I want to make up some electrical safety signs for a little connection box
near my boiler, in which in time I hope to add a time delay circuit/ or
component for the pump. I need standard stick on signs e.g. lightning
symbol, Isolate before opening, Danger 240V etc does anyone know where I can
obtain some free ClickArt to download.
I also need a 240 V ac circuit diag or suggestions for a pump "off" delay
Cheers
Tom

In an earlier contribution to this discussion,
Tom wrote:

I want to make up some electrical safety signs for a little
connection box near my boiler, in which in time I hope to add a time
delay circuit/ or component for the pump. I need standard stick on
signs e.g. lightning symbol, Isolate before opening, Danger 240V etc
does anyone know where I can obtain some free ClickArt to download.
I also need a 240 V ac circuit diag or suggestions for a pump "off"
delay Cheers
Tom

Sorry, can't help with ClickArt.

With regard to pump delay, I would suggest using a pipe stat mounted on the
flow pipe close to the boiler rather than a timer. This will run the pump
until the boiler has cooled sufficiently and is preferable to an arbitrary
delay.

The stat needs to have changeover contacts. Connect NC (the low temp
contact) to boiler switched live. Connect NO (the high temp contact) to
permanent live. Connect COM to the pump.

When the boiler starts up from cold, the pump will also run. When the flow
temperature exceeds the pipe stat setting, the stat contacts will change
over - and the pump will now be powered from the permanent live, and will
continue to run. When the boiler is turned off by the programmer or room
stat, the pump will continue to run until the flow temperature drops below
the pipe stat setting.
--
Cheers,
Set Square
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On Sun, 3 Oct 2004 21:33:52 +0100, "Tom"
wrote:

I want to make up some electrical safety signs for a little connection box
near my boiler, in which in time I hope to add a time delay circuit/ or
component for the pump. I need standard stick on signs e.g. lightning
symbol, Isolate before opening, Danger 240V etc does anyone know where I can
obtain some free ClickArt to download.
I also need a 240 V ac circuit diag or suggestions for a pump "off" delay


Best/easiest way is to use a modular time delay relay. Go to www.rswww.com
and search for part number 300 - 6045.

This is a variable off delay timer/relay. Cost = £35.00 but is all you
need except for a bit of din rail to mount it on.

If you have to deal with RS components you might as well get the sticky
warning labels there as well.

You don't really need a circuit digram. The unit takes 240v power and a
pair of contacts close when power is applied, they stay closed after power
is removed for the duration selected by a knob on the front (up to 10
mins) . Connection to the unit is via screw terminals so no other
plugs/sockets/connectors needed in yr. box.

RS will deal with individuals who do not have an account, but you'll
probably get referred to another department and may get charged postage.

DG

"Derek *" wrote in message
...

This is a variable off delay timer/relay. Cost = £35.00 but is all you
need except for a bit of din rail to mount it on.

You don't really need a circuit digram. The unit takes 240v power and a
pair of contacts close when power is applied, they stay closed after power
is removed for the duration selected by a knob on the front (up to 10
mins) . Connection to the unit is via screw terminals so no other
plugs/sockets/connectors needed in yr. box.



This is difficult to discuss without a diagram - but isn't there a danger
that the power to the pump will also be fed back to the boiler switched
live, enabling the boiler to fire again during the pump overrun time?

James




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On Sun, 03 Oct 2004 22:17:47 +0100, Derek * wrote:

Best/easiest way is to use a modular time delay relay. Go to
www.rswww.com and search for part number 300 - 6045.

This is a variable off delay timer/relay. Cost =3D =A335.00 but is all=

you need except for a bit of din rail to mount it on.

.... and a box to enclose the terminals?

How much is a pipe stat and a metre or two of heat resistant 4 core? I
think you'd have more than =A315 of change from that =A335... A pipe sta=
t
will work better as well, the pump will only run on for as long (or a
short) as is required.

--
Cheers
Dave. pam is missing e-mail

I need standard stick on signs e.g. lightning symbol, Isolate before opening,
Danger 240V etc does anyone know where I can obtain some free ClickArt to download.

Labels:
o www.tlc-direct.co.uk sell the labels in qty 1 as I recall.
---- "Isolate befire opening" is one of them
o If you want to scale it, convert to vector art first ideally
---- the proper labels are only a few p & plastic based

Timer/Relay control:
o Simplest is standard process control, DIN rail mount
o First - identify the functionality you need
---- www.rs-www.com is ideal for this, go thro the Tech-Info *.pdf files
---- the fewer functions the item does, the cheaper it will be
o Second - identify who is cheapest for that item
---- Newey & Eyre (electrical factors) will probably be cheaper than RS
---- Rapid Electronics have a fledgling industrial process control area too
---- Farnell also, if you know the brand/model by that point (re website search!)

Electrical factors will also do short lengths of top-hat DIN rail cheaply too.
--
Dorothy Bradbury

"Tom" wrote
| I want to make up some electrical safety signs for a little
| connection box near my boiler, in which in time I hope to
| add a time delay circuit/ or component for the pump. I need
| standard stick on signs e.g. lightning symbol, Isolate before
| opening, Danger 240V etc does anyone know where I can obtain
| some free ClickArt to download.

Not free, but ebay frequently has safety sign CD-ROMs intended for
signmakers. However, unless you have a vinyl cutter or sign printer,
home-made signs are unlikely to comply with BS in terms of colour and
longevity (ink jet print fades).

If they are standard signs and labels, probably cheaper to get them from
(almost) any of the safety sign mfrs, or your local signmaker will have an
account with a trade supplier and may be cheaper.

Owain

In article ,
"Tom" writes:
I want to make up some electrical safety signs for a little connection box
near my boiler, in which in time I hope to add a time delay circuit/ or
component for the pump. I need standard stick on signs e.g. lightning
symbol, Isolate before opening, Danger 240V etc does anyone know where I can
obtain some free ClickArt to download.

You can buy the signs from your local electrical wholesaler.

--
Andrew Gabriel

Thanks for the responses, regarding signs: I enjoy the thought of making up
my own using "Printshop" as installed on my computer,(BTW, Epson printer
with latest superb long lasting inks) however I require a few appropriate
symbols to import, I can make up the words myself, it's the symbols I need.
Pump time delay: I've seen most of the commercial time delays at approx
£25 --£35 inc RS, I'm unwilling to pay that kind of dosh, I just need a
circuit to build a delay timer based on a Triac or Thyristor, it can't be
very sophisticated as cheap bathroom fans have them, all I need to do is
upgrade the power for the CH pump and decrease the time by a factor of
approx 20.
After all it is a DIY forum :-)
Cheers
Tom

On Sun, 3 Oct 2004 23:21:51 +0100, "James"
wrote:


"Derek *" wrote in message
.. .

This is a variable off delay timer/relay. Cost = £35.00 but is all you
need except for a bit of din rail to mount it on.

You don't really need a circuit digram. The unit takes 240v power and a
pair of contacts close when power is applied, they stay closed after power
is removed for the duration selected by a knob on the front (up to 10
mins) . Connection to the unit is via screw terminals so no other
plugs/sockets/connectors needed in yr. box.



This is difficult to discuss without a diagram - but isn't there a danger
that the power to the pump will also be fed back to the boiler switched
live, enabling the boiler to fire again during the pump overrun time?


I see what you mean but it's not unavoidable the relay contacts are
isolated from the power/control input to the relay. So (figuratively
speaking) breaking into the power feed to the pump (only) and using that
as power/control inpt to the relay with the contacts switching another
source of (clean) mains power to the pump, should work OK.

DG

On Sun, 03 Oct 2004 23:50:01 +0100 (BST), "Dave Liquorice"
wrote:

On Sun, 03 Oct 2004 22:17:47 +0100, Derek * wrote:

Best/easiest way is to use a modular time delay relay. Go to
www.rswww.com and search for part number 300 - 6045.

This is a variable off delay timer/relay. Cost = £35.00 but is all
you need except for a bit of din rail to mount it on.

... and a box to enclose the terminals?


I thought he had the boxology to start with but maybe he didn't.

How much is a pipe stat and a metre or two of heat resistant 4 core? I
think you'd have more than £15 of change from that £35... A pipe stat
will work better as well, the pump will only run on for as long (or a
short) as is required.

Hmm, OK.

But if the pipeology is cold to start with how will the pump ever get to
know when to start?

DG

On Mon, 4 Oct 2004 21:02:28 +0100, "Tom"
wrote:


Thanks for the responses, regarding signs: I enjoy the thought of making up
my own using "Printshop" as installed on my computer,(BTW, Epson printer
with latest superb long lasting inks) however I require a few appropriate
symbols to import, I can make up the words myself, it's the symbols I need.
Pump time delay: I've seen most of the commercial time delays at approx
£25 --£35 inc RS, I'm unwilling to pay that kind of dosh,

I too think they are expensive. But they are built and independantly type
tested to a standard of electrical safety (including fire), and you can
rely on that.

Write it off over 5 years or so and it's only 2-3 pints /year. ;-]

I just need a
circuit to build a delay timer based on a Triac or Thyristor, it can't be
very sophisticated as cheap bathroom fans have them,

Didn't someone post links to some .jpgs on here a couple of months ago of
a fan overrun timer PCB burning up? Ah yes:

Message-ID:

http://www.challoner.com/temp/extractor.html

all I need to do is
upgrade the power for the CH pump and decrease the time by a factor of
approx 20.

Don't go down that route, there's a good chap.

The process control delay relay has the advantage that done properly it
would be completely Kosher and all connections could be restricted to
those built into the type tested relay.

The pipe thermostat idea would also work, possibly better, and certainly
more elegant, (Providing a suitable place for the temperature sensor can
be found) but would involve more ad-hoc connections at 240v.

After all it is a DIY forum :-)

I wouldn't encourage DIY lash ups with a handful of semiconductor devices
and passive components running on 240v mains, though doubtless a solution
could be created (something like the fan controller above) for a few
pounds.

If you need to ask about it you shouldn't be doing it .

DG

In an earlier contribution to this discussion,
Derek * wrote:


But if the pipeology is cold to start with how will the pump ever get
to know when to start?

I described a method of doing it in a post a couple of days ago. The pipe
stat needs to have change-over contacts. The one which connects when the
pipe is cold is connected to the boiler's switched live. The one which
connects when the pipe is hot is connected to permanent live. Common is
connected to the pump. So:
* Cold Pipe: the pump runs whenever the boiler receives a heat demand
* Hot Pipe: the pump runs until the pipe cools down

Simple, eh?
--
Cheers,
Set Square
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"Derek *" wrote in message
...


I see what you mean but it's not unavoidable the relay contacts are
isolated from the power/control input to the relay. So (figuratively
speaking) breaking into the power feed to the pump (only) and using that
as power/control inpt to the relay with the contacts switching another
source of (clean) mains power to the pump, should work OK.

DG

Yes - I understand what you are saying. I feel it would be better is there
were such a thing as a (time delay) relay which could switch the connection
between the switched live and a permanent live to the pump (in the manner
described by Set Square for the pipe stat). This would minimise the risk
of introducing another point of failure (ie boiler on, but pump not working)
should a fault occur in the relay.

James


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But if the pipeology is cold to start with how will the pump ever get to
know when to start?


I described a method of doing it in a post a couple of days ago. The pipe
stat needs to have change-over contacts. The one which connects when the
pipe is cold is connected to the boiler's switched live. The one which
connects when the pipe is hot is connected to permanent live. Common is
connected to the pump. So:
* Cold Pipe: the pump runs whenever the boiler receives a heat demand
* Hot Pipe: the pump runs until the pipe cools down

Simple, eh?
--
Cheers,
Set Square

I see, hmm, that's very elegant, I like it.
The pipe stat would have to be very reliable,
any recommendations?
There would be a very tiny (millisecond?) break in the power to the pump as
it changed over (break before make), but I don't suppose it would affect the
pump as it's an inductive load and the back emf would take care of that or
am I talking cobblers here as I dredge the depths of my school boy memories
[50 yrs ago, :-(. ]
Many Thanks
Tom

In an earlier contribution to this discussion,
Tom wrote:

But if the pipeology is cold to start with how will the pump ever
get to know when to start?


I described a method of doing it in a post a couple of days ago. The
pipe stat needs to have change-over contacts. The one which connects
when the pipe is cold is connected to the boiler's switched live.
The one which connects when the pipe is hot is connected to
permanent live. Common is connected to the pump. So:
* Cold Pipe: the pump runs whenever the boiler receives a heat demand
* Hot Pipe: the pump runs until the pipe cools down

Simple, eh?
--
Cheers,
Set Square

I see, hmm, that's very elegant, I like it.
The pipe stat would have to be very reliable,
any recommendations?
There would be a very tiny (millisecond?) break in the power to the
pump as it changed over (break before make), but I don't suppose it
would affect the pump as it's an inductive load and the back emf
would take care of that or am I talking cobblers here as I dredge the
depths of my school boy memories [50 yrs ago, :-(. ]
Many Thanks
Tom

Well, it's no different from the way in which the pump over-run stat works
in my Baxi boiler - and the pump doesn't mind that!
--
Cheers,
Set Square
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