Hi Cliff
I can't take photos as this is in my IBC tank.
We bought the glands
http://www.screwfix.com/p/tower-male-comp-gland-white-25mm-pack-of-2/72655 (for illustration purposes)
and we bought some conduit that will push into the end of the glands. We found with trial and error that we needed about 300mm of conduit. We also found that the conduit was a tight fit in the gland so we didn't need plastic glue (cement) to fix it permanently. One of the glands doesn't need its cable seal or nuts as it will act as a pivot for the cable going to the float switch. The other gland will need its rubber seal as this will hold the cable tight and prevent the float valve pulling it through. Drill a hole in the top of the ibc tank that is big enough to push the gland up from inside. We drilled a hole in the high section toward the back to give room for the float valve to work. We found the best way was to assemble everything and then fit it into the hole through the IBC screw top.
Float valve from Machine Mart
http://www.machinemart.co.uk/shop/product/details/float-switch-230v-2m-cable?da=1&TC=SRC-float+valveThe float switch came with a wiring diagram. It allows you to choose how you want the float switch to work. The idea is to have enough cable attached to the float switch to hold it vertically under the water just as the ibc tank is full. If you 'shorten' the length of cable, then the tank will not be quite as full. Once you get it adjusted right the gland outside the tank will hold the cable secure when you tighten it.
I wired this to a junction box and also wired in the wires from the Normally off solenoid valve to the same box. A nearby socket provides the power and is also wired into this junction box.
So when the tank is empty the solenoid switch will be hanging in the ibc tank and will be on. Current will pass through the float switch to the coil of the solenoid valve, activating it and opening the valve so mains water will pass into the r/o filling the ibc with pure water. Once water level reaches the float switch, the float switch will float on top of the water. But as the water level rises it will then be held in check and so will turn from a horiontal to a vertical position which will cut the switch. Once the power is cut, the solenoid valve will automatically close, switching off the mains water supply.
A booster pump can be added to this circuit so the float switch will activate and deactivate the booster pump at the same time it activates and deactivates the solenoid valve.
What I like about this is that we have to take about 300 litres from the ibc tank before the float switch will activate. This means that the r/o always runs for sometime, which is its most efficient way - no stop/starts.
For security sake, we also fitted an overflow flange and hose into the side of the ibc tank which will take any overflow to the drain outside the garage where our tank is situated.
If the lads come in and fill up the float switch works on it's own without supervision. When we had the slower 450GPD system the tank might only be full at 3 o'clock in the morning - but we didn't have to worry about that. It just switched off at whatever time it was full.
Its worked perfectly on our 450GPD r/o and also works perfectly on our 4040 r/o.
