Cant find fault!

[rob121]

Hi All,
First just wanted to say I passed my domestic installer a couple of weeks ago, so a big thankyou to al those who gave me advice and helped me out when I was a bit puzzled. So again thankyou!

Anyways back to the post, got callled to a job yesterday where the landlord had told me the tenant had complained that the "low level sockets" in the kitchen had stopped working. Anyways turns out its the sockets that supply the dishwasher and fridge/freezer. The house has only one ring supplying all sockets (built in 2004, new builds for you!), then off this ring theyve put a three gang switch, which supplies them and the washing machine.
So plugged my socket tester in and everything seemed okay, plugged dishwasher in - everything okay. So done IR tests, rcd trip test, cont test - again, everything fine. Took the switch and sockets off, no dodgy connections or anything untoward.
I cant see the customer had made a mistake either because he told me he left it for 10 minutes and still nothing, so hes pulled the dishwasher and fridge out, connected above worktop and volla it worked.
Has anyone got any ideas what it could be?

The only fault I found was that the three gang switch was rated at 20AMP fed of the 32A ring. Maybe its getting a bit warm inside and theres a dodgy connection inside?! Oh and forgot to mention that the dishwasher AND fridge went off both at the same time, and theyre fed seperately from the switch.

Interesting to see a new build with a 10mm main earthing conductor on a PME aswell :hurray:

Regards,

Rob

 

[telectrix]

think you're almost there. grid switches breaking down under load. poor internal connection. replace with MK. you'll have to change all of them along with the yoke and faceplate.

 

[malcolmsanford]

Can't be the load breaking down the 20amp grid switches unless the fridge and the W/m have 32 amp CEE sockets fitted to them.

I assume they have normal 13amp plugs tops on the appliances. So I can't see those switches being overloaded. Just because the supply to those switches are off the 32amp Ring Final, don't mean anything

Looks like it was that loose connection, that was most likely there since day one, or perhaps some work as been done on the tiles/wall and loosen it.

 

[telectrix]

i was thinking dodgy connection, but the OP hasn't mentioned anything about one, so i assumed the dodgy connection might be inside the switches, or the terminations to them.

 

[Rockingit]

On the basis that the simplest answer is invariably the right one - loose connection!!

 

[telectrix]

but my view is that as the OP said all the connections were sound, then the poor connection could be the actual switch contacts. i've replaced several cheap switches for this very same fault. even come across some that had been bridged out.

 

[Deleted member 26818]

Those 3gang sockets are fused.

 

[telectrix]

i thought he had a 3 gang grid switch. feeding separate sockets

 

[Deleted member 26818]

So if one switch works, and the other two don't, it would suggest a problem with the wiring of the switches.
It may be that the switches have been incorrectly wired, should be one leg of the RFC to the first switch, loop to the other switches and then the other leg of the RFC to the last switch.
They've probablly wired the switches, so the second two are spured off the first, and either the conductor or the termination has given up the ghost

 

[ackbarthestar]

Yep, I've seen this at the 20A grid switches used to supply separate radials to kitchen appliances. Often the box isn't deep enough and only way of connecting all of the appliances is to loop in the live and neutrals across each switch connecting the ring at one end only.
A continuity check across each of the radials and switches would be the first place to start.

 

[Deleted member 26818]

Unfortunately, that then effectivly means that you are spuring two sockets off of one.

 

[ackbarthestar]

Unfortunately, that then effectivly means that you are spuring two sockets off of one.

That may well be the case, but that is what one sometimes will find. Just check that the ring starts at one end and ends up at the other with phase/neurtal looped in across the switches.
Using double pole switches used in this manner on rfcs was quite common 10-15 years ago.

 

[Deleted member 26818]

That may well be the case, but that is what one sometimes will find. Just check that the ring starts at one end and ends up at the other with phase/neurtal looped in across the switches.
Using double pole switches used in this manner on rfcs was quite common 10-15 years ago.

Yes that's how it's should to be done, but as you said in your previous post, often it isn't.

 

[rob121]

Thanks for the replies.

No loose connection was found! All the terminals were checked and nothing wrong there. The switch is wired properly (suprising enough) with ring coming in one end, links accross then ring leaving at other end.

I do think the switch has the potential to be overloaded as you have 3X 13A appliances on a 32A ring with the switch rated at 20A. I know they arent going to be running at 13A but perhaps start up currents on the washing machine/dishwasher could be causing overheating and maybe a poor connection inside?! Dont think it would make a difference but theres only 1 32A ring that feeds the whole house, kitchen included. But cant see this would cause the two sockets to stop working.

So far ive given the customer a report on what I found including the 20A switch not suitable for 32A ring-recommended changing for 3 X fcu, and obviously made the customer aware of the earthing conductor being undersized. What code on a PIR would that be? (Undersized main earth).

Thanks again, Rob

 

[vernam616]

Is there power leaving the switchs?

I find it amazing how you gained domestic installer and cant work out basic faults like this, sorry if that sounds harsh, but it seems they give anyone a domestic installer

 

[ackbarthestar]

Thanks for the replies.

No loose connection was found! All the terminals were checked and nothing wrong there. The switch is wired properly (suprising enough) with ring coming in one end, links accross then ring leaving at other end.

I do think the switch has the potential to be overloaded as you have 3X 13A appliances on a 32A ring with the switch rated at 20A. I know they arent going to be running at 13A but perhaps start up currents on the washing machine/dishwasher could be causing overheating and maybe a poor connection inside?! Dont think it would make a difference but theres only 1 32A ring that feeds the whole house, kitchen included. But cant see this would cause the two sockets to stop working.

So far ive given the customer a report on what I found including the 20A switch not suitable for 32A ring-recommended changing for 3 X fcu, and obviously made the customer aware of the earthing conductor being undersized. What code on a PIR would that be? (Undersized main earth).

Thanks again, Rob

What about the continuity/IR of the radials and across the switches?

Also, the switch will not be switching 32A but only the size of the load connected to each of the switches, load side.

 

[vernam616]

I cant understand how so many people have replied without stating the very first obvious thing you would check, is there voltage at the feed and load of the switchs?

 

[rob121]

Is there power leaving the switchs?

I find it amazing how you gained domestic installer and cant work out basic faults like this, sorry if that sounds harsh, but it seems they give anyone a domestic installer

im suprised you managed to get this far on the forum if you cant read. As said before theres power leaving the switch and all the sockets are working fine, test results fine. So its an intermitent fault. Perhaps next time its worth reading the thread properly before making a judgement on someone.

Rob

 

[rob121]

What about the continuity/IR of the radials and across the switches?

Also, the switch will not be switching 32A but only the size of the load connected to each of the switches, load side.

IR tests fine, continuity fine.

As far as the switch goes, the fact its rated at 20 A would this be for each circuit or for the switch as a whole? I would have thought it would of been as a whole but perhaps not

 

[vernam616]

I read your original post, which says nothing about checking for voltage, hardly fault of the year is it, basic things which are learnt in your first few years, do apologise if i seem to have upset you, i stereotyped you as being a kitchen fitter, whos been signed off in a few weeks

 

[rob121]

"So plugged my socket tester in and everything seemed okay, plugged dishwasher in - everything okay"

I would have thought that would of given enough info to say that there was power to the sockets. And with 20 odd replies and no one pin pointing the problem yet I would hardly say its a basic fault such as a loose connection.

Anyway I'm not going to get into arguement about it, as thats not what im on here for.

Rob

 

[JUD]

IR tests fine, continuity fine.

As far as the switch goes, the fact its rated at 20 A would this be for each circuit or for the switch as a whole? I would have thought it would of been as a whole but perhaps not

Each of the switches is rated at 20A, not as a whole, and as each switch is only switching 13A max then they should be fine. The terminals will be rated at 32A.

As Tel said if all connections are sound then it could be faulty switches.

 

[vernam616]

Calm down flower, its hardly my fault you dont understand basic faults is it

For what its worth i reckon they are just cheap **** switchs which have broken down and create a intermittent fault like the other electricians have posted, for me id of just changed them for a more reputable make instead of making yourself look incompetant

 

[rob121]

Its hardly my fault you obviously dont have any common sense. Well isnt replacing the switch part of the advice I put in my post. The thread was started just out of interest to see if I was missing something other than the basics. Im sure youve never had something bug you and ask a general question about it. Anyway, so far your advice has been check the voltage which i mentioned had been done, and replace switch which I had already said I had advised the customer before. Why dont you just start copying and pasting everyones elses advice, just to make yourself seem really "competant"

 

[vernam616]

Im the one lacking common sense!?

You wouldnt last 5 mins working with us, ive met and worked with a few electricians of your calibre before, rather frustrating i must say

I really wouldnt shame myself of posting something so basic, if you were time served you really wouldnt need to ask these ill fated incompetant questions

God only knows how you scraped through a NICEIC inspection

 

[topquark]

I'd go with the dodgy switch theory, seen that before, sometimes you turn the switch on and nothing, turn it off/on again and it's "fine". I'd suggest a wee bit of functional testing on the switches would highlight that if it's the case.

 

[paturback]

Now Now Girls lets not get our knickers in a twist, if its not a loose connection, faulty switch would be a good bet, but others have said that already so don't know why I'm bothering really!

 

[rob121]

As much as I love discussing this with you vernam, i didnt join this forum to be one of them idiots making petit arguements and try to put people down. I joined it to gain a bit more info and when to clarify that the way ive carry out my work is correct, which by the way ive carried out the tests everyones advised im fairly happy I am. Now if you want to go on someone elses thread and try and derate them, maybe to make yourself feel better then go for it, im sure they will appreciate your helpful "advice" as much as what I have. I have to say all the time ive been on this forum Ive had some great advice and people have appreciated mine. Maybe you should read some other threads and at other peoples replies before going around making stupid remarks and trying to get in conflicts with people. Youve got a remarkable talent of being able to judge peoples competantcy from sitting at a computer screen.

 

[rob121]

I'd go with the dodgy switch theory, seen that before, sometimes you turn the switch on and nothing, turn it off/on again and it's "fine". I'd suggest a wee bit of functional testing on the switches would highlight that if it's the case.

cheers topquark. That was done and the switch seems fine. I tryed it with all the appliances connected, isolates them fine, closes fine. It just seems to come and go apparently. Anyway ive recommended replacing so im sure if it happens again ill get called out to change it over.
Cheers again,

Rob

 

[topquark]

On the faulty ones I've seen they often work fine, then all of a sudden when you try to turn them on again you get a bit of resistance and although the rocker goes over, the contacts don't make. If the clients turning them on/off regularly try asking if occasionally the switch seems "stiff".

 

[rob121]

On the faulty ones I've seen they often work fine, then all of a sudden when you try to turn them on again you get a bit of resistance and although the rocker goes over, the contacts don't make. If the clients turning them on/off regularly try asking if occasionally the switch seems "stiff".

They dont actually use the switches so he says (theyre helpfully positioned on the opposite wall to the kitchen sides tucked in a corner). Thats what bugged me about it suddenly cutting power to 2 of the appliances. They havent done any diy work either and they both go out at the same time, they unplug them and put in the sockets above worktop which are on same ring and its fine. But if the switch is rated at 20 A per circuit then it cant be overloaded. Anyway I best stop talking incase I look incompetant :13:

Cheers,
Rob

 

[telectrix]

if i can remember that far back, i advised changing the switches in post#2

 

[Des 56]

rob121

Take comments that have been critical with a pinch of salt
You and I know that the vast majority posting on here, would go out of their way to try to be of help,as you would do yourself

Well done on passing by the way

Look at the positive,every experience whether a pain in the neck (like the current one) or even mundane problems,it will all help to build your confidence and experience as the years go bye

 

[topquark]

if i can remember that far back, i advised changing the switches in post#2

In that case it's definately not that then

 

[telectrix]

:biggrinjester::59:

 

[rob121]

rob121

Take comments that have been critical with a pinch of salt
You and I know that the vast majority posting on here, would go out of their way to try to be of help,as you would do yourself

Well done on passing by the way

Look at the positive,every experience whether a pain in the neck (like the current one) or even mundane problems,it will all help to build your confidence and experience as the years go bye

Thanks a lot Des. Your absolutely right, every time something like this crops up it helps to build my knowledge and confidence. I dont come on here looking for an arguement, just different opinions and ways off looking at a situation.

After looking at the comments its pretty obvious that the chances are its the switch. Either that or the tenants just wasting a bit of the landlords money. Hes an electrician himself so suprised he didnt sort it himself.

Again I know its a simple fault and 9/10 that ive dealt with are just a dodgy connection somewhere, just suprised me that I couldnt find it and it had rectified itself without any work being done to it. As Des said its more of a confidence thing as its never re assuring walking away from a job where you didnt find the fault and tests to switch etc were all okay.

Thanks again for the constructive replies,

Rob

 

[topquark]

Now I've been fed (but not beered, yet!). The only things common to the two machines are either the switch or the supply. If plugging into the other socket on the same supply works, that just leaves the switch. As my learned friend suggested (in post 2) I'd second (or 10th) replacing the switch, but leave the customer with a caveat that it MAY not solve it. Check back with them in a week or so (depending on the regularity of the problem).

 

[Des 56]

Now I've been fed (but not beered, yet!). The only things common to the two machines are either the switch or the supply. If plugging into the other socket on the same supply works, that just leaves the switch. As my learned friend suggested (in post 2) I'd second (or 10th) replacing the switch, but leave the customer with a caveat that it MAY not solve it. Check back with them in a week or so (depending on the regularity of the problem).

hello topquark
Do you think it could be anything to do with the switch then

 

[topquark]

hello topquark
Do you think it could be anything to do with the switch then

Well, I did think that at first, but then when Tel pointed out he's already suggested that, I thought "can't be that then!". :crazy:

 

[rob121]

So its definately not the switch then?
:59:

And while you lads are here, you wouldnt know if a HSBC 10 year guarentee on a new build would cover the undersized earth would you? I dont do much work on new builds so wouldnt even think about going down that root but landlord was wondering if that would cover it? Got to be worth a try. Although I did point out most electrical contractors only offer a 5 year warranty.