Electrical Safety signs (small)& Pump delay info.

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

Reply to
Tom
Loading thread data ...

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.

Reply to
Set Square

Best/easiest way is to use a modular time delay relay. Go to

formatting link
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

Reply to
Derek *

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

Reply to
James

... 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.

Reply to
Dave Liquorice

Labels: o

formatting link
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

----

formatting link
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.

Reply to
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

Reply to
Owain

You can buy the signs from your local electrical wholesaler.

Reply to
Andrew Gabriel

Ultrachrome inkjet ink, manufacturers claim a 75 year life.

Certainly lasts well in shop windows. I put a newletter in the local post office. I used to use HP inks, fade in about a month. Canon about the same. Changed to an Epson, the posters still look like new after two years in bright sunlight.

Reply to
Steve Firth

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

Reply to
Tom

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

Reply to
Derek *

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

Hmm, OK.

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

DG

Reply to
Derek *

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. ;-]

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:

formatting link
all I need to do is

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.

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

Reply to
Derek *

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?

Reply to
Set Square

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

Reply to
James

know when to start?

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

Reply to
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!

Reply to
Set Square

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.