Is a 12V or 240V pump on an inverter better?

[BlueWolf]

Hi guys
Where I'm planning to setup my AP system is 225m from the house. So I'll need to use solar I think to power my pumps. Is it more efficient to use 12V pumps or 240V pumps running of an inverter?

And if using an inverter can it have a modified sine wave (they seem to be cheap) or a normal sine wave (not so cheap it seems)?

[Murray]

It is a good question.
I have been down that road.....the 12/24 volt road. Being a boat builder I figured that I could build a pretty good DC system. Trouble is that there are no low cost continuous operation 12/24 volt pumps out there.
Depending on the luck of the draw you will get 1 month or 6 months before they fail. (used in a continuous operation mode)

Great for a backup system, in fact I believe there is nothing better than a 12/24 volt pump system as a backup. Much better than a battery operated aerator, because the 12/24 volt pump backup system not only provides aeration, but water movement as well.

There are some very good quality 12/24 volt pumps available but be prepared to hand over a fair bit of cash to get one.

Another problem with the 12/24 volt option is the limited availability of pumps and spares for them , whereas 240 volt pumps can be picked up almost anywhere.

[Muchea]

Hi guys, I agree with Murry the low voltage pumps are not reliable so the inverter would be the better option, I`m going to use(or try to) green power as well Ive decided to try wind and solar. the wind ive made some wind gens out of the old fisher&paykle washing machine motors which work quite well(for those cloudy days), also i was going to use computer backup power(UPS) with a bigger battery. a lot of UPS`s get thrown out just cause the battery inside is stuffed, what a waste of a good inverter!! I picked up one from one of those throw out your dead(council rubbish pickups) got a 100ah gel battery from battery world which should run a 200-250w pump for about 4-5 hours through the UPS

[Murray]

Hi Muchea, good way to go. I wish I lived closer to the coast to be able to take advantage of the constant wind to run my systems.
Wind power is really the best of the lot....provided you have some of it.

It is relatively easy to build a wind driven gen set if you are a bit handy. Compared to solar, even a commercially avbl wind driven gen set is much more productive and cost effective.
Trouble is where I live we get very little wind at all.

[Outbackozzie]

A 200w pump will draw around 20A @ 12v via the inverter from the battery, so you could really only run it for 2 hours or so. You do not want to discharge the battery (even being a gel cell) below 50% ever.

My backup system (that runs 24/7) is two 100ah batteries, running 1/2 of the ap system pumps (all 240v).

I get over 10 hours to 75% capacity remaining. The batteries should last for years.

[BlueWolf]

thanks for the feedback. So it seems an inverter is the way to go. Do inverters last? I bought one from ebay for $60 and have been running it and the fan is getting noisy so I'm a bit concerned, so I guess the AP system should include a backup system from day one. Does anyone know if a pump requries an inverter with a full sinewave or is modified OK?

[Outbackozzie]

Mine is just a modified square wave. Cheapy ****smiths one, fan has got noisy as well, but it hasnt got really bad, never trips out, and it is in a tin shed which gets extremely hot.

It even has a very very loud alarm to tell you if you have forgot to turn the charger on lol.

I am not expecting miracle lifespan from it, you get what you pay for. Thats why I run it all the time, so if it stops I'll notice before a power out hopefully.