RCD problem...nuisance tripping

[xr4x4]

no you can't get an RCD fitted as the main switch in the MG board as it would have to be a 3 phase RCD and I don't think they'll work on single phase..

you need to get that wylex RCD changed to a 100mA type S RCD.. ( time delayed.. )
adding a 50A RCBO to the MG board won't help one bit..
the 30mA main RCD will still trip before the 100mA one in the crabtree board..

i know i need to change the main RCD now as its 30ma, i guess this is wrong anyway?..to low mA..? can you get standalone RCDs these days? didnt think you could.

trouble is, the crabtree CU is still a 100ma so wont we still trip if there is a problem at the crabtree end.. so i was thinking, rather than try and get a lower rcd in the crabtree, (which will most likey go for days without being noticed) get a RCBO in the merlin so we can see when there is a problem.

so could i do both?

 

[RF Lighting]

You can't supply a metal clad DB without RCD protection anyway in a TT installation...

 

[xr4x4]

what's the supply being TT got to do with having a 4 pole isolator?

you mean that the neutral should be through the isolator too....?

yes it should..

Yep, that is what I was getting at. All live conductors should be cut when opening the isolator. IIRC where the supply is TN and supplied in accordance with the ESQCR, and where the installation is supervised you can get away with just cutting the phase conductors.
The isolator is provided for isolation purposes and thus imo should cut all lives.

the red switch on the merlin cuts live and netrual...from the RCD i cant for the life of me work out why you think it wouldnt... sorry am i being dumb?

 

[RF Lighting]

The main switch on the merlin board is only 3 pole, but with a single phasing kit, so will isolate the line only, and NOT the neutral.

 

[xr4x4]

You can't supply a metal clad DB without RCD protection anyway in a TT installation...

i thought ALL TT supplys needed RCD/ELCB protection? metal CU or not..

 

[ColJack]

no, the red switch doesn't cut the neutral.. it's through that bit on the side and it's just a linking connector..

 

[xr4x4]

The main switch on the merlin board is only 3 pole, but with a single phasing kit, so will isolate the line only, and NOT the neutral.

be being stupid then. sorry...

i will take the cover off tomorrow and take a pic.

 

[RF Lighting]

Yes, but the RCD must be BEFORE the supply enters any metal clad equipment.

 

[xr4x4]

Yes, but the RCD must be BEFORE the supply enters any metal clad equipment.

ah..... penny drops...

can you still get standalone RCDs, im sure ive looked in the past.

 

[Spark123]

You can sometimes get insulating kits allowing a non RCD protected supply to feed a metal CU.

 

[RF Lighting]

Yep.

Do you know if the 30mA RCD has been installed for fault protection or for additional protection?

 

[xr4x4]

Yep.

Do you know if the 30mA RCD has been installed for fault protection or for additional protection?

no idea.. but i suspect its been fitted becasue the person didnt know what they where doing.... which is why im on here...!!



id just like to solve this tripping problem.. seems im digging a bigger hole...!

 

[xr4x4]

You can sometimes get insulating kits allowing a non RCD protected supply to feed a metal CU.

any idea what this is or where i could look into it?

 

[bongos]

Maybe you could get the DNO to provide a PME connection?

 

[xr4x4]

could i get one of these and a box for it to go in.

http://www.tlc-direct.co.uk/Products/MK6600.html

like this..?

http://www.tlc-direct.co.uk/Products/BHCT2.html