Calibrated current transformer 5000/1 A
Calibrated current transformer for billing metering · ratio 5000:1
One CELSA calibrated current transformer with a ratio of 5000/1 A: Calibrated clip-on current transformers (ALO-E). Accuracy class 0.2, 0.2 S, 0.5 or 0.5 S, rated burden 2.5–15 VA. From €471.60 incl. VAT, with datasheet, direct from the manufacturer.
Frequently asked questions
When do I need a calibrated current transformer?
Whenever energy is billed to third parties based on the measurement (e.g. sub-metering for tenants), legal metrology requires a calibrated transformer together with a MID meter. ALO-E and WALO-E are conformity-assessed; the type is approved by PTB. Calibration and MID →
What does 5000/1 A mean?
With 5000 A in the primary conductor, the transformer delivers 1 A to the meter or measuring device – a ratio of 5000:1. Meters and instruments are set to this CT ratio. The 1 A secondary keeps cable losses low on long measuring lines.
Which accuracy class?
For calibrated current transformers 5000/1 A, the classes 0.2, 0.2 S, 0.5 and 0.5 S are available here. Billing-relevant metering requires class 0.5 or better; for display and monitoring class 1 is usually sufficient. Accuracy class comparison →

