overload

[Norn Iron]

Hi Guys I hve a ring main that keeps tripping, but it also trips the main rcd on the board, is there a possibility that it is being overloaded? There are about 6 computers a franking machine a photocopier coffee machine and a few other gadgets on this one ring of 10 sockets! Should the ring be split down to maybe 2 or 3 seperate rings??? Take into account this is on a second dist board in a house that has had a conversion for a small office. There were only 3 lights and 10 sockets added on.

 

[Norn Iron]

Just one on each board each CCT is supplied by mcb

 

[Octopus]

blood and stone spring to mind

 

[Norn Iron]

Ahhhh, how many rcds you got?

Just 1 on each board the circuits are just fed by mcb's

- - - Updated - - -

Murdoch Joan and Kerr spring to mind

 

[sp4rk13]

. More rcds

 

[Norn Iron]

Items with switch mode power supplies such as laptops, PC's, printers etc can have standing leakage up to 3mA per device and this wouldn't be considered a fault current. From the load you describe there could be standing leakage in excess of 20mA which doesn't leave much before the 30mA tripping threshold is reached. Maybe clamp the live and neutral together in an earth leakage clamp meter and measure the normal standing leakage with all appliances switched on. You may need to install RCBO's on each circuit rather than a single main RCD.

With using rcbos for each circuit does this mean then that each circuit will have 30mA as opposed to every circuit having 30mA off the main RCD?

 

[Amp David]

Hell yeah, but they will be tripping at more like 20mA

 

[sp4rk13]

Throw your problem ring over to the non rcd protected side and add your rcbo over there. Yeah 30ma's per rcbo protected circuit.