Sierra Wireless DART 300 manual Access, Power Supply, Grounding, Wire Splicing

Installation DART 300 Modem

11.2. Access

Access to the front panel is very important for maintenance and troubleshooting in the field. This provides access to the power connector and switch, the DATA connector (serial port) for field upgrades of the modem firmware, and a clear view of the LED that indicates power and channel status.

The DART 300 can be mounted in cabinets or equipment racks with adequate ventilation. Choose a location which:

•Allows access to the connectors on the front and rear panels;

•Avoids excessive heat from nearby sources such as heaters, power supplies or other electronics;

•Protects it from weather and excessive moisture. The unit is NOT a sealed unit and should therefore be mounted out of the vicinity of leaks, spills, and splashes.

11.3.Power Supply

For installations with standard 110V AC power outlets, a power adapter can be used provided it meets the required specifications (Section 14.1 below). A suitable adapter is available from Sierra Wireless (part number 6000082).

Where there is a suitable existing DC power supply that can be used, the DART 300 can be connected to it using the splicing guidelines below.

11.3.1.Grounding

Proper grounding of the DART 300 and antenna system is critical, particularly when installed in a fixed outdoor location where it may be subject to the effects of lightning strikes. No amount of grounding will protect the system from a direct lightning strike, but the grounding should be designed to deal with the static build-up and surges that can result from nearby strikes. The following guidelines are provided, although professional installation of the antenna is recommended. You should also refer to your local and national electrical codes (the Canadian Electrical Code in Canada, or the National Electrical Code in the United States).

The antenna, the modem's power supply, and the modem itself should be grounded. The antenna cable should be grounded via an antenna discharge unit at the point where the cable enters the facility or enclosure. Be sure to mount the antenna and lead-in wires away from overhead power lines or other electrical circuits. Choose an antenna discharge unit that is appropriate to the DART 300, which operates in the 824 through 894 MHz band at power levels below 4 watts. If an antenna mast is to be used, it should also be grounded.

Note that all grounds require a considerable length of exposed metal surface to be in contact with earth below the permanent moisture level. Attaching grounds to metal posts encased in concrete does not allow them sufficient (or, in many cases, any) contact with earth below permanent moisture level, and does not provide an adequate ground. Your national electrical code stipulates minimum gauges for ground wires.

11.3.2.Wire Splicing

The wires of the power supply may be spliced to available 12V DC wiring. Proper splicing is essential to reliable operation of the modem. Note the following when connecting the power cord:

•The use of “quick taps” is strongly discouraged as they reduce the integrity of the wire that is cut and let moisture into the cable. In addition, the taps themselves are subject to corrosion, which will introduce voltage drops and interfere with current flow.

•An appropriate method of splicing is to strip a small portion of the insulation, solder the wires together, then heat-shrink the connection to re-insulate.

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