Dear Experts,

It is recommended in the SINAMICS S120 power units manual to use SIEMENS selectively switching AC/DC-sensitive residual-current circuit-breakers with a rated current of 63 A and rated fault current of 0.3 A.

However, it is highly desirable to also have protection against electrical shock which implies using RCCDs with 0.03 A rated fault current instead of 0.3 A.

I am wondering if it is possible to use RCCDs with 0.03 A rated fault current and if it would result in any problem e.g. frequent unnecessary tripping.

Thanks in advance and I look forward to your reply.

Regards.

aliman

Dear Experts,

It is recommended in the SINAMICS S120 power units manual to use SIEMENS selectively switching AC/DC-sensitive residual-current circuit-breakers with a rated current of 63 A and rated fault current of 0.3 A.

However, it is highly desirable to also have protection against electrical shock which implies using RCCDs with 0.03 A rated fault current instead of 0.3 A.

I am wondering if it is possible to use RCCDs with 0.03 A rated fault current and if it would result in any problem e.g. frequent unnecessary tripping.

Thanks in advance and I look forward to your reply.

Regards.

 0.03A is too litlle, it will trip when the drive is povered up.

Marko Bursic

This is not a home appliance. If the grounding is correctly then it should be no risk of electric shock.

 Thats true, 0.03A is to protect a human with household appliances that connect to a soccet outlet. 0.3A is to be a fire protection.

When  you have multiple inverters, even a 0.3A one will trip.

Line supply connection via residual-current devices - SINAMICS S120 Combi Manual - ID: 109754298 - Industry Support Siemens