Odd electrical fault

Eurorunner

My washer/dryer packed it in and I replaced with seperate washer and dryer. When I plugged the new wachine machine into the socket that the old one used to use, it trips the 'sockets' circuit. When swapping them around - and putting the dryer plug in that socket (its a double socket), theres no problem.

I find it a bit strange in that the dryer probably uses more energy? Its irrelevant i suppose as this has solved the problem but I'm just curious as to the cause.

Stoner

Eurorunner,

that sounds like a strange one, as it's a twin socket and you can have them both working at the same time , we can initially assume that it is not an overloading issue.
My gut feeling is that the twin socket might need replacing, you said that the socket trips , by this do you mean the actual socket MCB or the RCD that controls all the sockets in your house?.

As both appliances are new , it does sound like there may be a small issue with the actual socket, but it could be a number of things, a new twin socket will cost you about €5 so I'd start there, you could take a pic of the existing cabling while you are at it so we can see the type of cabling you have.

Once again I am assuming that you have tried this a number of times and that the MW or dryer are not pushed up against the plug top squashing it in etc?
also is it tripping straight away or does it only happen when the two appliances are going full steam?

Eurorunner

Stoner wrote:

you said that the socket trips , by this do you mean the actual socket MCB or the RCD that controls all the sockets in your house?

socket MCB.

Stoner wrote:

I am assuming that you have tried this a number of times and that the MW or dryer are not pushed up against the plug top squashing it in etc

No. there wasnt much space left but enough for me to slot the plug in after putting the machine in place.

Stoner wrote:

also is it tripping straight away or does it only happen when the two appliances are going full steam?

Trips straight away - and thats with no programme selected, havnt pressed start, etc.

Hoagy

I'd be a bit concerned that you may have both a faulty socket and a faulty washing machine.
If the earth contact on one side of the twin socket is not making contact and there is an earth fault on the washer, the machine would work when plugged in to the faulty side and trip when plugged in to the good side.
If that is the case you need to sort it out immediately before somebody gets a shock.

billy_beckham

"If the earth contact on one side of the twin socket is not making contact and there is an earth fault on the washer, the machine would work when plugged in to the faulty side and trip when plugged in to the good side."

If there were any earth fault problems then the ELCB/RCD would trip Hoagy not the MCB...

Stoner

Eurorunner

As it is the MCB and not the RCD that is tripping it does narrow it down.
MCBs trip mainly due to an overload or short circuit.
I still think the most likely thing is the socket needs to be replaced.
We have had some problems recently with Whirlpool washing machines in a domestic project we have on the books, they were tripping the MCB, the manufacturers were on to it straight away and simply changed the machines and the problem has not returned.
However like i said a new socket will set you back about €5.

As you have both machines working in one arrangement (at equal loadings) this should remove over current from the problem BTW typically it is not a good idea to have a WM and dryer on the same circuit. As this can cause an over current, you have gone from a system that washed and then dried straight after but never at the same time, now you will at some stage have both on at the same time so you'd want to watch that.

You could also leave the dryer plugged in and in the side of the twin socket that the washing machine trips the MCB, plug in a kettle or a toaster (something with a bit of a load) and see if that trips it. then change over the washing machine and the dryer and try it again.
It is a strange one though.

Hoagy

billy_beckham wrote:

"If the earth contact on one side of the twin socket is not making contact and there is an earth fault on the washer, the machine would work when plugged in to the faulty side and trip when plugged in to the good side."

If there were any earth fault problems then the ELCB/RCD would trip Hoagy not the MCB...

Not if the earth is not making a connection. You need an earth path for the RCD to trip.

(2nd attempt) On reflection you're right, sorry. I suppose what I should have said is that the actual fault situation may be there when the MCB doesn't trip.

Stoner

Hoagy wrote:

(2nd attempt) On reflection you're right, sorry. I suppose what I should have said is that the actual fault situation may be there when the MCB doesn't trip.

good call Hoagy, sometimes mad situations can arise and it is a combination of two problems causing a trip.

rogue-entity

Stoner wrote:

As you have both machines working in one arrangement (at equal loadings) this should remove over current from the problem BTW typically it is not a good idea to have a WM and dryer on the same circuit. As this can cause an over current, you have gone from a system that washed and then dried straight after but never at the same time, now you will at some stage have both on at the same time so you'd want to watch that.

Both the washing machine, and drier, can only draw a maximum of 13Amps at peak load, as that is the maximum rated amperage that any device can have when connected using a domestic 3Pin plug. With socket ring-mains, the entire circuit is "balanced" in that, current is supplied from both sides of the ring evenly. Im' not a sparks, but the MCB should not trip just because two 13A appliances are connected to the same socket, to give an example:

In my bedroom, I have my TV, DVD Player and PS2 and a PC connected to a home-made extension lead with a pair of double sockets, protected by a 10A MCB. The MCB on that has never tripped. That plugs into one socket, which is just a spur from somewhere, and I use the other socket on that to connect my laptop charger. The other socket in my room powers my other PC and broadband gear from a 4-way power strip and my computer speakers and printer using a 3-way adaptor. The ring circuit is protected with a 35A fuse only.

We also havent had a problem using two electric showers at the same time, and we have 3 in the house.

Stoner

rogue-entity,

If it is in a kitchen it should be a radial circuit not a ring circuit, rated at 20 Amps, if you have a 32AMp ring circuit in your kitchen I'd advise that you get it changed, one of the main problems with ring circuits is the fact that they are fed from both ends, i.e the cable can be badly damaged at one side of an appliance but still have a clean line from the other, increasing the risk of fault currents, a radial circuit does not have this problem, it does not have the same current carry capacity , but it is safer, particularly in a kitchen where there is water and a nice shiny steel sink bonded to the main earth.

Rogue entity what you have described as "a balanced load" is usually set aside for three phase circuits where it is important to keep the currents in each phase as similar as possible.

The washing machine and the dryer are sharing a circuit, but with what else ? fridge, dishwasher, freezer ,the 2KW kettle or the toaster or the 800W microwave. The load on the MCB is the sum of all the running currents on these items if the OP has them on the one circuit.

the max MCB rating on a ring circuit of cabled with 2.5.sq.mm cable is 32Amp. Traditionally typical 3 or 4 bed house had a ring circuit up stairs , one down stairs and a radial in the kitchen, increased amounts of appliances pushed the requirements to two radial circuits in a kitchen

rogue-entity,the situation you have describe in your bedroom is TBH not comparable to the loads that are in a typical kitchen.
I'm sure you know that fuses in extension leads etc are not an indication of the amount of load being drawn, they exist purely to protect the cable, ie your extension lead will draw a max of 10 amps then it's fuse will blow, if you short circuited the fuse then the cable would melt. A kettle can draw up to 4 times more current then a PC.


If you have the correct ESB supply to your house you can have as many electric showers on at the same time as you want running at full load.
It is all a matter of diversity and the current capacity of your main incomer. two showers running on half load will draw about the same a one shower running on full load. The ratings on MCBs, RCBOs and main fuses are not hugely over exaggerated and should always be observed.