ive jut wired my new cabin from the garage, i ran 6mmswa 25m from garage to te cabin to a new c/u. the cabin has 3 sockets and 2 lights, do i need to change the size of mcb in the main c/u in house that is feeding the garage as i have put in the xtra load. the cabin will be running to low volt heaters and a tv
log cabin
- Thread starter hartson
- Start date
Sponsored Links
Why not give us a f-king clue and actually tell us what size MCB is in at the moment, the installation method of the cable and proposed final circuit type and loading.
How on earth do you think we could even have the slightest incling without this information?
You say you have 2 lights. Are these 40W lamps or 1000W lamps???
What are low volt heaters?
What provisions have you made to provide RCD protection to this new wiring?
How on earth do you think we could even have the slightest incling without this information?
You say you have 2 lights. Are these 40W lamps or 1000W lamps???
What are low volt heaters?
What provisions have you made to provide RCD protection to this new wiring?
S
sparkyspike
6mm SWA will give you 40A maximum. The breaker at the house CU must be this size or smaller, regardless of the load. Are you fitting a CU in the cabin too, or just running off the garage CU?
the supply to garage is on a 32mcb wired in 6mm swa, 2 circuits in garage consists of 1 x 60w light, 4 sockets for tv and mini fridge, ive then took another circuit 25m 6mm swa from garage to cabin into another c/u again 2 circuits 3 x lights 3x sockets. 1x60watt and 2 x 12v 10watt spots , sockets is for a tv and jukebox and heater. when i put the two circuits on together the rcd trips out after 10 mins, but if i turn 1 circut off it stays on and vice versa. would adding a 40mcb in the house to supply the garage instead of the 32 thats in already. the cabin is protected by rcd at the main house as the garage is too.
Sponsored Links
Why does your total load need a 40A breaker? You've identified 140W of lighting plus a couple of TVs, a mini fridge, a jukebox and a heater. Over 7.3kW all in? Sure it's a log cabin and not a sauna?
Anyway - changing the rating of the MCB at the house is not going to stop an RCD from tripping. Something must be leaky in a way that gets worse as whatever it is runs and after 10 minutes it trips.
Have you tried both circuits together but without the fridge?
Anyway - changing the rating of the MCB at the house is not going to stop an RCD from tripping. Something must be leaky in a way that gets worse as whatever it is runs and after 10 minutes it trips.
Have you tried both circuits together but without the fridge?
50 - 1000V AC or 120 - 1500V DC
the mini fridge is in the garage, when i cut the supply to cabin everything stays on in the garage. but when i put cabin power back on it will only let me run either the lighting circuit or the socket circuit but not both at same time, it trips after 10mins when both is on.
Sounds like you've got some neutrals mixed up somewhere around the RCD feed in or out.
The usual mistake is to have the RCD's neutral in and out connected together somehow. When its like this the RCD will hold in for lowish current loads but will trip if the load goes over a certain level.
Usually someone has left a link between two neutral busbars..
The usual mistake is to have the RCD's neutral in and out connected together somehow. When its like this the RCD will hold in for lowish current loads but will trip if the load goes over a certain level.
Usually someone has left a link between two neutral busbars..
I would have thought that as RCDs trip in the mA range that they'd go instantly if there was a neutral path mix-up, no matter what the loads....
i didnt go near the rcd because the garage was already protected at the rcd. but i will go round and check all the neutrals again. what would likley be the cause of the both circuits triping but when individually on there own it works. thanks for all replies so far guys
S
sparkyspike
Have you tried disconnecting all the appliances, and seeing if it still trips? Have you tested any of the wiring. Do you have the means to test the wiring and the RCD?
I did go to a fault where the guys Dad had wired up the CU in the shed with the incoming neutral on the same bus as the RCD output.
The lights worked fine but the RCD tripped when he used a drill etc.
Did you test the wiring and the RCD(s) before putting them into service?
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
Sponsored Links
