230V Timer with trigger required

[Danny]

Hi

Does anyone know of a 230V timer that has trigger functionality?

I have attached a diagram of what I want to use it for. Some people may question the need to let the tank fill, if I didn't the pump would be constantly kicking in and out when raining.

I'm aware that I could use a time delay relay for this application but would prefer a self contained timer, less messing about with enclosures and din rail etc and probably less to go wrong.

Thanks
Danny

[Justme]

I think you are over complicating this. The float switch that I have for the bore hole storage has a large transition between on & off & then off & on. By carefull adjustment I can set it so that the tank will get to about 20% full then switch the pump on & stop at about 80-90% full. Thats a working range of about 600L or 60-70cm. It could be set to a larger range with weights on the cable. It does not cycle with a small water level change.

The type I have has a large metal ball inside so that once triggered its holds its position till the cable tightens on the fill or pushes up on the empty. It can be wired as a filler or an emptier.

Justme

[Alan]

I have not seen a float switch with an adjustable on period timer fitted.

As you say needs Din rail / box but you could use this switch.

http://www.maplin.co.uk/Module.aspx?ModuleNo=12167

and this multifunction timer.

http://www.rapidonline.com/Electrical-Power/Control-Gear-DIN-Terminal/Timers-Controllers/80-Series-16A-Modular-timer/61777/kw/timer.

Or

Another solution would be one switch for high level and one switch for low level

This would allow a system with a fixed differential.

High switch feeds the coil of relay terminal 2

http://www.rapidonline.com/Electronic-Components/Relays-Solenoids/Plug-In-Power/DPDT-10A-Power-relay/71155/kw/60-1676


240 volt part including base  No 60-1676

Low switch connects to terminal one on the relay base.

Terminal 3 on the relay base connects to the coil also which is terminal 2

Other side of the coil terminal 7 goes to neutral.

Other side of both float switches goes to live.

Terminal 8 is live

Terminal 6 is the feed to the pump


Regards

Alan

[Iain]

Hi
I have been running a similar system for a couple of years. I just use one of the float switches from machine mart(float on the end of a wire)http://www.machinemart.co.uk/shop/product/details/float-switch-230v-2m-cable
The switch works a treat(operates a contactor for my external pump), I have it through a gland in the side of the tank so the length of the cable is adjustable. This allows the differential to be adjusted. I have it set to cut in at about 60% cut out at about 20%. The only problem I have had is the capacitor on the pump failed and I lost a lot of the unpumped water through the tank overflow. Will now be installing a small float switch near the top of the tank just for an alarm/warning, strobe or sounder.

I prefer to try and keep the tank as near to empty as possible then if I do have a problem there is a greater reserve for storage and so much water isn't lost.
Iain