Voltcraft vc 34 multi tester voltcraft vc 34 p the vc 34 is intended as a fast function test of residual current circuit breakers common abbr fi or rcd in electric installations of category iii up to 250v the test device can be used to simulate different residual currents by means of 5 keys p p these residual currents are laid for fi circuit breakers commonly used in the average household up to special fi circuit breakers with residual currents of 0 5a the activation is signalled b