Campbell Scientific CR10X Measurement and Control System - Manual (Page 217)

14-1
SECTION 14. INSTALLATION AND MAINTENANCE
14.1 PROTECTION FROM THE
ENVIRONMENT
The normal environmental variables of concern
are temperature and moisture. The standard
CR10X is designed to operate reliably from -25
°
to +50 °C (-55° to +85°C, optional). Internal
moisture is eliminated by sealing the module at
the factory with a packet of silica gel inside.
The desiccant is replaced whenever the CR10X
is repaired at Campbell Scientific. The module
should not be opened by the user except to
replace the lithium coin cell providing back up
power to the clock and SRAM (Section 14.11).
Repeated disassembly/ assembly of the CR10X
will degrade the seal, leading to potential
moisture problems. Extra desiccant should also
be placed in the enclosure to prevent corrosion
on the Wiring Panel terminals and
CR10X/Wiring Panel connections.
Campbell Scientific offers two enclosures for
housing a CR10X and peripherals. The
fiberglass enclosures are classified as NEMA 4X
(water-tight, dust-tight, corrosion-resistant,
indoor and outdoor use). A 1.25" diameter
entry/exit port is located at the bottom of the
enclosure for routing cables and wires. The
enclosure door can be fastened with the hasp for
easy access. Both enclosures are white for
reflecting solar radiation, thus reducing the
internal enclosure temperature.
The Model ENC 12/14 fiberglass enclosure
houses the CR10X, 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, power supply, and several
peripherals. Inside dimensions of the ENC
16/18 are 16" x 18" x 9", outside dimensions
are 21.75" x 20.0" x 11.0" (with brackets);
weight is 17.2 lbs.
14.2 POWER REQUIREMENTS
The CR10X operates at a nominal 12 VDC.
Below 9.6 volts the CR10X does not operate
properly.
The CR10X is diode protected against
accidental reversal of the positive and ground
leads from the battery. Prolonged input
voltages in excess of 16 V may damage the
CR10X and/or power supply. A transzorb
provides transient protection.
System operating time for the batteries can be
determined by dividing the battery capacity
(amp-hours) by the average system current
drain. The CR10X draws <1 mA in the
quiescent state, 13 mA while processing, and
46 mA during an analog measurement; the
length of operating time for each datalogger
instruction is listed in the programming section.
Typical current requirements for common
CR10X peripherals are given in Table 14.2-1.
CAUTION: The 12 V and switched 12 V
terminals on the wiring panel are not
regulated by the CR10X; they obtain power
directly from the Power In terminal. If you use
the CR10X wiring panel to source power to
other 12 V devices, be sure the power supply
regulates the voltage within the range
acceptable to the connected device. The
maximum voltage output by a Campbell
Scientific power supply is approximately 16 V
(the charging voltage at –40°C).
CAUTION: The metal surfaces of the Wiring
Panel and mounting bracket are at the same
electrical ground as the power supply.
Caution must be exercised when connecting
power directly to the Wiring Panel's 12 V and
ground terminals. Connect the plus (+) side
of the supply first, keeping the minus (-) side
away from the Wiring Panel. Once the plus
side is secured, connect the power return.