Technical library

Detailed guidance on ROCOF testing with the Sverker 900, including information about connections and instrument settings.

Each issue of Electrical Tester has a range of hand-picked industry articles for high-voltage electrical engineers working on utilities.

The term Demand pertains to both power and energy parameters. When referring to AC Power there are 3 different parameters to access, active power, reactive power and apparent power.

This application note looks at what you should check when analysing the power quality data from a solar panel application.

When examining potential power quality issues associated with solar panels, your power quality analyser should be programmed to examine a variety of different parameters outlined in this application note.

Renewable energy sources can include solar photovoltaic (PV), solar hot water, geothermal, wind and biomass. Of all of them, solar prices are dropping the quickest, so we are seeing this industry grow the quickest. This is most notably true in the residential and small commercial markets.

The most significant danger facing wind turbines is damage from lightning strikes. Lightning faults cause more loss in wind turbine availability and production than the average fault. The number of failures due to lightning strikes is known to increase with tower height and a growing number of studies speculate that rotating wind turbines may be more susceptible to lightning strikes than stationary structures.

Megger provide a range of lead sets and clips of different sizes and electrical characteristics for use with Megger 5 kV and 10 kV insulation resistance testers, enabling the user to choose the most applicable lead set for the work in hand.

 Harmonics are caused by non-linear loads. Linear loads draw a linear current that follows the changing voltage of the AC waveform. Non-linear loads draw current pulses periodically, which creates distorted waveforms.

p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 10.0px Times} span.s1 {font: 10.0px Helvetica} Since there is no such thing as perfect insulation, if any conductor is raised to a potential above that of earth some current is bound to flow to earth from that conductor. The amount of current that flows is dependent on:Voltage on the conductorThe capacitive reactance between the conductor and earthResistance between conductor and earthCurrents that flow to earth are called leakage currents and are usually very small values, typically < 1 mA. However the amount of current that is required to cause distress or harm to a human being or animal is also small, these currents must be limited by circuit design to safe values.If this is not possible, then a 30 mA RCD (residual current device) or 30 mA RCBO (residual current device with overload protection) should be fitted for personal protection.