Campbell CR3000 Micrologger, Operator'S Manual, Page: 101 / 644

Section 7. Installation
101
FIGURE 29: Connecting to Vehicle Power Supply
7.2.4 Uninterruptable Power Supply (UPS)
A UPS (un-interruptible power supply) is often the best power source for long-
term installations. An external UPS consists of a primary-power source, a
charging regulator external to the CR3000, and an external battery. The primary
power source, which is often a transformer, power converter, or solar panel,
connects to the charging regulator, as does a nominal 12 Vdc sealed rechargeable
battery. A third connection connects the charging regulator to the 12V and G
terminals of the POWER IN connector..
7.2.5 External Power Supply Installation
When connecting external power to the CR3000, remove the green POWER IN
connector from the CR3000 face. Insert the positive 12 Vdc lead into the green
connector, then insert the negative lead. Re-seat the green connector into the
CR3000. The CR3000 is internally protected against reversed external-power
polarity. Should this occur, correct the wire connections and the CR3000 will
resume operation.
7.2.6 External Alkaline Power Supply
If external alkaline power is used, the alkaline battery pack is connected directly
to the POWER IN 12V and G terminals. Voltage input range is 10 to 16 Vdc.
7.2.7 Integrated Batteries
Internal batteries (battery bases) have a thermal fuse that limits source current and
minimizes the need for repair. If excessive current is drawn, the fuse gets hot,
increases in resistance, and limits current. When the problem is fixed, the fuse
cools and the resistance decreases, usually allowing current to eventually pass.
When excessive current is drawn, as will occur when shorting a positive lead to a
ground terminal, allow 10 to15 seconds for the fuse to cool before reconnecting
power.