Any DIY Problems??? Can I be of Help???

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stone-penge
Posts: 292
Joined: 5 Nov 2004 14:40
Location: Newlands park

Post by stone-penge »

Hello lemonade!
Can I ask you a question (its a long one I'm afraid)
First of all I will be calling an electrician anyway ,but Im just trying to understand what's going on.
Yesterday all the power in the house went off whilst my wife was in the middle of having a shower! Checking the fuses where ok I then looked at the LEB digital meter and noticed it was not illuminated. ( it normally has an little red LED to indicate it's recieving power, not to mention the LED meter readout was blank)So I figured it must be a local power outrage and waited for the leccy to come back on.
After an hour or so I figured something else must be up so I asked my neighbours if they had power, which they did ,without any interuption,so a call to the LEB brought out an engineer (in the meantime I had turned off the shower isolating switch) the electricity board man told me my main service fuse had gone. ( its in a sealed box that only the electricity company can get to.)
It was replaced and the power was back on!
Then this morning as I went to turn on my shower back on, as I flicked on the isolating switch, ( it's situated in my airing cupboard) it 'exploded' in a cloud of black smoke.The rest of the house's power was not affected.
I pulled all my household fuses and took off the cover of the shower isolating switch to take a look, expecting to find another fuse there but in fact all it is a switch box and the wires behind seem to have burnt away and melted!!
What am trying to figure out is why the shower's 45 amp fuse on the household fusebox doesn't seem to have blown either time and why the wires have, on this second occasion to my mind, effectively become the fuse by melting away at the shower switch point!!
The wiring in the shower unit itself looks ok and hasn't been compromised by water as far as I can see.

Any ideas?

Many thanks

SP
Illuminance
Posts: 84
Joined: 14 Mar 2005 16:49
Location: Tunbridge Wells

Post by Illuminance »

Hi Stone-Penge and Lemonade (sorry to hijack the thread!)

That was a pretty large fault to clear the Main Fuse, those things are designed to withstand a let-through energy (fault current) of many times their rated setting (we're talking kiloamps over milliseconds)

You say you have a 45A fuse which hasn't blown. Is it a re-wirable fuse, cartridge fuse or a miniature circuit breaker?

What is the rating of the shower?

Do you know the size and length of the cable feeding the shower?

The final circuit cable, in design terms, should be able to cope with a current greater than that of the breaker (fuse), which in turn should be able to cope with a larger current than the design current of the final circuit - in this case the shower.

45 Amps is a lot of juice, especially when you get in to the realms of Earth Fault Loop Impedence and Prospective Fault Current.

Basically, your shower cable - more specifically the earth wire inside - did its job the first time round when the Cut-out blew. This mornings incident suggests it didnt cope as well due to the cable being damaged by the heat produced yesterday.

Do not use this circuit until it has been checked out and rectified by a qualified sparks!

I would also recommend you get a Periodic Inspection Report done on the whole installation, to make sure your earthing arrangements are up to scratch.

Hope this is of help :)
Last edited by Illuminance on 11 Nov 2006 14:55, edited 1 time in total.
Illuminance
Posts: 84
Joined: 14 Mar 2005 16:49
Location: Tunbridge Wells

Post by Illuminance »

Extra:

The isolator in your airing cupboard does just that - isolates the 'fixed equipment' for maintenance. There is no requirement - in this instance- for the circuit to be fused other than at the distribution board (fuse box).
stone-penge
Posts: 292
Joined: 5 Nov 2004 14:40
Location: Newlands park

Post by stone-penge »

Hi illumance, thanks for the input.The shower fuse is a cartridge type, the shower is a 10.8 k unit ,distance from fuse box to shower is no more then ten feet.all the wiring for the shower was installed by a proper sparky some 5 years ago, the cable is marked 300/500v.One thing I did notice was that the earth wire in the isolater box seems to have burnt away, its a bit of a mess in there now and the plastic isolating surrounds have blackend so its hard to tell what is what but some ot the wires seem to be touching, I wonder if they got hot enough to melt the insulating plastic?
Just can't think why the 45 amp cartridge didn't go.

I dont intend to try and fix this myself BTW, would just like to understand what might be going on.
stone-penge
Posts: 292
Joined: 5 Nov 2004 14:40
Location: Newlands park

Post by stone-penge »

ahh the plot thickens!
Just went to cook my sardines on the oven grill (discount at waitrose!) and the oven is not working! checking the other fuses I find a 30 amp wire fuse is blown and so replaced it , oven still not working! put in 45amp cartridge, oven works
therefore 30 amp fuse for shower circuit !
45 amp for oven!
So the 30 amp fuse for the shower may of blown yesterday after all, although on the first inspection the wire was still present in the little channel it runs through between the terminals, Im now wondering if it did blow but re-melted again to form a connection.

This for me now is what passes for excitement on a saturday night :lol:
Illuminance
Posts: 84
Joined: 14 Mar 2005 16:49
Location: Tunbridge Wells

Post by Illuminance »

Hmmm :)

Shower design load = 10.8 kW

Supply voltage to earth = 230v

Therefore 10800 / 230 = 46.95 Amps

(or 45.0 amps if calculated to the old 240v method)

So the 45A fuse, in theory, should've been feeding the shower.

The fuse wire in your 30A carrier will have completely vapourised when it blew.

May have been loose connections in the shower isolator which led to the original fault. Wires do vibrate themselves loose over a number of years, even if the installation was sound when erected. The earth in the shower circuit may well have been damaged during the fault as well.

Hard to tell without looking but things really need checking out by the sounds of it. It was probably a short circuit current rather than an overload current which has produced these effects. The type that, worst case scenario, causes fires.

Please get it checked ASAP.

I'd love to give more advice here but my insurance company wouldn't be too impressed if something went wrong :?

Regards

Illuminance

EDIT:

a 45Amp Cartridge fuse (BS1361) should rupture at 240 Amps within 5 seconds

a 30Amp Rewirable fuse (BS3036) should rupture at 87 Amps within 5 seconds

The cables must be able to withstand these fault currents, otherwise you get an extra source of heating. Don't mean to scare you...
Last edited by Illuminance on 11 Nov 2006 19:15, edited 1 time in total.
stone-penge
Posts: 292
Joined: 5 Nov 2004 14:40
Location: Newlands park

Post by stone-penge »

Yep deffo a job for a proper electrician, now Im thinking at some point in the past I may of taken the 45 fuse out and put it back in the wrong place.:oops:

Baths only until the electrican comes!
Illuminance
Posts: 84
Joined: 14 Mar 2005 16:49
Location: Tunbridge Wells

Post by Illuminance »

Sensible plan :)

Good luck
Anne-Marie
Posts: 1
Joined: 11 Nov 2006 22:03
Location: Forest Hill

Radiator problems

Post by Anne-Marie »

I have noticed posts before about problems with radiators and I was wondering if anybody can provide advice to me.
I have thermostatic valves on most radiators in my flat but one seems to be stuck on maximum, while three others never warm up at all. I have tried bleeding the radiators but there is no air in them. Do I need to replace the thermostatic valves and if so is this something I can do without flooding my house?
Any suggestions would be most welcome.
stone-penge
Posts: 292
Joined: 5 Nov 2004 14:40
Location: Newlands park

Re: Radiator problems

Post by stone-penge »

Anne-Marie wrote:I have noticed posts before about problems with radiators and I was wondering if anybody can provide advice to me.
I have thermostatic valves on most radiators in my flat but one seems to be stuck on maximum, while three others never warm up at all. I have tried bleeding the radiators but there is no air in them. Do I need to replace the thermostatic valves and if so is this something I can do without flooding my house?
Any suggestions would be most welcome.

I'm no Lemonade esq expert, but is the circulation pump running?
If you put your hand on it(it may be quite hot) you should be able to feel , if not hear, that it is running.
lemonade
Posts: 144
Joined: 25 Oct 2005 23:01
Location: Croydon

Hello

Post by lemonade »

Hello
Sorry I've not replied to anyone recently, I've been away from my PC as it had developed a virus....It seems to be fixed now.
Luckily others such as Illuminance and Stone-Penge have answered questions well...Probably better than I would have.
Anne-Marie,
I would not have thought you'd have a problem with your thermostatic valves, especially as more than one radiator is a fault.
Yes it seems to me perhaps the pump is not running or perhaps a motorised valve is sticking.
If you know where the motorised valve is situated, switch between CH & HW and see if the valve moves.
Stone-Penge,
I guess you have a fault with your showers heater element and it has shorted to earth.
If you have a multimeter you can carry out a continuity check (WITH THE POWER OFF) between the element terminals and earth.
But best to callout a qualified electrician!
Megz
Posts: 1
Joined: 15 Nov 2006 17:20
Location: Lower Sydenham

Re: Any DIY Problems??? Can I be of Help???

Post by Megz »

Hi Lemonade! Hope you are well.....you seem to be a very popular chap on this site and I hope you can help me too. I seem to have a leak in my roof which has created damp patch in my bathroom ceiling, but also the water seems to have run down all the pipes from the watertank to my bathroom and then all the way down the pipes and a massive damp (and some nasty looking mushrooms) now in my hall way next to the pipes. (i am on the top 2 floors of a 4 story conversion, the bathroom being on the top floor so the water) The platerboard covering the pipes is wet through.....firstly..how do I go about finding where the the leak in the roof is coming from and secondly what do I do about it now!! Not sure if i need to call a plumber, roofer or plasterer (hopefully not all three!!).
Any help would be really appreciated! sorry if non of this email makes sense too!
Megz
lemonade
Posts: 144
Joined: 25 Oct 2005 23:01
Location: Croydon

Hello Megz

Post by lemonade »

Hello & Welcome!
I've sent you a Personal Message with my telephone number as this is far to complicated to guess over the www. Hopefully I can be more helpful by having a look for you. It could as you say be a leaky roof or burst pipes, but it's too easy to simply make wild guesses. It may even be a sticky ball valve and a blocked overflow or a cracked tank or a blocked downpipe....the list goes on.
May I ask do you have any idea the price of mushrooms these days? You could be making a fortune! :lol:
LisaCummins
Posts: 49
Joined: 30 Jul 2006 10:03
Location: Hall Drive

RE: My xmas lights

Post by LisaCummins »

Hey Lemonade, I hope you can help me with this one?

After being packed away for a year, I have put up my christmas tree. (plastic artificial) However I have developed a problem with the lights. I have had the lights ages, in fact thet were my mothers. Naturally I would probably be better off buying a new set, but I just cannot part with them :cry:

The lights do not come on. Is there a safe way to test which bulbs are blown or if it a loose connection?

At present I have my tree up complete with baubles and tinsel but sadly the lights do not light :(

Can you please be of help to me? :D

Lisa x
lemonade
Posts: 144
Joined: 25 Oct 2005 23:01
Location: Croydon

(Ooh a Message, I haven't had any for ages!)

Post by lemonade »

Hello Lisa
I'm assuming if they're as old as you've mentioned, they'd probably be mains operated and are wired directly to a 3 pin plug...and not used together with a low voltage mains transformer :?: (Please correct me if I'm wrong)
Firstly check the mains plug. Make sure all the wires are intact and connections are tight. Make sure you have no more than a 3 amp fuse fitted. A 3 amp fuse will offer far greater protection should a fault occur.
Mains Christmas lights are wired in series so if one bulb is blown, loose or smashed, the remainder of the bulbs will not light.
Usually there is a "special" bulb which is a Fuse bulb. This is sometimes painted with a white tip and is often placed at the end of the chain furthest from the mains plug.
Make sure the mains plug is UNPLUGGED!
Working from the furthest bulb from the mains plug, remove the bulb. The older bulbs were screw-in, but there are some which push-in. So what I'd suggest is using a glove or a dry cloth and placing it over the bulb and first try, unscrewing the bulb anticlockwise. (I suggest using a glove or cloth as this will allow a little extra grip on what can sometimes be a bit fiddley and also in case the sometimes fragile bulb breaks, you are far less likely to cut your fingers off!)
The simplest way to test each bulb is to remove it and place its terminals over the positive and negative terminals of a square 9volt (PP3) battery. If the bulb is OK it will light. Place the screw-in type bulb sideways allowing the bottom lead tip to touch either pos or neg poles of the PP3 and lay the edge of the screw part and touch it against the other vacant pole.....If you have the newer type which is push-fit; After removing the bulb, bend the copper wires from the bottom of the bulb in a way so you can touch each wire on the PP3's terminal poles. The same applies, if the bulb is OK it will light.
You will eventually reach the bulb which doesn't illuminate and simply swap it for a new one.
Plug in the lights and keep your fingers crossed! :D
If the lights still don't light, try the above method again starting from where you left off.
Try it and tell me how it went. All the best.
sarahc
Posts: 125
Joined: 16 Jan 2006 10:29
Location: Sydenham

Post by sarahc »

Hi Lemonade,

I have the same problem! I have a beautiful christmas garland that sits over my dining room mantelpiece. I have got it out this year and the fairy lights that are weaving in and out of the garland are not working. I've tried all the things you suggested - checking each individual bulb on a square battery (great tip by the way!) and have replaced the fuse and it is still not working. I really don't want to give up on it just yet, any more tips?

Tis the season to be jolly, tra la la la la la la! :)

Sarah
lemonade
Posts: 144
Joined: 25 Oct 2005 23:01
Location: Croydon

Fairy Lights

Post by lemonade »

Hello Sarahc
Are your lights 240 volt mains operated or do you use them with a transformer?
Check the 3 pin plug. Make sure all the connections are tight and fit an new fuse just in case the existing one is duff. Check all bulbs are fully tightened into their individual fittings. Re-check each bulb with the PP3 and retry...sorry if you've done all of this and are still having problems.
sarahc
Posts: 125
Joined: 16 Jan 2006 10:29
Location: Sydenham

Post by sarahc »

It does not have a transformer and I have already done the things you suggested. Oh well, worth a try. Thanks for your help and advice.

:(
lemonade
Posts: 144
Joined: 25 Oct 2005 23:01
Location: Croydon

Fairy Lights

Post by lemonade »

Hello Sarahc
In that case I can only think of 2 other possible causes. Maybe you have a loose connection where the wires join the bulb holder or a wire is broken somewhere. Using a continuity checker you could find the fault easily but I'm guessing you wouldn't have one. Check the cable restraint at the bottom part of the 3 pin plug. There may be a break in the cable(s)within there. I would recommend cutting off the cable at the bottom of the 3 pin plug and stripping back the mains cable again and re-making the 3 pin plug connections and refit the plug. If there is a break it usually happens around the bottom of the plug area as fairy lights often tend not to have insulation binding the cable cores together but just individual wires.
Don't throw them away if nothing you try works. We have the technology, we can rebuild it. :lol:
....And may I be one of the first on STF to wish you a very merry Christmas :wink:
LisaCummins
Posts: 49
Joined: 30 Jul 2006 10:03
Location: Hall Drive

xmas lights

Post by LisaCummins »

Hey Lemonade,

I have the screw in bulbs. I used the method described by you by getting a PP3 battery and tested each bulb and after a short while I found the offending bulb. It was red. I do not seem to have a white coloured bulb within the chain so I replaced it with a new one which I bought from Woolies today.

The PP3 idea is a very clever one and an ingenious way to check bulbs, So thank you so much! :D

Could I trouble you for the following information/help?

Can I check house bulbs the same way if I use longer wires to connect the poles or would I get an electric shock doing so? I have a large box of spare house bulbs under the stairs and I wonder if they are working. They are not in their original packing!?!

Thanks once again Lemonade. You have made my xmas much more colourful :lol:
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