11. RCDs operate by measuring the current balance between two conductors using a differential current transformer . 12. High-voltage current transformers are mounted on porcelain or polymer insulators to isolate them from ground. 13. Low-voltage single ratio metering current transformers are either a ring type or plastic molded case. 14. The company is known for their original portable appliance testers, clamp-on meters, current transformers , etc. 15. Split-core current transformers either have a two-part core or a core with a removable section. 16. Two identical current transformers are used for each winding of a transformer, stator, or other device. 17. Magnets can also saturate current transformers or power-supply transformers in electronic meters, though countermeasures are common. 18. It is simple to measure very high currents ( hundreds of amperes ) with the appropriate current transformer . 19. Accurate measurement of low currents ( a few milliamperes ) with a current transformer clamp is more difficult. 20. When a large fault current flows through the circuit breaker, this is detected through the use of current transformers .
