Square D 600 Volt rated current and voltage transformers are field-proven in well over a million installations where accuracy and longer, more dependable operation are essential. In most cases, the information contained in this catalog should be sufficient for the proper selection of the instrument transformer best suited for your application. Instrument transformers are ideally suited in the following applications such as indoor, switchgear assemblies, motor controllers. They can also be used with metering, relays, current sensing, over circuit breaker bushings and over power transformer bushings. This Torroidal Current Transformer has a transformer rating of 300/5 with a NEMA 1 rating and is 1 phase. This product is UL recognized with an 18 months, warranty. These transformers complys to UL & cUL standards.