I have a room that I use as a study. It has only one single mains socket
(the other is on the opposite side of the room and would require a long
trailing cable to reach the desk area).

I currently have a PC and LCD monitor, and wall-warts for various low-power
devices (router, phone, security camera, headphones etc) plugged into a
series of multi-way socket blocks (there is a 6-way with two 4-ways plugged
into it).

Obviously the overriding factor is that the total current does not exceed 13
A, and when I measured it, it was about 3A.

But is there any safety issue with lots of plugs, via multi-way socket
blocks, all going back to a single wall socket? Is there any advantage in
having the single socket changed for a dual one and plugging half the
appliances (via socket blocks) into one socket and half into the other? Is a
single socket block with 12 sockets in any way safer than a 6-way with two
4-ways plugged into it?

In article ,
NY wrote:
I have a room that I use as a study. It has only one single mains socket
(the other is on the opposite side of the room and would require a long
trailing cable to reach the desk area).

I currently have a PC and LCD monitor, and wall-warts for various
low-power devices (router, phone, security camera, headphones etc)
plugged into a series of multi-way socket blocks (there is a 6-way with
two 4-ways plugged into it).

Obviously the overriding factor is that the total current does not
exceed 13 A, and when I measured it, it was about 3A.

But is there any safety issue with lots of plugs, via multi-way socket
blocks, all going back to a single wall socket? Is there any advantage
in having the single socket changed for a dual one and plugging half
the appliances (via socket blocks) into one socket and half into the
other? Is a single socket block with 12 sockets in any way safer than a
6-way with two 4-ways plugged into it?

The safety issue is more likely to be tripping over that rat's nest. ;-)

--
*If at first you do succeed, try not to look too astonished.

Dave Plowman London SW
To e-mail, change noise into sound.

On Friday, 17 March 2017 14:43:51 UTC, NY wrote:
I have a room that I use as a study. It has only one single mains socket
(the other is on the opposite side of the room and would require a long
trailing cable to reach the desk area).

I currently have a PC and LCD monitor, and wall-warts for various low-power
devices (router, phone, security camera, headphones etc) plugged into a
series of multi-way socket blocks (there is a 6-way with two 4-ways plugged
into it).

Obviously the overriding factor is that the total current does not exceed 13
A, and when I measured it, it was about 3A.

But is there any safety issue with lots of plugs, via multi-way socket
blocks, all going back to a single wall socket? Is there any advantage in
having the single socket changed for a dual one and plugging half the
appliances (via socket blocks) into one socket and half into the other? Is a
single socket block with 12 sockets in any way safer than a 6-way with two
4-ways plugged into it?

none of those options are a safety issue


NT

NY formulated on Friday :
But is there any safety issue with lots of plugs, via multi-way socket
blocks, all going back to a single wall socket? Is there any advantage in
having the single socket changed for a dual one and plugging half the
appliances (via socket blocks) into one socket and half into the other? Is a
single socket block with 12 sockets in any way safer than a 6-way with two
4-ways plugged into it?

No safety issues, unless the adaptors are maybe cheap Chinese items.
Mainly it will look untidy, but better/safer than a long trailing lead
across a walking space.

On 17/03/2017 14:44, NY wrote:
I have a room that I use as a study. It has only one single mains socket
(the other is on the opposite side of the room and would require a long
trailing cable to reach the desk area).

I currently have a PC and LCD monitor, and wall-warts for various
low-power devices (router, phone, security camera, headphones etc)
plugged into a series of multi-way socket blocks (there is a 6-way with
two 4-ways plugged into it).

Obviously the overriding factor is that the total current does not
exceed 13 A, and when I measured it, it was about 3A.

So long as you stay inside the maximum current rating and don't start
plugging kettles and fanheaters into them it should be fine as long as
you don't trip up over the cables. You can get 8 way socket blocks.

You might find some advantage in having one smart socket so that when
the PC is powered down all the other peripherals are switched off too.
Some devices have surprisingly high standby currents...

I caught the church once with two 13A kettles plugged into a mostly
still wound up extension cable relying on their deity for protection.
The 13A plug was mad hot and the rolled up cable insulation melted!

But is there any safety issue with lots of plugs, via multi-way socket
blocks, all going back to a single wall socket? Is there any advantage
in having the single socket changed for a dual one and plugging half the
appliances (via socket blocks) into one socket and half into the other?
Is a single socket block with 12 sockets in any way safer than a 6-way
with two 4-ways plugged into it?

Apart from tripping up over the rats nest of cables no not really.

--
Regards,
Martin Brown

On 17/03/2017 14:44, NY wrote:
I have a room that I use as a study. It has only one single mains socket
(the other is on the opposite side of the room and would require a long
trailing cable to reach the desk area).

I currently have a PC and LCD monitor, and wall-warts for various
low-power devices (router, phone, security camera, headphones etc)
plugged into a series of multi-way socket blocks (there is a 6-way with
two 4-ways plugged into it).

Obviously the overriding factor is that the total current does not
exceed 13 A, and when I measured it, it was about 3A.

But is there any safety issue with lots of plugs, via multi-way socket
blocks, all going back to a single wall socket? Is there any advantage

In terms of total load its fine.

There is a more general danger with cascaded extension leads that the
earth loop impedance can rise too much, and then in the event of a fault
(say crushing a flex under a chair leg), the fault may not be cleared
fast enough to prevent something getting too hot and catching fire.
Having said that, with short leads that's unlikely.

in having the single socket changed for a dual one and plugging half the
appliances (via socket blocks) into one socket and half into the other?
Is a single socket block with 12 sockets in any way safer than a 6-way
with two 4-ways plugged into it?

It would be neater (and possibly less of a trip hazard). It would also
arguably be safer - but its hard to quantify how much. Its probably only
worth doing for neatness.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

To be honest the only issues I've found on doing this are trip hazards with
the cables and dodgy connections in the socket bars crashing things.

Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"NY" wrote in message
...
I have a room that I use as a study. It has only one single mains socket
(the other is on the opposite side of the room and would require a long
trailing cable to reach the desk area).

I currently have a PC and LCD monitor, and wall-warts for various
low-power devices (router, phone, security camera, headphones etc) plugged
into a series of multi-way socket blocks (there is a 6-way with two 4-ways
plugged into it).

Obviously the overriding factor is that the total current does not exceed
13 A, and when I measured it, it was about 3A.

But is there any safety issue with lots of plugs, via multi-way socket
blocks, all going back to a single wall socket? Is there any advantage in
having the single socket changed for a dual one and plugging half the
appliances (via socket blocks) into one socket and half into the other? Is
a single socket block with 12 sockets in any way safer than a 6-way with
two 4-ways plugged into it?

However do beware the next person plugging in a fan heater to one of the
trailing sockets and either overloading the fuse or more likely, crashing
the computer every time the thermostat operates!
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"Brian Gaff" wrote in message
news
To be honest the only issues I've found on doing this are trip hazards
with the cables and dodgy connections in the socket bars crashing things.

Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"NY" wrote in message
...
I have a room that I use as a study. It has only one single mains socket
(the other is on the opposite side of the room and would require a long
trailing cable to reach the desk area).

I currently have a PC and LCD monitor, and wall-warts for various
low-power devices (router, phone, security camera, headphones etc)
plugged into a series of multi-way socket blocks (there is a 6-way with
two 4-ways plugged into it).

Obviously the overriding factor is that the total current does not exceed
13 A, and when I measured it, it was about 3A.

But is there any safety issue with lots of plugs, via multi-way socket
blocks, all going back to a single wall socket? Is there any advantage in
having the single socket changed for a dual one and plugging half the
appliances (via socket blocks) into one socket and half into the other?
Is a single socket block with 12 sockets in any way safer than a 6-way
with two 4-ways plugged into it?

On Fri, 17 Mar 2017 14:44:03 -0000, "NY" wrote:

I have a room that I use as a study. It has only one single mains socket
(the other is on the opposite side of the room and would require a long
trailing cable to reach the desk area).

I currently have a PC and LCD monitor, and wall-warts for various low-power
devices (router, phone, security camera, headphones etc) plugged into a
series of multi-way socket blocks (there is a 6-way with two 4-ways plugged
into it).

Obviously the overriding factor is that the total current does not exceed 13
A, and when I measured it, it was about 3A.

But is there any safety issue with lots of plugs, via multi-way socket
blocks, all going back to a single wall socket? Is there any advantage in
having the single socket changed for a dual one and plugging half the
appliances (via socket blocks) into one socket and half into the other? Is a
single socket block with 12 sockets in any way safer than a 6-way with two
4-ways plugged into it?


It's fine, and there is even an argument that says a trailing socket
bar is safer for wall-warts than plugging them directly into wall
sockets.

You sometimes can't be sure that the approval stamps etc. on imported
wall-warts are genuine, and without breaking them open there is no way
to see if they even contain an internal fuse. The wall socket is
probably fused at 32A at the CU, you wouldn't want that to be the only
overload protection for your wallwarts. at least with a trailing bar
you know there is a 13A fuse in the plug, and in your case I would
swap it out for a 5A for further protection.


--

Graham.
%Profound_observation%

On 17/03/2017 14:44, NY wrote:

But is there any safety issue with lots of plugs, via multi-way socket
blocks, all going back to a single wall socket? Is there any advantage
in having the single socket changed for a dual one and plugging half the
appliances (via socket blocks) into one socket and half into the other?
Is a single socket block with 12 sockets in any way safer than a 6-way
with two 4-ways plugged into it?

Leave it all plugged into one socket then there won't be any confusion
if you need to kill the power quickly.

Bill

On Friday, 17 March 2017 14:43:51 UTC, NY wrote:
Is a single socket block with 12 sockets in any way safer
than a 6-way with two 4-ways plugged into it?

I think so, because of earth loop impedance as Mr Rumm states. I made a 10-way block with 5 x double sockets and a plank.

Or sir may wish to spend £25 quid on a ready made one

http://cpc.farnell.com/brennenstuhl/...-3m/dp/PL14407

or less

http://cpc.farnell.com/pro-elec/2710...usb/dp/PL15128

Owain

On Fri, 17 Mar 2017 16:55:19 +0000, John Rumm wrote:

there is a more general danger with cascaded extension leads that the
earth loop impedance can rise too much, and then in the event of a fault
(say crushing a flex under a chair leg), the fault may not be cleared
fast enough to prevent something getting too hot and catching fire.
Having said that, with short leads that's unlikely.

Surely that is what the 13A plug fuse is for?
2.5 Ohms max ZS for a 13A fuse, almost double the requirement for a 32A
circuit.

On 17/03/2017 19:39, Alan wrote:
On Fri, 17 Mar 2017 16:55:19 +0000, John Rumm wrote:

there is a more general danger with cascaded extension leads that the
earth loop impedance can rise too much, and then in the event of a fault
(say crushing a flex under a chair leg), the fault may not be cleared
fast enough to prevent something getting too hot and catching fire.
Having said that, with short leads that's unlikely.

Surely that is what the 13A plug fuse is for?

It much depends on the lead lengths (and a little on the quality of the
sockets etc). In the case of short multi-way leads its very unlikely to
be an issue unless the circuit feeding the socket is well out of spec.

2.5 Ohms max ZS for a 13A fuse, almost double the requirement for a 32A
circuit.

For a 13A fuse you probably want 95A of fault current to be sure of
being inside the typically required 0.4 secs disconnect time. So that
means about 2.4 Ohms at 230V. You could lose 1.44 ohms off that before
you even get to the plug on 32A circuit at maximum length.

So 40m is about your limit. Use multiple cascaded leads and it could be
quite significantly less due to the extra plug and socket connections.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

"NY" wrote in message
...
I have a room that I use as a study. It has only one single mains socket
(the other is on the opposite side of the room and would require a long
trailing cable to reach the desk area).

I currently have a PC and LCD monitor, and wall-warts for various
low-power devices (router, phone, security camera, headphones etc) plugged
into a series of multi-way socket blocks (there is a 6-way with two 4-ways
plugged into it).

Obviously the overriding factor is that the total current does not exceed
13 A, and when I measured it, it was about 3A.

But is there any safety issue with lots of plugs, via multi-way socket
blocks, all going back to a single wall socket?

Nope, that’s how I do mine, but with much bigger socket blocks.
All of which plug into another one which plugs into the wall socket.

Is there any advantage in having the single socket changed for a dual one
and plugging half the appliances (via socket blocks) into one socket and
half into the other?

Nope.

Is a single socket block with 12 sockets in any way safer than a 6-way
with two 4-ways plugged into it?

Nope.

One thing you do find is that some socket blocks are better
than others with more space around the sockets for the bigger
wall warts. Not such a problem now with most of the wall warts
being switch mode and fitting fine even in the more socket blocks
which have more closely spaced sockets.

On Friday, 17 March 2017 14:43:51 UTC, NY wrote:
I have a room that I use as a study. It has only one single mains socket
(the other is on the opposite side of the room and would require a long
trailing cable to reach the desk area).
...
Is a
single socket block with 12 sockets in any way safer than a 6-way with two
4-ways plugged into it?

Electrically, I expect no problem. Ensure that the other socket is visible and accessible, and that anyone who has cause, real or imaginary, to use electricity in that room for other purposes - handymen, family, friends, yourself, etc. - uses only that socket.

As you seem to be doing, daisy-chain as little as reasonably possible.

If possible, mount all of the distribution on fixed boards. Group the connections so that whatever you want always on is separate from what you switch off at night, etc.

Be aware that one can now buy small three-way switched adaptors - cubes with one male BS1363, three females, a trio of switches, one blank side.

ASIDE - caveat on adaptors : I have one - 4-way switched plus straight-through - from a moderately respectable supplier. Electrically, seems OK. But I ran a 2kW fan heater on the straight-through for a while - and later found that the heater would not unplug from the adapter, except by tool-assisted brute force. Evidently one pin had made poor contact, and the body of the adaptor was thermoplastic.

--
(c) Dr. S. Lartius, UK. Gmail: dr.s.lartius@

On 17/03/2017 14:44, NY wrote:
I have a room that I use as a study. It has only one single mains socket
(the other is on the opposite side of the room and would require a long
trailing cable to reach the desk area).

I currently have a PC and LCD monitor, and wall-warts for various
low-power devices (router, phone, security camera, headphones etc)
plugged into a series of multi-way socket blocks (there is a 6-way with
two 4-ways plugged into it).

Obviously the overriding factor is that the total current does not
exceed 13 A, and when I measured it, it was about 3A.

But is there any safety issue with lots of plugs, via multi-way socket
blocks, all going back to a single wall socket? Is there any advantage
in having the single socket changed for a dual one and plugging half the
appliances (via socket blocks) into one socket and half into the other?
Is a single socket block with 12 sockets in any way safer than a 6-way
with two 4-ways plugged into it?

From what I have heard, it is not recommended to daisychain multiple
multi-way sockets as it can increase the earth impedance and breach
fault trip times. Two into one won't be a problem though.

SteveW

"Steve Walker" wrote in message
news
On 17/03/2017 14:44, NY wrote:
I have a room that I use as a study. It has only one single mains socket
(the other is on the opposite side of the room and would require a long
trailing cable to reach the desk area).

I currently have a PC and LCD monitor, and wall-warts for various
low-power devices (router, phone, security camera, headphones etc)
plugged into a series of multi-way socket blocks (there is a 6-way with
two 4-ways plugged into it).

Obviously the overriding factor is that the total current does not
exceed 13 A, and when I measured it, it was about 3A.

But is there any safety issue with lots of plugs, via multi-way socket
blocks, all going back to a single wall socket? Is there any advantage
in having the single socket changed for a dual one and plugging half the
appliances (via socket blocks) into one socket and half into the other?
Is a single socket block with 12 sockets in any way safer than a 6-way
with two 4-ways plugged into it?

From what I have heard, it is not recommended to daisychain multiple
multi-way sockets as it can increase the earth impedance and breach fault
trip times. Two into one won't be a problem though.

No, I would only have two levels of multi-way sockets and not go beyond
that. I much prefer flat multi-way blocks rather than the older style of
cubic blocks that can feed three plugs, because I've found those sometimes
running a bit hot with something like a 1.4 kW vacuum cleaner.

Sadly our house is of an age where all the sockets are single rather than
dual, and are not very sensibly placed within rooms. For example the bedroom
that I use as a study has only one wall where a bedhead could be placed,
because of windows on one wall, fitted wardrobe on another and chimney
breast from fire downstairs on third. And yet neither of the sockets in that
room are on the bed head wall (for reading lamps) and one is behind a door
where it is unlikely any device (lamp, etc) might be placed. Hence my
problem with having to power all the paraphernalia of modern life from a
single socket (the one behind the door is no use to man nor beast, except
for transient things like plugging in the hoover).

Oh, and I'm aware of the rat's nest problem. I really *must* coil/bunch up
the longer cables to keep them as far away as possible from my feet under
the desk. Trouble is, as soon as you do that, you find the you need to
unplug and move something, hence needing to undo the Velcro ties that are
keeping everything tidy - I think it's a sub-clause of Sod's Law that you
never need to move anything until you've tied all the cables back to keep
them tidy :-)

In article ,
Steve Walker wrote:
From what I have heard, it is not recommended to daisychain multiple
multi-way sockets as it can increase the earth impedance and breach
fault trip times. Two into one won't be a problem though.

Best not to daisy chain, but feed as radials from one.

--
*Why are a wise man and a wise guy opposites? *

Dave Plowman London SW
To e-mail, change noise into sound.

On 18/03/2017 12:16, NY wrote:

Oh, and I'm aware of the rat's nest problem. I really *must* coil/bunch
up the longer cables to keep them as far away as possible from my feet
under the desk. Trouble is, as soon as you do that, you find the you
need to unplug and move something, hence needing to undo the Velcro ties
that are keeping everything tidy - I think it's a sub-clause of Sod's
Law that you never need to move anything until you've tied all the
cables back to keep them tidy :-)

If you're feeling keen, you could shorten the leads to the correct
length so no velcro or coiling/bunching.

In article ,
John Rumm writes:
On 17/03/2017 19:39, Alan wrote:
On Fri, 17 Mar 2017 16:55:19 +0000, John Rumm wrote:

there is a more general danger with cascaded extension leads that the
earth loop impedance can rise too much, and then in the event of a fault
(say crushing a flex under a chair leg), the fault may not be cleared
fast enough to prevent something getting too hot and catching fire.
Having said that, with short leads that's unlikely.

Surely that is what the 13A plug fuse is for?

It much depends on the lead lengths (and a little on the quality of the
sockets etc). In the case of short multi-way leads its very unlikely to
be an issue unless the circuit feeding the socket is well out of spec.

2.5 Ohms max ZS for a 13A fuse, almost double the requirement for a 32A
circuit.

For a 13A fuse you probably want 95A of fault current to be sure of
being inside the typically required 0.4 secs disconnect time. So that
means about 2.4 Ohms at 230V. You could lose 1.44 ohms off that before
you even get to the plug on 32A circuit at maximum length.

So 40m is about your limit. Use multiple cascaded leads and it could be
quite significantly less due to the extra plug and socket connections.

You need to add the resistance of the appliance flex too.
The rules don't really allow for extension leads.
Hence the max length of an extension lead is 12m for 1.25mm²,
and 15m for 1.5mm² cable (PAT testing guidelines).
Rules don't allow for adding of contact and fuse resistances
either, hence a reason not to daisy-chain them, and they're
almost never the quality of a proper 13A wall outlet.

I managed to pick up a few from an old employer for peanuts
where the extension lead sockets are actually MK 13A round
panel mounting sockets, but these were damn expensive to make,
and the company manufacturered them itself. There was enough
space inside to add a mains relay per socket, so I have each
socket individually switchable via my home automation.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 18/03/2017 14:47, Andrew Gabriel wrote:
In article ,
John Rumm writes:
On 17/03/2017 19:39, Alan wrote:
On Fri, 17 Mar 2017 16:55:19 +0000, John Rumm wrote:

there is a more general danger with cascaded extension leads that the
earth loop impedance can rise too much, and then in the event of a fault
(say crushing a flex under a chair leg), the fault may not be cleared
fast enough to prevent something getting too hot and catching fire.
Having said that, with short leads that's unlikely.

Surely that is what the 13A plug fuse is for?

It much depends on the lead lengths (and a little on the quality of the
sockets etc). In the case of short multi-way leads its very unlikely to
be an issue unless the circuit feeding the socket is well out of spec.

2.5 Ohms max ZS for a 13A fuse, almost double the requirement for a 32A
circuit.

For a 13A fuse you probably want 95A of fault current to be sure of
being inside the typically required 0.4 secs disconnect time. So that
means about 2.4 Ohms at 230V. You could lose 1.44 ohms off that before
you even get to the plug on 32A circuit at maximum length.

So 40m is about your limit. Use multiple cascaded leads and it could be
quite significantly less due to the extra plug and socket connections.

You need to add the resistance of the appliance flex too.

Indeed, although that's a bit harder to factor without knowing what is
plugged in.

The rules don't really allow for extension leads.
Hence the max length of an extension lead is 12m for 1.25mm²,
and 15m for 1.5mm² cable (PAT testing guidelines).

Yup, I expect my 50m 1.5mm^2 JoJo lead is probably out of spec more
often than its in it! ;-)

Rules don't allow for adding of contact and fuse resistances
either, hence a reason not to daisy-chain them, and they're
almost never the quality of a proper 13A wall outlet.

I managed to pick up a few from an old employer for peanuts
where the extension lead sockets are actually MK 13A round
panel mounting sockets, but these were damn expensive to make,
and the company manufacturered them itself. There was enough
space inside to add a mains relay per socket, so I have each
socket individually switchable via my home automation.

Handy...


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 17/03/2017 14:44, NY wrote:
I have a room that I use as a study. It has only one single mains socket
(the other is on the opposite side of the room and would require a long
trailing cable to reach the desk area).

I currently have a PC and LCD monitor, and wall-warts for various
low-power devices (router, phone, security camera, headphones etc)
plugged into a series of multi-way socket blocks (there is a 6-way with
two 4-ways plugged into it).

Obviously the overriding factor is that the total current does not
exceed 13 A, and when I measured it, it was about 3A.

But is there any safety issue with lots of plugs, via multi-way socket
blocks, all going back to a single wall socket? Is there any advantage
in having the single socket changed for a dual one and plugging half the
appliances (via socket blocks) into one socket and half into the other?
Is a single socket block with 12 sockets in any way safer than a 6-way
with two 4-ways plugged into it?

I have one of these under my desk, it will take 10 plugs or chargers.
The socket it connects to is inaccessible without moving the desk so
this also has a mains power switch.

https://www.dropbox.com/s/2o2ppvx2az...2010.jpeg?dl=0

Mike

In article ,
Muddymike wrote:
I have one of these under my desk, it will take 10 plugs or chargers.
The socket it connects to is inaccessible without moving the desk so
this also has a mains power switch.


I fitted a wall mounted switched FCU from the ring close to this computer.
The socket switched by that in a convenient place to feed the rats nest.

--
*You can't teach an old mouse new clicks *

Dave Plowman London SW
To e-mail, change noise into sound.