Fire-resistant cable splice
Fire resistant splices, kits, and methods for splicing fire resistant cables disclosed herein can maintain an operable connection and meet applicable fire codes to allow a 2 hour egress under extreme heat conditions. Splices disclosed herein can comprise an outer steel enclosure and an interior cable spliced within. Splices disclosed herein may comprise a layer of quartz material disposed immediately against a metal connector forming the electrical connection between conductors of each wire, and wrapped in a ceramifiable silicon rubber layer.
1 . A fire-resistant cable splice comprising:
a first cable comprising a first metal conductor;
a second cable comprising a second metal conductor;
a connector forming an electrical connection between the first and second metal conductors;
a quartz fabric consisting of quartz, wherein the quartz fabric is in contact with and surrounding the connector; and
an insulation layer in contact with and surrounding the quartz fabric, wherein the insulation layer comprises a ceramifiable silicon rubber;
wherein the fire-resistant cable splice remains operational up to temperatures of at least 1850° F.
2 . The splice of claim 1 , wherein the quartz fabric is a quartz wool, a quartz yarn, a quartz roving, a chopped quartz, a quartz veil, or a quartz felt.
3 . The splice of claim 1 , wherein the quartz fabric is a quartz felt or quartz wool.
4 . The splice of claim 1 , wherein the quartz fabric has a compressed thickness in a range from 0.1 mm to 2 mm.
5 . The splice of claim 1 , wherein the insulation layer has a thickness in a range from 0.1 mm to 2 mm.
6 . The splice of claim 1 , wherein the splice does not comprise a jacket layer surrounding the insulation layer.
7 . The splice of claim 1 , wherein either or both of the first and second cables is an insulated cable selected from a THHN cable, a THWN cable, a THWN-2 cable, a XHHW cable, or a XHHW-2 cable.
8 . The splice of claim 1 , further comprising an enclosure surrounding the connection between the first and second metal conductors.
9 . The splice of claim 8 , wherein the enclosure is a NEMA-1 enclosure.
10 . The splice of claim 8 , wherein the enclosure has a fiberglass construction.
11 . The splice of claim 8 , wherein the enclosure comprises a conduit fitting configured to receive a conduit surrounding either of the first and second cables.
12 . The splice of claim 11 , wherein either or both of the first or second cables enters the enclosure from a conduit disposed within a conduit.
13 . The splice of claim 12 , wherein the conduit is an electrical metallic tubing.
14 . A fire resistant cable splice kit comprising:
a connector configured to secure a first metal conductor to a second metal conductor;
a quartz fabric consisting of quartz fibers;
a tape comprising a ceramifiable silicon rubber; and
an enclosure.
15 . The kit of claim 14 , wherein the connector is a steel crimp sleeve connector or a steel crimp butt connector.
16 . The kit of claim 15 , wherein:
the enclosure comprises conduit fittings sized to receive a conduit with a conduit diameter in a range from ½″ to 1″ and an overall dimension of 4″×4″×12″;
the enclosure comprises conduit fittings sized to receive a conduit with a conduit diameter of 1¼″ and an overall dimension of 6″×6″×12″; or
the enclosure comprises conduit fittings sized to receive a conduit with a conduit diameter of 2″ and an overall dimension of 6″×6″×16″.
17 . The kit of claim 14 , wherein the quartz fabric is a quartz felt or quartz wool.
18 . The kit of claim 14 , wherein the ceramifiable silicon rubber is Elastosil® R 512/70.
19 . A method for forming a fire-resistant connection between two fire resistant cables, the method comprising:
inserting a first conductor and a second conductor into an enclosure;
forming an electrical connection between the first and second conductors;
surrounding the electrical connection with a quartz fabric consisting of quartz fibers; and
applying a tape comprising a ceramifiable silicon rubber to the quartz fabric; wherein the tape surrounds the electrical connection; and
closing the enclosure.
20 . The method of claim 19 , wherein applying the tape comprises forming an overlapping helical layer of the tape extending axially from a first conductor insulation and across the electrical connection to a second conductor insulation.