Filter
Top Products
18 Pelco Manual C585M-B (11/98)
3.3.3.1 Long Distance Cable Installation
Because of the many options available, long distance video wiring is at your discre-
tion. Review the following to determine the best method of wiring video for your
application.
Maximum Distance Recommendations for Coaxial Cable
There are a number of variables to consider when specifying the type of coaxial
cable to run. It is best to avoid the use of video amplifiers. Video amplifiers should
be regarded as a remedy for an existing problem not as an installation aid.
Coaxial Splicing
Although not recommended, a splice in a coaxial cable is sometimes unavoidable
in long runs or difficult conduit pulls. A female-to-male BNC splice is the first choice
when splicing coaxial cable. An acceptable substitute is female-to-female with a
barrel adapter (although there is more signal loss inherent in this type of splice.)
The use of “F” connectors or barrels is not preferable because of the inferior
mechanical connections and poor signal transmission characteristics inherent in
those connectors.
Direct Burial
Direct burial cabling should only be used when the cabling is specifically rated for
direct-burial use. Dig trenches and lay cable to a sufficient depth to accommodate
climate and other conditions and local codes. Protect cabling from damage that
may result from backfilling, traffic, burrowing animals, trenching, and other
conditions.
Underground Conduit
Ensure that the cable is appropriate for use in underground conduit. Direct burial
cable is usually not acceptable for use inside a buried conduit that may fill with
water. Direct burial type of cable utilizes the earth surrounding the cable to wick
moisture away from the cable. Call your cable supplier or manufacturer for their
recommendations on the correct type of cable to use in circumstances where the
cable will be used in conduit.
One-inch PVC is the minimum recommended size for underground conduits. Allow
no more than two 90-degree bends between pull boxes. Make sure pull boxes and/
or splice boxes are as water-resistant as possible and that splices stay above any
water accumulation.
When using PVC, be sure to separate high voltage carrying conduits from video
conduits by enough distance to ensure that the video signal is not degraded. When
dealing with 120 VAC, about 12 inches of separation should be sufficient.
Aerial Spans
In some applications, it is preferable to run cable to a location overhead. If you want
to use existing poles consult with the owners, warrantors, or maintaining entities.
The poles may not be available for your use if the poles are owned by a public
service, utility, or cable TV provider.
If poles are in use by others, make sure that the addition of your cable and wire
complies with local codes and regulations. Proper spacing from existing wire and
cable, the descending order of voltage-carrying cable, and the minimum
low-clearance specifications over roads, alleys, and driveways etc. should be main-
tained.
Be aware of electrical inference that might be generated by high-voltage cables
sharing the poles with the video cabling. Legal spacing may not be enough to pre-
vent electrical inference if radiated levels are high.
Hardware on poles should be appropriate to sustain the weight and stress of the
cable during adverse weather conditions.
Microwave
The WX8000 Series is excellent for microwave control. Consult with microwave
equipment manufacturers and/or suppliers for recommendations regarding operat-
ing specifications, and installation.