1. Introduction. Calculation of electrical load is the basis for designing power supply system of any capital. construction object. T he system structure, power, and, correspondingly, the cost of Ohm's Law is the basic formula used in all AC and DC electrical circuits. So if you know two of the three characteristics, your can calculate the third one. Electrical designers use it to determine how much voltage is required for a certain load, like a motor, a computer, or even a house full of appliances. the corresponding electrical load calculations. 1. Electrical Riser Diagram : A diagram as shown in Figure 5 is an important element of the electrical power plan. It usually depicts the power source and its distribution on the outside wall of the building. In Figure 5, the three phase electric power of "277/480V" comes in either P = Power in Watts (W) R = Resistance in Ohm (Ω) Z = impedance = Resistance of AC Circuits in Ohms. Cosθ = Power factor = Phase difference between voltage and current in AC circuits. VPH = Phase Voltage. VL = Line Voltage. Also, XL = Inductive reactance. XL = 2πfL…Where L = Inductance in Henry. The complete list of electrical & electronics engineering basic formulas cheat sheet for PDF download to help users to use them offline to learn or workout how to execute or solve the various calculations of voltage, current, resistance, conductance, capacitance, inductance, impedance, resistor color coding, voltage divider, AC induction motor characteristics, motor starting & running current Learn the Power Formula. We've seen the formula for determining the power in an electric circuit: by multiplying the voltage in "volts" by the current in "amps" we arrive at an answer in "watts." Let's apply this to a circuit example: How to Use Ohm's Law to Determine Current. In the above circuit, we know we have a battery voltage of 18 volts and a lamp resistance of 3 Ω. 11 Power in a d.c. and Purely Resistive a.c. Circuit 67 Mechanics 78 Mass, force and weight 80 Effi ciency 92 12 Power Factor 99 understanding of how to carry out electrical calculations. The calculations which need to be performed vary from those which an electri- cian needs almost on a daily basis, such as cable calculation or the amount Calculate the voltage. Z×I=U 265×0.4 = 110 volts EXAMPLE 4The current through an impedance of 32 is 8A. Calculate the voltage drop across the impedance. U=I×Z = 8×32 = 256 V EXAMPLE 5The current through an electric motor is 6.8A at 230V. Calculate the impedance of the motor. U=I×Z At a minimum, the following types of calculations should be made where applicable: Load calculations Conductor sizing Conduit sizing Motor branch circuit sizing Power factor improvement Transformer primary and secondary circuit sizing Voltage drop Motor starting voltage dip Short circuit analysis Lighting levels Handbook of Electric Power Calculations Arthur H. Seidman, H. W. Beaty, Haroun Mahrous Published 1 August 1996 Engineering, Physics Electric power engineers and technicians can turn to the revision of this popular handbook for step-by-step calculation procedures for solving over 300 problems commonly encountered in electrical power engineering. Electrical Plan Review: Calculations Answer Sheet — — Download: Fault Current Download — FIPS 94 - Electrical Power for Computer Installations This is excellent publication (1-23-99) — — Download: kVar Calculator Electrical Form