SECTION 14. INSTALLATION AND MAINTENANCE

14.1PROTECTION 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)
PeripheralQuiescentActive

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

14-1