RU68173U1 - POWER CABLE - Google Patents

Abstract

The utility model relates to cable technology, namely to power cables for a voltage of 1 kV. The cable contains from 3 to 5 copper conductors with insulation from a cross-linked halogen-free polyolefin composition, an inner and outer sheath of a halogen-free polyolefin composition, with an oxygen index of at least 45. The cores are twisted into a core around a bundle of a polyolefin composition that does not contain halogen free. On top of the inner shell is the armor of two galvanized steel tapes. The cable may also contain a winding of glass tape, applied over the inner sheath, and also over each core a barrier of mica tape. The technical result is an increase in fire resistance of the cable.

Description

The utility model relates to cable technology, namely, to the construction of power cables with plastic insulation and a sheath, designed for the transmission and distribution of electrical energy in stationary electrical installations at an alternating voltage of 1000 V with a frequency of up to 100 Hz at an ambient temperature from minus 50 ° С to plus 50 ° C and relative humidity up to 98% at a temperature of plus 35 ° C.

PPGNG-HF brand power cables are known for voltages of 1000 V and frequencies up to 100 Hz, having copper conductive cores, insulation and a sheath made of halogen-free polymer compositions (Information and Technical Collection "Cable Products" vol. 1, part 1, p. 62, Moscow, JSC "VNIIKP", 2007).

However, such cables do not meet the fire resistance requirements.

The task was to develop a design of a power cable that does not spread combustion when laying the cable in bundles and is fireproof.

The technical result is achieved in that in a power cable for a voltage of 1 kV, containing from 3 to 5 conductive copper conductors with insulation from a halogen-free polymer composition, an extruded inner sheath from a halogen-free polymer composition, and an outer sheath from a polymer composition, halogen-free, additionally contains a halogen-free polyolefin composition tow, located in the center of the core, armor made of two galvanized steel tapes overlaid on the inside of olochki and insulation made of crosslinked polyolefin composition containing no halogen, the inner and outer membrane of a polyolefin composition containing no halogen, an oxygen index of not less than 45.

The preferred ratio of the nominal thickness of the outer shell (δ _n.d. ) and the nominal thickness of the inner shell (δ _n.d. ) is δ _n.d. / δ _B.O. ≥1.75.

The cable may also comprise a winding of at least one glass tape superimposed overlapping on top of the inner sheath.

The cable may also contain on top of each conductive core a thermal barrier of at least one mica tape, overlapped with an overlap of at least 40%.

The utility model is illustrated in the drawing, which shows a power cable in section.

The cable contains copper conductive conductors 1, in the center of the core twisted from insulated conductive conductors, a tow 2 of a halogen-free polyolefin composition, insulation 3 of a cross-linked halogen-free polyolefin composition, an extruded inner sheath 4 of a halogen-free polyolefin composition, with an oxygen index of at least 45, on top of the inner shell, an armor 5 of two steel galvanized tapes and an outer shell 6 of a halogen-free polyolefin composition with oxygen in eksom least 45 windings, at least one glass tape 7 superposed with an overlap over the inner shell, each current-carrying conductor 8 has a thermal barrier with at least one mica tapes, overlaid with overlap of at least 40%,

The preferred ratio of the nominal thickness of the outer shell (δ _n.d. ) and the nominal thickness of the inner shell (δ _n.d. ) is δ _n.d. / δ _B.O. ≥1.75.

The following is information confirming the feasibility of the utility model.

As the insulation material of 3 cables, a halogen-free polyolefin composition was used.

As the material of the inner sheath 4 of the cable, a halogen-free polymer composition with an oxygen index of at least 45 was used.

As the material of the outer sheath 6 of the cable, a halogen-free polyolefin-based polymer composition with an oxygen index of at least 45 was used.

As the material of the tow 2, a halogen-free polyolefin composition was used.

Used for the manufacture of the proposed cable polyolefin compositions are commercially available.

Conductors 1 are made of copper wire, traditional for electric cables, the twisting of the cable elements is carried out on conventional twisting equipment.

Insulation 3, inner 4 and outer 6 shells are applied on extrusion equipment.

The application of a thermal barrier 8 of mica tape and a winding of glass tape 7 is carried out on known equipment traditionally used in the cable industry.

The application of armor 5 of steel tapes is carried out on known equipment, traditionally used in the cable industry.

Samples 1-3 (Table 1.) of the proposed power cable were tested for non-proliferation of combustion when placed in a bundle in accordance with GOST R IEC 60332-3-22-2005 and for fire resistance in accordance with GOST R IEC 60331-21-2003.

Table 1. Oxygen Indices of Materials of Cable Construction Elements Design element name Material oxygen index Sample Number one 2 3 Inner shell 45 fifty 55 Outer shell 45 fifty 55

The same results were obtained for all samples, which are shown in Table 2.

Table 2. Cable specifications Name of characteristic Technical requirements Cable product Famous cable Suggested cable. Samples 1-3 Compliance of cables with fire safety requirements: - non-proliferation of combustion in accordance with GOST R IEC 60332-3-22-2005 The length of the burnt area is not more than 2.5 m no more than 1,5 m, corresponds no more than 1,0 m, corresponds - fire resistance in accordance with GOST R IEC 60331-21-2003 maintaining operability in conditions of exposure to an open flame for at least 180 minutes no more than 5 min., does not correspond more than 180 min., corresponds

Claims (4)

1. Power cable for a voltage of 1 kV, containing from 3 to 5 conductive copper conductors twisted into a core with insulation from a halogen-free polymer composition, an extruded inner sheath from a halogen-free polymer composition, and an outer sheath from a polymer composition not containing halogens, characterized in that it additionally contains a bundle of a halogen-free polyolefin composition located in the center of the core, an armor of two steel galvanized tapes, placed on top of the inner shell, and the insulation is made of a crosslinked halogen-free polyolefin composition, the inner and outer shell of a halogen-free polyolefin composition with an oxygen index of at least 45. 2. Cable according to claim 1, characterized in that the ratio of the nominal outer shell thickness (δ _n.d.) and the nominal thickness of the inner shell (δ _VO) is δ _n.o ./δ _VO ≥1.75. 3. The cable according to claim 1, characterized in that it further comprises a winding of at least one glass tape, superimposed overlapping on top of the inner shell. 4. The cable according to claims 1 and 3, characterized in that it further comprises, on top of each conductive core, a thermal barrier of at least one mica tape applied with an overlap of at least 40%.