Measuring water flow (or pressure or both?) from dam pump

Just wondered if anyone could suggest a way to measure water flow (or perhaps pressure - but water flow might be more reliable). Recently had an issue where irrigation from a dam pump failed as the impeller had jammed. The system looked like it was watering as the C-Bus SELV was switching the solenoids on as required but of course no water was flowing.

There is a C-Bus relay located at the dam pump (so C-Bus available) - just wondered what would be a reliable method of determining that the water is actually flowing.

Thanks in advance for any suggestions.

Andrew

 

Does it have to interface with C-Bus, or is a stand alone solution ok?

If you search eBay for "water flow meter" you will find stand alone sensors and displays.

You will also see just the sensors (water wheel type thingies) that I have used to interface with the C-Cbus measurement application, but it requires custom hardware/software. They output a pulse with a varying frequency vs flow rate, so you would need something that can handle that, and send it to C-Bus. I don't think the General Input Unit can do that.

Cheers

Rohan

 

Yeah, a 4-20ma pressure sensor tapped into the output side of the pump would give you an indication that the pump is pumping.

In addition the General Input Unit can read 4-20ma devices and broadcast it on C-Bus.

Cheers

Rohan

 

Thanks Rohan and Nick for the help/suggestions.

Would need to put this on the pump outlet as suggested as there are about 20 different solenoids (at the moment).

It does need C-Bus connection so that status can be displayed on HomeGate and also email warning can be sent if a problem since not always obvious if watering has taken place (property can be vacant at times).

Time to start researching sensors!

 

Have a look at "Ocean Controls", they sell that kind of stuff.

They also appear to have a couple of flappy paddle flow switches, which would be fine if you only need a flow/no flow indication. Add a bus coupler and your good to go without the need for a GIU or external power.

I haven't bought such a device from them, so I can't directly vouch for them, but I have bought other stuff which has been fine.

And for the record I have no association with them.

Cheers

Rohan

 

Thanks Rohan. Something like this would probably do the job I think: https://oceancontrols.com.au/CMS-402.html

If my reading is correct on coupler spec the max distance wiring is 10m from bus coupler to flow switch?

 

If I'm reading the spec right it says will work on 1"-3" pipe so I'm hoping its a 1.5" pipe which would work ok.

https://oceancontrols.com.au/datasheet/com/cms_402.pdf

Re-reading the bus coupler specs you are right! 10m is MAX on entire network - 1m per switch....

• A maximum of 1 metre of wire may be used to connect an individual
switch or LED to a C-Bus Bus Coupler’s input or indicator terminal.

• A maximum of 10 metres of wire in total may be used to connect
switches to all C-Bus Bus Couplers present on an individual C-Bus
network. Examples of this are 10 channels at 1000 mm each or 24
channels at 415 mm each. Exceeding this length may adversely affect
C-Bus network communications. If longer connections are required, it
is recommended that an L5504AUX C-Bus Auxiliary Input Unit be
used.

 

This one is much cheaper https://oceancontrols.com.au/TRS-028.html

I THINK the idea is you cut the paddle to the required length, but don't take my word for it, check with the supplier.

Cheers

Rohan

 

Nah, my tiny 60W solar heating pump does 20L/M.

Even the smallest pool type pump will do a couple of hundred L/M at least.

My only reason for now (yes I changed my mind) leaning towards a flow sensor vs a pressure sensor is because the pressure will depend on the flow resistance of whatever is on the end of the pipe (broadly speaking). Also if it is blocked then the pressure will be high, but no water will be flowing. A flow sensor will tell you water is actually going somewhere.

Anyway, you have heaps of options and you can choose the most appropriate.

Cheers

Rohan

 

Keep it simple.

You want to know if the system is working. Use a pressure switch (with adjustable set point). Much easier to install than the flow switch as well.

https://oceancontrols.com.au/ADS-313.html

Dont use a bus coupler - too limited with distance. Use an AUX input unit.

Even with all valves open, there is pressure from the pipe work so you will always see something at the outlet of the pump.

No pressure means something is not working - it could also mean a complete failure of the pipe work near the pump if you set it right. A good bit of extra protection that a flow switch wont give you.

Some logic is required.
- No pressure and pump off means all OK
- No pressure and pump on there is a problem (pump not actually running or pipe failure)