Protecting the Worms

I have a worm based sewerage system. This has a small air pump that runs 24/7 and a pump to send the 'water' to underground drainage when it reaches a particular level.

A 240v circuit runs to the system and a return 240v line comes back to an alarm buzzer. The alarm triggers if the water level rises too high in the system (ie: too much input, can't handle output).

The flaw in this is that the system uses the same circuit for the pump and alarm and this can't be changed since the alarm triggers from the unit so if the power goes the alarm won't go off (doh!).

Occasionally (1-2 times a year) the circuit trips which means there is no way to know since the alarm doesn't go off. The only way to know is check the switchboard. This happened the week before Christmas and we didn't notice until it bubbled out the top and had drowned all the worms....(sorry - too much detail)

I have a GIU and could display (via Homegate) the status of the two circuits and thought the following might work, but look forward to wiser suggestions.

Since I can't measure directly the 240v into the GIU I thought I could wire a (say) 20va icon core transformer to the main supply circuit to the system and connect the output of the transformer to a channel on the GIU giving a voltage reading of 1-20v on the GIU. If this goes to zero I know the power has failed.

Additionally, to test for the alarm, I do the same on the (return) alarm circuit to another channel and if this turns on (ie: has voltage) I know there is a problem.

It's easy enough to monitor via the GIU once the voltage is reduced but is this a practical way to a) reduce voltage to GIU levels and b) test a circuit is on/off when the original circuit is 240v?

Thanks for the advice,

Andrew

 

If you only need to know the on/off status of the 240V going to the system you could always connect the 240V to the coil of a 240V relay and then connect the output/contacts of that relay to an input channel of a DIN Auxiliary Input unit?

 

Thanks Newman,

There is one small problem (which I should have mentioned). The 240v circuit is approx 50m from my house. I am on an acreage and this was installed in the original cottage. We've since moved into a new house 50m away.

I have a spare Cat6 cable between the two locations so a follow up question (if first thoughts were ok) was to ask if I could run the 12v over the Cat 6. Since it is only measuring the voltage (and not drawing current as such) I thought this would be ok (less voltage and current than C-Bus). This also seemed a pretty cost effective method as it only requires 2 transformers and no new C-Bus gear.

Andrew

 

Sounds good to me. Actually, if you use the DIN Auxiliary Input unit, you might not need to use 12V at all. The Aux Input unit will drive the line and will register an impedance of less than 1000 ohms as a closed contact. With this approach all you'd need would be something to close the contacts at the pump end of the Cat6 and connect the DIN Aux Input unit to the other end.