a radial, a ring, it's a kitchen thing!
- Thread starter Ejaz
- Start date
Sponsored Links
Interesting read - at risk of starting Joe (the floor tile adhesive expert) off again I can see some merit in part of his argument....
In a ring circuit fused at 32 A (MCB) each leg of the ring can be carrying up to 16 amps. So the connection at the back of a double socket can see 16 Amps going through it to sockets further round the ring and hence should be rated to carry 16A - this is before you plug anything in to that socket (either of them). So what bearing does MK's 13 Amp rating have on this? (just using MK as an example)
The heat damage seen in the pictures arises from the pin contact (plug to socket) and these can very from so tight it is difficult to get the plug in to so loose you have to waggle the plug to get a connection (Have taken a few apart in the past to squeeze up the "spring contact"- experts will be aghast but money was tight then). Seeing a heat damaged socked does not necessarily mean it has been overloaded, it may just have a loose contact/connection. I presume that the issue is that the heat build up in the unventilated space behind the unit is what causes them to be limited to 13A total output and not the current carrying capability of the conductors/contacts.
Overall if a twin/single socket is rated at 13A why are they used on circuits where they can expect to pass though 16 amps and where do MK say their component is suitable for this?
++++++++++++++++++++++++++++++++
Could someone please clarify what MK say on here
http://www.mkelectric.co.uk/PDF/technical/LOGIC_PLUS_tech.pdf
The words they use are "Current rating: 13A per socket outlet (except 3 gang which is 13 amps in total)"
If a "socket outlet" is one unit whether single, twin or triple then they do not need the qualifying statement aboput the triple as the first part of the statement would limit its load to 13A!, the implication of this is that the rating is 13 Amps per socket and not per unit, otherwise they would say 13A in total for the twin as well.
BTW - I think the version with switches on the outside looks awful!
Edit: Having read further the filtered socket IS limited to 13A for a twin so I would say that the standard twin is rated at 2x13A=26A or it would be described the same way as the filtered twin!
In a ring circuit fused at 32 A (MCB) each leg of the ring can be carrying up to 16 amps. So the connection at the back of a double socket can see 16 Amps going through it to sockets further round the ring and hence should be rated to carry 16A - this is before you plug anything in to that socket (either of them). So what bearing does MK's 13 Amp rating have on this? (just using MK as an example)
The heat damage seen in the pictures arises from the pin contact (plug to socket) and these can very from so tight it is difficult to get the plug in to so loose you have to waggle the plug to get a connection (Have taken a few apart in the past to squeeze up the "spring contact"- experts will be aghast but money was tight then). Seeing a heat damaged socked does not necessarily mean it has been overloaded, it may just have a loose contact/connection. I presume that the issue is that the heat build up in the unventilated space behind the unit is what causes them to be limited to 13A total output and not the current carrying capability of the conductors/contacts.
Overall if a twin/single socket is rated at 13A why are they used on circuits where they can expect to pass though 16 amps and where do MK say their component is suitable for this?
++++++++++++++++++++++++++++++++
Could someone please clarify what MK say on here
http://www.mkelectric.co.uk/PDF/technical/LOGIC_PLUS_tech.pdf
The words they use are "Current rating: 13A per socket outlet (except 3 gang which is 13 amps in total)"
If a "socket outlet" is one unit whether single, twin or triple then they do not need the qualifying statement aboput the triple as the first part of the statement would limit its load to 13A!, the implication of this is that the rating is 13 Amps per socket and not per unit, otherwise they would say 13A in total for the twin as well.
BTW - I think the version with switches on the outside looks awful!
Edit: Having read further the filtered socket IS limited to 13A for a twin so I would say that the standard twin is rated at 2x13A=26A or it would be described the same way as the filtered twin!
IJWS15 said:
Actually BS7671 assumes 20A per leg, as the ring isn't going to be perfectly balenced all the time, and good question
but no cigar... BS1363 AFAIK requires sockets and FCUs to be suitable for connecting to such a circuit it gets interesting when people run an unfused spur from a 20A DP switch and place the supply terminals of that switch directly on the ring because there are no requirements for the terminals to be suitable for such use, of course if you can get the manufacturer to state their products are suitable for this use (as 20A switches may be, as they may well use the same terminals as FCUS) then all is rosy... I beleive our good friend, ban did try and get an answer out of MK on this point but didn't get anything but a wishy-washy, non-commital response...
ejaz
you sound like your not a sparky and your about to do work in the kitchen, so unless you inform the local building inspector so he can check what your going to do before you start and after you've finished and certify it as safe. i agree with the second commenter in this posting, get a sparky who is part p registered to comply with the law.
also youve got a BS3036 board and you will need rcd protection unless your in a flat where your kitchen sockets can't supply equipment outside the equipotential zone
good luck
you sound like your not a sparky and your about to do work in the kitchen, so unless you inform the local building inspector so he can check what your going to do before you start and after you've finished and certify it as safe. i agree with the second commenter in this posting, get a sparky who is part p registered to comply with the law.
also youve got a BS3036 board and you will need rcd protection unless your in a flat where your kitchen sockets can't supply equipment outside the equipotential zone
good luck
Sponsored Links
No one shooting down the logic behind a twin socket being rated at 2x13A?
We've had the argument before.
It's useful if people installing them are aware of the limitation.
The overload is unlikely to occur anywhere except in a kitchen or utility room with an adjacent washing machine and tumble-drier
It's useful if people installing them are aware of the limitation.
The overload is unlikely to occur anywhere except in a kitchen or utility room with an adjacent washing machine and tumble-drier
My "concern" is as a user. MK seem to be quite happy for a double socket to carry 26A but the professional installers on here argue that this is not the case!
Joe did not post evidence to support his argument, for MK I have posted a link which supports him - now which view is correct?
i.e. where does the MK technical information limit the total load on a 13 A standard twin socket to 13A?
Joe did not post evidence to support his argument, for MK I have posted a link which supports him - now which view is correct?
i.e. where does the MK technical information limit the total load on a 13 A standard twin socket to 13A?
Well according to that MK spec sheet they rate their sockets at 13A per outlet NOT per plate!!!
(Stick thrown at wasp's nest)
(Stick thrown at wasp's nest)
ricicle said:
I have just un-wrapped an MK K2747 13A 2G DP switchsocket
13 A / 250 v is embossed on the back of the socket over the terminals
Not 2 x 13
So in my mind that suggests the terminal to front is thirteen amps.
But that is not what the MK data sheet states!
Given that the majority of problems are related to poor or overloaded contacts points - why not look at the issue from that viewpoint.
The plug contacts and cable clamps are generally the same size on triple/double/single sockets, so we have the situation where:
a) Each individual plug contact (in good condition) is capable of handling 13A (perhaps with a little allowance for heat from adjacent plugs in doubles/triples).
b) However the cable clamps are only rated at 13A, therefore each plate (triple/double/single) can only handle 13A.
QED?
The plug contacts and cable clamps are generally the same size on triple/double/single sockets, so we have the situation where:
a) Each individual plug contact (in good condition) is capable of handling 13A (perhaps with a little allowance for heat from adjacent plugs in doubles/triples).
b) However the cable clamps are only rated at 13A, therefore each plate (triple/double/single) can only handle 13A.
QED?
Surely cable clamps have to be rated at 20A - Possible max ring current - see above!
And a question for the pros, if you really believe the limit is 13A per plate, how many of you tell your customers not to use twins for more than 13A in total when you install them?
And a question for the pros, if you really believe the limit is 13A per plate, how many of you tell your customers not to use twins for more than 13A in total when you install them?
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
Sponsored Links
