Energy and Power
Power Measurement On Four-Wire System Using Wattmeter Methods
A four-wire system is suitable to supply unbalanced, three-phase loads or single phase loads distributed on all three phases of a low voltage installation. When measuring power on a three-phase… Read more
Apr 06, 2016 | By Edvard
Energy and Power
Guidelines To Metering Challenges and How To Overcome Them
In the course of any metering exercise, there will be challenges that arise – these may occur in planning, specifying, purchasing, installing, or in the maintaining of the metering system. This… Read more
Mar 19, 2016 | By Edvard
Metering
Measurement of residual currents on a distribution feeder
The measurement of the earth fault or residual currents on a distribution system feeder can be done by the so-called summation connection, where the three current transformers, one in every… Read more
Jan 22, 2016 | By Edvard
High Voltage
Capacitive Voltage Transformers (CVT) For HV Measurements
Capacitive voltage transformers (CVTs) are used on higher voltage levels, starting from 66 kV and upwards. The type of the CVT is always a single-pole one, thus the connection is… Read more
Dec 26, 2015 | By Edvard
Energy and Power
Learn To Interpret Single Line Diagram (SLD)
We usually depict the electrical distribution system by a graphic representation called a single line diagram (SLD). A single line can show all or part of a system. It is… Read more
Dec 19, 2015 | By Edvard
Metering
Protective relay – The brain that detects abnormal system conditions
For medium voltage circuit breaker applications, protective relay serve as the “brain” that detects abnormal system conditions and direct the circuit breaker to operate. They also serve to provide specialized… Read more
Dec 12, 2015 | By Edvard
Energy and Power
Learn How To Specify Current Transformers
Current transformers are used to supply information to the protective relays and/or current, power and energy metering “instruments”. For this purpose they must supply a secondary current proportional to the… Read more
Dec 05, 2015 | By Edvard
Metering
Resistance measurement of non-conductive walls and floors
There are certain situations where it is desirable for a room to be totally isolated from the Protective Earth conductor (e.g. for conducting special tests in a laboratory etc.). These rooms… Read more
Aug 05, 2015 | By Edvard
Medium Voltage
Current and voltage sensors as an alternative to traditional CTs and VTs
As an alternative for traditional primary current and voltage measurement techniques, the use of sensor technique is gaining field. This technique is typically applied to current and voltage measurement in… Read more
May 25, 2015 | By Edvard
Metering
Understanding the ratios of magnetic HV instrument current transformers
The primary winding is a part of the network, carrying the actual load current. The transformer’s secondary circuits usually consist of several units, each of them having its own magnetic… Read more
May 22, 2015 | By Edvard
Energy and Power
The consumer power substation with metering on medium voltage side
A consumer power substation with metering on medium voltage side is an electrical installation connected to a utility supply system at a nominal voltage usually between 1kV – 35kV, which… Read more
Jan 12, 2015 | By Edvard
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… Read more
Nov 14, 2014 | By Edvard
Metering
Instrument transformers (CTs, VTs) in the system
The three main tasks of instrument transformers are: To transform currents or voltages from a usually high value to a value easy to handle for relays and instruments. To insulate the… Read more
May 19, 2014 | By Edvard
Energy and Power
Electrical Thumb Rules You MUST Follow (8)
Accuracy Class of Metering CT Accuracy Class Letter of CT Accuracy Class of Protection CT Continued from part 7: Electrical Thumb Rules You MUST Follow (Part 7) Metering Class CT… Read more
Mar 10, 2014 | By jiguparmar
Energy and Power
Power measurement in a three-phase system
Electrical power is measured with a wattmeter. A wattmeter consists of a current coil connected in series with load, while the other potential coil is connected parallel with load. Depending… Read more
Jan 19, 2013 | By Edvard
