System and method for electrical power installation

A flat multiconductor cable power distribution system has a discrete wire multi-phase feeder, a main flat cable having at least four conductors, the cable being connected to the feeder to have plural phase energization. An insulation-piercing adapter overlies and is connected to the main cable and is energized with a selective one of the plural phases. In a particular arrangement, a secondary multiconductor cable is connected to the main cable by the adapter. A power outlet may be electrically connected to the secondary cable at the juncture of the main and secondary cables and the adapter.

FIELD OF THE INVENTION 
This invention relates generally to distibution of electrical power and 
pertains more particularly to multiconductor flat cable power distribution 
and methods for installing systems therewith. 
BACKGROUND OF THE INVENTION 
From its inception in the course of a program sponsored in the early 1970's 
by NASA, flat conductor cable power distribution has been extensive 
evolution. The rudimentary sysrem which emanated from the NASA program 
made use of cables having three conductors of rectangular cross-section 
embedded in electrical insulation and effected interconnection of plural 
such cables by arranging same in mutual abutment in the same plane, i.e., 
upon a floor. This system employed connectors in the form of straps 
underlying the cables and having end portions for making 
insulation-piercing connection with the conductors to be joined. A number 
of present commercial undercarpet wiring systems follow this approach. 
One of the initially introduced commercial undercarpet wiring systems, that 
of Thomas & Betts Corporation, the assignee of the subject application, 
involves a method of laying one cable upon another and interconnecting 
conductors by forming an opening through the conductors, placing a 
generally L-shaped insulation-piercing connector in the opening and 
crimping same upon exterior surfaces of the cables to provide 
interconnection without the connector straddling or otherwise extending 
over any conductors other than those intended to be interconnected. 
In conducting power from a first or main cable run connected to the power 
feeder of a building to a desired power location, both of the above types 
of systems extend a second cable, connected as described above to the main 
cable, to such location and there discretely wire a power outlet pedestal 
of conventional character to a transition fitting which itself is in 
insulation-piercing relation with the second cable at such location. 
Successively to such initial system versions, the evolution of flat 
conductor cable power distribution systems embraced an improvement whereby 
the power outlet pedestal was rendered energized without need for discrete 
wiring. Pedestals have thus become known which may be applied directly to 
a single-phase, three-conductor cable, insulation-piercing contacts of 
such pedestals having internal connectors having insulation-piercing end 
portions for electrical connection with the cable conductors and other end 
portions adapted for engagement with the prongs of plugs inserted in 
pedestal power outlet receptacles. A device of this type is shown in 
commonly-assigned U.S. Pat. No. 4,479,692, issued on Oct. 30, 1984 and 
entitled "Receptacle for Flat Multi-Conductor Cable". 
In a still further development, such as is shown in commonly-assigned U.S. 
Pat. No. 4,480,889, issued on Nov. 6, 1984 and entitled "Apparatus and 
Method for Tapping or Splicing Flat Multi-Conductor Cable", the capability 
of the above discrete-wire-free pedestal was expanded to also provide for 
the splicing of another cable to the cable energizing the receptacle. 
Ninety-degree folding of such additional cable effectively provides a tap 
connection spatially coincident with the pedestal termination. 
Despite the progress of such evolution in flat conductor cable power 
distribution systems, the installation planner still presently has limited 
horizon to the extent that one can only realize the advantage of the last 
two-mentioned improvements after having tapped such pedestal-energizing 
cable to the main cable run, or having run all three conductor cable 
branches from the wall. Thus, the only known connections to be made 
directly to a five conductor flat cable do not encompass the use of 
insulation-piercing pedestals, be they of splice or non-splice variety, 
but involve tapping or splicing a second cable thereto. Based on 
requirements to balance loads among the three phases typically at hand, a 
minimum of three such non-outlet associated connections need be made in 
the system installation. 
As an additional consideration, the known connections directly to five 
conductor flat cable are not at visibly determinable locations upon 
completion of system installation and placement of carpeting atop the 
system. Thus, the abutting and overlapping connections alluded to at the 
outset above are not power outlet locations, but are secreted beneath the 
carpeting in locations only determinable by reference to the installation 
wiring drawings or, in their absence or departure therefrom, only by 
removing carpet squares and inspecting the system. In this connection, 
there remains a vestige of practical difference between undercarpet power 
distribution systems and the traditional conduit systems, the latter 
involving cable connections only at power outlet locations, such as 
junction boxes and pedestals. 
SUMMARY OF THE INVENTION 
The present invention has as its primary object the provision of improved 
planning and installing of flat conductor cable power distribution 
systems. 
Another general object of the invention is to provide undercarpet power 
distribution installations with the practically desirable characteristic 
of traditional conduit systems above noted. 
A more particular object of the invention is to expand interconnections to 
five conductor flat cable and thus effect a reduction in required numbers 
of non-pedestal connections in the installation of such systems. 
In attaining the foregoing and other objects, the invention provides a 
method of successively effecting pedestal connections, directly upon a 
flat cable main run with multiple five conductors, at respective different 
phases of such main run. By this practice, one can achieve full system 
installation without resort to non-pedestal connections. Further, in the 
latter exclusion of non-pedestal connections, one eliminates need for 
resort to installation wiring diagrams or carpet tile removal for an 
appreciation of the installed system, all connections being at power 
outlet locations, as in the traditional conduit systems. 
In preferred practice and system in accordance with the invention, all 
needed service outlet locations can be served by secondary cables of three 
or four conductors having connection to the main cable run at power outlet 
locations thereon. 
The foregoing and other objects and features of the invention will be 
further understood from the following detailed description of practices 
thereof and apparatus therefor and from the drawings wherein like 
reference numerals identify like parts throughout.

DESCRIPTION OF PREFERRED EMBODIMENTS AND PRACTICES 
Referring initially to FIG. 8, an installation area is shown wherein a 
system planner has elected to distribute power on a per phase basis 
respectively into different zones I-1, I-2, II and III, for 
phase-balancing or other purposes. 
In implementing such planned system in accordance with the invention, one 
connects power mains or discrete feeder conductors 210, comprising phase 
conductors 212, 214 and 216, ground conductors 218 and neutral conductor 
220 at transition box 222, to flat conductor cable 224. Cable 224 has an 
electrically conductive shield 226 and individual rectangular 
cross-section phase conductors 228, 230 and 232, ground conductor 234 and 
neutral conductor 236, all encased in electrically insulative casing 238. 
Perforated margins 240 intervene encased conductors to facilitate tearing 
or otherwise separating individual insulated conductors from the cable. 
Cable 224 extends in a main run from box 222 to first phase pedestal power 
outlet 242, the structure of which will be discussed in detail below, 
whereat secondary cable 244 has its three conductors respectively 
electrically connected to phase conductor 228, ground conductor 234 and 
neutral conductor 236 of cable 224. Secondary cable 244 extends through 
outlet connection 242 and is folded upon itself aside same to define 
secondary cable runs 244a and 244b, which have indicated opposite sense 
run directions, as shown, perpendicular to cable 224. Pedestal power 
outlets 246 and 248 are applied to cable run 244a and pedestal power 
outlet 250 to cable run 244b, other outlets being added as desired on runs 
244a and 244b, which may be further folded to effect directional changes. 
Outlets 246, 248 and 250 may be of type shown in the above-referenced '661 
application. 
Main cable 224 continues beyond pedestal connection 242 and cable run 244b 
into second phase pedestal power outlet 252 at which another secondary 
cable 254 has its three conductors respectively, electrically connected to 
phase conductor 230, ground conductor 234 and neutral conductor 236 of 
cable 224. 
Secondary cable 254 extends through connection outlet 252 and is folded 
upon itself aside same to define cable runs 254a and 254b, which have 
indicated like sense run directions, as shown, perpendicular to cable 224. 
Pedestal power outlets 256 and 258, of like type to units 246, 248 and 
250, are applied respectively to cable runs 254a and 254b. 
Main cable 224 further continues beyond pedestal connection 252 and cable 
run 254b into third phase pedestal power outlet 260, which may be the 
final termination for cable 224. Here, further secondary cable 262 has its 
three conductors respectively connected to phase conductor 232 of cable 
224 and has its ground and neutral conductors connected to those of cable 
224. 
Cable 262 extends to one side of outlet connection 260 and is folded at 
such side to define secondary cable run 262a, to which pedestal power 
outlet 264, again of type shown in the application noted above, is 
connected. 
At any or all of pedestals 246, 258, etc. of FIG. 8, further three 
conductor branches may be added to the phase of such pedestals by use, at 
the pedestal, of the three conductor tap adapter of the above-noted '662 
application. Referring to FIG. 1, a connecting device for use as units 
242, 252 and 260 and thus enabling the system and practice of FIG. 8 is 
shown, including contact support member 10, base 12 and cover 14. Support 
member 10 is formed of a suitable insulative material and is generally of 
rectangular configuration, being elongate in direction E and upstanding in 
direction U. A first contact element set comprising contact elements 16, 
18 and 20 is disposed in fixed positional manner on first surface 22 of 
support member 10, for confronting a three conductor cable 24. Cable 24 
includes flat conductors 26, 28 and 30 disposed in insulative casing 32. 
For reference purposes, and by way of accepted industry convention, 
conductor 30 is an electrical neutral conductor and casing 32 includes a 
white coloration to identify this conductor. Conductor 28 is the ground 
conductor and casing 32 includes a green coloration overlying same. 
Conductor 26 is a live (single-phase) conductor and may bear overlying 
casing indication in the colors black, red or blue. Contact elements 16, 
18 and 20 are of insulation-piercing type including conventional 
insulation-piercing elements 16a, 18a and 20a and will respectively engage 
electrically conductors 26, 28 and 30 upon assembly. 
A second contact element set is included in support member 10, to be 
discussed more particularly below in connection with FIG. 2, and is 
disposed at the underside of support member 10 for insulation-piercing 
engagement with conductors of a cable 34. Cable 34 is shown to be of five 
conductor (three-phase) type having neutral conductor 36, ground conductor 
38 and individual phase conductors 40, 42 and 44 (A, B and C phases). The 
conductors of cable 34 are also typically color-coded. 
Base 12 includes cable guides 46-52 aside cable receipt expanse 53 which is 
defined by an insulative layer 54 disposed atop metal substrate 56. 
Securing means 58 is preferably integral with substrate 56 and is in the 
form of a threaded member having an annular insulator 60 adjacent 
insulative layer 54. The positioning of threaded means 58 in relation to 
guides 46-52 is such that, upon placement of cable 34 upon base 12, means 
58 passes through cable 34 at location 62, i.e., through the insulation 
between conductors 38 and 40, at which time annular insulator 60 is 
resident in cable 34, precluding electrical continuity, through means 58, 
between conductors 38 and 40. It should be noted that with four-conductor 
cable, for example, such poitioning of threaded means 58 through the cable 
can be assured by using the neutral conductor 36 as a reference and 
placing the adjacent edge of the cable into engagement with base guides 
46-48. Upstanding posts or projections 64 and 66 will, upon assembly of 
member 10 with base 12, nest in underside recesses in member 10 one such 
recess being shown at 65. Guides 46-52 in combination with support member 
tabs 47 and 49 will provide an anti-bowing or anti-deflection capability 
for base 12 and cable 34 seated thereon. Posts 64 and 66 include threaded 
central openings 68 and 70, respectively, for assembly purposes. A white 
indicium 72 is applied to insulative layer 54 to indicate to the user the 
proper polarization of cable 34 with respect to base 12, namely, that 
white (neutral) conductor 36 should overly indicium 72. 
As will be seen, support member 10 includes a central lower indentation 74 
through which cable 34 will extend upon assembly. Legs 76 and 78 of member 
10 will abut the upper surface of base 12 on assembly. Cover 14 is 
dimensioned to fit telescopically over support member 10 on assembly and 
includes upper surface openings 80, 82 and 84, through which contacts 16, 
18 and 20 respectively extend to engage cable 24 when the latter is 
applied to the upper surface of cover 14. In assembly, openings 14a and 
10a are aligned, as are openings 14b and 10b to permit threading of screws 
into posts 64 and 66. A nut is applied in opening 10c to securing means 
58. 
Referring to FIG. 2, wherein the contact elements are shown in exploded 
manner relative to support member 10, it will be seen that upper surface 
22 includes contact seats 86, 88 and 90, the perimeters of which extend 
upwardly from surface 22 in measure equal to the depth of cover 14 
adjacent openings 80-84 of FIG. 1. Elongate channels 92 and 94 extend in 
both directions from contact seat 86. Channels 96 and 98 extend 
rightwardly of contact seat 88 and into contact seat 90. Channels 100 and 
102 extend rightwardly of contact seat 90. 
Contact element 16 has flanges 104 and 106 integral therewith and serving 
as conductive means for electrically connecting contact element 16 with 
its counterpart contact element 108 of the second set of contacts referred 
to above. As will be discussed further below, contact element 108 includes 
conventional insulation-piercing elements 109 projecting from its 
undersurface and is supported in flanges 104 and 106 for translatory 
movement in support member 10. Contact element 18 includes flanges 110 and 
112, again integral therewith, and serving as conductive means for 
interconnecting contact element 18 with its counterpart contact element 
114 of the second set. Conventional insulation-piercing elements 115 
project from the undersurface of contact element 114. Contact element 20 
has integral flanges 116 and 118 serving as conductive means for 
connecting same with its counterpart contact element 120 of the second 
set. Conventional insulation-piercing elements 121 project from the 
undersurface of contact element 120. 
Contact element 16 includes in flange 104 a track 104a to support contact 
element 108 for translation into any selective one of three positions. For 
defining such positions, flange 106 includes detents in the form of 
through openings 106a, 106b, and 106c. Contact 108 includes end flanges 
108a and 108b, which are respectively exteriorly aside flanges 104 and 106 
upon assembly of contact elements 16 and 108. Wall 108c is struck upwardly 
from the floor of contact element 108 to provide a channel 108d, in which 
flange 104 resides. A threaded member 107 passes through opening 108e, 
through track 104a and is threaded into opening 108f to secure the 
assembly. Boss 108g is situated on the interior side of flange 108b and is 
sized to removably reside in any of openings 106a, 106b or 106c to effect 
the proper positioning of contact element 108. 
An assembly of a first set contact element and a second set contact element 
is shown in FIG. 2 in the case of contact element 18 and its counterpart 
second set contact element 114 in FIG. 2 with parts being identified in a 
manner similar to those designated for contact elements 16 and 108. 
In assembling support member 10 and its first and second set contact 
elements, the first set contact elements are first inserted as follows. 
Flanges 104 and 106 are disposed in channels 92 and 94, whereby contact 
element 16 resides on seat 86. Flanges 110 and 112 are disposed in 
channels 96 and 98, whereby contact element 18 resides on seat 88. Flanges 
116 and 118 are disposed in channels 100 and 102, whereby contact element 
20 resides on seat 90, being spaced by member 10 above flanges 110 and 
112, which are stepped down as indicated. Next, contact elements 114 and 
120 are inserted into the underside of member 10 and secured respectively 
to flanges 110, 112 and 116, 118. Selection is made for the state of 
contact element 108 and it is inserted into the underside of member 10, 
translated into selected position and secured in place. The showing of 
member 10 in FIG. 1 is thus reached. 
Referring to FIG. 3, the assembly of components above discussed is expanded 
to include receptacle 122 and the respective and fastener screws 124, 128 
and a grounding fastener screw 126. The receptacle 122 carries indicia as 
at 130 which are cooperative with the indicia on the cable indicative of 
proper receptacle orientation to insure correct polarity of electrical 
connections to be made. Further in this regard and to insure proper 
placement orientation of the receptacle on the cable, the receptacle has 
screw-through passages which function as a telltale cooperative with cover 
openings 14c-e and support member openings 10d-f (FIG. 1) when correct 
receptacle placement is effected to indicate such condition. Another 
safeguard that insures that proper orientation must be employed to 
installed the receptacle is provided by tabs 136, 138 at the underside of 
the receptacle which must pass through cable 24 at perforations 137, 139 
between the ground conductor and the live and neutral conductors and be 
received in openings 134, 135 of cover 14 and support member 10, 
respectively, in order for the receptacle to seat properly. If reciprocal 
orientation were attempted, the tabs would not line up with openings 134, 
135 and hence not pass therethrough preventing proper seating. 
The protective metallic or grounding shield 140 on top of cable 24 will, as 
a preliminary to connecting the receptacle thereto, be removed or cut and 
laid back in the rectangular pattern as shown in regions overlying the 
live and neutral conductors 26 and 30 of the cable leaving exposed the 
insulative covering in which said conductors are encased. The shield may 
be cut and laid back by folding same rightwardly on top of uncut portions 
of the shield since this facilitates effecting repair to the shield in the 
event the receptacle is removed. Like cable preparation is made for cable 
34 of FIG. 1. It should be appreciated, however, that the cable may be 
prepared by full displacement of the cable shield so as to expose the 
entire upper surface thereof for insulation-piercing connection to the 
receptacle. More specific understanding of the receptacle will be had by 
consideration of the U.S. Pat. No. 4,479,692 identified hereinabove and 
hereby incorporated by reference. In particular, FIGS. 2-5 of such patent 
show the contact elements thereof as having first end portions for 
engaging the appliance prong terminals and second end portions for 
insulation piercing the cable. For immediate reference purposes, FIG. 4 
hereof shows a typical section of the pedestal with appliance prongs shown 
at 142, 144, with contact element first portions at 146, 148 and with 
second end portions 150, 154. 
Referring to FIG. 5, contact support member 10 is shown schematically in 
first operative state between cables 24 and 34, as it would be upon 
securement of the FIG. 3 pedestal to the FIG. 1 connection device with the 
cables in indicated position. As will be seen, cable 24 is laterally 
centered with respect to support member 10, as is also the case for cable 
34. Although neutral conductor 30 laterally overlies ground conductor 38, 
the support member effects a lateral connection transition of one 
conductor step, whereby conductor 30 is connectable to its counterpart 
neutral conductor 36, flanges 116 and 118 effecting such transition 
between first set contact element 20 and second set contact element 120. 
A like one step transition is also fixedly provided as between ground 
conductors 28 and 38 through flanges 110 and 112 interconnecting first set 
contact element 18 and second set counterpart element 114. 
In the FIG. 5 setting of support member 10, a further one step transition 
rightwardly is also provided as between phase conductors 26 and 40 through 
flanges 104 and 106. 
Referring to FIG. 6, contact support member 10 is shown schematically in 
second operative state. As will be seen, cable 24 is again laterally 
centered with respect to support member 10, as is cable 34. 
The one step transitions are present for the neutral and ground conductors, 
but support member is now set such that contact element 108 is in 
registration with conductor 42, the second phase conductor of cable 34. 
This setting thus provides for interconnection of conductor 26 of cable 24 
with conductor 42, and the associated pedestal is powered by the B phase, 
rather than A phase, as was the case in the FIG. 5 setting. 
Referring to FIG. 7, contact support member 10 is shown schematically in 
third operative state. Cable 24 is again laterally centered with respect 
to support member 10, as is cable 34. The one step transitions are present 
for the neutral and ground conductors, but support member is now set such 
that contact element 108 is in registration with conductor 44, the third 
phase conductor of cable 34. This setting thus provides for 
interconnection of conductor 26 of cable 24 with conductor 44, and the 
associated pedestal is powered by the C phase. 
By way of summary of the foregoing, it will be seen that the invention 
broadly provides a flat conductor cable power distribution system 
comprising a discrete wire multi-phase feeder, a main flat cable having at 
least four conductors and connected to the feeder allowing plural phase 
energization and an insulation-piercing power outlet receptacle connected 
to the main cable and energized with a selective one of such phases. The 
system may further include a secondary flat conductor cable connected to 
the main cable at the power outlet receptacle and energized by such one 
phase. The system is typically multiphase wherein the foregoing practice 
is repeated for each phase. 
In another aspect, a flat conductor cable power distribution system is 
shown comprising a discrete wire three-phase feeder, a main flat cable 
having five conductors and connected to the feeder to have energization in 
first, second and third phases and first, second and third 
insulation-piercing power outlet receptacles connected to said main cable 
at different locations thereon and energized respectively by the first, 
second and third phases. Further shown is a flat conductor cable power 
distribution system disposed upon a substrate and covered by an overcover, 
the system including a main cable energized in plural phases, a plurality 
of secondary cables connected to the main cable and power outlet 
receptacles connected to the main cable and the secondary cables, each 
such connection of the main and secondary cables being discernible by 
structure of the receptacles disposed visibly upon the overcover. 
Various changes to the illustrated embodiment of the invention may be 
introduced without departing from the invention. Thus, the particularly 
discussed and described preferred embodiment is intended in an 
illustrative and not in a limiting sense. The true spirit and scope of the 
invention are set forth in the following claims.