensated with included probe.
Indicator LED:
l
1 blink per 2 seconds
- Bulk delivery stage
l
2 blinks per 2 seconds
- Absorption stage
l
3 blinks per 2 seconds
- Float stage
l
Continuous blinking
- Equalization stage
l
No blinking
- Loss of input voltage or loss of
battery voltage sense line (automatic shut-down
within 30 seconds typical, one minute maximum).
Page 7
equalization voltage has been reached, 4 hours, or
manually by pressing the front panel button for
four seconds, whichever occurs first.
The correct absorption, float and equalization
voltages are dependent upon temperature and
battery chemistry. The higher the temperature the
lower values of absorption, float and equalization
voltages that must be used to optimize battery life.
For this reason a remote sensor is used to monitor
battery temperature and adjust the voltages
accordingly. The SAR-20 also has some
programming jumpers inside to tell it what type of
battery you are using and further adjust the charging
voltages accordingly.
During the bulk delivery phase the SAR-20 will
command the alternator to deliver maximum output
continuously until the absorption voltage is reached.
While many modern alternators can do so, some
alternators are not "hot rated" to deliver full output
continuously and can be damaged by excessive
heat. For this reason the SAR-20 can be told
whether your alternator is hot rated or not and will
automatically cut back the output of a non hot-
Figure 2 - SAR-20 Connections
and Jumper Locations
Now check your wiring carefully. After you are
sure there are no errors in the wiring, program the
jumpers as described on page 13 and 14.
Turn on the ignition switch to apply power to the
SAR-20 At this point the front panel LED should
flash one time every two seconds. If not, re-check
your wiring. If all is working properly, install the
front cover
.
Note: After allowing the engine to warm up for 60
seconds, the SAR slowly ramps up the current over
the next 20-30 seconds so as to minimize belt
slippage.
Important - Connect Black
temp. sense wire to Terminal B
