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.

 

[Hiddo]

What is the rating of the RCD for starters?

 

[telectrix]

sounds more like a leakage problem. do the usual tests. IR being the favorite.

 

[Norn Iron]

The circuit runs for a few days and then just trips the breaker and kills the whole board

 

[sp4rk13]

Main rcd?? Is it tt system?

 

[Hiddo]

Main rcd?? Is it tt system?

It will be one of those garage/shower units. It's fed from the main house CU.

 

[Octopus]

More information required else we will be peeing in the wind.

 

[Marvo]

There are about 6 computers a franking machine a photocopier coffee machine and a few other gadgets on this one ring

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.

 

[sp4rk13]

God only knows!

 

[shanky887614]

could be the computers as cheap psu's can leak power to earth as they are always drawing power even when not powered up

 

[sp4rk13]

It will be one of those garage/shower units. It's fed from the main house CU.

Where are you getting your info?

 

[Norn Iron]

It will be one of those garage/shower units. It's fed from the main house CU.

No it's a 2nd 12 way dist board for the house

 

[sp4rk13]

Ahhhh, how many rcds you got?

 

[Norn Iron]

If it is leakage how do I combat that?

 

[Octopus]

OP, please read post #7 and start again!

 

[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?