duke energy transformer clearance requirements

There are additional tests that may be applicable, depending upon how and where the transformer will be used. Can I replace a tree that has been cut down? If our attempts to notify you are unsuccessful, work will proceed without further direct notification. Most soils are able to withstand a bearing pressure of 2500 lbs/sq ft. In maintained areas, we attempt to provide notification prior to vegetation maintenance work. Never attempt to check the output voltage at the transformer. If the structure is wooden and 30 to 40 feet tall with or without transformers attached, it is typically a distribution pole. fzVAm_mRJ}GoE>Mb-LBo^8p:>db[[wRI)9:K^>P[A$K)-Jc]!AwDI3rJ7aZVv0%DYxX^{{iQ]7-n%3wvg=yr Our understanding of their general characteristics will allow the designer and end user to make the proper selection for the electrical system application. Call, For additional information please visit our. down from each of the ends of the long sides. The tap setting should also be verified for the proper voltage. We have worked with various logo designers, and they are the cream of the crop. The usual sound levels for liquid-filled transformers range from 40 dB to 60 dB for units below 500kVA, about 65 dB for units between 4000kVA to 5000kVA, 73 dB for transformers with ratings between 6000kVA to 7500kVA, and 76 dB for units between 8000kVA and 10,000kVA. %PDF-1.7 % Locating a unit at the end of a long, narrow room, or in the corner of a room can cause a megaphone effect and amplify the transformer's sound. The greater the differences in these parameters, the greater the magnitude of the circulating current. The installation of power transformers and transformer vaults must comply with the requirements of National Electrical Code (NFPA 70) article 450 and specific local authority having jurisdiction requirements. You take your choice; extra safety and extra cost or regular-sized cables. Other factors that should be considered in selecting transformers are voltage ratings for both primary and secondary, voltage taps, efficiency, impedance value, type of cooling and temperature rise, voltage insulation class, basic impulse level, and sound level. transformers must be pre-approved by Duke Energy. They supply the required incoming electrical service to the buildings. Then, without connecting the load, energize the transformer. Our objective is to promote low-growing vegetation to minimize potential electric power interruptions, which also enhances wildlife habitat. Transformers are usually designed and built to provide good electrical connections using either copper or aluminum cable. If you cannot gradually increase the load, then full load may be applied. Next, connect the load and energize the transformer. What happens when trees come into contact with power lines? What types of trees and/or plants may be planted near pad-mounted transformers and power lines, and what do I need to consider prior to planting? 2023 Endeavor Business Media, LLC. endobj Magazine: 3-Phase Padmount Transformer Concrete Foundation - Duke Energy. The loads, which are calculated as part of the building electrical system design phase, are shown in the construction documents respective equipment schedules in VA or kVA. Duke Energy uses aerial application of herbicides in areas with high brush density and rough terrain and that are hard to access to control trees and other vegetation that can pose power outage threats. This has been the subject of debate for years, and I know of no clear resolution. My own opinion is that a transformer does not require working clearance, but rather only requires "breathing room" (i.e., 6" from any wall). Before working on the connections make sure all safety precautions have been taken. For a limited time we are offering our logo design services for $29 only. This category only includes cookies that ensures basic functionalities and security features of the website. But opting out of some of these cookies may affect your browsing experience. Performance cookies are used to understand and analyze the key performance indexes of the website which helps in delivering a better user experience for the visitors. Our logos are stylish, unique and memorable. Dangerous high voltage will be present within the transformer enclosure. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. Foundation preparation usually includes an evaluation of soil characteristics and concrete work. The industry trend is to continue building transformers with less core losses, and that comply with Energy Star efficiency requirements. For information about planning and planting vegetation around electrical facilities please visit: Yes, Duke Energys rights of way in non-landscaped/unmaintained areas are initially mowed, making identification of compatible versus incompatible species impractical. Information on minimum wire bending space clearances at terminals for conductors is found in NEC Sec. Copyright www.CreateLogoDesign.com. hbbd```b``z"H-dfH`?dirdl"?$L@{b`Ig` / As stated in the Occupational Safety and Health Authority (OSHA) standards and ANSI Z133, an unqualified person should not work within 10 feet of overhead power lines with voltages below 50,000 volts. In addition, a good design and installation require the proper transformer feeder and overcurrent protection device size based on NEC articles 240, 250, 450, and applicable sections of Article 310 (Figure 2). These provisions will vary depending upon the weight, size, and mechanical configuration of the unit. The average temperature of the cooling air during a 24-hour period is 86 F. The temperature of the cooling air at no time exceeds 104 F. When rollers are used on transformers without a structural base, you should use skids to distribute the stress over the base. It is good practice to regularly test this type of transformer in order to determine dielectric breakdown, which affects its useful life. We do UNLIMITED REVISIONS until you are 110% satisfied with your logo. 820 0 obj <> endobj Even mounting the unit a distance that is an exact multiple of the 120 Hz wavelength from a solid reflective surface may reinforce the sound waves, causing the transformer to seem louder than it actually is. [ILLUSTRATION FOR FIGURE 1 OMITTED]. ; 2 Unlimited revisions. Mounting the unit on a platform that has less mass than the transformer will make the platform serve as a sounding board, just like the body of a violin. Otherwise, they can be installed on open walls or steel columns or above suspended ceilings. Who can request trimming or removal of a tree? The first set of logo ideas were terrific. Duke Energy to invest $36B on power projects by 2026. Letterhead and They gave us 6 logo ideas to start with. 7. If this is not the case, deenergize the transformer and contact the manufacturer before proceeding further. However, for low-voltage (600V and below) transformers, this is not practical. Duke Energy schedules periodic vegetation maintenance along power lines to minimize outages caused by trees in or near transmission and distribution rights of way. Functional cookies help to perform certain functionalities like sharing the content of the website on social media platforms, collect feedbacks, and other third-party features. Why do you apply herbicides via helicopter? You should arrange for an insulation resistance test to be carried out to make certain that no windings are grounded. When changing taps, the same changes must be made for all phases. Such terminations are available from electrical distributors. hb```7,^ cb'60H6wZ $(|`n`h`` ``{_j j[e13b{@38O=)HpG17hCDC i. Caution is required when operating in parallel. In non-landscaped sites, pruned vegetation and wood are left in place to biodegrade. Therefore, the transformer size required for converting the system voltage from 480 V, 3-phase, 3-wire to 208 Y/120 V, 3-phase, 4-wire is: Transformer size in kVA = 42 kVA x 1.25 = 52.5 kVA. Why are you trimming or cutting down my trees? Before your transformer is scheduled to be shipped to its designated site, it's important that you coordinate with the manufacturer what acceptance tests should be carried out. When received, a transformer should be inspected for damage during shipment. Arbor Day Foundation, Right Tree in the Right Place, United States Department of Agriculture, Natural Resources Conservation Service, University of Florida, Trees and Power Lines, Transmission Easement/Right of Way Use Guidelines, Do Not Sell or Share My Personal Information (CA). We do not round trees over because it contributes to poor tree health. These cookies track visitors across websites and collect information to provide customized ads. By studying the overall mounting and terminal dimensions, it's possible to plan the installation with an orderly arrangement of connections. Reproduction, We have a dedicated team of logo designers producing customized logo design solutions. Click here to start this process. document.getElementById('copyright').innerHTML = new Date().getFullYear(); As appropriate, you should make arrangements to adequately support the incoming/outgoing connecting cables to ensure that there is no mechanical stress imposed on transformer bushings and connections. Extremely fast turn around, easy to work with, and creative designs - they are simply a fantastic group to work with!! You should note, though, that transformers serving large harmonic loads can produce a higher audible noise. The additional tests that can be conducted include the following: * Impulse (where lightning and switching surges are prevalent); * Sound (important for applications in residential and office areas and that can be used as comparison with future sound tests to reveal any core problems); * Temperature rise of the coils, which helps ensure that design limits will not be exceeded; * Corona for medium voltage (MV) and high-voltage (HV) units, which helps determine if the insulation system is functioning properly; * Insulation resistance (megohmmeter testing), which determines dryness of insulation and is often done after delivery to serve as a benchmark for comparison against future readings; and. Nonventilated dry-type transformers are similar to the ventilated type but are totally enclosed. Division 01 - General Requirements Division 02 - Existing Conditions Division 03 - Concrete Division 04 - Masonry Division 05 - Metals Division 06 - Wood, Plastics, and Composites ;#Qs3s=*gi This does not apply to bottom ventilation openings. In this electrical system design, the transformer can be used as part of a substation, primary unit substation, secondary unit substation, or network configuration. 1&Ub64#C #") "7KWpzJz1YeHB.r32Az{`gC~;jiV[Ceb*1rAz96lnA|3$ An IVM program evaluates vegetation and determines the best methods for maintenance and tree removal to ensure reliable service. As prescribed by NEMA standards, transformers are shipped with both high and low-voltage windings connected to their highest rated voltage (except transformers that have taps above the rated voltage, in which case they will be shipped connected for rated voltage). Are you sure you want to delete your template? There are different ways in which transformers are installed and used as part of a commercial building electrical system. 0 0 They were great at following our directions to the letter, while adding their own creative flair. Re-tighten all cable retaining bolts after the first 30 days of service. Roles and Responsibilities Associated with Clearances, 1 of 8 Our new online service request capability walks you through the process, auto-populates saved information from your profile, and gives you more control over when and Check all of the tap jumpers for proper location and for tightness. stream All Rights Reserved. Consult the transformer diagrammatic nameplate for information on what tap must be used to correct for extra high or extra low incoming line voltage. Facility Connection Requirements . Till date we have designed more than 5,000 business logos. The most common building industry standard ratings are 3, 6, 9, 15, 30, 37.5, 45, 75, 112.5, 150, 225, 300, 500, 750, and 1,000 kVA. clearances, it is the responsibility of the builder or owner to notify PECO Energy and make arrangements to achieve proper clearances or barriers. The cookie is used to store the user consent for the cookies in the category "Other. 4 0 obj The magnitude of the voltages shown (line-to-ground and line-to-line) should be very similar. The 18,688-seat FIU football stadium was designed with about 12 transformers as part of the electrical system distribution in order to supply general-use receptacles, small motors, and other loads in the stadium building structure and the attached field house building. Where their use is required, After I submit activities, construction or landscaping plans, what type of authorization will I receive for the use of a Duke Energy easement? endstream endobj startxref The development was easy because Steffi provided unlimited revisions, so we went through a series of small changes until we got a final. Clay soils are compressible and can cause problems that may require stabilizing back-fill. Lifting from the base frame may require the use of a spreader bar to avoid damage to the enclosure panels. Before energizing a 3-phase transformer, you should arrange to monitor the voltages and currents on the low-voltage side. The above simple calculation meets the intent to achieve the normal life expectancy of a transformer, which is based on the following basic conditions: Transformer selection starts with the kVA rating required to supply the loads connected in the electrical system. The installation of conductors should be performed only by personnel qualified and experienced in high-voltage equipment. Learn about the current state of the retail & distribution industry, and developments in technology. For example, trees can grow into the electrical equipment or fall across power lines, causing outages. The transformer is equal to or less than its rated kVA and rated voltage. When we can properly trim the tree to allow sufficient clearance until the next scheduled trim cycle, we make every effort to only trim the tree. Retail & Schools Depending upon the size and load requirements of the facility, the large majority of schools (except for some very large universities) and retail facilities are served by driveways clearance with limited building heights Public roads and commercial driveways (except State Highways and Interstates Railroad electrified) * Supply service drops You should ground the transformer as per NEC Sec. Member Resources. This website uses cookies to improve your experience while you navigate through the website. Duke Energy Florida Power & Light Gulf Power Company Oklahoma Gas & Electric Tampa Electric 6. These cookies do not store any personal information. The location should not expose the transformer to possible damage from cranes, trucks, or moving equipment. Other site considerations require closer analysis. Two good references to dry-type transformer requirements are ANSI/IEEE C57.12.01-1989, IEEE Standard General Requirements for Dry-Type Distribution and Power Transformers Including Those With Solid Cast and/or Resin-Encapsulated Windings, which addresses general requirements, and C57.12.91-1995, IEEE Test Code for Dry-Type Distribution and Power Transformers, which addresses testing. These application types include: Indoor distribution transformers are used with panelboards and are separately mounted to supply the specific electrical load requirements in a system-specific application within the system distribution. more than ten (10) 600 MCM or smaller conductors per phase, or more than eight (8) Sealed dry-type transformers are similar to dry type in most of their characteristics. You may also hire a company to remove the debris or contact your local public works to see if they remove yard debris. Therefore, compatible versus incompatible species are subject to removal through mowing. They can be installed outdoors or indoors. Note that for MV transformers, the secondary neutral is sometimes grounded through an impedance. Electric Service. We will most definitely return should we have additional needs!! In maintained or landscape settings, our policy is to dispose of any small limbs and brush. Serious injury or death may result from climbing a tree and making direct contact with or coming too close to an energized line.