Water Tank Installation [long post]

["Frank Mc Alinden" <frankmc@xxxxxxxxxxxxxxxx>]

Hi Guys

Have just completed my Watertank installation which has taken up all my
free
time over the last 6 weekends....I have a zoned water irrigation system
sitting idle for the past 12 months or more due to water restrictions here
in Oz...So at long last i can now put it back into action....

When contemplating installing a water tank i initially thought i would
design my own pic based controller for it, i then decided to purchase a
Splatt Controller for it but ended up using an old TSX17 Telemecanique plc
since i had a handheld programmer for it and the plcs can be picked up on
ebay for approx 50 Euros....Even got some spare units and another
programmer
cheap..

I didnt want the water tank located near the house so decided to put a pit
in near the stormwater drain located at the rear of my property....While
doing a google for a suitable inground tank i came across another solution
which i thought was better ....what i liked about it was that no pit was
required.... and also it captured a lot more water .....Have a look
here.....

http://www.everydropwaterharvester.itaustralia.org/webpage.html

I contacted Phil the designer and ordered one of his systems..........I
used
his controller to initally fill my water tank, as i was building my own plc
based controller.... I had some issues with his drain plug and ended up
using a homebrew one (plunger based see pics)......

My eldest lad Dan got me a 6000L  water tank at a good price which he and i
installed on the first weekend...Phils controller was also installed at
this
point and with a couple of good days of rain the tank was full.....

Meanwhile i built the plc based controller and valve stand......
I have programmed the plc for two main modes
Harvesting Mode...
A float switch in the drain triggers this mode and causes the 2 harvesting
valves to energise followed by the pump...The harvesting valves direct the
water from the drain into the tank...This mode is exited if the drain water
drops below the drain float low level or the water tank full floatswitch is
activated.......

Irrigation Mode
This mode is activated by a plc input which is connected to a relay
connected to one of my HV I/O Expanders....So when Homevision is ready to
irrigate it turns on the required zone and sets this "start irrigation
relay"....The 2 irrigation valves on the "valve stand" are
turned on by the
Water tank plc followed by the pump....This mode is exited by Homevision
turning of the "start irrigation relay"...

Theres actually a third mode which i call "Forced Irrigation"
Forced Irrigation
If the Water tank is full and theres water in the drain to be Harvested the
water tank plc operates a relay which is connected to Homevision PortB 1
...This is a request "forced irrigation" input....Homevision will
then
operate my irrigation zone 3 valve (this zone is mostly under cover) and
then Homevision will turn on a relay (Forced Irrigation Ack) which is
connected to the Water tank plc allowing it to start Forced
Irrigation....This mode directs the water from the drain to the irrigation
system (using 1 harvesting valve and 1 irrigation valve) and  runs until
either the drain float indicates low level or Homevision zone 3 timer
expires (approx 5 minutes)....The idea is to make use of the access water
rather than letting it go down the drain......Theres also a timer in the
plc
to stop this mode from continually be triggered..........

I also wanted some visual indication of how much water i had in the tank
and
depending on how much water was left i could make decisions on wether the
garden beds get watered or just the vegie garden or both  (vegie garden
irrigation yet to be done)....I designed a pcb around a microchip based
controller sold by an Oz company here in Melbourne...
http://www.coolon.com.au/download/DS_CL4L.pdf

I made a mistake with the pcb...i forgot the relay coil was polarity
sensitive and got the connection wrong....But instead of cutting tracks i
mounted the relays under the board  and all was well...The relay contacts
are connected to the Water tank plc inputs so its easy for me to modify the
program to suit my needs... I made up my water level probe using plastic
conduit and coupling with some jubilee clip (see pics)..........

Have got the system working quite well now and i can control everything
using an x10 rf remote (using xPL) or via scheduled events in Homevision
....So hopefully this summer my wifes garden beds wont be as dry as last
year......

Things yet to do
Theres a spare water board mounted in the waterboard panel and im
considering using two of its inputs as backup for the drain floatswitch
....The other 2 inputs on the spare board im thinking of connected one to
the main drain point and the other to the water tank overflow inspection
point (see pics)...with these two inputs i can assume the following........

If i sense water on the main drain sensor and also water on the overflow
inspection point this means my full float switch has failed....

If i sense water only on the main drain but not the tank overflow
inspection
point this means my Plunger (drain plug) is leaking so requires
checking.........

I also need to put guttering on my pergola and connect it to the stormwater
drain....Im getting enough water now of the roof but during summer we need
to catch every possible drop.......
Heres a link to the photos ........
http://s195.photobucket.com/albums/z38/frankmc_2007/

Frank


www.armaghelectrical.com.au


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