RCCB won't operate.

[MBElectrical]

Testing a RCCB installation off a Crabtree Starbreaker. TT installation. All non powered tests good however 30mA RCCB failed all tests. Even tried at the Dist. board still no joy. Replaced RCCB and still the same. Earth earth loop impedance via earth electrode is 248 ohms which although a tad high is within range. Is this a supply problem??

Thanks in advance,

Martin

 

[sparkinlee]

Supply problem unlikely I'd have thought (prepared to be corrected though!).

More likely something with the board configuration (or the test kit!). I'd suggest you check the settings on the tester, and post a picture of the Consumer Unit as it's hard to be more specific on the info so far.

 

[Blowcat]

Does the test button on the RCD operate the device.
As sparkinlee says check the setting on your tester, on several occasions I have been scratching my head as to why an RCd wont trip only to realise I got the tester on the wrong mA range.
Also shorting N-E on any circuit should trip the RCD (even with that circuits MCB off)

 

[MBElectrical]

Thanks for feedback guys :wacko:. I will check as per yoursuggestions and let you know.

 

[Engineer54]

''248 ohms but it's within range'' Really?? Just as well your trying to sort out that RCD device then!!! This installation will have naff all else protecting it against earth faults will it!!!........