Technical Parameters Parameter Category Specification / Interpretation Type Window-Type (Bushing-Type), Single-Turn Primary, Cast Resin Insulated Current Transformer Standard IEC 61869-1 & IEC 61869-2 (formerly IEC 60044-1) Rated Primary Current (Ipn) Likely 100A, 150A, 200A, 300A, or 400A. The exact value is defined by the full model. "107" might indicate a 100A base. Rated Secondary Current (Isn) 1 A or 5 A (Most common secondary ratings). Accuracy Class -AA Suffix Interpretation: • The first 'A' very likely stands for the protection core's accuracy class (e.g., 5P or 10P). • The second 'A' often indicates the metering core's accuracy class (e.g., 0.5 or 1.0). Thus, REA 107-AA is highly probable to be a Dual-Core CT with one core for protection and one for measurement. Rated Output (VA) Protection Core: Typically 10 VA or 15 VA at specified accuracy class (e.g., 10P10). Metering Core: Typically 5 VA or 10 VA at specified accuracy class (e.g., 0.5). Accuracy Limit Factor (ALF) For Protection Core (if 5P or 10P): Typically 10 or 15 (e.g., 10P10 means 10% composite error at 10 times rated current). Rated Dynamic Current (Idyn) Typically 2.5 x Ith (Rated short-time thermal current). Rated Short-Time Thermal Current (Ith) Expressed in kA for 1s or 3s. For a CT of this size, could be in the range of 10 - 25 kA for 1s. Rated Insulation Level (kV) Likely 12/24/36 kV (Rated voltage / Power-frequency withstand / Lightning impulse withstand). Common for 7.2kV or 12kV systems. Example: 12/28/75 kV. Window Diameter / Size Determines the maximum size of the primary conductor (busbar) that can pass through. A common size is Ø50mm or 50x100mm (rectangular). Mounting Designed for fixed installation on a panel structure, often with mounting feet or brackets. Ambient Temperature Operating: -5°C to +40°C (up to +55°C with derating) Weight Approx. 3 - 7 kg, depending on size.