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Turning now to the drawing FIG. 1, a bit of service entrance cable is shown usually at 10. Cable 10 is comprised of a cluster, herein three, of insulated stranded conductors 12. Special cable insulation tape 14 to be described presently is helically wrapped concerning the clustered conductors 12 with the adjacent turns of the tape overlapping one another. Turning now to FIG. 2, tape 14 is comprised of a 20 × 10 open weave glass fiber cloth or scrim 22. A steady film 24 made of polyester, reminiscent of that offered below the tradename "Mylar," is bonded to the scrim using a comparatively low viscosity fireplace-retardant plastic laminate adhesive 26. Suitable adhesive materials embrace acrylic, fire retardant cable acrylic-polyvinyl chloride copolymers and polyurethane. Pat. No. 3,602,636. Basically, it uses an open weave glass fiber tape wrapped across the clustered conductors. A barrier layer in the type of a skim coat of flame-retardant unvulcanized polychloroprene is calendered on the glass cloth and eventually an outer jacket of synthetic rubber is extruded in place onto the tapered conductors and fused to the underlying barrier layer.

Therefore, the thickness and, hence, weight of the tape as a whole are lower than those of standard service entrance cable tape incorporating a natural or synthetic rubber barrier layer which is calendered instantly onto the scrim. Therefore, the two layers are urged together without the glass fibers within the scrim being cracked by extreme stress. All of those components make the current tape a highly successful industrial product whose attributes are also enjoyed by the cable system into which the tape is integrated. First, while satisfying the entire UL mechanical and electric tests for such cable, the present product is ligher in weight. Briefly, the current cable tape has a backing composed of an open weave glass fiber scrim. The present cable has a number of distinct advantages over its typical counterparts as exemplified by the cables described within the aforesaid patents. Such a cable is described in the aforesaid U.S.

That prior type of cable is disadvantaged too because the unvulcanized barrier layer is just not utterly continuous; it accommodates pinholes which offer passages for air or moisture which adversely have an effect on the dielectric power of the cable insulation. Also, the glass cloth should be dipped in weave set of chlorprene which acts as a primer previous to being coated with the barrier layer. The web result is a superior insulating, bedding and binding tape which can be made at a decrease value than prior comparable merchandise and which, when integrated into an exterior cable system, permits the latter to simply move the entire UL exams for such cables. Yet another object of the invention is to offer a service entrance cable tape which satisfies all of the UL tests. That additional step, coupled with the truth that a full crew is required to calender the fabric onto the glass cloth, means that the general cost of the prior cable is higher than need be. This layer is composed of pretty dense materials and is comparatively thick so that it offers the overall cable a relatively excessive unit weight. The most prevalent sort of service entrance cable in use right this moment employs conductors wrapped with a layer of polyethylene terephthalate which is, in turn, surrounded by braided in situ fiber sheath impregnated and covered with asphalt after which lacquered.

Fairly not too long ago, another sort of cable has been introduced which does not require the aforesaid braided sheath. While that kind of cable passes the required UL assessments and is an enchancment over the prior braided cable by way of cost, it still has certain drawbacks. Exterior cable of this sort need to satisfy the stringent take a look at requirements of the Underwriters' Laboratories, Inc. For instance, service entrance cable, which is the cable which conducts electricity from overhead power strains right into a person's house, should cross the UL 300 amp. Still further, the tensile energy of the prior cable tape is not as high because it could be, though it does pass the UL take a look at for this characteristic. This test is described intimately in U.S. FIG. 2 is a scrap view with parts broken away exhibiting the bedding and binding tape in the FIG. 1 cable in higher detail. Accordingly, this invention goals to offer a tape for insulating a cable similar to a service entrance cable which is relatively easy to make in uniform quality heaps. An additional object of the invention is to offer an improved hearth-retardant cable tape.