ext. current transformer for N conductor for 3-pole circuit breakers accessory for circuit breaker 3WL10 / 3VA27 Accessories and spare parts for air circuit breakers 3WL10 to 1250A. (also 3VA27 – 1600A) The accessories and replacement parts of the 3WL10 air circuit breaker can easily be replaced or retrofitted at any time. The accessories and replacement parts of the 3WL10 air circuit-breakers are especially characterized by: 1. Simple to configure, build and modify, thanks to modular design 2. RoHS-compliant. 3. Replaceability of the main contacts by customer himself.