MCCB with RCD settings

[Bradley6969]

MCCB with RCD bolt on, anyone know how to work these settings out? Ignore settings now but this is upfront RCD TT system so I want to top one to be 0.3 for 300mA but unsure on bottom?

 

[telectrix]

not seen one of these before, but it loks like the topdial is for the tripping current, and the bottom one for the required tripping time.

 

[Deleted member 26818]

Yes, as Tel says, it’s the delay setting.

 

[Bradley6969]

Thanks so tripping current would be 0.3 which is 300mA? Unsure on bottom how to set

 

[snowhead]

Top one is currently set to 500ma
Bottom one is currently set to 500ms.

 

[Bradley6969]

Top one is currently set to 500ma
Bottom one is currently set to 500ms.

Yes I know lol not set it yet, obviously it’s upfront RCD so for discrimination I’m gonna set to 300mA as various other panels have 100mA but how would I set ms

 

[telectrix]

Yes I know lol not set it yet, obviously it’s upfront RCD so for discrimination I’m gonna set to 300mA as various other panels have 100mA but how would I set ms

put a screwdriver in the slot and turn it..

 

[The Ghost]

As a matter of interest, why does it need to be changed?

 

[Deleted member 26818]

Disconnection time for TT distribution circuits is 1s.

 

[DPG]

I not sure I understand the question. You do realise that the time setting on the device is marked in seconds, and so you need to convert milliseconds to seconds?

 

[Bradley6969]

I not sure I understand the question. You do realise that the time setting on the device is marked in seconds, and so you need to convert milliseconds to seconds?

New to me didn’t know that so it’s wants to be 1 for TY?

 

[Bradley6969]

TT

 

[snowhead]

Is the question, what is the appropriate time delay setting for the installation?

The minimum that doesn't cause a nuisance and at or below the reg requirement or customers spec.

 

[Bradley6969]

As a matter of interest, why does it need to be changed?

It was left on 0.1 so 100mA and was nuisance tripping, hench I’ve changed to 300mA

Is the question, what is the appropriate time delay setting for the installation?

The minimum that doesn't cause a nuisance and at or below the reg requirement or customers spec.

Yes that was all, couldn’t find anything online I knew how to set current just the time

 

[The Ghost]

So does that acheive disconnection times satisfactorily now that you have changed it to 3 x the original ma? Is it not the case if it is tripping that some investigation may be due? Maybe IR tests if it is possible?

 

[westward10]

That is commonly called a vigi module. You will notice when set for 30ma there is a line down indicating to set to no delay so additional rcd protection is provided.

 

[Bradley6969]

That is commonly called a vigi module. You will notice when set for 30ma there is a line down indicating to set to no delay so additional rcd protection is provided.

Yes I’ve only seen a couple of these, on another vary similar model it also has the option for ON and TEST which is a good feature

 

[Bradley6969]

So does that acheive disconnection times satisfactorily now that you have changed it to 3 x the original ma? Is it not the case if it is tripping that some investigation may be due? Maybe IR tests if it is possible?

Yes all sub circuits and feed from mains all tested fine with IR, now set to 300mA it’s all fine there’s discrimaination now 300mA to 100mA and so on, just didn’t understand the bottom dial

 

[Bradley6969]

So does that acheive disconnection times satisfactorily now that you have changed it to 3 x the original ma? Is it not the case if it is tripping that some investigation may be due? Maybe IR tests if it is possible?

Yes all sub circuits and feed from mains all tested fine with IR, now set to 300mA it’s all fine there’s discrimaination now 300mA to 100mA and so on, just didn’t understand the bottom dial

 

[PEG]

Out of interest,what did you set the delay,to?