Littelfuse CT-300-F-20 300:5 2.0" Window Footed Style Current TransformerLittelfuse CT 300 F 20 Product Description CT 300 F 20 Current Transformer detects phase current or ground fault current; available in a wide array of ratios with a diameter between 1 3 inches. Littelfuse CT 300 F 20 Current Transformer Typical Application Well Pump Reservoir Pump Transfer Pump Sewage Pump Littelfuse CT 300 F 20 Current Transformer Technical Details 200: 5 Ratio Footed Style 2" Window