Metrel newsletter

PQA: Current clamp selection


One of the most important steps before starting any power quality analysis is proper selection of current clamps since they are the single most prominent (modifiable) factor influencing reliability and accuracy of measurements. Influencing factors pertaining to current clamps themselves are:
  • Overall accuracy
  • Phase angle error
  • Current range
  • Whether they are used for AC or DC current measurements
  • Measurement environment
Our power quality analysers have accurate to a tenth of a percentage when it comes to current measurements, while most types of current clamps have accuracy that is measured in whole percentage points. Choosing the wrong type of current clamps for certain applications can have disastrous consequences for the quality of obtained measurements, making them unsuitable for serious troubleshooting and analysis.

We offer two types of current clamps: iron clamps and flexible (flex) clamps, operating on the Rogowski coil principle. Both have their advantages and disadvantages. Iron clamps are on average more accurate than flexible ones, while flexible clamps support larger current measurement range, from a few A to a few kA (up to 12 kA), and can be mounted on larger / more complex measured objects (measurement sensors up to 90 cm in length).

We also offer so-called Smart current clamps, which support multiple measurement ranges and auto-range selection by the connected instrument for great accuracy. However, the use of auto-ranging feature is discouraged for detection of inrush currents and current transients in favour of fixed range selection prior to use.
More about PQA products
Metrel d.d.

Ljubljanska c. 77
SI-1354 Horjul
Slovenia
Contact Us

+386 1 75 58 200
+386 1 75 49 226
info@metrel.si
Visit metrel.si
  
 Follow Us