These periodic mechanical movements create sound vibrations with a fundamental frequency of 120 Hz and harmonics derivatives of this fundamental. The weight distribution should be studied by examining the inside of the transformer enclosure for dry-type units. Before specifying any additional tests, you should contact the manufacturer to find out what data it has accumulated from testing essentially duplicate units. Pruning trees around power lines should only be attempted by qualified professionals. endstream endobj startxref It was great service with real professionalism from start to finish. We also use third-party cookies that help us analyze and understand how you use this website. Some equipment could have a different torque requirement than shown. Introduction, 1 of 7 , active Introduction; Instructions, 2 of 7 Instructions; Circle of Safety, 3 of 7 Circle of Safety; Overview, 4 of 7 Overview; Objectives, 5 of 7 Objectives; Section Menu, 6 of 7 Section Menu; Clearances, 7 of 7 Clearances; Lesson 1, 2 of 7 Lesson 1. We work diligently to capture the look and feel that you always desired for your logo. Why do you apply herbicides via helicopter? You should consider contributing to our CFE Media editorial team and getting the recognition you and your company deserve. You should note, though, that transformers serving large harmonic loads can produce a higher audible noise. 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. For pad mount transformers with ratings 75kVA through 500kVA, a typical concrete base would be 5 1/2 by 6 1/2 ft and 10 in. Some manufacturers require that the megohmmeter readings and date of energizing be sent to them within a specified time after the transformer is placed in service for the warranty to be valid. This website uses cookies to improve your experience while you navigate through the website. The electrical size of the transformer load is rated in kVA. Thanks! The larger pieces of wood are cut to the length of firewood and stacked or consolidated at the edge of the right of way for the property owner's use or disposal. This tool is a safer and more effective alternative to sending crews on foot to perform backpack spraying in rough and mountainous terrain or hard-to-access areas, while also maintaining effective vegetation management along our power lines. I have found the after sales service to be as professional as the original work, nothing being too much trouble to ensure that the customer is completely satisfied. Notification may be made via door hanger, telephone call, letter, in-person contact or a combination of these methods. The cookie is used to store the user consent for the cookies in the category "Other. This cookie is set by GDPR Cookie Consent plugin. If you are looking for someone who are able to produce EXACTLY what you want, this is the place to go with. We offer a 100% Satisfaction Guarantee. North America | April 5, 2018. Small transformers, arguable those below 400kVA, usually don't have extensive testing as they are often installed far downstream in a power system; as such, their importance is not as vital as compared with larger units. The maximum continuous load a transformer can handle is indicated on its nameplate. 2013-2014 | All Rights Reserved MERIT MEDIA INT. Both the voltages and currents should change in a similar fashion. If this is not the case, deenergize the transformer and contact the manufacturer before proceeding further. Torque specifications are sometimes listed on the hardware. There may be local nonprofits that will collect and distribute wood to those in need. Member Resources. In the presence of a magnetic field, the core laminations elongate and contract. *[L EgptA80~@GI#Q@hxMGPhMgoQ ] $ k. 3, on page 42. If you cannot gradually increase the load, then full load may be applied. Check all of the tap jumpers for proper location and for tightness. [CDATA[// >