HVAC
Jet pumps used for private well systems or low flow irrigation applications
Jet Pumps are mounted above ground and lift the water out of the ground through a suction pipe. Jets are popular in areas with high water tables and warmer climates. There are two categories of jet pumps and pump selection… Read more
Aug 12, 2013 | By Edvard Csanyi
Electric Motor
7 Most Common Motor Enclosure Types Defined By NEMA Standards
The enclosure of the motor must protect the windings, bearings, and other mechanical parts from moisture, chemicals, mechanical damage and abrasion from grit. NEMA standards MG1-1.25 through 1.27 define more than 20 types of enclosures under the categories of open… Read more
Aug 09, 2013 | By Edvard Csanyi
Electric Motor
Motor Service Factor (SF) Defined By NEMA
Motor Service Factor (SF) is the percentage of overloading the motor can handle for short periods when operating normally within the correct voltage tolerances. This is practical as it gives you some ‘fudge’ in estimating horsepower needs and actual running… Read more
Aug 07, 2013 | By Edvard Csanyi
Power Substation
Where do the strongest electric and magnetic fields come from in a power substation?
Electric substations produce electric and magnetic fields. In a substation, the strongest fields around the perimeter fence come from the transmission and distribution lines entering and leaving the substation. The strength of fields from equipment inside the fence decreases rapidly… Read more
Aug 05, 2013 | By Edvard Csanyi
Electric Motor
NEMA Definition Of Motor Full Load Nominal Efficency (Standard MG1-12.54.2)
Efficiency is defined as the ratio of the power output divided by the power input. Machine losses are in the form of heat, and include: Stator winding loss, Rotor loss, Core loss (hysteresis and eddy current), Friction and windage, and… Read more
Aug 02, 2013 | By Edvard Csanyi
High Voltage
Talking about HV shunt reactor switching (part 2)
Continued from first part: Talking About HV Shunt Reactor Switching (part 1) Scope (explained in previous part) Shunt reactors application (explained in previous part) Closing operation (explained in previous part) Opening operation Conclusions In the case of shunt reactors the… Read more
Jul 31, 2013 | By Nicola
High Voltage
Talking about HV shunt reactor switching (1)
These notes aim to give basic idea of the main criticalities related to HV shunt reactor switching, particularly in terms of voltage, and how such problems are faced and solved by modern switching technology. Content: Shunt reactors application Closing operation… Read more
Jul 29, 2013 | By Nicola
Electric Motor
Selection Of Crane Duty Motors (Part 3)
Continued from second part: Selection Of Crane Duty Motors (Part 2) N = Duration of motor operation under rated conditions R = Duration of motor at rest and de-energised ØMax = Maximum temperature attained during Duty cycle Unless otherwise specified,… Read more
Jul 27, 2013 | By Ashok Parikh
Energy and Power
Equipotential Bonding For Metal Installations
The electrical low voltage consumer’s installation requiring certain earthing resistances (disconnection conditions of the protective elements) and the foundation earth electrode providing good earthing resistances at cost-effective installation, the foundation earth electrode is an optimal and effective complement of the… Read more
Jul 26, 2013 | By Edvard Csanyi
Electric Motor
Selection Of Crane Duty Motors (Part 2)
Continued from first part: Selection Of Crane Duty Motors (Part 1) Following two types of motors are widely used for crane duty applications. Squirrel Cage Crane Duty Motors Slip ring and Wound Rotor Crane Duty Motors The crane motors are… Read more
Jul 24, 2013 | By Ashok Parikh
Electric Motor
Selection Of Crane Duty Motors (Part 1)
The operating conditions such as duty cycle, startup, temperature and operating environment are vital considerations in the motor efficiency and reliability. It is absolutely essential to match the motors to their specified operating conditions for minimizing stresses on the motors… Read more
Jul 22, 2013 | By Ashok Parikh
Energy and Power
Micro Hydro Power Plant With Automatic Frequency and Excitation Control
First of all, I am very glad to say that our project was successful. It is hydro power plant which was completed totally by our five members team namely me, Chitransh Shrivastava, Akshay Tiwari, Pranjan Lele, Pankaj Sonwane and special… Read more
Jul 19, 2013 | By Aakash Johari
High Voltage
Commissioning of HV Panel – Operational and Functional Checkup
The main objective of the test is to check the proper operation function of the circuit breaker; in this test we do the following: This test is conducted by manual, Local and Remote. For the manual Operation test, we will… Read more
Jul 17, 2013 | By Edvard Csanyi
Energy and Power
NEC Branch Circuit Requirements
The National Electrical Code (NEC 2011) provides guidance for electrical contractors and electricians, but it is really intended for use by governmental agencies that have legal jurisdiction over electrical installations and authorized electrical and insurance inspectors. The many mandatory chapters… Read more
Jul 15, 2013 | By Edvard Csanyi
Energy and Power
Calculation Example of Small Photovoltaic (PV) Residential Stand-Alone System
– Array Size: 10, 12-volt, 51-watt modules; Isc= 3.25 amps, Voc= 20.7 volts – Batteries: 800 amp-hours at 12 volts – Loads: 5 amps DC and 500-watt inverterwith 90% efficiency. The PV modules are mounted on the roof. Single-conductor cables… Read more
Jul 12, 2013 | By Edvard Csanyi
