Current Transformer (CT) supplier in delhi/ncr A Current Transformer (CT) is a type of instrument transformer used to measure alternating current (AC) by producing a reduced current proportional to the current in the circuit, which can be safely monitored and recorded. ________________________________________ 🔧 Basic Purpose of a CT: • Measurement: For metering AC current without directly connecting meters to high-current lines. • Protection: Feeding current signals to protective relays in switchgear or motor control centers. ________________________________________ ⚙️ How It Works: • A CT has a primary winding, usually just a single conductor (the wire carrying the current), and a secondary winding (many turns of fine wire). • When current flows through the primary, it induces a proportionally smaller current in the secondary. • Common ratio: 100:5 or 1000:5, meaning 100 A in = 5 A out. ________________________________________ 📏 CT Types: Type Use Case Notes Wound CT Low current/high accuracy Has its own primary winding Toroidal (Donut) CT General-purpose metering Primary is a pass-through wire Split-core CT Retrofit applications Can be clamped around conductors Bar-type CT High-current busbar installations Primary is an integral bar ________________________________________ ⚠️ Important Usage Notes: 1. Never open-circuit a CT secondary while energized – it can produce dangerously high voltage! 2. Always short the secondary when not connected to a load/meter. 3. CTs are rated by burden (VA) and accuracy class (e.g., 0.5, 1.0). ________________________________________ 🧪 Common Applications: • Energy meters (kWh meters) • Circuit protection (feeding into overcurrent relays) • Generator/motor monitoring • Substation monitoring ________________________________________ 📘 Example Nameplate Data: • Ratio: 400/5 A • Class: 0.5 (for metering) or 5P10 (for protection) • Burden: 10 VA • Frequency: 50/60 Hz