Just picked up a new fridge, and it says you shouldn't plug it into an
extension lead...

Why the hell not ?

In article ,
Colin Wilson o.uk writes:
Just picked up a new fridge, and it says you shouldn't plug it into an
extension lead...

Why the hell not ?

Is it a big American one?
Have you seen their extension leads? ;-)

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

On Sat, 10 Oct 2009 18:54:50 +0100, Colin Wilson
o.uk wrote:

Just picked up a new fridge, and it says you shouldn't plug it into an
extension lead...

Why the hell not ?

Generally it's bad practise .

Plugged into a socket out of sight and sound of the fridge (IE round a
corner) it could be unplugged by the cleaner ( or somebody ) and get
plugged back in at the end of her shift and nobody would ever know it
had spent a few hours warming up. Potentially this could happen every
day.

The compressor could take a big surge at start up, many that do are
susceptible to low mains voltage. It could potentially sit there in a
stalled rotor condition, 'till it burnt out.

The fridge may come with the same set of instructions as it does when
sold into a different market which uses radial wiring and not ring
mains.

The extension lead may be too feeble for the job.

Or perm any 1, 2 , or 3 out of 4.

Derek

Is it a big American one?

Nah, standard under-counter larder fridge

Have you seen their extension leads? ;-)

Not recently :-}

Perhaps because most fridge compressors have induction motors. These can
pull quite high inrush currents (fom 5*In to 9*In). Add too much extra
resistance and the motor may stall on startup.

Sounds like a reasonable explanation to me - thanks :-)

That said, it wouldn't be dangling off a reel, it'd be the shortest
uncoiled extension / adaptor I could find just to assist access, as
the socket is behind an adjacent kitchen unit - to get the old one out
a few months ago I had to cut the plug off it, as there was no way to
get it out otherwise !

(aka no inductive reactance to worry about)

On Sat, 10 Oct 2009 19:20:02 +0100
Derek Geldard wrote:

On Sat, 10 Oct 2009 18:54:50 +0100, Colin Wilson
o.uk wrote:

Just picked up a new fridge, and it says you shouldn't plug it into an
extension lead...

Why the hell not ?

Generally it's bad practise .

Plugged into a socket out of sight and sound of the fridge (IE round a
corner) it could be unplugged by the cleaner ( or somebody ) and get
plugged back in at the end of her shift and nobody would ever know it
had spent a few hours warming up. Potentially this could happen every
day.

Reminds me of a problem we had at work years ago. The computer (a
DEC VAX) rebooted every night, we could not work out why. Turns out the
cleaner's large backside hit the reset button when she bent over to
change the nozzle on her vacuum-cleaner. Every night!

Cleaners are a menace around electrics.

R.

On Oct 10, 8:45*pm, Colin Wilson
o.uk wrote:
That said, it wouldn't be dangling off a reel, it'd be the shortest
uncoiled extension / adaptor I could find just to assist access, as
the socket is behind an adjacent kitchen unit - to get the old one out
a few months ago I had to cut the plug off it, as there was no way to
get it out otherwise !

Just stick it on 1.5mm Arctic - ok for 16A & low resistance.
Remember even a small "larder" fridge/freezer is fused at 13A.

Alternatively just create a spur off the existing kitchen unit for it.

On Oct 10, 6:54*pm, Colin Wilson
o.uk wrote:
Just picked up a new fridge, and it says you shouldn't plug it into an
extension lead...

Why the hell not ?

Its fine to do that. Saying not to can cut their customer calls
slightly though, since some issues will turn out to be due to a faulty
extension lead.

Startup current isn't an issue. A 1/4A fridge might eat 10x = 2.5A or
16x = 4A during startup, and even bell wire can handle that.


NT

On Sat, 10 Oct 2009 18:07:34 +0000, Andrew Gabriel wrote:
Is it a big American one?
Have you seen their extension leads? ;-)

:-)

You should see the one we have for our drier - like an elephant trunk it
is...

Alternatively just create a spur off the existing kitchen unit for it.

There's a spur already behind it, but it's already sticking out of the
unit, and putting the plug in there would make it protrude by another
half an inch

cut the plug off the new one, feed the flex through the hole then, and
fit a new plug.

The flex is too short to do that already (it barely reaches the top of
the fridge as it is...

Dispose of the cut-off plug carefully.

Nah, give it to the kids to play with :-p

"Colin Wilson" o.uk wrote
in message ...
cut the plug off the new one, feed the flex through the hole then, and
fit a new plug.

The flex is too short to do that already (it barely reaches the top of
the fridge as it is...

http://www.maplin.co.uk/Module.aspx?ModuleNo=13144

Andrew Gabriel wrote:
In article ,
Colin Wilson o.uk
writes:
Just picked up a new fridge, and it says you shouldn't plug it into
an extension lead...

Why the hell not ?

Is it a big American one?
Have you seen their extension leads? ;-)

Ferzacerly. Amercans have yet to discover exactly how electricity should be
provided.

I have an American ectension lead, looks more like a 1/2" garden hose.

Americans use gasoline powered presure washers.

Americans use truck mounted (engine driven) carpet cleaning machines.

Americans use propane powered floor polishers in shopping malls.

The reason? Their poxy useless 115v spur type electrical system can't hack
anything else.

I worked for an American floor cleaning machine company once. We ended up
sending them a 13 amp double socket outlet and a 13 amp plug top with
relevant details & they were completely & utterly gobsmacked by the concept.


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

"Colin Wilson" o.uk wrote
in message ...
Just picked up a new fridge, and it says you shouldn't plug it into an
extension lead...

Why the hell not ?

It's ********.

Bill

On Sat, 10 Oct 2009 21:14:05 +0100, TheOldFellow wrote:

On Sat, 10 Oct 2009 19:20:02 +0100
Derek Geldard wrote:

On Sat, 10 Oct 2009 18:54:50 +0100, Colin Wilson
o.uk wrote:

Just picked up a new fridge, and it says you shouldn't plug it into an
extension lead...

Why the hell not ?

Generally it's bad practise .

Plugged into a socket out of sight and sound of the fridge (IE round a
corner) it could be unplugged by the cleaner ( or somebody ) and get
plugged back in at the end of her shift and nobody would ever know it
had spent a few hours warming up. Potentially this could happen every
day.

Reminds me of a problem we had at work years ago. The computer (a
DEC VAX) rebooted every night, we could not work out why. Turns out the
cleaner's large backside hit the reset button when she bent over to
change the nozzle on her vacuum-cleaner. Every night!

Cleaners are a menace around electrics.

R.

Had similar at work, but cleanereither unplugging a 19" cabinet with 12"
discs in it or plugging a polisher into the next socket - on a UPS!
We fitted Electrax plugs and sockets on the UPS circuits - the cleaners
couldn't even manage to unplug them!

BTW, Electax are good for 'secure' plugging and are completely
child-/rep./engineer-proof

http://uk.farnell.com/mem/az0010/soc...85?Ntt=538-085
--
Peter.
The head of a pin will hold more angels if
it's been flattened with an angel-grinder.

"Colin Wilson" o.uk wrote
in message ...
Perhaps because most fridge compressors have induction motors. These can
pull quite high inrush currents (fom 5*In to 9*In). Add too much extra
resistance and the motor may stall on startup.

Sounds like a reasonable explanation to me - thanks :-)

That said, it wouldn't be dangling off a reel, it'd be the shortest
uncoiled extension / adaptor I could find just to assist access, as
the socket is behind an adjacent kitchen unit - to get the old one out
a few months ago I had to cut the plug off it, as there was no way to
get it out otherwise !

(aka no inductive reactance to worry about)

I cannot see a small extension like that causing a problem.

Adam

On Oct 11, 1:58*am, John Rumm wrote:
NT wrote:
Startup current isn't an issue. A 1/4A fridge might eat 10x = 2.5A or
16x = 4A during startup, and even bell wire can handle that.

Its not damage to the cable you are worried about, but drop in voltage.


Yup.

0.5mm2 bell wire has 88mV drop per amp per metre. A modern 60w fridge
thus sees 22mV per metre drop.

Lets say the lead is a huge 10m long, giving 0.44v total drop. So the
230v rated fridge, which must be capable of operating on the lower
limit of French 220v, ie only a bit over 200v, thus sees 240v - 0.44v
= 239.56v.

Sensible extension leads have even less effect.


NT

"Colin Wilson" o.uk wrote
in message ...
cut the plug off the new one, feed the flex through the hole then, and
fit a new plug.

The flex is too short to do that already (it barely reaches the top of
the fridge as it is...

Dispose of the cut-off plug carefully.

Nah, give it to the kids to play with :-p

I often see inappropriate instructions, almost all seem to be someone making
H&S up as they go along. This one falls into that category. Unless it's a
big, industrial, FO fridge even the startup current can't be that much.

Of course from their POV an extension lead means:
Unknown cable sizing
More connections
Possibly coiled cable
All of those could lead to problems.

I'm sure you already do but I'll say it anyway, When cutting off a plug
always remove the fuse.

On Sat, 10 Oct 2009 18:54:50 +0100, Colin Wilson
o.uk wrote:


Just picked up a new fridge, and it says you shouldn't plug it into an
extension lead...

Why the hell not ?

Elfin safety paranoia. If the extension lead is left coiled on a drum
it will overheat at a small fraction of its rated current. Fridges go
on and off by themselves so the overheating and possible subsequent
combustion may take place at night or when no one is in.

On Sun, 11 Oct 2009 02:00:30 -0700 (PDT), NT
wrote:


Its not damage to the cable you are worried about, but drop in voltage.


Yup.

0.5mm2 bell wire has 88mV drop per amp per metre. A modern 60w fridge
thus sees 22mV per metre drop.

Lets say the lead is a huge 10m long, giving 0.44v total drop. So the
230v rated fridge, which must be capable of operating on the lower
limit of French 220v, ie only a bit over 200v, thus sees 240v - 0.44v
= 239.56v.

Sensible extension leads have even less effect.


Where do you get that amps figure from ?

What is your figure for the inrush current?

You have measured it ?

From
http://wiki.answers.com/Q/Typical_current_draw_for_a_refrigerator

Typical current draw for a refrigerator?

My 20 year old upright freezer is about 10A starting, 3.27 amp running
(263 watts)

My 10 year old fridge is very similar

(Figures from the US)

Derek

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember Colin Wilson
o.uk saying something
like:

Just picked up a new fridge, and it says you shouldn't plug it into an
extension lead...

Why the hell not ?

Load of ********. It'll be fine if it's a short lead and not coiled.

Reminds me of a problem we had at work years ago. The computer (a
DEC VAX) rebooted every night, we could not work out why. Turns out the
cleaner's large backside hit the reset button when she bent over to
change the nozzle on her vacuum-cleaner. Every night!

Cleaners are a menace around electrics.


Ever seen nurses thumping in crooked plugs in a hospital.

"Grimly Curmudgeon" wrote in message
...
We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember Colin Wilson
o.uk saying something
like:

Just picked up a new fridge, and it says you shouldn't plug it into an
extension lead...

Why the hell not ?

Load of ********. It'll be fine if it's a short lead and not coiled.

I agree

Adam

On Oct 11, 10:40*am, Derek Geldard wrote:
On Sun, 11 Oct 2009 02:00:30 -0700 (PDT), NT
wrote:

Its not damage to the cable you are worried about, but drop in voltage..

Yup.

0.5mm2 bell wire has 88mV drop per amp per metre. A modern 60w fridge
thus sees 22mV per metre drop.

Lets say the lead is a huge 10m long, giving 0.44v total drop. So the
230v rated fridge, which must be capable of operating on the lower
limit of French 220v, ie only a bit over 200v, thus sees 240v - 0.44v
= 239.56v.

Sensible extension leads have even less effect.

Where do you get that amps figure from ?

from the 60w typical rating. Admittedly I ignored power factor, which
will add maybe 25% on, but makes no qualitative difference to the
outcome.


What is your figure for the inrush current?

You have measured it ?

From
http://wiki.answers.com/Q/Typical_current_draw_for_a_refrigerator

*Typical current draw for a refrigerator?

My 20 year old upright freezer is about 10A starting, 3.27 amp running
(263 watts)

My 10 year old fridge is very similar

(Figures from the US)

Derek

US fridges are different animals to UK ones. Typical run power on a
new machine here is around 60w. At 240v thats 0.25A, or a bit more
considering power factor.

If we use your ratio of 3:1 for startup current, then the Vdrop during
startup would be about 1.3v, leaving 238.7v for the compressor that's
rated to run on 220v nominal as well as 240v nominal.

Even if we used an aggressive figure of 16x start current, 16x 0.44v =
7v drop, leaving the machine 233v, when its rated to run ok at a bit
over 200v.

http://wiki.diyfaq.org.uk/index.php?...s#230v_or_240v

Numbers reveal the truth.


NT

On Oct 11, 10:27*am, Peter Parry wrote:
On Sat, 10 Oct 2009 18:54:50 +0100, Colin Wilson

o.uk wrote:

Just picked up a new fridge, and it says you shouldn't plug it into an
extension lead...

Why the hell not ?

Elfin safety paranoia. *If the extension lead is left coiled on a drum
it will overheat at a small fraction of its rated current. *Fridges go
on and off by themselves so the overheating and possible subsequent
combustion may take place at night or when no one is in.

Even bell wire could cope with an intermittent quarter amp load
coiled.


NT

On Sun, 11 Oct 2009 12:01:20 +0100, "John"
wrote:


Reminds me of a problem we had at work years ago. The computer (a
DEC VAX) rebooted every night, we could not work out why. Turns out the
cleaner's large backside hit the reset button when she bent over to
change the nozzle on her vacuum-cleaner. Every night!

Cleaners are a menace around electrics.


Ever seen nurses thumping in crooked plugs in a hospital.


Nurses are not a patch on 20 y. old female radiographers, (although we
came across a few nurses who used to stand at the lab door and just
throw the blood at their Blood Gas Analyser )

- enormous steel handles just "come off" in their hands.

R.N. Captain overheard at a trade exhibiton in 1970 about the (very
first Philips VCRs) ...

It's not "Sailor Proof").

Derefgk

Calvin Sambrook wrote:

I often see inappropriate instructions, almost all seem to be someone
making H&S up as they go along.

Latest one I came across is the warning label stuck on the side of a brand
new Ikea stainless steel kitchen sink.

"This appliance must be earth bonded (IEE regulations 15th edition 1981)"

People making dogmatic H&S utterances really should try to keep up to date.
I don't know if earth bonding kitchen sinks was a requirement in the 15th
edition (it was in the old 13th edition that I still have a copy of) but it
hasn't been needed since the 16th.

--
Mike Clarke

On Sun, 11 Oct 2009 04:16:52 -0700 (PDT), NT
wrote:

Even bell wire could cope with an intermittent quarter amp load
coiled.

A. You are assuming that's all that is plugged in.
B You are forgetting the Elfin Safety writer had probably stopped
taking the dried green frog pills.

It never pays to confuse Elfin Safety with reality.

Peter Parry wrote:
On Sat, 10 Oct 2009 18:54:50 +0100, Colin Wilson
o.uk wrote:


Just picked up a new fridge, and it says you shouldn't plug it into
an extension lead...

Why the hell not ?

Elfin safety paranoia.

I think the term Effin Softy sums it up nicely :-)


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

On Oct 11, 2:57*pm, Peter Parry wrote:
On Sun, 11 Oct 2009 04:16:52 -0700 (PDT), NT
wrote:

Even bell wire could cope with an intermittent quarter amp load
coiled.

A. *You are assuming that's all that is plugged in.

Not really, even a 20A load on a sensible 5m extension lead wouldn't
take the fridge out of its voltage spec.


NT

In article , The Medway
Handyman writes

I worked for an American floor cleaning machine company once. We ended up
sending them a 13 amp double socket outlet and a 13 amp plug top with
relevant details & they were completely & utterly gobsmacked by the concept.

To connect to the cooker/washing machine point?

--
(\__/)
(='.'=) Bunny says Windows 7 is Vi$ta reloaded.
(")_(") http://imgs.xkcd.com/comics/windows_7.png

In article ,
John Rumm writes:
NT wrote:

What is your figure for the inrush current?

You have measured it ?

From
http://wiki.answers.com/Q/Typical_current_draw_for_a_refrigerator

Typical current draw for a refrigerator?

My 20 year old upright freezer is about 10A starting, 3.27 amp running
(263 watts)

My 10 year old fridge is very similar

(Figures from the US)

Derek

US fridges are different animals to UK ones. Typical run power on a
new machine here is around 60w. At 240v thats 0.25A, or a bit more
considering power factor.

If we use your ratio of 3:1 for startup current, then the Vdrop during
startup would be about 1.3v, leaving 238.7v for the compressor that's
rated to run on 220v nominal as well as 240v nominal.

Startup inrush would more likely be 5 x In, perhaps as high a 9 x In.
The power factor could add getting on 50% top of that. If the fridge is
genuinely only 60W or so, then its a non issue since we are talking a
couple of amp tops. If its one that sucks a couple of hundred W then the
number creep up quite quickly.

I haven't measured a fridge, but I have measured by aircon compressor.
The normal power rating is 1.5kW, and I observe the consumption varies
between 1.0 and 1.5kW. When the compressor fails to start with a locked
rotor, the consumption is 4.5kW (for a few seconds before it gives up,
and waits for the pressure differential to decay away before retrying).
A fridge or freezer does exactly the same, in expecting that the
compressor will sometimes fail to start, and need to wait and retry.

I haven't measured the current draw when this happens, and that might
be more than the 3:1 or 4:1 ratio for the power consumption.

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

Mike Tomlinson wrote:
In article , The Medway
Handyman writes

I worked for an American floor cleaning machine company once. We
ended up sending them a 13 amp double socket outlet and a 13 amp
plug top with relevant details & they were completely & utterly
gobsmacked by the concept.

To connect to the cooker/washing machine point?

Yup. Thats why it really confused them.

Which bit of "American floor cleaning machine company" didn't you
understand?


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

wrote:

My earliest copy (not to hand at the moment) is 13th edition (about 1966)
and I don't recall any mention of bonding sinks. I think bonding and
equipotential zones came in in the late 70s or early 80s. A lot was
overdone at first as a CYA exercise.

In my 1963 issue there's a requirement in Regulation 404 to bond exposed
baths, metal pipes, sinks and tanks with a note that it applied to
bathrooms, kitchens, sculleries, laundries and milking-sheds. But it does
say that this only applied where segregation from metalwork and other
services is impracticable and the exemption to Regulation 214(a) was
invoked. Regulation 214(a) applied where cables were drawn into the same
ducts as extra low voltage circuits, the exception applied to multicore
cables for lifts so perhaps it didn't apply to domestic situations. All a
bit confusing but fortunately just of historical interest now.

--
Mike Clarke

On Sat, 10 Oct 2009 23:12:08 +0000, The Medway Handyman wrote:
The reason? Their poxy useless 115v spur type electrical system can't hack
anything else.

TBH, i've never seen an issue with higher-powered 115V devices (e.g.
things like carpet cleaners), nor with fixed wiring at 240V (the fixed
wiring for our cooker, drier, well pump, water heater etc. don't seem any
beefier than UK equivalents).

The problem seems to be with the cables sold for "240V consumer use" in
the US - e.g. the last few feet of 'flex'* for the cooker, drier etc. - as
these seem to be massively over-specced for the job (I assume someone had
a H+S wibble about it once, and now everyone's stuck with a crap standard).

* yeah, right.

US plugs/sockets for 240V use are similarly ridiculous, and like something
out of the ark. OTOH US folk find the massive fused UK 13A plugs
hilarious, so it works both ways :-)

cheers

Jules

On 10 Oct, 22:27, Colin Wilson
o.uk wrote:
cut the plug off the new one, feed the flex through the hole then, and
fit a new plug.

The flex is too short to do that already (it barely reaches the top of
the fridge as it is...

Dispose of the cut-off plug carefully.

Nah, give it to the kids to play with :-p

I've always been amused by the warning on this item in the RS
catalogue: http://uk.rs-online.com/web/search/s...ct&R=048920 1
"Warning
The free end of these cable assemblies must be terminated prior to
inserting the mains plug into a live socket"

ARWadsworth wrote:

"Colin Wilson" o.uk wrote
in message ...
pull quite high inrush currents (fom 5*In to 9*In). Add too much extra
resistance and the motor may stall on startup.

That said, it wouldn't be dangling off a reel, it'd be the shortest
uncoiled extension / adaptor I could find just to assist access, as

I cannot see a small extension like that causing a problem.

We have three fridges chained on two 4-way adaptors and haven't had any
starting problems. (There's only two sockets on that side of the room and
the other one is used by the toaster so no other way to plug them). I
hadn't thought about the inrush current when there's a power cut and they
all startup together... but the inrush /was/ a problem when I put one on a
plugin power meter and it tripped the 1KW software-set overcurrent. Set the
overcurrent to 3KW [1] and it was fine).

Presumably there are big problems after a power cut when everyone's
appliances pull their inrush at the same time, which is when I might expect
voltage drops and starting problems.


Theo

[1] I'm not sure 'overpower' is the right word, but on this meter you set
the maximum power draw rather than current.

In article ,
Theo Markettos writes:
ARWadsworth wrote:

"Colin Wilson" o.uk wrote
in message ...
pull quite high inrush currents (fom 5*In to 9*In). Add too much extra
resistance and the motor may stall on startup.

That said, it wouldn't be dangling off a reel, it'd be the shortest
uncoiled extension / adaptor I could find just to assist access, as

I cannot see a small extension like that causing a problem.

We have three fridges chained on two 4-way adaptors and haven't had any
starting problems. (There's only two sockets on that side of the room and
the other one is used by the toaster so no other way to plug them). I
hadn't thought about the inrush current when there's a power cut and they
all startup together... but the inrush /was/ a problem when I put one on a
plugin power meter and it tripped the 1KW software-set overcurrent. Set the
overcurrent to 3KW [1] and it was fine).

Presumably there are big problems after a power cut when everyone's
appliances pull their inrush at the same time, which is when I might expect
voltage drops and starting problems.

Modern fridges and freezers have a bit of a delay before starting.
Older ones don't.

I remember an incident when I was living in London in the early
1980s. Power tripped out to a large supermarket (Safeway in
Brunswick shopping centre). They couldn't turn it back on, until
they'd gone round and switched off a good number of the fridge/
freezer cabinets.

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