Campbell Scientific RF310, RF312, RF313 Narrowband Radios - Manual (Page 35)

Section 3. Radiotelemetry Network Components
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wires. The enclosure door can be fastened with the clasp for easy access. The
enclosure’s clasp door can be secured with a basic lock. Both enclosures are
white for reflecting solar radiation, reducing the internal temperature.
The Model ENC 12/14 fiberglass enclosure houses the CR10X and power
supply, and one or more peripherals. Inside dimensions of the ENC 12/14 are
14" x 12" x 5.5", outside dimensions are 18" x 13.5" x 8.13" (with brackets);
weight is 11.16 lbs.
The model ENC 16/18 fiberglass enclosure houses the CR10X or CR23X and
power supply, and two or more peripherals. Inside dimensions of the ENC
16/18 are 18" x 16" x 8.5." Outside dimensions are 21.75" x 21" x 11" (with
brackets); weight is 17.2 lbs.
3.4.2.2 CR7 Enclosures
Most CR7 radiotelemetry applications have special needs depending on the
individual system. The ENC-24 is normally used in CR7 RF applications.
Contact Campbell Scientific's customer service department for special
applications.
3.4.3 Power Supply
A radiotelemetry network requires a reliable power supply at each station. A
solar panel or 110/220 VAC charging source is normally required due to the
large current drain of the radio.
3.4.3.1 Lead Acid Batteries
Lead acid batteries are designed to be float charged by a solar panel or AC
power source. The role of the lead acid battery is to supply power when the
charging source is absent, e.g., in case of power failures (AC charging), or
during times of zero charge with a solar panel.
21XL and CR7 lead acid batteries do not have the required capacity for a
typical RF station, they are only 2.5 Amp-hour batteries. Generally, we
recommend a minimum of 7 Amp-hour batteries for RF applications.
3.4.3.2 PS12LA Lead Acid Power Supply
The PS12LA power supply includes a 12V, 7.0 Amp-hour lead acid battery,
AC transformer, and a temperature-compensated charging circuit with a charge
indicating diode. An AC transformer or solar panel should always be
connected to the PS12. The charging source trickle charges the lead acid
batteries which power the datalogger. The internal lead acid battery continues
to power the datalogger if the charging source is interrupted. The PS12LA
specifications are given in Table 3-6.
The two leads from the charging source should be inserted into the CHG ports,
polarity doesn’t matter. A tranzorb provides transient protection to the
charging circuit. A sustained input voltage in excess of 40V will cause the
tranzorb to limit voltage.