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## Available variants

---
title: "Miniature single-phase open-type transformer — Variant: Split-core CT 100/5A, Power rating 1.5 VA, Class 1"
sku: "TOM-100-5"
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title: "Miniature single-phase open-type transformer — Variant: Split-core CT 125/5A, Power rating 1.5 VA, Class 1"
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title: "Miniature single-phase open-type transformer — Variant: Split-core CT 200/5A, Power rating 1.5 VA, Class 1"
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title: "Miniature single-phase open-type transformer — Variant: Split-core CT 300/5A, Power rating 1.5 VA, Class 1"
sku: "TOM-300-5"
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TOM-X: Miniature single-phase open-type transformer

The current transformer is used to proportionally change large current intensities into smaller values, suitable for the measurement ranges of control and measurement devices.

The conductor with the measured current passes through the main opening of the transformer (P1/P2), which is equivalent to one turn of the primary winding. The terminals of the secondary winding S1 and S2 are connected to the terminals of the measurement circuit of the control or measurement device.
The ratio of currents in the two windings is a constant quantity.
This is the current ratio IPn/ISn=N, where
IPn - nominal primary current;
ISn - nominal secondary current;
N - transmission ratio value.
From the value of the current flowing in the secondary winding, the value of the current flowing in the primary winding can be determined:
ISm*N=IPm, where
ISm - measured primary current;
IPm - measured secondary current.

**NOTE**
It is recommended to connect the secondary system with a wire of at least 2.5 mm² diameter.
Grounding of terminal S2 is recommended.
It is forbidden to disconnect the secondary circuit during transformer operation (possibility of high voltage resulting in electric shock to people or damage to equipment).

 

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