Backyard Aquaponics
A place to discuss aquaponics

With holidays fast approaching and the prospect of leaving a system to a housesitter with 200+ nearly plate size fish in the tanks, I decided it was really time to act on the back up power. I have seen the need for extra DO, and added a air pump, but what happens if the power fails? Also, if the growbeds are full when the power goes off, the sump will overflow and I would lose possibly 1200 litres of water.

So, step 1) I have a 12 volt bilge pump with a float switch attached to a brick in the bottom of my sump. It is wired into a fail over switch which, when the power fails, switches over to 4 x 13 Amp Hour UPS batteries linked together, which are fed by a trickle charger. All up, over 50 amp hours of power from them and when the water rises in the sump, it pumps it back to the fish..
step 2) I have a second 12 volt pump in the vat, wired to the same setup so when the power fails, it circulates water around the tanks and aerates via splashing. All up I should be good for up to 6 hours

where did you get the fail over switch from? Is it something common?
I presume it also plugs into the power?

Stu, for the piece of mind, go buy a standard car battery for $45, it sould give you around 40AH. Won't like being discharged flat, but i'd be happy to waste a $45 battery for 250 plate sized barra!

I have one which I bought from Murray at www.aquaponics.net.au . Works a treat. Stu - where did you get yours.

I would second that.

Just don't leave car batteries siting on concrete floors.

For some reason (don't know why) it discharges them and stuffs them up.

I have a mate who sells and services UPS's as his business.The batteries are brand new. Apparently, people buy the UPS's then want more battery power so he has piles of these that come as standard fare with the UPS's sitting around having never been used. He gave them to me for nothing. Also, as far as I am aware, they don't mind going flat.

I have had one pump run for about 8 hours on the batteries without them going flat.

FJ and VB, the mate of mine who sells UPS' is an alectrician. He made the switch up for me. I am electrically challenged so I was lucky. FJ yep, the switch plugs into the power.

to make a failover switch wire up a double throw relay so that the mains supply turns the relay on and the relay is connected do that the NO contacts provide the mains power. Connect the battery to the NC connection so that when the power fails the relay de-energises and connects the battery.

We used something like this + car battery and cheap inverter for years as a low cost UPS.

has been covered in much depth earlier in the thread njh, but thanks anyway.

People like me and Stu don't understand what any of you electonics knowledgable people are talking about - so we have to outsource.

I am still confused with all this jargon, but I will google and will read the rest of the thread, right after I wake up...

muzza has them for sale for those that think a cap is something you put on your head, instead of charge up to 320VDC and throw to a mate saying "catch"

I am sure that is something unpleasant but I like the idea. I presume it gives them a zap?

ya.

Was once a funny thing to do at trade school........along with "meggering" the back of someones neck..............Either/or would get you expelled now................And i wonder why i have issues with atrial fibrillation LOL

I was in Whitehorse in Winter last year - fancy that. Stayed at place called "Inn on the Lake". minus 30 degrees C. Fantastic for a Perth boy like me...

Good old mega machines. We had heaps of fun with an old wind up one. A mega is a machine that creates high voltage, low current for testing the integrity if insulation and other non conductors.