converting single to triple socket

[davek]

Hi, I'm thinking of converting several single sockets to triples using the surface-mounted conversion kits from Screwfix. The house was built in the 1960s and there just aren't enough sockets for my 21st century needs - I believe all the sockets I want to convert are on the ring main rather than spurs. But I have a couple of questions...

- will the new sockets be rated 13A each or a total of 13A for the three, as if I had just used a plug-in adapter?

- is this likely to overload the ring main or cause any other problems of this nature?

thanks in advance for any advice,

d.

[Christian McArdle]

Triples will be rated at 13A total. This will be enforced by a fuse. Double sockets are rated at 20A total, with a max 13A each, but the 20A cap is not enforced.

It will reduce the potential point load of a socket point on the ring main.

Your 21st century needs, if they relate to audio visual equipment) are likely to be lots of points taking very little current each.

If you are talking about kitchen appliances, things are very different and you should not install a triple socket to run laundry or cooking appliances.

Christian.

[zikkimalambo]

IMHO These converters are ugly and don't acheive anything that a 4 way adapter and or extention lead couldn't acheive better. In theory you have to watch out for earth imedence getting too high with such combinations, but I wouldn't worry too much.

We passed the early days of this millenium house sitting in a 60's bungalow which generally (apart from the kitchen) has one single 13A socket per room. Ext leads and or 4 ways dealt with our (admittedly small) collection of gadgets.

The only thing i'd do different with hindsight is to use a 2 way adapter made from a double 13A socket, a piece of heavy duty flex and a

13A Plug, rather than a cheap 4 way in order to run the TV and the Tumble Frier off the same socket.

Tumble Frier was a typo, but if you'd seen the way it welded it's plug to the socket on the 4 way, perhaps it's an appropriate one!

[davek]

Bah! So my proposed solution doesn't really solve my problem, does it?

Yes, that's the gist of it, but even though the various bits of kit take up very little current individually, they add up to more than can be provided by the sockets I've got... (eg the room that is being used as my office has precisely one socket, which is being supplemented at the moment by an extension cable to a socket in the next room)

And there are one or two current-hungry items among them, eg a LCD monitor.

thanks for your help - even if it's not what I wanted to hear...

d.

[davek]

Hmm. Thing is, I'm after a way to increase the overall current available to each room - if converting the sockets won't achieve this then they are no use to me, and I agree - in this case, extension cables/adapters are a preferable solution.

We've only just moved in and have had an electrical survey carried out. There is plenty of work that needs doing and we are planning on getting extra sockets put in at the same time (by a qualified electrician who can get all the work appropriately certified, of course) but for various reasons we can't get the work done just yet and really I'm hoping for a short-term fix to my problem that doesn't involve long extension cables trailing all over the house... any suggestions?

Unfortunately, my collection of gadgets is not so small... The main problem is having two computers plus assorted peripherals in the office, and only one socket to share between them. Elsewhere in the house we can just about make do with what we've got for the time being.

LOL

Thanks for your helpful comments,

d.

[Harry Bloomfield]

davek used his keyboard to write :

They will be rated at 13A each, though obviously they cannot all provide for a 13A load at the same time - 3x 13A = 39A, your MCB trips at 32A.

The ring main works on the basis that it is unlikely you might need to draw this amount of current in such a small area as covered by the ring circuit.

[Harry Bloomfield]

davek pretended :

Are you guessing at the load, or actually measuring it?

LCD monitors are not usually considered to be current hungry. My 42" plasma screen only uses 220w. I could run around 12 to 15 of these from a single 13A outlet.

[davek]

Erm... I worked it out by adding up the rating for each device according to the size of the fuse fitted, which is how I was told to do it, once upon a time. I haven't actually measured anything. I suppose that counts as guessing?

OK, that's good news - the reason I assumed it was current-hungry is because the plug on the power lead came fitted with a 13A fuse.

I guess perhaps I was taught wrong, or maybe I misunderstood what I was told... I can see I am going to have to get better educated.

d.

[davek]

(Actually 30A as it's a cartridge fuse until we get it upgraded.)

Right. I shall now go away and read a book or something, and make sure I actually know what I'm talking about next time I ask a question about electricals... :-)

d.

[Harry Bloomfield]

davek explained on 22/09/2005 :

It should certainly not have come fitted with a 13A fuse, 1 or 3A would have been more appropriate. The idea of the fuse is to protect the flex and the appliance from fault currents. It should therefore be as low in value as possible, such that it just comfortably copes with the load and any surge at switch on.

The best way to calculate the loading of each appliance is to look at the rating plate. This should give the maximum wattage for each appliance and from this you can calculate the maximum current.

[Owain]

One which I suggest should be added to the official uk.d-i-y lexicon

Owain

[Owain]

Rather drastically over-estimating.

You have to consider the fuse when sizing flex or cable, but as fuses for plugs only come in 3A and 13A (5A for FCUs) it's a rather crude measurement, especially as some appliances will consume only a few hundred watts but need a 13A fuse because of high in-rush current.

The fuse on the power lead really only has to protect the lead, and all modern power leads should be good for 16A as that's what they use with unfused plugs on the conninent.

Owain

[Owain]

They should all run happily enough off one 13A, but cascading 4-way blocks brings its own problems.

have some nice multiway power strips (I have no financial interest in this company despite suggesting them twice in as many days) or you could make one up using

13A sockets, cable grip/gland, heavy 13A flex.

Owain

[John Rumm]

other than less trailing leads (trip hazards), and lower earth impedances...

Extension leads will be 13A fused as well, so you will be no better off with them. Are you sure you actually want more "current" in each room? Given that most modern devices have modest current requirements. The usual problem is just lack of sockets.

Why "of course", this is a DIY group ;-)

Short term, multiway extensions may be the answer if used sensibly. Cables can be tacked to skirtings etc to keep the leads out of the way. Don't stick high current devices on them, and don't cascade them.

Most computer kit is very low current, and so well suited to runing from a multiway extension. Much of it is powered by wall wart type PSUs that probably don't have an earth either.

[John Rumm]

Huh? Under 50W I bet! (even a big CRT is typically less than 200W these days)

Add up the power consumption figures on the various gadgets. If the total comes to less than 3000W then you should be ok.

(If it comes to more than 3000W, I suggest you throw out the computer and get a nice new one that uses integrated circuits in place of the valves in your current one!)

[John Rumm]

Not guessing as such, but it will give you a figure way over the actual consumption of the devices.

Good chance it has the wrong fuse then....

I can see the logic of why you were told that - but it is rather simplistic for modern usage which tends to be lots of low power devices rather than a few big ones.

If you were talking about your tumble driver, toaster and kettle, then the adding fuses approach is likely to be less inaccurate.

A better way is to look at the power consumption in watts for each device. If you divide that figure by 240 you will get the current being drawn in Amps. Even this will tend to over estimate the requirement since the figures quoted will tend to be the maximum figures rather than the normal ones. (i.e. a computer PSU may be rated at 300W, but if you measure it there is a fair chance it will be taking less than 140W most of the time).

[Rob Morley]

A couple of 6-gang extensions plugged into a two way adapter plugged into your single socket will work fine for computer stuff - just don't start plugging in toasters and kettles or daisy-chaining extension leads.

[Owain]

I was wondering how much power one of these would need ...

that I've got room in the bedroom for a PC the size of a vending machine, but I've always wanted to set up a home media server / PVR ...

Owain

[Capitol]

As Christian said, the 3 way sockets are fused at 13A for the total current of all 3. Personally, nowadays indoors, I use the rather nice vertical 10 way socket extenders available from CPC (part no. PL02450, as these are very desk/floor space efficient. Combined with a 3 way converter socket, you can achieve 30 outlets!! Worth a try? The only power hungry IT equipment I have found is a laser printer which can hit

1.5KW on warm up. The rest is very low power.

Regards Capitol

[Rob Morley]

So is screwing regular 4-gang or 6-gang extensions to the wall, and you can spread them around where you need them.