Current transformers 1 A
Secondary current 1 A · all designs and ratios x/1 A
50 CELSA current transformers with 1 A secondary current in 40 ratios from 1 A – 6000 A primary. Accuracy class 0.2, 0.2 S, 0.5, 0.5 S, 1 or 3, rated burden 0.2–60 VA.
50 products
Products
Frequently asked questions
When is 1 A secondary the better choice?
With long measuring leads. The cable loss rises with the square of the current: at 1 A it is one twenty-fifth of the loss at 5 A. With 10 m one-way lead length and 2.5 mm² copper, 5 A secondary consumes 3.56 VA in the leads, 1 A only 0.14 VA. Calculating the burden →
Does the meter have to be a 1 A meter?
The current input of the meter or instrument must match the secondary current. CT-operated meters such as DMC6 MID and ECM6 MID are available for 1 A or 5 A secondary; the ratio is set on the meter. Current transformers for meters →
Is a 1 A transformer less accurate than a 5 A transformer?
No. The accuracy class applies to the ratio regardless of the secondary current. Since a 1 A transformer needs less burden for the same lead, it is often the more accurate solution in practice.
What does 400/1 A mean?
With 400 A in the primary conductor the transformer delivers 1 A to the meter – a ratio of 400:1. Every ratio has its own overview page with all matching types.
Overview, guide and all designs: Current transformers