Current through Register 1531, September 27, 2024
(1)
General.
Recommendation. Cable should be
capable of withstanding tests applied in accordance with an applicable standard
issued by a recognized organization such as the Association of Edison
Illuminating Companies, the Insulated Power Cable Engineers Association, the
National Electrical Manufacturers Association or the American Society for
Testing and Materials.
(a) The design
and construction of conductors, insulation, sheath, jacket and shielding shall
include consideration of mechanical, thermal, environmental and electrical
stresses which are expected during installation and operation.
(b) Cable shall be designed and manufactured
to retain specified dimensions and structural integrity during manufacture,
reeling, storage, handling, and installation.
(c) Cable shall be designed and constructed
in such a manner that each component is protected from harmful effects of other
components.
(d) The conductor,
insulation, and shielding shall be designed to withstand the effects of the
expected magnitude and duration of fault current, except in the immediate
vicinity of the fault.
(2)
Sheaths and
Jackets. Sheaths and/or jackets shall be provided when necessary
to protect the insulation or shielding from moisture or other adverse
environmental conditions.
(3)
Shielding.
(a)
General.
1.
Conductor shielding should be provided in accordance with an applicable
standard issued by a recognized organization such as the Association of Edison
Illuminating Companies, the Insulated Power Cable Engineers Association and the
National Electrical Manufacturers Association.
2. Insulation shielding shall be provided for
cable operating at more than 5 KV to ground and is recommended for cables
operating above 2 KV to ground.
Exception: Shielding is not required for short jumpers which do
not contact a ground surface within enclosures or vaults provided they are
guarded or isolated.
3.
Insulation shielding may be sectionalized provided that each section is
effectively grounded.
(b)
Material.
1. The shielding system may consist of
semi-conducting materials, non-magnetic metal or both. The shielding adjacent
to the insulation shall be designed to remain in intimate contact with the
insulation under all operating conditions.
2. Shielding material either shall be
designed to resist excessive corrosion under the expected operating conditions
or shall be protected.
(4)
Joints and
Accessories.
(a) Cable joints,
materials and accessories shall be designed to withstand the mechanical,
thermal, environmental and electrical stresses expected during
operation.
(b) Cable joints shall
be designed and constructed in such a manner that each component of the cable
and joint is protected from harmful effects of the other components of the
cable or joint.
(c) Cable joints
shall be designed and constructed to maintain the structural integrity of the
cables to which they are applied and to withstand the magnitude and duration of
the fault current expected during operation, except in the immediate vicinity
of the fault.
(d) For insulating
joints, see 220 CMR 126.33(3)(a)3.
