Transformer Sizing Calculator

High frequency bandwidth is also dependent on how the. Using the base 320 MVA solve for primary ampere and CT output current. txt) or view presentation slides online. 2 Modifying transformer specifications , manual Term or abbreviation Explanation Sizing, dimensioning Calculation of the correct size , price information and, thus, cost optimizing has to be performed manually. For example, a building that has a total NEC demand load of 60 kVA on the 120/208-V, 3 phase, 4-wire system. Transformer winding turns and voltage Ratio calculatorV1, N1, V2, N2. Volts' Utility Transformer Characterization module offers a complete format to enter basic values while obtaining a complete and accurate character. With this coil calculator you can design and calculate the properties of a coil or transformer. The largest is a 200va with 277 pri/24sec voltage. Calaculate power factor, apparent power, reactive power and correction capacitor's capacitance. root of T) Where, ISH :SHORT CIRCUIT CURRENT IN KA (r. Step 3 - Check / Calculate Voltage Drop: Check for voltage drop with the cable size chosen. To minimize risk and investment, each step of the process needed to be investigated and improved. What size genset is needed to start a 3 phase electric motor Direct on Line (DOL) start; HP of Motor = the above calculations are an estimate only because other factors such as site conditions, motor efficiencies and iron losses are not taken into. Transformer size is determined by the KVA of the load. Tube Amp Power Transformer Current Draw Calculator JavaScript must be enabled in order for the calculations to work. The industry standard ratings for a 480V - 208/120V transformers are: 3, 6, 9, 15, 30, 37. Class 1 circuit conductors supplied by the secondary of a si. The main purpose of a transformer at the amplifier input is matching impedance between microphones, connecting cables and the amplifier input. ZIG-ZAG GROUNDING TRANSFORMER MODELING FOR ZERO-SEQUNCE IMPEDANCE CALCULATION USING FINITE ELEMENT METHOD Diyala Journal of Engineering Sciences, Vol. Transformer Capacity Calculator ; The above three-phase transformer capacity formula in this page is a simple formula which will be useful in the place where the need for a transformer for three-phase industrial application is more. Size the secondary wire to fill the other half of the winding window. Transformer Sizing Calculations Course Course Description: This course is intended to prepare the target persons with the ability to perform Transformer Sizing Calculations for all types and special cases of transformers. A detailed description of each conductor property is described below Table 1. Output amperage of transformer. Wye transformer sizing example: What size transformer (480 to 208Y/120V, 3Ø phase. Examples of transformer regulation curves are shown in Figure 1. 1 Entering transformer data. As the transformer window dimensions are 17. How to calculate the power consumption of that transformer when it's in idle (everything in the warehouse is shut off, but the transformer is on and buzzing)? We have given: 11. Accurately, Amps = Watts / Volts. Three Phase Transformers. The Transformer Table 3. Transformer size in kVA = 56 kVA * 1. This note will look at several methods, with particular attention being paid to protection class CTs sized in IEC 60044, which is adopted internationally. Let's take a closer look at 240. Prevent the costly effects of poor power quality with our comprehensive line of products that convert, protect and back up power throughout production facilities. An online transformer product selector is available in the Transformer section of our website or you can use the following steps below to manually select a trans form er. EXAMPLE: A feeder supplies three-phase power to a 480 volt transformer. Note that when doing calculations for a coil with very thin wire as with the crystal radio and the Tesla coil shown above (e. 3 in particular} and (d) check Art 240 to aid in sizing overcurrent protection and conductor sizing {240. (Refer to question #2 in the Transformer Question and Answer section of Acme's Marketplace. For 3Ø fault calculations, a single primary conductor impedance is used from the source to the transformer. ABB's Electrification business has always been at the forefront of innovative electrification and today is writing the future of safe, smart and sustainable electrification. In order to calculate the wire size, it is necessary to assign an acceptable power loss PL to each winding. 5): Tweet. Starting current will depend on the type of start (DOL,S/D. please, keep following for the new Release of our blog very soon. electrical design calculations 1. Because the output power for this design example is Po=36W, we select the EER28 core size. We can calculate the HV cable BY USING FORMULA ISH = K x A/( sq. 16 of the National Electrical Code. If you don't know anything about assembling transformers, please don't use calculations from this program for building your own transformer!. will include costs for changing the type of dielec-. The targeted Persons: Design engineers, new graduate engineers, under graduate engineering students. 004 What are the differences in the core and coil designs of one-end-, unbalanced-mid-point-, and balanced-. Enter units of product and conversion is made to show number of transformers needed. 5 250A 250A 139-0553-00 Transformer Sizing Guide. CPT Series Control Transformers Get years of reliable service from a quality transformer at a practical price CPT transformers for industrial applications The CPT series of control transformers is specifically designed for high inrush applications requiring reliable output voltage stability. Find the rating of a single phase transformer. I intend to run the primary conductors from the panel to the transformer, then the secondary to a 200A disconnect then to the machine. Free excel sheet for transformer design calculation. Much smaller transformers may be used in Buck - Boost applications, since the size of the transformer is roughly proportional to the change in voltage. Our recommended wire gauge calculator helps determine the correct wire gauge for your application based upon the input parameters of length, current, voltage and more. Calculate the wire area, Aw, with insulation , using a fill factor, size. The HPS Buck-Boost Selector is for information purposes only. Short circuit capacity calculation is used for many applications: sizing of transformers, selecting the interrupting capacity ratings of circuit breakers and fuses, determining if a line reactor is required for use with a variable frequency drive,. WaAc = P o D cma K tB max ƒ FREQUENCY kHz 1000 1500 2000 500 0 10 30 60 100 300 600 1000 FLUX DENSITY VS. Calculate here to how much your choice of transformer will cost. Inductance. Hi all, was hoping someone could confirm that my calculations for sizing transformers for small dc loads is correct. Transformer calculator. High frequency bandwidth is also dependent on how the. What is total wattage? _____ 2. (1) shows the zig-zag transformer smaller in size. For an examplelet’s use Load voltage = 480 volts, Load current, = 80 Amps and Line voltage = 208 volts. ” The “C” transformer is actually a single unit. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Yet another basic calculation that an electrical professional will have to perform at some point in their career and that some perform many times a day. Many things like trace length, board size, board thickness, copper thickness, number of planes, mounting of board, position of trace on board, and airflow can all affect the temperature rise of the trace. The rating of transformer is given in terms of its kVA, HV/LV voltage and phase rotation (for three phase transformer). How to calculate the full load ampacity of a Transformer. It's awesome that you listed the specific calculations for the voltages and frequencies for the main transformer. pdf), Text File (. Delta transformer sizing. The amount of loss is dependent on transformer load current, as well as oil temperature. Sizing an electrical transformer is an easy task once you understand the nomenclature or language that is used. These connections determine the way the transformer will behave, and they also determine the methods of calculation required for properly applying a given transformer. Calculate here to how much your choice of transformer will cost. Conversely, if you know the actual LOAD on the transformer in amperes or the existing fuse size, the you can calculate the VA rating for the voltage so you can properly replace a transformer. Specially intended for electrical engineers and contractors, Electrical Calculator enables you to perform various calculations and determine the values on both sides of the transformer. About: This calculator computes RAID capacity characteristics for the most commonly used RAID types. Transformer Calculation v0. • Phase shifting transformer and more diodes limit harmonics. CONSTANT VOLTAGE OR FERRORESONANT TRANSFORMER SIZING FOR SUPERIOR VOLTAGE REGULATION Tuesday, April 12, 2011. Delta-connected transformers have the windings of three single-phase transformers connected in series with each other to. However, if by chance, the Rockstone Power Voltage Transformer Converter doesn’t work, then it's most likely means the fuse needs to be replaced. 03square centimeter, and discounting 20% for insulation an some clearence, the available space for the coils could be 14. please, keep following for the new Release of our blog very soon. 2 + 4 + 4 + 4 or 40. 44(f)(B)(N)(a) where E is the voltage in the winding either primary or secondary, f is the frequency, B is the flux density in the core, N are the number of turns on the winding, and a is the cross area of the core. Multiply worst case phase wattage x 3 phases. For small transformers, they are essentially the same and interchangeable. Transformer calculator. Alfa offers a complete range of new and reconditioned low voltage dry type transformers including general purpose, drive isolation, motor-starting autotransformers. Welcome to Phase Technologies' electronic transformer website. For continuous load purposes, multiply the watts total by 125%. A transformer is an electrical device used to convert power from the source, usually a utility company, to the power required by the load. 1 1000 kVA …. Here is the rating of Transformer is 100kVA. transformer. The method was developed to select the distribution transformer size required to. Distribution Transformer Calculations Excel Spread Sheet. 21(D) Primary Side of Transformer. I want input from you guys to add to my sizing/costing. Cirris Systems provides you with a calculator to measure wire resistance. Standard and custom designs through 10 MVA, up to 35kV. For better understandings, go through the following steps for calculations. Use the following instructions to determine the load resistance of an unknown audio output transformer. Click above if you wish to include X/R ratios and better Utility information. Transformer kva rating selection or transformer sizing is a very important step of electrical engineering. Electrical engineering is one of the newest branches of engineering, and ranges from microscopic electronic devices right up to huge power systems and generators. Volts Number of Fixtures. Distribution Transformer Calculations Excel Spread Sheet. Initial transformer sizing for single-phase residential load Abstract: The authors describe a method for determining the correct economic size of distribution transformers using end-use appliance load profiles and the ANSI/IEEE Standard C57. 5 cm pig-tails: MHz: uH: pF: ohms: turns: inches - cm : Enter uH to Calc number of turns. This calculator will compute your regular military compensation based on your inputs. 2V) getting 2. If the codes require a maximum usage of 70 percent of the transformer's capacity, multiply 40 times 1. If the secondary voltage of the transformer is 24 V, then the minimum VA rating of the transformer needs to be 26. To calculate what input power is needed, the square root of three (1. Transformer Sizing for Motor Loads 11/25/2012 1:04 PM. Accurately, Amps = Watts / Volts. 03, September 2015 65 2-GROUNDING TRANSFORMER The grounding (or Earthing) transformer is a transformer primarily to provide a. The secondary side of a transformer refers to low voltage side of the transformer. Delta transformer sizing. There is a few simple formulas which will help you work this out. Select Short Circuit Rating of 480 V MCC zE. With this coil calculator you can design and calculate the properties of a coil or transformer. Explore how much energy you can save by switching to an Eaton high efficiency transformer. by Jim Nash Transformer Fault Current Calculation. It has to be protected at its ampacity. Leverage Watlow's growing toolkit of calculators, equations, reference data and more to help design your thermal system. Coils, wire thickness, buttons: Input and output number of coils. The power transformer short-circuit requirement "transformer impedance and basic impulse level (BIL)", are also considered by the MVA transformer sizing module. Get The Latest New Now. The step-voltage regulator is basically a transformer that has its high-voltage winding (shunt) and low-voltage winding (series) connected to either aid or oppose their respective voltages. Qi-compliant system as a transformer For many near-field wireless power systems such as the one specified by the WPC, the behavior of the magnetic power transfer can be modeled by a simple transformer. At present, numerous high voltage XLPE cable systems with nominal voltages up to 500 kV and. xlsx), PDF File (. It is a conversion calculator which converts the apparent power in Kilovolts-amps and power factor to Kilowatts. This website uses cookies to improve your experience, analyze traffic and display ads. the cost of mitigation. EXAMPLE: A feeder supplies three-phase power to a 480 volt transformer. Surge Watts 0 (0 kW). Lighting Transformer - Selects the size of the transformer that provides single-phase power in a delta or open-delta bank (Typically the largest transformer in the bank). 1 is program for calculating number of coils and wire thickness. SPECIFICATIONS The Isolation Transformer 3 maintains efficient power to operate even with the worst of power problems, providing superior dependability and reliability commercial/industrial environments in a small footprint. About: This calculator computes RAID capacity characteristics for the most commonly used RAID types. Delta transformer sizing. This article is excerpted from "Premium-Efficiency Motors and Transformers", a CD-ROM available from CDA by going to the Publications List. so we need to calculate the short circuit current rating of the equipment and. Determine the load current and the buck or boost voltage and calculate the required size of the buck-boost transformer. If you had a transformer with known AC output voltage at the secondary, and you needed to know the DC voltage to expect after rectification, then this page will help. The following is only a simplified way to find out major core dimensions Ac and Aw. This method of sizing wire will lead to a very inefficient system since these tables are generally based on higher voltage (110/220 volts A/C), and the main concern is safely transmitting the power without heat build up. We use cookies to ensure that we give you the best experience on our website. Transformation Efficiency: Transformants / μg DNA or: Transformants / ng of DNA * This calculation assumes that no futher dilutions of the transformation reaction are made after DNA, competent cells, and media are added. Normal magnetizing inrush currents for power transformers can range from 10 times to 12 times the transformer full load current, for up to 6 cycles, and as high as 25 times transformer full load current at 0. Transformer Calculator. ) Transformer. To access the Transformer MVA Sizing module, double-click on the transformer icon in the one-line diagram to access the Transformer editor. Inductance calculator. Total Watts: 6 * 20 W = 120 W. Single Phase Three Phase Power Rating. DOL starters have a large in-rush kVA in the order of 5 - 8 times the FL kVA and the transformer size tends to be very large compared with the static load. Transformer Calculator. It's a relatively simple calculation for 3 phase power. GE Transformer & Short Circuit Calculator Transformer Calculations without X/R and Utility Impedance Choose from the drop down menue or fill in the blnk were required. Analysis of Specific Inductor Design F. With consumer type breakers, or a really outsized transformer, it can be a problem. The industry standard ratings for a 480V - 208/120V transformers are: 3, 6, 9, 15, 30, 37. Explore how much energy you can save by switching to an Eaton high efficiency transformer. Calculator that provides voltage drop caused by the starting of motors at the substation transformer primary and secondary leads. As the load on battery on increases, battery voltage will be less than 12 volt. A 10-amp fuse would "blow-out" consistently before the necessary power was delivered. In other words, the fault level on the primary side of the transformer is considered to be infinite. Calculator can be used for step down transformer as well as step up. Line voltage, or primary voltage, is the voltage from the source. When voltage at the beginning of a length of cable (at the transformer) is higher than the voltage at the end, the difference is known as "voltage drop". Rex Power Magnetics Mini Power Centers combine three individual components, prewired into one NEMA 3R enclosure: a primary main breaker, a single-phase or three-phase dry-type encapsulated transformer (Type EP), and a secondary distribution load center with main breaker. Transformer Values Calculator This calculator requires the use of Javascript enabled and capable browsers. current rating needs to be recalculated from the D. The following is only a simplified way to find out major core dimensions Ac and Aw. A three-phase, fused disconnect with 300A fuses will be installed on the primary side of this transformer. HOW TO CALCULATE BREAKER SIZE, WIRE SIZE AND WATTAGES The chart below will help you determine fuse or breaker size and the necessary wire size to service various wattage loads. Volts Number of Fixtures. The transformer you select must have a kVA rating equal to or greater than the load on the transformer. TDR Calculator. Volts' Utility Transformer Characterization module offers a complete format to enter basic values while obtaining a complete and accurate character. Inductor/Transformer Design Relationships B. The transformer needs to be 250 watts. Output amperage of transformer. 44(f)(B)(N)(a) where E is the voltage in the winding either primary or secondary, f is the frequency, B is the flux density in the core, N are the number of turns on the winding, and a is the cross area of the core. As an alternative to these calculations, you may prefer to use the charts below. We’re only taking continuous loads at 125% for the purposes of sizing conductors and overcurrent. Power Handling Chart rates the ZP42915TC at 240W at 50kHz, with a conservative flux density of 1,300G (another doc said 215W)” My guess is that this core can run 215 to 240W continuously. 6 amperes wire size must be #4 copper based on NEC Art 310; This value, 76. Proper Transformer Sizing and Copper Windings Mean Lowest Total Owning Cost, Fastest Payback. P=Volt X Current X Cos α. The length of wire runs will also factor into what size you will need since the resistance in the wire acts as additional wattage or "load". Micron’s transformers are electrically tested to the appropriate regulatory standards with automatic test equipment. Just type in a metric or standard size tire and click calculate. (Amps = Watts divided by Volts) - PR10301501. Typically, the next size up will be chosen, such as a 30 VA transformer. TDR Calculator. Current Transformer calculations Enter values in white, CT values are calculated automatically. Transformer Winding Calculation Software. Frequently Asked Questions about Power Inverters. Designed to meet industrial applications where. Select transformer phase. List of Contents1 Transformer kVA to Amps Calculator2 Transformer Amps from kVA rating Formulas3 Examples for Transformer Amps calculations3. Three Phase Transformers. According to 725. ©2018SchneiderElectric AllRightsReserved 14-1 TableofContents Section14 Transformers EZSelector-SelectionAssistance 14-2 LVTransformersEZSelector-SelectionAssistance 14-2. To calculate wire ampacity for a circuit, use the Wire Ampacity Calculator or the Advanced Wire Ampacity Calculator. All of these factors are considered in calculations of thermal transformer performance. The TCO Calculator provides directional guidance on possible realized savings when deploying AWS. ASUS Support Center helps you to downloads Drivers, Manuals, Firmware, Software; find FAQ and Troubleshooting. How to use Kohler's Home Generator Sizing Calculator. The load can be a house, building or any other electrical system or appliance. We provide sustainable solutions that help our customers effectively manage electrical, hydraulic and mechanical power – more safely, more efficiently and more reliably. 480 kV , impedance 5. please, keep following for the new Release of our blog very soon. Starting current will depend on the type of start (DOL,S/D. I think yours is probably OK. (Voltage drop tends to be the dominant design consideration in the sizing of long power distribution cable runs. Once the order is placed, the supplier should submit design calculations for approval for the purpose of the conformity of the designed transformer for inverter duty. 732 1000 List ed Cer ti fi ed Selection Steps A. 433 kv, 800 kVA Transformer. If you have some experience in assembling transformers, then this program is perfect for you. At present, numerous high voltage XLPE cable systems with nominal voltages up to 500 kV and. The transformer you select must have a kVA rating equal to or greater than the load on the transformer. Transformer Measurements. HOW TO CALCULATE THE REQUIRED KVA SIZE NEEDED FOR A D-M-E SINGLE PHASE POWER TRANSFORMER 1. The transformer has to be tested in presence of BHEL engineers for dispatch clearance. The root-problem is that my calculation leads to customers having to provide a much larger power drop for one of our machines. Delta-connected transformers have the windings of three single-phase transformers connected in series with each other to. Consequently, an autotransformer is smaller, lighter in weight, and less costly than a comparable kVA size insulating transformer. Wire or cable thickness is defined in terms of gauge. We hope to provide you with the best online voltage drop calculator, as well as all relevant information regarding voltage drop formulas, equations, and calculations, and more!. Costs to replace or retrofill (1) Load duration. This means 7. Calculate Transformer Over current Protection (NEC 450. Much smaller transformers may be used in Buck - Boost applications, since the size of the transformer is roughly proportional to the change in voltage. Below is the formula to calculate the voltage drop of an electrical circuit based on the wire size and load current. Interphase transformers are used in systems that have two rectifier systems being used in parallel. Thus the transformer. SFDR Calculator. Three Phase Transformers. Transformers are used in virtually every commercial and industrial building, from the service transformer reducing the distribution voltage to a more usable voltage for the building, to step-down transformers serving individual floors, to small transformers for individual apparatus or functions. line reactor is required for use with a variable frequency drive, etc. 002 How are Neon Transformers different from the more common“power” transformers? 3. Use the following instructions to determine the load resistance of an unknown audio output transformer. When current in the primary 1 circuit changes, a changing magnetic field will induce a changing voltage in the secondary 2 circuit. Power Handling Chart rates the ZP42915TC at 240W at 50kHz, with a conservative flux density of 1,300G (another doc said 215W)” My guess is that this core can run 215 to 240W continuously. 2 Needs of transformer short-circuit current calculation Today more than ever before, the electricity grid is developing so quickly — the power (Size ≥ 110. Know how to choose the right type of transformer and the different options that you may need. Three Phase Electric Motor Protection. TDR Calculator. The design of an audio transformer is a process full of compromises; here are some guidelines and considerations: Physical core size is determined on the power and low frequency limit that is needed, however the larger the core the more winding capacitance there will be limiting bandwidth. load current. ETAP, Jefferson Electric and CSG Network offer. It also determines the turns ratio and type of transformer. Normally it is an empirical value based upon KVA rating. According to 725. Therefore, when sizing a genset, it is critical to accurately predict voltage dips and to understand how much excess starting capability is available in the motor and what amount of voltage dip can be allowed. This calculator provides the missing variable in the three transformer characteristics. 8MHz to 30MHz 50ohm-balun is easy. A three-phase, fused disconnect with 300A fuses will be installed on the primary side of this transformer. 5 250A 250A 208V 225A 50 400A 400A 240V 80A 15 100A 100A 240V 150A 25 250A 250A 240V 200A 37. March 4, 2020 January 1, 2019 by Electrical4U. This means 7. We feature Lionel, American Flyer, MTH, Atlas O, Williams Trains, K-Line, Weaver Models, and more. fuse size should be within 125% of the transformer full-load amps. Single Phase Motor Protection. Calculating Transformer & Generator Sizing. Actually it is very simple for us when we are provided with the right information and you can help by. We use cookies to ensure that we give you the best experience on our website. For single phase equipment. The table below shows the relationship between general output power for a flyback converter and the required core size. It is important to note, however, that these solutions are best only for those experts who have knowledge and experience with assembly transformers. Current Transformer Example No1. Distribution Transformer Calculations Excel Spread Sheet. 5T for iron. The power rating for determining the size of the transformer is shown below as Pac (Watts). so when buying a 12v transformer/driver do I just have to make sure the total max Watts is ample to drive the length of cut LED Strip? eg. This number determines the magnetic flux density within the core. Regulation. Assuming a voltage dip of 50 kV at the primary side. allow transformer primary conductor sizing down to 1/3 of. The ratio of the current transformer can be also modified by altering the number of secondary turns by forward or back-winding the secondary lead through the window of the current transformer. Current depends on the load resistance. The ideal transformer identity shown in eq. The transformer calculator uses the following formulas: Single Phase Transformer Full-Load Current (Amps)= kVA × 1000 / V Three Phase Transformer Full-Load Current (Amps) = kVA × 1000 / (1. Call MIDWEST at 800. If we increase the breaker size then the conductor size has to increase too. soft starter) employed. Many transformer manufacturers actually recommend running at no more than 80% of the transformer’s capacity. This is in agreement with your formula but it does not apper to be correct. Amortization is paying off a debt over time in equal installments. By providing the relative efficiency, cost and board size needed by. 2 + 4 + 4 + 4 or 40. Transformer kva rating selection or transformer sizing is a very important step of electrical engineering. What is electrical engineering? Electrical Engineering is a field of engineering that studies the use of electricity, electronic and electromagnetism. What You Need to Know. I want to design the installation of a 500KVA Distribution Transformer to supply a neighborhood in Nigeria. For long conductor runs where voltage drop may be an issue, use the Voltage Drop Calculator to determine proper conductor sizing and maximum circuit length. Trafo calc. Restricted earth fault protection is provided in electrical power transformer for sensing internal earth fault of the transformer. Once your landscape lighting design is complete, you can figure out what size of low-voltage transformer you need. of Electrical and Computer Engineering University of Minnesota A. Consider this method the next time you're sizing delta-connected transformers, where most of the loads are line-to-line. Size Transformer to 480 V Loads zC. High switching frequency can be used to reduce transformer size, but care must be taken to avoid increased AC losses from core loss, proximity effect, and skin effect. Find kva or amps or volts fast using the transformer calculator easy tool. Ohm's Law Calculator 3-Phase Delta / Wye Calculator. Short circuit calculations on a single-phase center tapped transformer system require a slightly different procedure than 3Ø faults on 3Ø systems. This section describes how to access the Transformer MVA Sizing calculation, sizing options, required input data, and available results. Get answers to all of you power inverter questions including what a power inverter is and what it can be used for, how to size and install it properly, as well as useful tips and precautions to be aware of. Also, learn more about different types of loans, experiment with other loan calculators, or explore other calculators addressing finance, math, fitness, health, and many more. The 2008 NEC Handbook Section 210. : A 10KVA load at 240v can be increased to 264v, a 10% change can be achieved with a 1KVA transformer. We are currently integrating the Peter W. Thus the transformer. The Rockstone Power Voltage Transformer Converter is built strong to last long term with routine usage. Easy to use. Frequently Asked Questions about Power Inverters. Built-in Voltage Regulator In some countries, the voltage fluctuates so much that it can damage electronics. There are no hidden codes on the transformer, just abbreviations. Calculator The Blakley calculator allows you to carry out various electrical calculations. Today, we are here with another comprehensive Copper and aluminum wire size calculator As we have discussed in detail the topic of "How to calculate the proper wire size for Electrical Wiring. Load voltage, or secondary voltage, is the voltage needed to operate the load. kVA (1Ø) = Volts x Amps 1000 kVA (3Ø) = Volts x Amps x 1. To calculate the rating of the transformer for both single phase and three phase, the load required to be fed and voltage at which load is to be fed must be known or should be …. Our reconditioned transformers pass MIDWEST Switchgear Division's Quality Control Program of cleaning, maintenance, and testing. Get valuable information about selecting the correct Voltage Converter / Transformer on these pages.