Jignesh Parmar
74 awesome technical articles
Jignesh Parmar has completed M.Tech (Power System Control), B.E (Electrical). He is member of Institution of Engineers (MIE), India. He has more than 20 years experience in transmission & distribution-energy theft detection and maintenance electrical projects.
Transformers
Star-Delta Transformer Connection Overview
In this type of transformer connection, then primary is connected in star fashion while the secondary is connected in delta fashion as shown in the Figure 1 below. The voltages… Read more
Jun 10, 2012 | By jiguparmar
Energy and Power
Understanding Vector Group of Transformer (2)
Continued from first part Understanding Vector Group of Transformer (part 1) Vector Groups are the IEC method of categorizing the primary and secondary winding configurations of 3-phase transformers. Windings can… Read more
Jun 04, 2012 | By jiguparmar
Electrical Lectures
Understanding Vector Group of Transformer (Part 1)
Three phase transformer consists of three sets of primary windings, one for each phase, and three sets of secondary windings wound on the same iron core. Separate single-phase transformers can… Read more
Jun 03, 2012 | By jiguparmar
Power Substation
Transformer Connection Star-Star
The windings of three phase transformers may be connected in by Y or Δ in the same manner as for three single phase transformer. Since the secondary’s may be connected either… Read more
May 23, 2012 | By jiguparmar
Maintenance
Measurement of insulation resistance (IR) – 2
Continued from first part: Measurement of insulation resistance (IR) – Part 1 1. IR Values For Electrical Apparatus & Systems 2. IR Value for Transformer 3. IR Value for Tap Changer… Read more
Apr 29, 2012 | By jiguparmar
Cables
Measurement of insulation resistance (IR)
The measurement of insulation resistance is a common routine test performed on all types of electrical wires and cables. As a production test, this test is often used as a… Read more
Apr 28, 2012 | By jiguparmar
Electric Motor
Direct On Line (DOL) Motor Starter
Different starting methods are employed for starting induction motors because Induction Motor draws more starting current during starting. To prevent damage to the windings due to the high starting current… Read more
Apr 22, 2012 | By jiguparmar
Electric Motor
Star-delta motor starter explained in details
Most induction motors are started directly on line, but when very large motors are started that way, they cause a disturbance of voltage on the supply lines due to large… Read more
Apr 10, 2012 | By jiguparmar
High Voltage
How HV transmission lines affects humans and plants?
By increasing population of the world, towns are expanding, many buildings construct near high voltage overhead power transmission lines. The increase of power demand has increased the need for transmitting… Read more
Mar 20, 2012 | By jiguparmar
Energy and Power
The real truth behind household power savers
A household power low voltage saving devices has recently received a lot of attention from both consumers and manufacturers. It is generally used in residential homes to save energy and… Read more
Mar 07, 2012 | By jiguparmar
Electrical Lectures
Types of neutral earthing in power distribution (part 2)
Resistance grounding has been used in three-phase industrial applications for many years and it resolves many of the problems associated with solidly grounded and ungrounded systems. Resistance Grounding Systems limits… Read more
Feb 09, 2012 | By jiguparmar
Electrical Lectures
Types of neutral earthing in power distribution (part 1)
In the early power systems were mainly Neutral ungrounded due to the fact that the first ground fault did not require the tripping of the system. An unscheduled shutdown on… Read more
Feb 06, 2012 | By jiguparmar
Cables
EHV/HV Underground Cable Sheath Earthing (part 1/2)
In urban areas, high voltage underground cables are commonly used for the transmission and distribution of electricity. Such high voltage cables have metallic sheaths or screens surrounding the conductors, and/or… Read more
Jan 19, 2012 | By jiguparmar
Electric Motor
NEC Code for Size of Cable for Motor
Size of Cable for Branch circuit which has Single Motor connection is 125% of Motor Full Load Current Capacity. What is the minimum rating in amperes for Cables supplying 1… Read more
Dec 30, 2011 | By jiguparmar
Protection
Transformer Protection – Abstract from NEC
According to NEC 450.4, “each transformer 600 volts, nominal, or less shall be protected by an individual overcurrent device installed in series with each ungrounded input conductor.” Such overcurrent device… Read more
Dec 26, 2011 | By jiguparmar
