RSCC Wire & Cable LLC © 2015 • 20 Bradley Park Road • East Granby, CT 06026 • 800-327-7625 • 800-653-8300 • Fax: 860-653-8321 • www.vitalinkcable.com
19
taken when working around energized cables
and equipment. Any cable lubricant spilled on
the floor should be cleaned up or covered
immediately.
Cables should not be pulled around corners
that have sharp edges such as corners in cable
trays, or other obstructions. Cables may be
hand fed around such corners or the use of
cable sheaves of the proper radius or other
suitable devices may be employed, provided
the minimum allowable cable pulling radius
and cable sidewall pressure is not violated.
The mechanical stresses placed upon a cable
during installation should not be such that
the cable is excessively twisted, stretched or
flexed.
During the time that the cables are exposed and
during cable pulling activities, they should be
protected from nearby or overhead work to pre-
vent damage to the cable jacket/insulation (e.g.,
do not step on or roll equipment over cables,
etc.). Take care to ensure that cables are not left
exposed in high traffic areas where the potential
for inadvertent damage is significant. Care
should also be taken to protect existing cables,
splices and/or terminations from damage when
installing new cables through enclosures.
When cable pulling is completed or when cable
is partially pulled, the portion of cable not yet
routed to its final destination should be coiled
and supported to keep the cable off the floor
and prevent damage. The coil should be tied in
at least two separate locations or a saddle or
similar support should be used so that the cable
does not support the coil. Train the cable with
as large a radius as practical and not less than
the minimum allowable. The cable should be
protected so the ties do not damage the cable
jacket. If coil location requires additional protec-
tive measures, a protective cover should be
provided. Special care should be exercised dur-
ing welding, soldering, and splicing operations to
prevent damage to cables. Appropriate precau-
tions should be taken in the handling, storage,
and disposal of materials.
Installation Equipment
Where mechanical assistance is required,
pulling equipment of adequate capacity such as
a winch that provides a steady continuous pull
on the cable should be used. The pulling equip-
ment should be size based on the maximum
allowable tension plus a safety margin. The unit
should also be capable of developing the max-
imum speed required with adequate margin.
Pull rope diameter and length will depend on
the pull to be made and construction equipment
available. If a pull rope is used it should be
sized to have a breaking strength not less than
the maximum allowable tension times a safety
factor. This is a safety precaution to help ensure
that the pull rope does not break during the
installation. Pull ropes should be chosen with
minimum stretch to reduce the possibility of
galloping. All cable monitoring equipment
should be calibrated before use.
A swivel should be used between the cable
pulling device and the pull rope on all mechani-
cally assisted pulls. On more difficult hand pulls,
a swivel may also be advantageous. The primary
purpose of the swivel is to prevent damage to
the cable from possible twisting forces imparted
when pulling the cable. Swivels should be
selected that will swivel under anticipated load
conditions. Swivels that do not swivel under high
load conditions should never be used.
Cable rollers and sheaves used for cable pulling
should have a smooth surface, use cupped
rollers of adequate size, be in good working
order, be properly lubricated, and free spinning.
The radius of rollers, pulleys, and sheaves
should be considered when calculating estimat-
ed sidewall pressure. When using properly
designed segmented sheaves (a fixed combina-
tion assembly of rollers), the cable conforms to
the radius of the overall assembly with no appre-
ciable increase in pressure from the individual
rollers. So, the overall radius of the assembly,
rather than the radius of the individual rollers,
may be used. Typically, if these devices were
used, they should be used on the feeding end
Содержание VITALink MC
Страница 8: ...VITALink MC 2 Hour Fire Rated Cable UL FHIT 120 ULC S139 FHIT7 120 Installation Manual...
Страница 50: ......
