If an appliance is plugged into an extension lead, and the lead is plugged
into a socket outlet - will a fault in the appliance blow (a) the fuse in
its own lead, (b) the fuse in the extension lead or (c) both?

Is there a general rule of thumb?

The MCB isn't tripping.

(trying to fault find daughters washing machine over the phone, can't get
round till tomorrow pm).


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

On 01/09/2009 21:02, The Medway Handyman wrote:
If an appliance is plugged into an extension lead, and the lead is plugged
into a socket outlet - will a fault in the appliance blow (a) the fuse in
its own lead, (b) the fuse in the extension lead or (c) both?

Is there a general rule of thumb?

The MCB isn't tripping.

(trying to fault find daughters washing machine over the phone, can't get
round till tomorrow pm).


The most inaccessible will blow - Everytime!

Silly question - I assume the fuses fitted in the plug and the extension
lead the same rating?

The current drawn through them is the same so the 'weakest' of the two
will blow.

"Peter Watson" wrote in message
...
On 01/09/2009 21:02, The Medway Handyman wrote:
If an appliance is plugged into an extension lead, and the lead is
plugged
into a socket outlet - will a fault in the appliance blow (a) the fuse in
its own lead, (b) the fuse in the extension lead or (c) both?

Is there a general rule of thumb?

The MCB isn't tripping.

(trying to fault find daughters washing machine over the phone, can't get
round till tomorrow pm).


The most inaccessible will blow - Everytime!

Silly question - I assume the fuses fitted in the plug and the extension
lead the same rating?

The current drawn through them is the same so the 'weakest' of the two
will blow.

Are you sure the extension lead can handle the current? Is it unwound fully?
If partly coiled it will get dangerously hot. Do you know the current rating
of the washer?

John wrote:
"Peter Watson" wrote in message
...
On 01/09/2009 21:02, The Medway Handyman wrote:
If an appliance is plugged into an extension lead, and the lead is
plugged
into a socket outlet - will a fault in the appliance blow (a) the
fuse in its own lead, (b) the fuse in the extension lead or (c)
both? Is there a general rule of thumb?

The MCB isn't tripping.

(trying to fault find daughters washing machine over the phone,
can't get round till tomorrow pm).


The most inaccessible will blow - Everytime!

Silly question - I assume the fuses fitted in the plug and the
extension lead the same rating?

The current drawn through them is the same so the 'weakest' of the
two will blow.

Are you sure the extension lead can handle the current? Is it unwound
fully? If partly coiled it will get dangerously hot. Do you know the
current rating of the washer?

Lead is only a 1 metre 3 gang, fully 'unwound' - not that you could wind it
really.


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

Peter Watson wrote:
On 01/09/2009 21:02, The Medway Handyman wrote:
If an appliance is plugged into an extension lead, and the lead is
plugged into a socket outlet - will a fault in the appliance blow
(a) the fuse in its own lead, (b) the fuse in the extension lead or
(c) both? Is there a general rule of thumb?

The MCB isn't tripping.

(trying to fault find daughters washing machine over the phone,
can't get round till tomorrow pm).


The most inaccessible will blow - Everytime!

Silly question - I assume the fuses fitted in the plug and the
extension lead the same rating?

The current drawn through them is the same so the 'weakest' of the two
will blow.

Alas all 13 amp :-(


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

The Medway Handyman presented the following explanation :
If an appliance is plugged into an extension lead, and the lead is plugged
into a socket outlet - will a fault in the appliance blow (a) the fuse in its
own lead, (b) the fuse in the extension lead or (c) both?

If both are the same value of fuse, either or both could blow -
assuming the washing machine is the only load on the extension.
Normally an MCB would be the first to trip.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

Harry Bloomfield wrote:
The Medway Handyman presented the following explanation :
If an appliance is plugged into an extension lead, and the lead is
plugged into a socket outlet - will a fault in the appliance blow
(a) the fuse in its own lead, (b) the fuse in the extension lead or
(c) both?

If both are the same value of fuse, either or both could blow -
assuming the washing machine is the only load on the extension.
Normally an MCB would be the first to trip.

Tumble drier & small dishwasher are on the same lead, their fuses seem to
survive.

Latest reports (via phone) are that there is a 'flash & bang' from
'somewhere near bottom of washing machine'.

Bear in mind this is a daughter who calls me to ask me to make a shelf
'three Argos catalogues long'.


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

On Sep 2, 12:06*am, "The Medway Handyman"
wrote:
Harry Bloomfield wrote:

Bear in mind this is a daughter who calls me to ask me to make a shelf
'three Argos catalogues long'.

Hmm, length-wise or width-wise ?

As a unit of measurement, it'lll not catch on that quickly

Paul.

"Harry Bloomfield" wrote in message
k...
The Medway Handyman presented the following explanation :
If an appliance is plugged into an extension lead, and the lead is
plugged into a socket outlet - will a fault in the appliance blow (a) the
fuse in its own lead, (b) the fuse in the extension lead or (c) both?

If both are the same value of fuse, either or both could blow - assuming
the washing machine is the only load on the extension. Normally an MCB
would be the first to trip.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk



Depends on fuse rating and fault current. It's not unknown for both fuses
to go and the circuit MCB.

If the fault current is relatively low it will just take out the weakest
fuse.

Current can still flow through a molten wire or plasma of metal vapour. I
have known glass fuses to shatter, but not the standard mains ceramic, sand
filled types.

In message , The Medway
Handyman writes
If an appliance is plugged into an extension lead, and the lead is plugged
into a socket outlet - will a fault in the appliance blow (a) the fuse in
its own lead, (b) the fuse in the extension lead or (c) both?

Is there a general rule of thumb?

The MCB isn't tripping.

(trying to fault find daughters washing machine over the phone, can't get
round till tomorrow pm).

Weeeeeeeellllll....

You would think that the appliance fuse (given that they were the same
type of fuse with the same rating) would go first, but there is no hard
and fast rule that can be applied


I've had cases where e.g. a 2A fuse in a circuit has survived when a
4A one (of the same type) has wimped out first

Fuses can be complicated little beasties - they blow according to I^2xt
(current squared x time it is applied for) in an ideal world

--
geoff

"geoff" wrote in message
...
In message , The Medway
Handyman writes
If an appliance is plugged into an extension lead, and the lead is plugged
into a socket outlet - will a fault in the appliance blow (a) the fuse in
its own lead, (b) the fuse in the extension lead or (c) both?

Is there a general rule of thumb?

The MCB isn't tripping.

(trying to fault find daughters washing machine over the phone, can't get
round till tomorrow pm).

Weeeeeeeellllll....

You would think that the appliance fuse (given that they were the same
type of fuse with the same rating) would go first, but there is no hard
and fast rule that can be applied

No you would not.
There is no reason to expect the appliance fuse to fail before the
extension's fuse.

In message , "dennis@home"
writes


"geoff" wrote in message
...
In message , The
Medway Handyman writes
If an appliance is plugged into an extension lead, and the lead is plugged
into a socket outlet - will a fault in the appliance blow (a) the fuse in
its own lead, (b) the fuse in the extension lead or (c) both?

Is there a general rule of thumb?

The MCB isn't tripping.

(trying to fault find daughters washing machine over the phone, can't get
round till tomorrow pm).

Weeeeeeeellllll....

You would think that the appliance fuse (given that they were the
same type of fuse with the same rating) would go first, but there is
no hard and fast rule that can be applied

No you would not.
There is no reason to expect the appliance fuse to fail before the
extension's fuse.

He obviously thought that one of them would have gone first - that's
why he asked, most people think that the one nearest the fault would go
first. TMH is not someone with the depth of knowledge in such things -
again, which is why he asked

dickhead

--
geoff

On Tue, 1 Sep 2009 23:40:48 +0100, geoff wrote:

If an appliance is plugged into an extension lead, and the lead is plugged
into a socket outlet - will a fault in the appliance blow (a) the fuse in
its own lead, (b) the fuse in the extension lead or (c) both?

Is there a general rule of thumb?

The MCB isn't tripping.

(trying to fault find daughters washing machine over the phone, can't get
round till tomorrow pm).

Weeeeeeeellllll....

You would think that the appliance fuse (given that they were the same
type of fuse with the same rating) would go first,

Why?

On Sep 1, 9:02*pm, "The Medway Handyman"
wrote:

If an appliance is plugged into an extension lead, and the lead is plugged
into a socket outlet - will a fault in the appliance blow (a) the fuse in
its own lead, (b) the fuse in the extension lead or (c) both?

Is there a general rule of thumb?

The MCB isn't tripping.

(trying to fault find daughters washing machine over the phone, can't get
round till tomorrow pm).

If you look at fuse rating curves, you quickly notice 2 things
a) what large currents are needed to pop them
b) how widely their characteristics tend to vary

in short, there's no way to know which 13A fuse will pop. However if
more than one appliance were on at once, the fuse seeing highest
current would be more likely to pop first, ie the extension lead fuse.

9kw on a 13A lead - fun! Hope shes got a camera, smoke alarms and a
designated fire escape route.

As it sounds like a dead short I cant see how she'd solve it, surely a
WM can wait till tomorrow?


NT