Electrical Thumb Rules

Current rating of Transformer / Generator (I)    KVA  X  1.4   Impedence of  Transformer  (Z)  5 %   Short circuit rating of Transformer    Current Rating / % Impedence  =  I / Z   No Load Current of Transformer < 2 % of rated current of Transformer   Impedence of Generator...

Electrical Engineering Thumb Rules

Earthing Resistance:   Earthing Resistance for Single Pit=5Ω ,Earthing Grid=0.5Ω As per NEC 1985 Earthing Resistance should be <5Ω. Voltage between Neutral and Earth <=2 Volts Resistance between Neutral and Earth <=1Ω Creepage Distance=18 to 22mm/KV (Moderate Polluted Air) or Creepage Distance=25 to 33mm/KV (Highly Polluted Air)   Minimum Bending...

Choice of a circuit-breaker

Choice of a circuit-breaker   The choice of a CB is made in terms of:   ·         Electrical characteristics of the installation for which the CB is intended ·         Its eventual environment: ambient temperature, in a kiosk or switchboard enclosure, climatic conditions, etc. ·        ...

Low Voltage Circuit Breakers

Based on IEC 60947-2 (LV switchgear and controlgear - Part 2: Circuit breakers):   In (Rated current)   The rated continuous / uninterrupted current that the circuit breaker can carry.   Icm (Rated short-circuit making current)   The short-circuit current that the circuit breaker can withstand as it is closing where the act of closing initiates the...

Power factor calculation

The power factor correction capacitor should be connected in parallel to each phase load.   Single phase circuit calculation   Power factor calculation: PF = |cos φ| = 1000 × P(kW) / (V(V) × I(A))   Apparent power calculation: |S(kVA)| = V(V) × I(A) / 1000   Reactive power calculation: Q(kVAR) = √(|S(kVA)|2 - P(kW)2)   Power factor...

Electronics & Electrical Engineering

BYC. JAMES ERICKSON Retired Principal Consultant, E. I. du Pont de Nemours & Co., Inc.CHARLES D. POTTS Retired Project Engineer, E. I. du Pont de Nemours & Co., Inc. BYRON M. JONES Consulting Engineer, Assistant Professor of Electrical Engineering,University of Wisconsin—Platteville.DOWNLOAD :http://www2.hcmuaf.edu.vn/data/phamducdung/thamkhao/Mark's%20Standard-Handbook/Electronics.pdf ...

Medium Voltage Design Guide (Schneider Electric)

  DOWNLOAD : http://www.schneider-electric.ie/documents/panelbuilders/en/shared/technical-ressources/mv_design_guide.pdf ...