Water. Solenoid & UK Socket Confusion!

[jagillham]

Wondered if anybody can help - I'm going mental here!

I want an automatic system to let water into my aquarium. The 'idea' to combine my 7 day timer from Argos (www.argos.co.uk/static/Product/partNumber/9822911.htm) with a "normally closed" solenoid valve attached to some 15mm pipe.

What I cannot work out is how to physically do this. All the solenoid valves I have seen are not wired, and usually have just 2 'faston' connections. I need to somehow get some a solenoid (maybe something like this: http://www.store.connexion-developments.com/115BC-RPE-solenoid-valve?language=en&currency=GBP) to a UK plug to go into the timer.

Any help very much welcomed!

 

[ban-all-sheds]

And the reason you can't connect a flex between the plug and the solenoid is....?

BTW - the solenoid must be placed inside a housing into which the flex can enter before the sheath is removed.

 

[jagillham]

This is what I wanted to check.

So can I take flex (no earth) direct from a 3 pin plug to one of the faston tabs each if using the 230v solenoid?

 

[ban-all-sheds]

Yup.

3A fuse.

How do you plan to put the connectors on the end of the flex?

 

[jagillham]

Had thought it would be solder directly onto the tabs?

Open to ideas. When you said before the whole thing needs to be inside a casing, can you buy these - do they have a special name?

 

[bernardgreen]

So can I take flex (no earth) direct from a 3 pin plug to one of the faston tabs each if using the 230v solenoid?

A better and safer option would be use a 24 volt solenoid and a 230 to 24 volt transformer. The transformer and the 230 volt wiring is then away from the water

http://cpc.farnell.com/1/1/84865-ac-ac-power-supply-24v-0-5a-universl-t2840st-stontronics.html

There is also a version with a flexible lead instead of Fast-ons

Also check that the solenoid can be energised continuously for the length of time you want water to flow. Some solenoid can only be energised for a few minutes before they become excessively hot.

From the data sheet
Media under 60°C 100%
60°C+ (60% Duty 2 min ON - 3 min OFF)

so it looks OK provided the water is below 60°C and flows freely when the valve is open.

 

[jagillham]

It will be cold water going in, and "warm" water out (max is going to be 28C).

At a guess the valve will be open for somewhere between 15-30 mins, how do I find out if this is an issue?

That one you linked, would I need to take the end off and put different connectors?

 

[ban-all-sheds]

No - solder the cable to female spade connectors, preferably ones with insulating covers.

As for the enclosure I'm not aware of any specific purpose-designed one - you'll need to look for an (ideally plastic) box big enough to enclose it. The flex will need strain relief too.


OOI, are there no products you can buy which do this aquarium job?

 

[ban-all-sheds]

It will be cold water going in, and "warm" water out (max is going to be 28C).

It's a solenoid valve.

How does it heat the water?

 

[jagillham]

Not that I can see sadly! I've spend best part of a day & 1/2 looking into this so far with not much luck.

There is one for injecting CO2 into the tank exactly like what I need, just ofcourse thats for gas only....

http://www.co2supermarket.co.uk/co2-solenoid-regulator.html

Ideally I'd have it all singing and dancing with float switches too, but getting the basics is proving complicated enough at the moment.

 

[ban-all-sheds]

At a guess the valve will be open for somewhere between 15-30 mins, how do I find out if this is an issue?

Look at the specs for it.

 

[jagillham]

It will be cold water going in [the aquarium], and "warm" water out [the aquarium] (max is going to be 28C).

It's a solenoid valve.

How does it heat the water?

The general idea is one solenoid opens to allow water to drain from the aquarium (which is already heated). The other opens later to let cold water in from the mains.

 

[bernardgreen]

Not my day today, the 12 and 24 volt solenoids are DC so the AC supply i linked to is not the one you need. ( small print in the data sheet and ancient eyes )

This is a DC 24 volt output supply.

http://cpc.farnell.com/stontronics/s2263st/ac-dc-linear-psu-24v-400ma-universl/dp/PW02843

Cut the plug off the end of the 24 volt lead and connect to the Fast On connectors Polarity is not important if there are no + and - signs on the solenoid.

 

[ban-all-sheds]

Presumably you've got controls which will ensure that you never get any failure modes where one solenoid doesn't work when it should and you end up either draining or flooding the tank?

 

[jagillham]

Without boring you with too much detail on the specifics of keeping fish...

There will be a standpipe in the tank half way up, so I'll drain down to 50% at the most. There will also be another standpipe above the water line again to the drains, so the water level cannot exceed the top of the tank.