Current transformers for meters
Metering CTs for energy meters with CT connection · 1 A or 5 A secondary
61 CELSA current transformers for energy meters with CT connection, 1 A – 6000 A primary, 1 A or 5 A secondary. Accuracy class 0.2, 0.2 S, 0.5, 0.5 S, 1 to 3, rated burden 0.2–60 VA.
Products
Matching CT-operated meters (7)
DMC6 MID and ECM6 MID are connected to the secondary side of the transformers; the ratio is set on the meter. ECM6 MID: class B to EN 50470-3.
Frequently asked questions
Which current transformer fits my meter?
The secondary current must match the current input of the meter (1 A or 5 A), the primary current is chosen just above the highest operating current of the conductor, and the ratio is set on the meter. For a three-phase meter each phase gets its own transformer of the same ratio. Choosing a current transformer →
Which class do I need for a meter?
For billing third parties the metering point operator sets the class, usually 0.5, 0.5S, 0.2 or 0.2S, and the transformers must be calibrated. For energy monitoring and cost centres class 1 is usually sufficient, for load profiles with a lot of partial load class 0.5 or 0.5S. Accuracy classes →
Which transformers are approved for billing?
Calibrated (conformity-assessed) transformers together with an MID meter: at CELSA the plug-on CTs ALO-E and the wound primary CTs WALO-E with PTB type approval, with the CT-operated meters DMC6 MID or ECM6 MID. Calibration and MID →
How much burden does a meter need?
The current path of the meter consumes a fraction of a VA; the measuring leads usually consume more. Rated output = meter consumption plus cable loss, which the VA calculator works out from length and cross-section. VA calculator →
Can several feeders be metered by one meter?
Yes, with a summation current transformer: it adds the secondary currents of 2 to 9 main transformers into one output of 1 A or 5 A for a single meter. Summation current transformers →
Overview, guide and all designs: Current transformers