US3271714A

US3271714A - Electrical inductive apparatus having means to prevent contamination

Info

Publication number: US3271714A
Application number: US425725A
Authority: US
Inventors: Raleigh J Cossaart
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1965-01-15
Filing date: 1965-01-15
Publication date: 1966-09-06
Anticipated expiration: 1983-09-06

Description

Sept. 6, 1966 coss -r 3,271,714

-ELECTHICAL INDUCTIVE APPARATUS HAVING MEANS TO PREVENT CONTAMINATION Filed Jan. 15, 1965 5 Sheets-Sheet l PRIOR ART WITNESSES INVENTOR m Raleigh J Cossourt I AT ORNEY Sept. 6, 1966 R. J. COSSAART 3,271,714

ELECTRICAL INDUCTIVE APPARATUS HAVING MEANS TO PREVENT CONTAMINATION 5 Sheets-Sheet 2 Filed Jan. 15, 1965 Sept. 6, 1966 R. J. COSSAART 3,271,714

ELECTRICAL INDUCTIVE APPARATUS HAVING MEANS TO PREVENT CONTAMINATION 5 Sheets-Sheet 3 Filed Jan. 15, 1965 United States Patent 3,271,714 ELECTRHCAL INDUCTIVE APPARATUS HAVING MEANS TO PREVENT CONTAMINATION Raleigh J. Cossaart, Muncie, Ind., assignor to Westinghouse Electric Corporation, Pittsburgh, Pa, a corporation of Pennsylvania Filed .lan. 15, 1965, Ser, No. 425,725 4 Claims. (Cl. 33690) This invention relates in general to electrical inductive apparatus, such as transformers, and more particularly to an enclosure for electrical inductive apparatus.

The demand for transformers with higher voltage and higher kva. ratings has created shipping problems for the manufacturers, as higher voltage and kva. ratings mean a corresponding increase in the physical size of the transformer. Bridge, tunnel, and other obstacles on the shipping routes dictate the maximum physical size of any one component of the transformer. At first, the problem was solved by merely removing the transformer bushings, and install-ing them at the point of use. This necessitated opening the transformer enclosure or tank for only the short period of time required to install the bushings through openings in the tank wall or top, and contamination of the transformer insulation and liquid dielectric was not a serious problem. As the physical size of the transformers continued to increase, however, removing the bushings did not solve the problem. It became necessary to take advantage of the fact that the enclosure or tank was considerably higher than the enclosed core-coil assembly, by sectionalizing the enclosure. In sectionalizing the transformer enclosure, a first or lower section of the transformer enclosure is constructed which is only high enough to clear the enclosed core-coil assembly, and a shipping cover provided to enclose the unit for shipping. A second or upper section of the transformer is constructed to complete the enclosure to the desired height. At the point of use, the shipping cover is removed, and the lower and upper sections are assembled. The electrical bushings may then be mounted and electrically connected. While this procedure solved the immediate shipping problem, it produced other equally serious problems. The removal of the shipping cover exposes the transformer core and coil assembly and its liquid dielectric to the atmosphere for a much longer time than when it was merely necessary to insert electrical bushings, resulting in the possibility of weakening the coil insulation and the insulating value of the cooling dielectric through the addition of moisture or water vapor into the enclosure, as well as other foreign material which may have a deleterious effect on the useful operating life of the unit.

Accordingly, it is an object of this invention to provide a new and improved enclosure for electrical inductive apparatus.

A further object of the invention is to provide a new and improved sectionalized enclosure for electrical transformers.

Another object of the invention is to provide a new and improved enclosure for electrical transformers that allows the transformers to be shipped sectionalized and reassembled at the point of use, exposing the electrical coils and liquid dielectric to the atmosphere for substantially the same period of time as an unsectionalized transformer.

Briefly, the present invention accomplishes the above cited objects by providing a sectionalized tank or enclosure in which the shipping cover is a permanent portion of the enclosure. The shipping cover contains covered openings for the electrical bushings, tap changer shafts, and the like. In the field, the top section is installed in position over the shipping cover, before the covered openings on the shipping cover are removed. Thus, the trans former coils and liquid dielectric are exposed to the atmosphere for only the short period of time required to insert the electrical bushings, the same as for an unsectionalized transformer.

Further objects and advantages of the invention will become apparent as the following description proceeds and features of novelty which characterize the invention will be pointed out in particularity in the claims annexed to and forming a part of this specification.

For a better understanding of the invention, reference may be had to the accompanying drawings, in which:

FIGURE 1 is a perspective view, partially cut away, illustrating a typical prior art sectionalized transformer arrangement;

FIG. 2 is a perspective view illustrating one section of a transformer enclosure constructed according to the teachings of this invention;

FIG. 3 is a perspective view, illustrating another section of a transformer enclosure constructed according to the teachings of this invention; and

FIG. 4 is a perspective view, partially cut away, of an assembled sectionalized transformer enclosure constructed according to the teachings of this invention.

Referring now to the drawings, and FIGURE 1 in particular, there is illustrated a perspective view, partially cut away, of a prior art sectionalized transformer 10. Transformer 10 includes high and low voltage windings 12, disposed in inductive relation with a magnetic core 14. The windings 12 and magnetic core 14 are disposed within a metallic tank or enclosure 22, which is constructed in two compartments or sections, a lower section 24, and an upper section 26. High

voltage bushing members

16, 18 and 20 are mounted on suitable bushing mounting means through openings in the upper section 26 of enclosure 22, and each have an internal conductive rod 17, 19 and 21, respectively, connected to electrical windings 12. Low voltage bushing memlbers, tap changers, indicating instruments, and heat exchangers, are not illustrated for purposes of simplicity.

It will be noted that considerable space is provided between the top of the electrical windings 12 and the top portion 27 of upper enclosure section 26. This space is necessary for providing electrical clearances, allowing expansion of the liquid dielectric, and the mounting of tap changers, and the like. In sectionalizing electrical transformers to reduce their overall height for shipping purposes, the transformer enclosure 22 is divided into lower and upper sections, 24 and 26, respectively, with the lower sections 24- being of suflicient height to enclose the core 14 and electrical windings 12. A shipping cover (not shown) is provided over the lower section 24, and the lower section 24, upper section 26,

electrical bushings

16, 18 and 20, and other accessories, are all separately shipped to the point of use for field assembly. The field assembly includes removal of the shipping cover from the lower enclosure section 24, and placement of the upper enclosure section 26 on the lower enclosure section 24. The upper and lower enclosure sections, 26 and 24, include mating flanged

portions

32 and 34, respectively, and a plurality of bolts 36 are inserted through mating openings in the flanged

portions

32 and 34 and engaged by suitable nuts to firmly secure the upper and

lower sections

26 and 24 together. A gasket member (not shown) is inserted between the

mating flanges

32 and 34 before assembly to insure that the enclosure 22 will be fluid tight.

The removal of the shipping cover from the lower enclosure section 24 necessarily subjects the windings 12 and liquid dielectric to the atmosphere for a relatively long period of time, resulting in the possibility of contaminating the liquid dielectric with moisture and foreign bodies, and weakening the coil insulation. Since moisture and foreign material may seriously impair the operating -13 life of high voltage transformers, it would be desirable to reduce the amount of time the windings 12 and liquid dielectric are subjected to the atmosphere to an absolute minimum.

This invention allows transformers to be sectionalized for shipment, and yet allows the lower enclosure section 24 to be open to the atmosphere during field reassembly for only a very short period of time, a period which is substantially the same as for unsectionalized transformers.

FIGS. 2 and 3 are perspective views of a transformer enclosure, illustrating lower and upper metallic enclosure sections, 40 and 42, respectively, constructed according to the teachings of this invention. Instead of constructing the lower section 40 with a temporary shipping top, a top 44 is permanently secured to the lower section 40, by welding, or other suitable means. Top 44 contains a plurality of coverable openings, such as openings for receiving high voltage bushing assemblies, sealed by

covers

46, 48 and 50, openings for receiving low voltage bushing assemblies sealed by covers 52, 54 and 56, an opening for allowing cooling dielectric to enter the upper enclosure section 42, sealed by cover 58, and other sealed openings (not shown) for tap changer shafts, indicating instruments, and the like. The top or cover 44 may extend beyond the sides of lower enclosure 40 for a predetermined distance to form a flanged portion 60. Flanged portion 60 has a plurality of openings 62 disposed therein for receiving suitable fastening means, such as bolts.

Top 44 may be constructed of metal, such as steel, or it may be formed of a suitable electrical insulating material. If the latter, the flanged portion 60 may be part of the lower section 40. v

The upper section 42 includes a flanged Portion 64, which has a plurality of openings 66 disposed therein for receiving fastening means, and a plurality of additional openings, such as

openings

68, 70 and 72 having means, such as

bushing bosses

69, 71 and 73, for receiving high voltage bushing assemblies,

openings

74, 76 and 78 having means, such as

bushing bosses

75, 77 and 79 for receiving low voltage bushings, and a suitable access opening sealed by cover 80. Thus, lower section 40 and upper section 42 are shipped to the point of use for field assembly, as shown in FIGS. 2 and 3.

' FIG. 4 is a perspective view illustrating the lower and

upper enclosure sections

40 and 42 of FIGS. 2 and 3, assembled and ready for the mounting of the electrical bushing members. More specifically, the upper section 42 has its open bottom portion disposed over the lower section 40, with the openings 62 and 66 in the flanged

portions

60 and 64, respectively, being aligned. Suitable fastening means, such as bolts 82 are inserted into the aligned openings 62 and 66, and secured firmly with suitable nuts. A gasket member (not shown) is disposed between the mating flanged

portions

60 and 64 before assembly to insure a fluid tight seal between the upper and lower sections. Once the upper section 42 is secured to the lower section 40, the

covers

46, 48, 50, 52, 54, 56, and 58 may be removed from the top 44, or they may be loosened and all the fastening means removed but one. The covers may be rotated about the remaining single fastening means, such as bolt 90, to a position which allows complete access to the opening, and then tightened to secure the cover in its new position. The covers are thus readily available in the event the transformer has to be moved again. Thus, the assembly of the upper and

lower sections

42 and 40, and associated components may be accomplished without opening the lower section 40 to the atmosphere. It is only when the bushings are ready for mounting that the lower section 40 need be opened, and then only small openings are made, just as though the transformer were of the non-sectionalized type. When the upper and

lower sections

42 and 40 are assembled,

openings

46, 48 and 50 are aligned with

openings

68, 70 and 72, respectively, and

openings

52, 54 and 56 are aligned with

openings

74, 76 and 78 respectively. The bushing members, such as bushing member 81, are

then mounted on the bushing mounting means, with the lower portion of the bushing extending into the lower compartment through the appropriately aligned opening. After the bushing members are mounted, opening 100 may be used to make electrical connections, and opening 100 is left in its open position to allow liquid dielectric to freely pass from the lower section 40 to the upper section 42.

Thus, there has been disclosed a new and improved tank or enclosure for electrical transformers, which possesses the advantages of sectionalized transformers in allowing the transformer to be shipped in sections, and also the advantages of non-sectionalized transformers, as the enclosed windings and liquid dielectric are opened to the atmosphere only for the length of time necessary to install the bushing members.

Since numerous changes may be made in the above described apparatus and different embodiments of the invention may be made without departing from the spirit thereof, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim as my invention:

1. Electrical inductive apparatus comprising electrical windings,

a magnetic core,

said electrical windings being disposed in inductive relation with said magnetic core,

a first enclosure section having a top portion which has a plurality of coverable openings therein,

said electrical windings and magnetic core being disposed in said first enclosure section, a second enclosure section having a top portion and sidewall portions which define a bottom opening,

said second enclosure section being re'mcvably secured to said first enclosure section, with the bottom opening in said second enclosure section being disposed over the top portion of said first enclosure, the top portion of said second enclosure section having a plurality of openings therein,

a plurality of electrical bushing members,

said plurality of electrical bushing members being disposed in the openings in the top portion of said sec ond enclosure section,

means securing said electrical bushing members to the top portion of said second enclosure section,

and means electrically connecting said bushing members with said electrical windings through certain of the openings in the top portion of said first enclosure section.

2. The electrical inductive apparatus of claim 1 wherein the top portion of the first enclosure section is formed of an electrical insulating material.

3. The electrical inductive apparatus of claim 1 including liquid dielectric means disposed in said first enclosure section to a predetermined level, the openings in the top portion of said first enclosure section allowing unrestricted expansion of said liquid dielectric means into said second enclosure section.

4. The electrical inductive apparatus of claim .1 wherein certain of said bushing members extend through openings in the top portion of said first enclosure section.

References Cited by the Examiner UNITED STATES PATENTS 1,508,201 9/1924 Treanor 220-85 1,524,762 2/1925 Treanor 22085 1,620,411 3/ 1927 Temple 22085 1,872,308 8/ 1932 Llewellyn 22085 LEW-IS H. 'MYERS, Primary Examiner.

JOHN F. BURNS, ROBERT K. SCHAEFER,

Examiners. D. I. BADER, Assistant Examiner.

Claims

1. ELECTRICAL INDUCTIVE APPARATUS COMPRISING ELECTRICAL WINDINGS A MAGNETIC CORE, SAID ELECTRICAL WINDINGS BEING DISPOSED IN INDUCTIVE RELATION WITH SAID MAGNETIC CORE, A FIRST ENCLOSURE SECTION HAVING A TOP PORTION WHICH HAS A PLURALITY OF COVERABLE OPENINGS THEREIN, SAID ELECTRICAL WINDINGS AND MAGNETIC CORE BEING DISPOSED IN SAID FIRST ENCLOSURE SECTION, A SECOND ENCLOSURE SECTION BEING REMOVABLY SECURED SIDEWALL PORTIONS WHICH DEFINE A BOTTOM OPENING, SAID SECOND ENCLOSURE SECTION BEING REMOVABLY SECURED TO SAID FIRST ENCLOSURE SECTION, WITH THE BOTTOM OPENING IN SAID SECOND ENCLOSURE SECTION BEING DISPOSED OVER THE TOP PORTION OF SAID FIRST ENCLOSURE, THE TOP PORTION OF SAID SECOND ENCLOSURE SECTION HAVING A PLURALITY OF OPENINGS THEREIN, A PLURALITY OF ELECTRICAL BUSHING MEMBERS, SAID PLURALITY OF ELECTRICAL BUSHING MEMBERS BEING DISPOSED IN THE OPENINGS IN THE TOP PORTION OF SAID SECONE ENCLOSURE SECTION, MEANS SECURING SAID ELECTRICAL BUSHING MEMBERS TO THE TOP PORTION OF SAID SECOND ENCLOSURE SECTION, AND MEANS ELECTRICALLY CONNECTING SAID BUSHING MEMBERS WITH SAID ELECTRICAL WINDINGS THROUGH CERTAIN OF THE OPENINGS IN THE TOP PORTION OF SAID FIRST ENCLOSURE SECTION.