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US 9,175,791 B2Granted
Low EMF compact duct spacer
AssigneeUnderground Devices, Inc.
InventorDonald P McCoy
Life of this patent
Estimating the term…
Abstract
Conduit spacers useful in preparing duct banks with reduced electromagnetic fields (EMF) are disclosed. The conduit spacers are designed to maximize phase cancellation of EMF from a closely-spaced series of electric power cables placed in conduits supported underground by the conduit spacers. The spacers are also designed to minimize the EMF above ground by reducing the distance needed to bury the cables for a given EMF above ground. In one embodiment, the spacers place conduits adjacent one another for maximum cancellation of a single three-phase cable installation. In another embodiment, the spacers place conduits adjacent one another for maximum cancellation for a dual three-phase cable installation, including cross-phase cancellation, e.g., A-B-C and C-B-A.
Claims30
A conduit spacer, comprising:
- a plastic spacer having three bodies, each body having an opening adapted to support a conduit or pipe of a same diameter, wherein the three bodies are adjacent one another with no intervening bodies, conduits or pipes and wherein centers of the three bodies approximate an equilateral triangle with a base in a nominally vertical direction;
- and
- a base spacer having two bodies adjacent one another, each of the two bodies adapted to support a conduit or pipe,
- wherein an arrangement of energized electric power cables supported by a sequence of a plurality of the plastic spacers, the cable supported in the three adjacent conduits or pipes, with no intervening conduits or pipes, is effective to reduce electromagnetic field (EMF) emissions from the energized electric power cables.
1 more element
A conduit spacer, comprising:
- a plastic spacer having a plurality of openings, wherein three of the plurality of openings have a same diameter and wherein centers of the three openings approximate an equilateral triangle having a base in a vertical direction, each of the three openings adapted to support a conduit or pipe,
- wherein arranging energized electric power cables in three conduits or pipes supported by the openings in a plurality of the plastic spacers in a sequence is effective to reduce electromagnetic field (EMF) emissions from the energized electric power cables, and
- wherein the three openings are adjacent one another with no intervening openings, conduits or pipes, the plastic spacer comprising at least one additional opening for supporting a pipe of a diameter different from the same diameter.
A conduit spacer, comprising:
- a lower plastic spacer comprising two bodies, the bodies adjacent one another with no intervening bodies, conduits or pipes between the two bodies, a first body of the lower spacer having an opening adapted to support a conduit or pipe of a first diameter and a second body of the lower spacer having an opening adapted to support a conduit of pipe of a second diameter;
- and
- an upper plastic spacer, the upper plastic spacer comprising four bodies, the four bodies comprising two lower bodies and two upper bodies, the two lower bodies adjacent one another and the two upper bodies adjacent one another, and the two lower bodies adjacent the two upper bodies with no intervening bodies, conduits or pipes between the two lower bodies and the two upper bodies, each body of the upper plastic spacer having an opening adapted to support a conduit or pipe,
- wherein a first lower body of the upper plastic spacer is adapted to support a conduit or pipe of the first diameter, and wherein a second lower body of the upper plastic spacer and the upper bodies of the upper plastic spacer are adapted to support three conduits or pipes of the second diameter, wherein the three conduits or pipes of the second diameter approximate an equilateral triangle with a base in a nominally vertical direction,
- wherein an arrangement of energized electric power cables in the adjacent conduits or pipes of a plurality of conduit spacers, with no intervening conduits or pipes, in a form of the equilateral triangle is effective to reduce electromagnetic field (EMF) emissions from the energized electric power cables.
2 more elements
A conduit spacer, comprising:
- a first plastic spacer including a base and two adjacent support bodies above the base, the support bodies having open ends extending upwards away from said base, the first plastic spacer further comprising a first supporting rib between the two adjacent support bodies and attached to each of the two adjacent support bodies one of the two adjacent support bodies adapted to support a conduit or pipe of a first diameter and the other of the two adjacent support bodies adapted to support a conduit or pipe of a second diameter;
- a second plastic spacer for placement above the first plastic spacer, the second plastic spacer comprising four bodies, the four bodies comprising two lower bodies and two upper bodies, the two lower bodies adjacent one another and the two upper bodies adjacent one another, and the two lower bodies adjacent the two upper bodies with no intervening bodies, conduits or pipes between the two lower bodies and the two upper bodies, each body of the second plastic spacer having an opening adapted to support a conduit or pipe, wherein a first lower body of the second plastic spacer is adapted to support a conduit or pipe of the first diameter, and wherein a second lower body of the second plastic spacer and the upper bodies of the second plastic spacer are adapted to support three conduits or pipes of the second diameter, wherein the three conduits or pipes of the second diameter approximate an equilateral triangle with the base in a nominally vertical direction;
- a third plastic spacer for placement above the second plastic spacer, the third plastic spacer comprising four bodies, the four bodies comprising two lower bodies and two upper bodies, the two lower bodies adjacent one another and the two upper bodies adjacent one another, and the two lower bodies adjacent the two upper bodies with no intervening bodies, conduits or pipes between the two lower bodies and the two upper bodies, each body of the third plastic spacer having an opening adapted to support a conduit or pipe of the second diameter, wherein the two lower bodies of the third plastic spacer are adapted to support the two conduits or pipes of the second diameter that are supported by the second plastic spacer, and wherein the two upper bodies of the third plastic spacer are adapted to support a fourth and fifth conduit or pipe of the second diameter;
- and
- a fourth plastic spacer for placement above the third plastic spacer, the fourth plastic spacer containing four bodies, the four bodies comprising two lower bodies and two upper bodies, the two lower bodies adjacent one another and the two upper bodies adjacent one another, and the two lower bodies adjacent the two upper bodies with no intervening bodies, conduits or pipes between the two lower bodies and the two upper bodies, each body of the fourth plastic spacer having an opening adapted to support a conduit or pipe, wherein a first upper body of the fourth plastic spacer is adapted to support a conduit or pipe of the first diameter, and wherein a second upper body of the second plastic spacer and the lower bodies of the second plastic spacer are adapted to support the fourth and fifth conduits or pipes of the second diameter and a sixth pipe or conduit having the second diameter, wherein centers of the fourth, fifth and sixth conduits or pipes of the second diameter approximate a second equilateral triangle having a base in a nominally vertical direction,
- wherein supporting energized electric power cables in a sequence of conduit spacers is effective to reduce electromagnetic (EMF) emissions from the energized power cables supported by the three conduits or pipes of the second diameter and from the energized power cables supported by the fourth, fifth and sixth conduits or pipes of the second diameter.
3 more elements
Dependencies are inferred from the claim text.