Accessories
4.8 Residual current devices
3VA molded case circuit breakers with IEC certificate
Manual, 03/2019, A5E03603177010-03
481
Alignment of conductors in the summation current transformer
In order to prevent measurement errors or spurious tripping, it is absolutely essential to
ensure that the conductors are properly aligned or arranged in the summation current
transformer.
Note
With MRCD type A, the summation current transformer used for the application must have
an inside diameter which is at least 1.5 times larger than the outside diameter of the
conductors which pass through it. With MRCD type B, the inside diameter must be at least 2
times larger.
If the combination MRCD, summation current transformer, trip unit and molded case circuit
breaker/switch disconnector is to be installed, the minimum clearances must be observed.
For more information, refer to the operating instructions.
