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. There should be no attempt to handle a transformer in any other position. Watch Jana's Story. These cookies track visitors across websites and collect information to provide customized ads. Where their use is required, A number of manufacturers require that insulation resistance testing be successfully completed prior to the transformer being placed in service for the warranty to be valid. 1 0 obj 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. The basis for proper pruning is that each limb removed from a tree is removed either where it joins another limb or at the trunk. The electrical size of the transformer load is rated in kVA. It does not store any personal data. Serious injuries and even fatalities have occurred when untrained individuals have done this work without the assistance of qualified professionals. What is the time frame expected for the completion of customer-requested tree trimming? 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. A check sheet should be used to record all items, and verification should be made that these items have been properly accounted for upon completion of work. Our logos are stylish, unique and memorable. The cookie is used to store the user consent for the cookies in the category "Performance". Foundation preparation usually includes an evaluation of soil characteristics and concrete work. % Duke Energy Corporation. YUMPU automatically turns print PDFs into web optimized ePapers that Google loves. We believe it speaks for itself. Transformers that are not over 600 V and are part of the indoor building electrical system distribution have both primary and secondary voltages below 600 V with the most common voltage level change from 480 V to 208 Y/120 V. Pad-mounted transformers are installed outside and are considered the first option for supplying service entrance voltage to the building electrical system based on the project size and requirements. Although there are no moving parts in a transformer, the core does generate sound. Click here to start this process. If our attempts to notify you are unsuccessful, work will proceed without further direct notification. A general approach to determining transformer capacity and selecting the proper rating for the design application is to obtain the calculated design load from the respective electrical schedule and add 20% spare capacity for future load growth to be shown in the equipment schedule, unless otherwise directed by the facility based on design parameters. Personnel should be instructed that should any service work be required to the unit, the lines that power the transformer must be opened and appropriate safety locks and tags applied. %PDF-1.7 % Your Satisfaction is Guaranteed! Baeza is a principal and senior electrical engineer at TLC Engineering for Architecture in Miami. A note of caution: The information presented here is not meant to supersede any manufacturer's instructions. Cast-coil transformers are constructed with the primary and secondary windings encapsulated in reinforced resin. Before a power line is built, Duke Energy acquires easements from property owners along the selected route. When specifying a transformer to be operated in parallel with existing units, all these parameters should be discussed with the transformer manufacturer. The right tree or shrub, planted in the right place, can give you years of beauty and value without the potential dangers of getting too close to power lines. Web10-Clearances o 10.06-01 Minimum Guy Clearances 11-Metering Many of the standards in the following subsections are applicable: o 11.01 Self-Contained Metering General o 11.09 Transformer-Rated Metering, Primary, Three-Phase o 11.11 Transformer-Rated Metering, Primary, Three-Phase - UG DEP UG Distribution Standards This material will provide additional general guidelines for installing and testing both dry-type and liquid-filled transformers for placement into service. The same adjustment should be made to compensate for voltage drop in the output due to long cable runs. For new buildings, you should work with the structural engineers so that the transformer's placement is included in the building plans. Take care not to damage the base or tip it over. Letterhead and 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. Consult the transformer diagrammatic nameplate for information on what tap must be used to correct for extra high or extra low incoming line voltage. Is Duke Energy responsible for cleanup after trimming trees or weather events? In the past two years, two large projects in Miami Dade County have been built: the Florida International University football stadium and Miami International Airport South Terminal. Call, For additional information please visit our. The successful operation of a transformer is dependent on proper installation as well as on good design and manufacture. Sometimes, when testing is carried out at the manufacturer's plant, the manufacturer will also allow a purchaser or a representative, such as a consulting engineer, to witness the tests. 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. Why do you apply herbicides via helicopter? We also use third-party cookies that help us analyze and understand how you use this website. A number of these tests are done on the plant floor, while other tests are conducted usually after delivery is made. Newer Energy Efficient (EX Type) require .5" from rear and sides to any obstruction. Standard transformer tests performed for each unit include the following: * Polarity for single- and 3-phase units (because single-phase transformers are sometimes connected in parallel and sometimes in a 3-phase bank); * Phase relationship for 3-phase units (important when two or more transformers are operated in parallel); * Excitation current, which relates to efficiency and verifies that core design is correct; * No-load core loss, which also relates to efficiency and correct core design; * Resistance, for calculating winding temperature and [I.sup.2]R component of winding losses (usually not required on 600V class units); * Impedance (via short circuit testing), which provides information needed for breaker and/or fuse sizing and interrupting rating and for coordinating relaying schemes; * Load loss, which again directly relates to the transformer's efficiency; * Regulation, which determines voltage drop when load is applied; and. Can I replace a tree that has been cut down? Other uncategorized cookies are those that are being analyzed and have not been classified into a category as yet. I highly recommend that if you are looking for a graphic designer than createlogodesign is your first port of call. On-site health department permit shall be in place at this time. Adequate surrounding air space must be maintained for the required transformer "heat loss" ventilation. Exercise care during handling to prevent equipment damage and/or personnel injury. 7. Linear loads include resistive heating and induction motors; nonlinear loads are produced by electronic equipment that contributes to the distortion of the electrical power signals by generating harmonics. <> Advertisement cookies are used to provide visitors with relevant ads and marketing campaigns. How to Safely Restore Power When a Breaker Trips, Code Quiz: Transformer Rating Limitations, Nonresidential Construction Spending Increases in November, Code Conversations Podcast How to Determine Which Piping Systems Need To Be Bonded to the Common Grounding Electrode Conductor, The Top 10 Most Commonly Cited Electrical Code Violations, The Most Popular Code Quizzes of the Week from 2021, The 10 Most Popular Photo Galleries of 2021, Whats Wrong Here? I was so impressed with the finished result that I've asked them to undertake future work. Why are you trimming or cutting down my trees? You should note, though, that transformers serving large harmonic loads can produce a higher audible noise. Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. For example, trees can grow into the electrical equipment or fall across power lines, causing outages. 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. You have already flagged this document.Thank you, for helping us keep this platform clean.The editors will have a look at it as soon as possible. However, anyone is encouraged to report unsafe conditions. The installation of conductors should be performed only by personnel qualified and experienced in high-voltage equipment. [CDATA[// >