Campbell NW8002, Instruction Manual

Page: 14 / 39

SECTION 1. WEATHER STATION DESCRIPTION AND INSTALLATION
1-9
1.5 POWER SUPPLY OPTIONS
1.5.1 AC POWER
A -120 to 16 VAC Transformer is supplied with
the NW8002 Weather Station. The transformer
must be connected to 120 VAC according to
national and local electrical codes. The
distance that the low level 16 VAC voltage can
be run depends upon the size of the wire used.
A 22 awg wire can be run up to 600 feet. An 18
awg wire can be run up to 1500 feet. It is
recommended to run 110 VAC to the base of
the weather station, and then install the
transformer into a weather tight enclosure
according to electrical codes. The low level 16
VAC voltage is then run up the mast structure to
the PS12-LA.
The PS12 Power Supply provides 12 volts,
regulates incoming AC power, limits current
from the battery, and provides circuitry to
connect an external 12 volt battery. The
terminals on the PS12 are exposed by
unscrewing the two set screws, as shown in
Figure 1.5-1.
The two 12 volt and two ground terminals are
for supplying power to the datalogger or other
12 volt devices.
The two terminals, labeled CHG, are for
connecting a 16 to 20 VAC RMS or solar panel
to charge the batteries.
The ON-OFF switch controls power to the 12V
ports. Charging of the batteries still occurs
when the switch is off. The red charge light is
on when the battery is being charged by AC
power or a solar panel.
NOTE: An AC transformer or solar panel
should be connected to the PS12 at all
times. The charging source powers the
CR10 while float charging the lead acid
batteries. The battery powers the
datalogger if the charging source is
interrupted. The PS12-LA specifications
are given in Table 1.5-1.
FIGURE 1.5-1. PS12 12 Volt Power Supply and Charging Regulator