Switch Power High Frequency Current Transformer Bh-0.66-CT

Selection of the Current Transformer
 
To select the current transformer correctly, the following points should be clarified:-The application (for measuring or protection).-The features of the working environment (Indoor or outdoor, operating temperature, air humidity etc….).-Operation voltage and frequency.-Range of the primary current (maximum and minimum of the current to be measured).-Dimension of the cable or Bus bar.-Data of the overload.-Short circuit current.-Specification of the measuring device associated with the current transformer (Accuracy, rated current, consumption etc…).-The diameter and length of the cable, the cable which is used to connect the current transformer and associated measuring device. 








Power Losses of the CT
 
In the practical application, the power generated by the primary current should be equal or bigger than the power requirement of the associated measuring device plus the consumption of the connecting line.
 
Losses in the line, PL:
This is the power loss, through heat, generated by current through the resistance RL in the cable, in the transformer's secondary circuit.
 
Factors to be taken into account:
Secondary current: PL = RL / 2
 
Cable diameter: RL is inversely proportional to the square of the diameter cable length: RL is proportional to the length of cabling (there and back).
 
Power: The nominal apparent power (VA) with a specified power factor, which was supplied by the Current Transformer, to the secondary current with the assigned current when it is connected to its nominal load. Sc (VA) = Zc (/sn)2 According to Standards, for apparent power greater than or equal to 5VA, the power factor is 0.8 inductive. For apparent power less than 5VA the power factor is considered to be one (unity).

Specifications

 Current Ratio..................................................................................200/5AAccuracy.........................................................................................Class 0.5Burden.............................................................................................See Selection Form.Security Factor................................................................................FS<5Max System Voltage.......................................................................720V ACTest Voltage.....................................................................................3kV AC. (1 min.)Frequency........................................................................................50/60HzRated Short-time Thermal Current (Ith)........................................Ith = 60 X InRated Dynamic Current (Idyn).......................................................Idyn = 2.5 X IthContinuous Overload.....................................................................1.2 X InWorking Temperature....................................................................-25°C ~ +50°Cinsulation Rating.............................................................................Class BHousing Self-extinguishing Class.................................................VOBus-bar Support Mounting.............................................................ProvidedPanel Mounting................................................................................ProvidedHinged Sealable Terminal Cover....................................................ProvidedStandards.........................................................................................IEC/EN60044-1, VDE0414-44-1, BS3938, BS7626