Current Transformer Developments

Traditional current transformers provide a current output to the meter. The CT is rated for both its primary current and its secondary current, the primary being the level of current flowing in the circuit it is to measure, the secondary being the current flowing in the CT’s output circuit (the one connected to the meter)

An alternative 21st century approach is the 'voltage output' CT.

In simple terms this design allows smaller, lighter, CTs to be used, which offer the additional advantage of virtually unrestricted cable runs for their secondary connections. These CTs can only be used with meters specifically designed to work with them, but where new meters are being installed they provide some significant advantages.

These CTs may only be used with AEM33 V meters which are available in panel and DIN versions. However the following rules should be noted:

• Always use the correct CT type with the correct meter type. Failure to do so will damage either the meter, the CT or both!
• Voltage output CT's are used with 'V' type meters only
• 'V' type meters cannot be used to replace existing meters unless the existing CTs are also replaced

Rating	Class
50/5	1
100/5	1
400/5	1
800/5	1