thanks & a 12v H20 pump question

[kerry wise]

First: Thanks to everyone who has responded to my "newbie" questions.
Considering my still very limited knowledge in this area, I really do
appreciate the info and help.

Now, the question. (One of many more to come, I'm sure.) I will be running a
12VDC water pump to supply water from a water tower. Assuming I will be
using a battery bank of 6VDC batteries wired to provide 24VDC, is it
possible to use the 12 volt water pump? If so, how do I go about it?

 

[Windsun]

Get a 24 volt pump.

 

[George Ghio]

First: Thanks to everyone who has responded to my "newbie" questions.
Considering my still very limited knowledge in this area, I really do
appreciate the info and help.

Now, the question. (One of many more to come, I'm sure.) I will be running a
12VDC water pump to supply water from a water tower. Assuming I will be
using a battery bank of 6VDC batteries wired to provide 24VDC, is it
possible to use the 12 volt water pump? If so, how do I go about it?

Well you could use a 24VDC pump.

How tall is your tower. It may be that you already have enough water
pressure to not need to pump at the house.

George

 

[ptaylor]

Hi Kerry

The other two respondents are right - a 24v pump would be best.
However, you obviously have some reason for asking about using a 12
volt pump - probably its already installed?
You can get a dc-dc converter (24v to 12v) - this would be the
switched-mode type - which is relatively efficient. However, the cost
may outweigh the advantages of converting to a 24v pump.
If you are into circuit building, ty a search for a "dc motor speed
controller circuit" (or a pwm circuit or schematic))- there are many
on the internet. Some kitsets are available from electronics suppliers
and will generally handle up to 10 to 20 amps.
If you can't find anything, I have plenty of circuits I have
downloaded. However, you need to be reasonably confident about circuit
building before attempting something like this.

Eric

Well..you 'could' just connect the pump across only half your
batteries..it would work,but the imbalance might cause problems with
charging/discharging...and is probably not the best way to go about it..
Perhaps switching between the two sets of batts(batts 1,2 then 3,4) each
pumping cycle,so the batteries are at the same charge level,on average?

I'd opt for the 24V pump,or if you're stuck with 12V,get a dc-dc
converter sized for the job (Google for a company named "Vicor",they
make some large dc-dc modules.) I've got a smaller 75W 48V-12V dc-dc
from them. (no real use for it,yet.maybe soon.)

But yeah,if the tower is tall enough,and the pipe is a decent size,I'd
think gravity would be all you'd need.
Or are you trying to pump out of the *top* of the tower?
In that case,I'd think you could still use gravity,once you got some
siphon action going..Just run the pump long enough to get it started,and
maybe bypass it all together with a (electric/solenoid) valve once the
flow got going?..That way the pump wouldn't impede the flow once the
siphoning action took over.(some pumps may be better/worse than others
in this respect?)
I dunno, just thinking out loud..

 

[Nelson Gietz]

Big snip

But yeah,if the tower is tall enough,and the pipe is a decent size,I'd
think gravity would be all you'd need.
Or are you trying to pump out of the *top* of the tower?
In that case,I'd think you could still use gravity,once you got some
siphon action going..Just run the pump long enough to get it started,and
maybe bypass it all together with a (electric/solenoid) valve once the
flow got going?..That way the pump wouldn't impede the flow once the
siphoning action took over.(some pumps may be better/worse than others
in this respect?)
I dunno, just thinking out loud..

Just an observation... I use a gravity feed water tank. It makes no
sense to
pump out of the top of the tank. Pump the water in and out from the bottom,
just like all those small town water towers. One pipe is all that's needed.
I use a "jet" pump, running off the inverter. Fifteen minutes pumping
provides
three (or more) days' water. The downside is that the pressure is not high
unless
the tank is. You have to make sure your sink fittings have a larger bore
than the
"fashionable" quarter-inch piping in many of them.
Nelson