Energy and Power
4 Low Voltage Switchboard Partitioning Forms Defined By IEC 61439-2
There are 4 main reasons for partitioning a switchboard. To protect persons against direct contact with dangerous parts. The minimum degree of protection must be IPXXB. To protect the switchboard against the penetration of solid foreign bodies. The minimum degree of protection must be… Read more
Mar 20, 2015 | By Edvard Csanyi
Low Voltage
Degradation of Insulation in Switchgear (What’s Really Happening)
Electrical insulation is subjected to electrical and mechanical stress, elevated temperature and temperature variations, and environmental conditions especially for outdoor applications. In addition to normal operating conditions, there are a host of other factors that may trigger accelerated aging or… Read more
Mar 04, 2015 | By Edvard Csanyi
Low Voltage
Inspection, Test and Measurement Procedures for LV and MV (up to 36kV) Switchgear
Installed in clean, well ventilated or air-conditioned locations, switchgear will require little routine maintenance. Major inspection should be scheduled for power plant shutdowns and concentrate for low voltage switchboards on identifying contact wear, correct operation of interlocks, correct overload settings and fuse… Read more
Jan 16, 2015 | By Edvard Csanyi
Energy and Power
Electrical life (durability) of LV circuit breakers due to the switching operations
According to the standard IEC 947-2, there is actually no defined stipulation regarding the requirements of electrical life of a circuit breaker. The numbers of switching operations which a circuit breaker under no-load, normal load, overload and short-circuit conditions has… Read more
Dec 01, 2014 | By Edvard Csanyi
Low Voltage
7 practical tips for installing a good measuring system
There are different product families on the market: instruments that measure a single electric parameter (voltage, current, frequency, phase angle cosϕ), generally used in single phase systems, as instrumentation on the machine, and instruments that enable all the electric parameters to… Read more
Nov 14, 2014 | By Edvard Csanyi
Low Voltage
Guidelines to maintenance of low voltage switchboard
A well-executed maintenance program can provide the following benefits: Longer life of switchboard and fewer replacements; Reduced time on repairs and overhauls, and the option of scheduling them at an opportune time; Fewer failures with unexpected outages; Timely detection of any… Read more
Oct 24, 2014 | By Edvard Csanyi
Energy and Power
Rating Definitions Applied to Low Voltage Molded-Case Circuit Breaker (MCCB)
The molded-case circuit breaker is the “workhorse” for system protection 600V and below. A circuit breaker is a device designed to open and close by nonautomatic means and to open the circuit automatically on a predetermined overcurrent without damage to itself when… Read more
Sep 19, 2014 | By Edvard Csanyi
Energy and Power
Methods Of Securing LV Circuit Breakers
Circuit breakers are typically secured in place by one of the following methods: Through bolts Bolted to the bus Stab locked to the bus or some type of receptacle connection Din rail mounted When a longer service life breaker is… Read more
Aug 11, 2014 | By Edvard Csanyi
Energy and Power
Methods Of Mounting LV Circuit Breakers
Methods used to mount circuit breakers can be divided into three general groups, those being: Fixed Removable (disconnectable unit), and Drawout (withdrawable) A review of these mounting methods follows. A circuit breaker that is bolted in its enclosure and wired… Read more
Aug 08, 2014 | By Edvard Csanyi
Low Voltage
10 Important Precautions When Working On Low Voltage Energized Equipment
For most work, the electrical equipment must be de-energized because there is a high risk of injury to workers if they work on energized equipment. It may be possible to schedule such work outside of normal work hours to limit the inconvenience. Sometimes… Read more
Jul 18, 2014 | By Edvard Csanyi
Energy and Power
Harmonic distortion and high frequency applications
The presence of harmonic frequencies in addition to the fundamental 50Hz, bring about distortion of the fundamental sine wave. Considerable problems may arise dependant upon the level of this distortion. Sources of harmonic distortion can be: Variable Speed Drives UPS… Read more
Jul 07, 2014 | By Edvard Csanyi
Electric Motor
How to measure insulation resistance of a motor
If the motor is not put into operation immediately upon arrival, it is important to protect it against external factors like moisture, high temperature and impurities in order to avoid damage to the insulation. Before the motor is put into… Read more
Jun 09, 2014 | By Edvard Csanyi
Energy and Power
What affects the operating temperature within LV switchgear
BS EN 60439 states a maximum indoor ambient temperature of 40ºC, a maximum daily average of 35ºC and a minimum ambient of -5ºC. As a general guidance rule, the temperature within the low voltage switchgear should not exceed 50/55ºC. If… Read more
Apr 30, 2014 | By Edvard Csanyi
Energy Efficiency
Automatic transfer switch (ATS) between two low-voltage utility supplies
Multiple utility services may be used as an emergency or standby source of power. Required is an additional utility service from a separate source and the required switching equipment. Figure 1 shows automatic transfer between two low-voltage utility supplies. Utility… Read more
Jan 15, 2014 | By Edvard Csanyi
Low Voltage
Example of MV/LV network structure with dual fed main MV switchboard
Connected to article: Example of standard MV/LV network structure MV consumer substation; The main MV switchboard can be backed up by a generator set and it feeds two MV/LV transformers; MV switchboard can be GIS or AIS and consist of… Read more
Jan 06, 2014 | By Edvard Csanyi
