Can someone shed any light on this as it is puzzling me? Looking on
eBay for "UK 3 Pin 24HR 24 Hour Timer Programmable Mains Wall Home
Socket Plug-IN Switch", these are generally rated at 3200 or 3000
watts - yet they all look the same, and the one with the 3200 rating
also includes a warning that it is not to be used for washing machines
- which is exactly what I do want it for. I haven't scrabbled round
the back of my washing machine to see what wattage it is, but I can't
see it being more than 3000 watts, so why should there be this
warning?

Keith

On 08/02/2012 09:19, Keefiedee wrote:
Can someone shed any light on this as it is puzzling me? Looking on
eBay for "UK 3 Pin 24HR 24 Hour Timer Programmable Mains Wall Home
Socket Plug-IN Switch", these are generally rated at 3200 or 3000
watts - yet they all look the same, and the one with the 3200 rating
also includes a warning that it is not to be used for washing machines
- which is exactly what I do want it for. I haven't scrabbled round
the back of my washing machine to see what wattage it is, but I can't
see it being more than 3000 watts, so why should there be this
warning?

Keith

The important characteristic is how much current it can switch. 3200
watts is 13 amps - but some devices have much higher startup currents
than this - which are not sustained for long enough to blow the fuse but
which could nevertheless wreck the contacts in a time switch. Maybe
washing machines come in the category?
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

On Wed, 08 Feb 2012 01:19:11 -0800, Keefiedee wrote:

Can someone shed any light on this as it is puzzling me? Looking on
eBay for "UK 3 Pin 24HR 24 Hour Timer Programmable Mains Wall Home
Socket Plug-IN Switch", these are generally rated at 3200 or 3000 watts
- yet they all look the same, and the one with the 3200 rating also
includes a warning that it is not to be used for washing machines -
which is exactly what I do want it for. I haven't scrabbled round the
back of my washing machine to see what wattage it is, but I can't see it
being more than 3000 watts, so why should there be this warning?

Keith

These timer switches tend to be just 2 pieces of contact that touch and
release. Anything with a big motor in it will be an inductive load, which
will cause arcing, and could fuse the contacts together. You'd need the
timer switch to switch a contactor relay which you plug your washing
machine into.

On Wed, 08 Feb 2012 10:26:42 +0000, Roger Mills wrote:

The important characteristic is how much current it can switch. 3200
watts is 13 amps - but some devices have much higher startup currents
than this - which are not sustained for long enough to blow the fuse but
which could nevertheless wreck the contacts in a time switch. Maybe
washing machines come in the category?

I sort of thought that but all the washing machines I've ever
encounterd don't start the motor the moment you switch 'em on or the
heater come to that. They need to, at least partially, fill with
water first... Thus the time switch won't be required to make/break a
high load. Well not unless you are daft enough to set it such that it
switches off before the cycle has finished...

--
Cheers
Dave.

On Feb 8, 10:26*am, Roger Mills wrote:
On 08/02/2012 09:19, Keefiedee wrote:

Can someone shed any light on this as it is puzzling me? *Looking on
eBay for "UK 3 Pin 24HR 24 Hour Timer Programmable Mains Wall Home
Socket Plug-IN Switch", these are generally rated at 3200 or 3000
watts - yet they all look the same, and the one with the 3200 rating
also includes a warning that it is not to be used for washing machines
- which is exactly what I do want it for. *I haven't scrabbled round
the back of my washing machine to see what wattage it is, but I can't
see it being more than 3000 watts, so why should there be this
warning?

Keith

The important characteristic is how much current it can switch. 3200
watts is 13 amps - but some devices have much higher startup currents
than this - which are not sustained for long enough to blow the fuse but
which could nevertheless wreck the contacts in a time switch. Maybe
washing machines come in the category?

If that were the problem it wouldnt be washing machines they dont
recommend, it would be appliances with high startup current.

And why would any timer manufacturer save 0.5p by shrinking the
contacts to the point where they couldnt cope with any 13A load.


NT

Inductive loads?

Brian

--
Brian Gaff -
Note:- In order to reduce spam, any email without 'Brian Gaff'
in the display name may be lost.
Blind user, so no pictures please!
"Keefiedee" wrote in message
...
Can someone shed any light on this as it is puzzling me? Looking on
eBay for "UK 3 Pin 24HR 24 Hour Timer Programmable Mains Wall Home
Socket Plug-IN Switch", these are generally rated at 3200 or 3000
watts - yet they all look the same, and the one with the 3200 rating
also includes a warning that it is not to be used for washing machines
- which is exactly what I do want it for. I haven't scrabbled round
the back of my washing machine to see what wattage it is, but I can't
see it being more than 3000 watts, so why should there be this
warning?

Keith

On Feb 8, 11:28*am, "Brian Gaff" wrote:
...

Can someone shed any light on this as it is puzzling me? *Looking on
eBay for "UK 3 Pin 24HR 24 Hour Timer Programmable Mains Wall Home
Socket Plug-IN Switch", these are generally rated at 3200 or 3000
watts - yet they all look the same, and the one with the 3200 rating
also includes a warning that it is not to be used for washing machines
- which is exactly what I do want it for. *I haven't scrabbled round
the back of my washing machine to see what wattage it is, but I can't
see it being more than 3000 watts, so why should there be this
warning?

Keith

Inductive loads?

Brian

Washers are mainly resistive (element).


NT

On Feb 8, 1:13*pm, Owain wrote:
On Feb 8, 11:02*am, NT *wrote:

And why would any timer manufacturer save 0.5p by shrinking the
contacts to the point where they couldnt cope with any 13A load.

Because when you make millions of something, all those 0.5ps add up.

Owain

There was a TV programme a few years back where a couple had built
their dream home and went off for a well earned break to the U.S.A.
only to return to a burnt out shell. The problem was traced to a
timer switch which had been set to cycle light on and off as a
security measure. It failed and started the fire.

Paul Mc Cann

On 2012-02-08, Jethro wrote:

On Wed, 08 Feb 2012 01:19:11 -0800, Keefiedee wrote:

Can someone shed any light on this as it is puzzling me? Looking on
eBay for "UK 3 Pin 24HR 24 Hour Timer Programmable Mains Wall Home
Socket Plug-IN Switch", these are generally rated at 3200 or 3000 watts
- yet they all look the same, and the one with the 3200 rating also
includes a warning that it is not to be used for washing machines -
which is exactly what I do want it for. I haven't scrabbled round the
back of my washing machine to see what wattage it is, but I can't see it
being more than 3000 watts, so why should there be this warning?

These timer switches tend to be just 2 pieces of contact that touch and
release. Anything with a big motor in it will be an inductive load, which
will cause arcing, and could fuse the contacts together. You'd need the
timer switch to switch a contactor relay which you plug your washing
machine into.

I used to use a timeswitch like that on my washing machine (nothing
said not to use it that way), with no problems. Was I lucky, or had I
bought an unusually good timer? Or have they pared down the quality
in the past few years?

(My current machine has a built-in delay timer.)

On Wed, 08 Feb 2012 15:00:12 +0000, Adam Funk wrote:

On 2012-02-08, Jethro wrote:

On Wed, 08 Feb 2012 01:19:11 -0800, Keefiedee wrote:

Can someone shed any light on this as it is puzzling me? Looking on
eBay for "UK 3 Pin 24HR 24 Hour Timer Programmable Mains Wall Home
Socket Plug-IN Switch", these are generally rated at 3200 or 3000
watts - yet they all look the same, and the one with the 3200 rating
also includes a warning that it is not to be used for washing machines
- which is exactly what I do want it for. I haven't scrabbled round
the back of my washing machine to see what wattage it is, but I can't
see it being more than 3000 watts, so why should there be this
warning?

These timer switches tend to be just 2 pieces of contact that touch and
release. Anything with a big motor in it will be an inductive load,
which will cause arcing, and could fuse the contacts together. You'd
need the timer switch to switch a contactor relay which you plug your
washing machine into.

I used to use a timeswitch like that on my washing machine (nothing said
not to use it that way), with no problems. Was I lucky, or had I bought
an unusually good timer? Or have they pared down the quality in the
past few years?

As others have posted, it's not usual for the machine to start with the
motor on, so the load may not cause an arc ... I was just speculating why
the OP was advised against using the timer for a washing machine.


(My current machine has a built-in delay timer.)

So has mine, but I don't think we have ever used it.

On Wed, 8 Feb 2012 01:19:11 -0800 (PST), Keefiedee
wrote:

and the one with the 3200 rating
also includes a warning that it is not to be used for washing machines
- which is exactly what I do want it for. I haven't scrabbled round
the back of my washing machine to see what wattage it is, but I can't
see it being more than 3000 watts, so why should there be this
warning?

In case you inadvertently switch the machine off with the timer when
it is operating at full load and speed. The contacts are not capable
of handling the high back EMF and will often weld shut.

On Wed, 8 Feb 2012 01:19:11 -0800 (PST)
Keefiedee wrote:

Can someone shed any light on this as it is puzzling me? Looking on
eBay for "UK 3 Pin 24HR 24 Hour Timer Programmable Mains Wall Home
Socket Plug-IN Switch", these are generally rated at 3200 or 3000
watts - yet they all look the same, and the one with the 3200 rating
also includes a warning that it is not to be used for washing machines
- which is exactly what I do want it for. I haven't scrabbled round
the back of my washing machine to see what wattage it is, but I can't
see it being more than 3000 watts, so why should there be this
warning?

It could be the inability to handle the inductive load as some have
said but another point to consider is that some washing machines with
digital controls require you to press a "Start" button after selecting
the programme. Pressing this button without the power being on will
have no effect [1] so an external timer would not be appropriate.
Perhaps they've had too many complaints from people who bought them and
then found they were not suitable so decided to go for a dumb-ed down
warning saying "not to be used for washing machines".

[1] yes you might be able to start the machine then turn off the power
and set the timer to let the machine continue from where it left off.
But it's a bit of a kludge.

--
Mike Clarke

On Wed, 8 Feb 2012 05:40:11 -0800 (PST), fred
wrote:

There was a TV programme a few years back where a couple had built
their dream home and went off for a well earned break to the U.S.A.
only to return to a burnt out shell. The problem was traced to a
timer switch which had been set to cycle light on and off as a
security measure. It failed and started the fire.

Similar on Grand Designs a couple of years back - holidaying couple's
neighbour spotted a glow as the house went up at 2am; caused by a
fridge/freezer in an attached outbuilding.

Keefiedee writes:

Can someone shed any light on this as it is puzzling me? Looking on
eBay for "UK 3 Pin 24HR 24 Hour Timer Programmable Mains Wall Home
Socket Plug-IN Switch", these are generally rated at 3200 or 3000
watts - yet they all look the same, and the one with the 3200 rating
also includes a warning that it is not to be used for washing machines
- which is exactly what I do want it for. I haven't scrabbled round
the back of my washing machine to see what wattage it is, but I can't
see it being more than 3000 watts, so why should there be this
warning?

Motors represent a fairly inductive load so might cause a lot of
sparking, and that can cause the digital timer to do strange things.

I have two timers which work well with a washing machine, and another
of different make which resets itself in arbitrary ways when so used.

Might just be a dud timer, of course, but having arcing relay contacts
near to a CMOS clock circuit is always likely to be a bit tricky, as
anyone who has ever used an oscilloscope on such circuits will know.

--
Windmill, Use t m i l l
J.R.R. Tolkien:- @ O n e t e l . c o m
All that is gold does not glister / Not all who wander are lost

"Dave Liquorice" writes:

On Wed, 08 Feb 2012 10:26:42 +0000, Roger Mills wrote:

The important characteristic is how much current it can switch. 3200
watts is 13 amps - but some devices have much higher startup currents
than this - which are not sustained for long enough to blow the fuse but
which could nevertheless wreck the contacts in a time switch. Maybe
washing machines come in the category?

I sort of thought that but all the washing machines I've ever
encounterd don't start the motor the moment you switch 'em on or the
heater come to that. They need to, at least partially, fill with
water first... Thus the time switch won't be required to make/break a
high load. Well not unless you are daft enough to set it such that it
switches off before the cycle has finished...

It would be daft, but you might do it unthinkingly while obsessing about
the letter from the bank, or whatever!

And the solenoids which control filling etc. are inductive.

--
Windmill, Use t m i l l
J.R.R. Tolkien:- @ O n e t e l . c o m
All that is gold does not glister / Not all who wander are lost

On Feb 8, 1:13*pm, Owain wrote:
On Feb 8, 11:02*am, NT *wrote:

And why would any timer manufacturer save 0.5p by shrinking the
contacts to the point where they couldnt cope with any 13A load.

Because when you make millions of something, all those 0.5ps add up.

Owain

Valid principle, but on a timer this is pretty well unheard of.


NT

On 2012-02-08, Peter Parry wrote:

On Wed, 8 Feb 2012 01:19:11 -0800 (PST), Keefiedee
wrote:

and the one with the 3200 rating
also includes a warning that it is not to be used for washing machines
- which is exactly what I do want it for. I haven't scrabbled round
the back of my washing machine to see what wattage it is, but I can't
see it being more than 3000 watts, so why should there be this
warning?

In case you inadvertently switch the machine off with the timer when
it is operating at full load and speed. The contacts are not capable
of handling the high back EMF and will often weld shut.

Good point. The timer I used to use for a washing machine was the
kind with pins that you put in any holes in the on-ring and off-ring,
along with a switch you could flip. I used to have only one pin in
the timer to switch the machine on early in the morning, so the timer
would never cut the machine off automatically. (I'd flip the switch
to off immediately after setting the machine in the evening.)

On 2012-02-08, Jethro wrote:

On Wed, 08 Feb 2012 15:00:12 +0000, Adam Funk wrote:

I used to use a timeswitch like that on my washing machine (nothing said
not to use it that way), with no problems. Was I lucky, or had I bought
an unusually good timer? Or have they pared down the quality in the
past few years?

As others have posted, it's not usual for the machine to start with the
motor on, so the load may not cause an arc ... I was just speculating why
the OP was advised against using the timer for a washing machine.

(See my other post just now: I used to set the timer to switch on
automatically, but I switched it off myself.)

(My current machine has a built-in delay timer.)

So has mine, but I don't think we have ever used it.

I'm an Economy 7 nerd.

The cheap electromechanical timers can be quite poor quality, that
includes ones from Asda Tesco etc.

They can stick on or more often off.
More an issue with frost heating where walking in to 2oC floor
temperature and vulnerable pipework.

Contacts are indeed small & flimsy.
Bigger & far better quality contacts on a car window regulator switch
for example.

They run warm on high loads.
A 2kW load for 15mins generates quite noticeable heating. A washer is
only going to run its 3kW heater for a very short time even on a 95oC
wash though.

China generics supply a competent production sample and utter trash
for production run. The money to be made is simply astronomically, but
so is the money to be lost if you are not the cheapest and china is
NOT a low cost area anymore compared to many other Asian makers.


So... how about an LCD timer, that avoids the crude mechanical
contacts (£2 plug-in timers are not Sangamo quality!) and might just
get you a 16A rated relay. It will be rated less for inductive, but I
think the only inductive load at startup is going to be the solenoid
valves "juddering" if yours does that.

I would add, there are little flood alert alarms available for about
£4.99-9.99 - so you may want to add one of those... just in case.

Economy 7 does not save much on a wash unless 60-95oC, it is drying
where it saves a fair chunk over a year.