Measurement and Control Module Operators Manual

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
CR10 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 three packets of silica gel (0.75
g each) inside. The desiccant is replaced
whenever the CR10 is repaired at Campbell
Scientific. The module should not be opened
by the user except for the infrequent purpose of
PROM replacement (refer to Appendix G).
Repeated disassembly/assembly of the CR10
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
CR10/Wiring Panel connections.
Campbell Scientific offers two enclosures for
housing a CR10 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, or with
the two supplied screws for more permanent
applications. The white plastic inserts at the
corners of the enclosure must be removed to
insert the screws. Both enclosures are white for
reflecting solar radiation, thus reducing the
internal enclosure temperature.
The Model ENC 12/14 fiberglass enclosure
houses the CR10, 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 CR10 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 CR10 operates at a nominal 12 VDC.
Below 9.6 or above 16 volts the CR10 does not
operate properly.
The CR10 is diode protected against accidental
reversal of the positive and ground leads from
the battery. Input voltages in excess of 18 V
may damage the CR10 and/or power supply. A
transzorb provides transient protection by
limiting voltage at approximately 20 V.
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.
TABLE 14.2-1. Typical Current Drain for Common CR10 Peripherals
Typical Current Drain (mA)
Peripheral Quiescent Active
RF100 VHF 5 Watt Radio 30 1730
RF200 UHF 4 Watt Radio 30 1530
RF95 RF Modem 1.4 30
SM192/SM716 Storage Module 0.25 3
CSM1 0.5 18
CR10KD Keyboard/Display <1 0.3 (*6 Mode)
DC112 Phone Modem <1 45
SDM-AO4 10.5 --
SDM-CD16 6.0 11/LED lit
SDM-INT8 0.4 6.5
SDM-SW8A 3 6