User guide
Canopy System User Guide Protecting Cables and Connections
pmp-0229 (Mar 2013)
181
On a site where you are deploying a mix of 30-V DC and 56-V DC radios (to the limit of 8 radios
supported by one CMM), you can use a CMM4 that is connected to both a
30-V DC power supply and a 56-V DC power supply.
Due to the full metallic connection to the tower or support structure through the AP antenna or a
connectorized BH antenna, grounding the AP or BH and installing a 600SS surge suppressor
within 3 ft (1 m) of the AP or BH is strongly recommended. This suppresses overvoltages and
overcurrents, such as those caused by near-miss lightning. APs and BHs provide a grounding lug
for grounding to the tower or support structure. A pole mount kit is available for the 600SS. The
pole mount kit provides a grounding point on one of its U-bolts that can be used for terminating
ground straps from both the 600SS and the AP.
NEC Reference
NEC Article 810, Radio and Television Equipment, and associated documents and discussions are
available from http://www.neccode.com/index.php?id=homegeneral
,
http://www.constructionbook.com/xq/ASP/national-electrical-code-2005/id.370/subID.746/qx/default2.htm,
and other sources.
Conforming to Regulations
For all electrical purposes, ensure that your network conforms to applicable country and local
codes, such as the NEC (National Electrical Code) in the US. If you are uncertain of code
requirements, engage the services of a licensed electrician.
Protecting Cables and Connections
Cables that move in the wind can be damaged, impart vibrations to the connected device, or both.
At installation time, prevent these problems by securing all cables with cable ties, cleats, or PVC
tape.
Over time, moisture can cause a cable connector to fail. You can prevent this problem by
• using cables that are filled with a dielectric gel or grease.
• including a drip loop where the cable approach to the module (typically a CMM) is from
above.
• wrapping the cable with weather-resistant tape.