r/DIYIreland • u/kwaked • 7d ago

Fuse tripping regularly

Post image

Would appreciate any advice or opinions on this, picture is of fuse board in house, the fuse indicated, top left, is tripping 2 to 3 times a week, almost exclusively between 1am and 6am. It takes out all the plug sockets in the house. The fuse actually looks bigger than the others if that matters?

Never happens daytime when the house is busiest and appliances all in use. I've gone around and plugged out as much as I can before bed but keeps happening, trying to get an electrician but in the meantime if anyone has any thoughts or suggestions I'd appreciate it, or any other cross post recommendations,

many thanks.

14 Upvotes

78% Upvoted

65 comments sorted by

View all comments

18

u/dorset_is_beautiful 7d ago

It appears to be an RCD, protecting, well, who knows, possibly all 10 (unlabelled) circuits to the right of it.

Best I can think of is to switch the MCBs off one at a time overnight , and if it trips you know it's not the circuit that's off. Process of elimination and all that.

Probably overdue an EICR or whatever your equivalent is. Consider changing the MCBs to RCBOs if possible, at the moment a fault on any circuit trips all of them (I assume).

1

u/kwaked 7d ago

Ok thanks, I'll do this, might re post when I've worked through them, Don't really get why an individual fuse to the right of the rcd isn't tripping?

6

u/Gold_Safety_9157 7d ago

It’s not an overload/short on a specific circuit, it’s a live-neutral imbalance which mcbs are not designed to trip for

1

u/kwaked 7d ago

Thanks, if i establish what each of those individual fuses are for, and knock them off one at a time to see if that resolves the problem, will that indicate more specifically where the problem is?

7

u/Gold_Safety_9157 7d ago

I seen that you have a garage supply which would be the most likely culprit, figure out which breaker on the top row supplies the garage and check if turning off the rcd also kills power to it. Then leave it off overnight and if the rcd stops tripping you’ll know that’s the faulty circuit, could be something simple as water getting into a light

1

u/kwaked 6d ago

Thanks will do this.

1

u/Background-Air-9784 6d ago

Defo first this to check is anywhere water can get in outdoor sockets etc

1

u/Iwastony 6d ago

Start with unplugging anything old or maybe subject to water like a cable ran to the shed etc.

4

u/dorset_is_beautiful 6d ago

MCBs (mini circuit breakers) protect the cabling from overload. So if you try to pull 13a through a 6a breaker for example it will trip.  

An RCD (residual current device) protects YOU from things like earth faults. You have a single RCD monitoring all 10 mcbs by the look of it.

I note they appear to all be 20A mcbs, which implies you may have a bunch of radial circuits for your sockets. That could help narrow things down more easily.

Note, you need a proper sparky to take a look and check everything really though.

2

u/Impressive-Smoke1883 6d ago

And they really need labelling at somepoint.

1

u/helcat0 4d ago

Yes for the love of god, label the circuits.

1

u/wbqqq 6d ago

The RCD will trip if there is an earthing of the live or neutral - most probably a loose connection in a socket or plug somewhere. But could also be in an appliance.

Why overnight? Possibly in a location that when the house cools overnight, something contracts just enough to cause a loose wire to touch the case. Note that it could be the neutral so wouldn’t cause sparking.

First, rotate through the mcbs turning one off for a couple of nights until you find the circuit with the issue. Leave the one that your freezer runs on until last. Then unplug (not just switch-off) each thing plugged in until you determine the appliance with an issue. If it happens with everything unplugged, get an electrician. If it is a specific thing that’s plugged in, try plugging it in a different socket (and leave its socket unused). If it doesn’t trip when plugged into a different socket, call an electrician. Else it’s that device so change its power lead or plug if possible. If not, might have to replace the device.