RCD Protection

[AndyZ]

Hi, recently, during my design, I noticed when selecting protection devices, there is a tick box for the 'additional RCD/Earth fault protection'; and another tick box for 'RCD Devices are only used for additional protection'. I wonder in what condition those box should be ticked? Thanks.

[Mert]

Hi AndyZ,

If that box is not checked EOM will consider the overcurrent protection device as the main device for the earth fault calculations and checks. If it is checked, the RCD data will be used for earth fault calculations instead. This is only relevant to TN systems.

Hope that helps.