Technical FAQs

Ask a Question

Is it proper to select a measuring current transformer with high value of rated output?

Selection of a suitable value of rated output is essential to confirm the capability of the current transformer secondary winding to carry the connected load (burden) including the wiring (cabling) losses. However, it remains important to make sure the value is not significantly higher than the actual/needed burden in order to avoid negative effect/impact on measuring accuracy. 

Example: 
Load (measuring instrument) burden = 3.5VA
Wiring losses (estimated) = 0.6VA
Total burden connected = 4.1VA
In this case, the suitable value of CT rated output is 5VA, selection of higher values may increase measurement errors of the current.
Was this helpful?
What can we do to improve the information ?