Mains problem! advice needed

Your Airbag

Hi Folks, I require a little help with an electrical problem I'm having at home.

Every now and again the mains switch will trip killing all power to the sockets in my house. On the fuse board there is a bank of trip switches for the upstairs and downstairs sockets. The main power switch will only go back up and stay up/on if the kitchen sockets are switched off.

If I leave them off for a certain amount of time, usually overnight, then they can be switched back on without causing the main circut breaker to trip. Its like something is recharging but lately the problem has become more frequent and the recharging time needs to be longer. I'm an electrical noob as you surely have guessed by now from my terminology so it may not be a recharging thats taking place so feel free to correct me on this.

I have seen no correlation between a device in the kitchen and this problem. It has happened when no device was in use before. I have had no recent electrical reworking or any work done on my kitchen.

My questions are (1) What is the most likely cause and is it an easy fix?

(2) What can I check for? Would unscrewing the sockets from the wall and looking for faulty wiring on the sockets be step 1, please advise. As I'm an electrical noob and a little cautious of working with electricity feel free to yell hire an electrician as I will only do the basics myself.

(3) If I need an electrician to fix this problem what cost am I looking at? Moneys a little tight for me right now. If you can adivse me on what to purchase and steps to fix the problem that would be much appreciated but I will obviously hire somebody if its other than basic.

Thanks for listening.

congo_90

if the mains switch is dropping you've got big problems. if other switches are dropping leave them off until you establish why they're dropping. also with the switch down you can establish which devices are working.

could it be a faulty appliance? eg fridge or oven? are you running an excessive load from several high energy appliances?

dathi1

It's not your main switch it sounds like your ELCB. Plug out all devices in your kitchen. Put the ELCB trip back up. Plug in and power on devices one by one and see if it trips again.If a particular device trips the ELCB that's your problem. Otherwise you have a fault on fixed devices like the washing machine or dryer or you may have a fault on the kitchen circuit like moisture build up from steam in sockets, fan or somewhere else.

Bruthal

Sounds like your RCD is tripping because of a fault on a kitchen socket circuit, probably an appliance in the kitchen.

If possible plug everything in the litchen out, reset all breakers on board, if it stays on then plug in kitchen appliances at a time, and see if any trip it.

Might be helpful to first plug in something like a radio so you can tell if the sockets trip again unless you can easily hear the breaker trip from kitchen.

Bruthal

yes do actually operate each item as you plug it in too.

leeomurchu

As all have said above it's most likely your RCD, at least you seem to have isolated the fault to the kitchen well done on that.:D After that its a case of finding the item causing the fault. Usually these faults occur due to a faulty appliance could be your fridge,dishwasher or even your kettle or iron(very common one) Have you noticed any routine to the fault occurring. Usually if its a big appliance fridge of washing machine the fault wont be intermittent so once it trips the RCD you wont be able to reset it. Possible it could be the wiring I've found faults like yours where the socket feeding the dishwasher under the units has been soaked by a leak in the waste for the sink. It could be a loose connection in the back of a socket unlikely though as this would usually short to earth and trip the MCB feeding it as well as the RCD. Next time it happens unplug one appliance at a time a try reset the RCD eventually you'll unplug one and it'll reset and there you have it your faulty appliance. If no joy with that might be worth gettin a spark to look at it cant imagine he'll charge much these days more than half of us are out of work myself included:( best of luck keep up with the posts and eventually we'll crack it. Ps best not go pulling off any sockets faces lookin for a loose connection with the power on:eek:

leeomurchu

Just noticed there that you said this can happen when no appliance is plugged in or in use. you'd be surprised what ya might over look. your fridge for one would probably be on 24/7. Also another point not sure if this is of any relevance to you but If its a samsung american style fridge freezer there was a recall of sorts on some of those,appointments had to be made for an engineer to call and install/replace faulty circuit boards.

Bruthal

Well i neutral touching earth can cause it without tripping the MCB, but probably an appliance alright, water based appliances are more likely as well,

maxim

We had a similar problem, eventually (after many trips to the fuse board!) discovered the problem was caused by the kettle. It would take quite some time from after boiling before the trip would re-set. Changed the kettle - problem solved!

leeomurchu

True Robbie could be a neutral alright but figure it wouldn't be a wiring fault if he's still got power in the kitchen, sure it wouldn't reset if it was a neutral to earth fault anyway

Bruthal

leeomurchu wrote: »

True Robbie could be a neutral alright but figure it wouldn't be a wiring fault if he's still got power in the kitchen, sure it wouldn't reset if it was a neutral to earth fault anyway

It would reset if there was nothing plugged in on or no load on the circuit in question usually, although very large loads from a different circuit can trip RCD due to a neutral earth fault on a different circuit.

I was not actually saying it is a neutral to earth fault, just that can cause it without tripping the MCB in reference to you saying it could be a loose connection in socket but a live to earth would trip MCB,

Its probably not happening in this case, but there have been plenty where it has, even moisture between neutral and earth and the fault can be intermittent depending on how much load is on at a given time when the neutral earth fault is not direct but with dampness,

With live to earth fault through moisture, this can also be intermittent as the moisture dries up, but a sizzling can sometimes be heard in this case. Dishwasher elements or washing machine elements are another one to cause it.

meercat

probably neutral to earth short as others have said
i would also make sure your immersion is turned off
i have seen faulty elements cause similar problems

handydandy

maxim wrote: »

We had a similar problem, eventually (after many trips to the fuse board!) discovered the problem was caused by the kettle. It would take quite some time from after boiling before the trip would re-set. Changed the kettle - problem solved!

I have seen so many faulty kettles, old ones leaking where the power cord is plugging into the pins for the elements.

The kettle is always a good one to check out.

Bruthal

handydandy wrote: »

I have seen so many faulty kettles, old ones leaking where the power cord is plugging into the pins for the elements.

The kettle is always a good one to check out.

Definitely worth a look alright.

Your Airbag

Thanks everybody for the help. Much appreciated. I have just purchased a new kettle and will see how it goes.

Your Airbag

Update time folks, and its not good news, the problem is still there

I noticed our old kettle would take longer then usual to switch off when it reached boiling point so I changed it. The new kettle worked fine the first couple of times but last week when using it it caused the mains to trip again and I had to leave the power switch to the kitchen off to get the main switch back on.

As the kettle is brand new I doubt the element has gone already so I used it on other sockets around the house and the weird thing is it trips off at the right time, just about when the water begins to bubble. I used it on most of the sockets in the kitchen and was careful not to overfill but still it seems to go past the normal trip off point on all sockets in the kitchen.

Also today a trip occurred again when no device was in use. The new kettle was used and turned off before boiling point and the power went about 10 minutes later and I'm certain its happened before when no device has been recently used or is in standby.

My fridge is plugged into a dual socket near the entrance to the hall in the kitchen but its going back to different point on the distribution board, the same as the rest of the downstairs hall sockets.

So there is a problem with the wiring I'm guessing? you guys have mentioned neutral and earth wiring. What do I need to check for when I unscrew the sockets and how should they be rewired? or should I call in a sparky?

Thanks for all the help so far by the way.

meercat

make sure your immersion is turned off

probably time for a sparks to call and have a look

Bruthal

These types of problems can be hard to find even for good sparks. A lot of these problems are caused by neutral earth faults, and it is possible for something like a dishwasher to have a problem and cause this even though it is not in use, but is plugged in.

Items that use water in them can leak and cause a neutral to earth fault, and this can cause trips of the RCD, but as its water and not a solid connection between neutral-earth, it can take a bit of a load like a kettle to then cause a trip, and can be intermittent. If possible unplug everything in the house then do your kettle test, even if the socket has a switch its still better to unplug the items as most sockets dont switch the neutral.

If it was a good neutral to earth connection like a neutral wire touching an earth then an instant trip would be expected when you use the kettle or anything else on the affected circuit. Also turn off the immersion as suggested along with plugging everything out.