Water Pumps

In addition to my previous post:

Get rid of the #14 ASAP.

The conductors are too small for this distance and load.

Effluent pumps are not the most efficient pumps for this job. It will do it, and by all means take to heart the wire size suggestions, but effluent pumps are designed so they don't jam or clog when chunks flow through.

My dad used to sell them. One customer used them to pump a slurry of corn mash in an ethanol plant. It worked quite well for that application.

Thanks all for your input. I guess using an electric pump is out. The wire would cost more than the pump. I have a gasoline pump now, but it won't stay running and I also need it to run continuously for at least a day. The pump is used to fill my fish pond which is about 250' away from any electricity. We haven't had any rain for over a month and my fish are cooking. Hopefully we may see some rain today. The pond holds about 100000 gallons. I was thinking of running long hoses from the house, but I don't think running my well pump for that long is a good idea for the pump or for the well.

Ronseto - Good answers so far. One thing I don't understand. Sounds like your fish pond is where the water is needed. But where is the source? Is that what is 250 feet away from the electricity?

A thought here - A 250 foot spool of 3 wire indoor shielded #10 cable sitting on the ground for a few days would work fine. Then wind it up when you are done. If you decide to go permanent spend a bit more for UF. And later dig a trench.

FWIW -- At my house my well has a 1/2hp submersible 400 feet down the well. The well head is 330 feet from the house/electric box and the connecting wire is #8 at 240 volts. Total 720 feet. Works fine; 25 years. But the submersible pump motor may be designed to work at a greater voltage drop than your average open dripproof fractional HP pump motor.

Also note the connecting 320 foot pipeline is 16 pieces of 1" sch40 PVC with just a handfull of elbows at each end. Pipe conections are 1" screwed PBC fittings with teflon tape sealant and are quite easy to transport, assemble and disassemble. This assembly and disassembly facilitates easy disassembly of the pump string when the pump must be pulled from the well for repair or replacement.

PVC pipe would be to store when not needed if a temporary line laying on the ground were anticipated. Make a nice little stack against a long wall and block each end with a cement block to keep the critters out. In my temperate climate pipe is buried 6-12 inches in the ground from house to well head. I imagine in your sandy Mississipi soil that would be easy. (or isn't it sandy like southern Alabama?)

Ed Weldon

The source of water for the pond is a shallow well 20' from the edge of the pond.

Ronseto - You may have a continuing problem with longer early summer drought periods in years to come. A very practical solution for only 20 feet of head may be a small submersible pump that will run off a solar panel continuously delivering to the pond at a few gallons per hour. I've heard of these pumps but have not yet researched them. 20 feet at a reasonable flow rate is beyond your little fountain pumps.

What would you estimate is the daily water loss from the pond in your current weather situation? ............. Ed Weldon

Ed, Cost as always is a factor that I have to take into consideration. Fixing the gas pump is the cheapest solution, but the quality of gasoline available keeps the pump from working properly. The water level is so low that I would have to run the pump continuously for a few day. One fill up runs the pump for about 2 hours. There have been some ominous storm clouds on the horizon. Maybe a rain dance would work.

Hi ron,

A quick thought that doesn't answer your question, but I don't want your fish to cook.

Try contacting your local fire department. They have a schedule in which they have to flush out and refill their tanker trucks. This is typically potable water. I've seen them here just blowing the water into an empty field. You may be able to get them to come by and release into your pond.

Heck, if it works out and you buy the guys lunch, you might be able to get them on a schedule where you don't need a pump.

Hope this helps..................hot and bone dry here too.

I didn't respond earlier, but I was going to say that the #14 wire is just close to marginal at 220 / 240 volts. IIRC, the NEC requires that a permanent installation be sized for no more than a 3% voltage drop.

If your load is 5 amps at 220 / 240 volts, the voltage drop for 500 feet of #14 is 6.25 volts (1.25 ohms times 5 amps). Divided by 220 volts, that is a 2.84% voltage drop.

If you already have the #14 cable, and can set the pump to use 220 volts, I'd give it a try. Keep the motor in the shade, and in a place where a breeze can get to it. Consider using a small fan to blow extra air on it.

(Also, to the extent feasible, try to keep the wire in the shade--but let air circulate to it also--the resistance of the cable will increase with temperature, also.)

If the #14 cable is in several pieces of extension cord, I'd consider cutting the connectors off and splicing the cables together--I'd use solder to minimize the resistance.

A1: while it can, it is not a good idea as the wetted materials might not be compatible with potable water. It is better to select the correct pump.

Just a suggetion:

How about if Ron used, lets say #10 or # 8 for the first 100' then downsized to #14 for the remaining 150' . Does that make the voltage drop alittle more acceptable at 220.

This would keep Ron's costs down if he had to buy the wire but he might be able to borrow or rent a more common 100' vs a 250' length.

That being said : if Ron needs to buy the # 10 or # 8 wire it might be smarter to use that money to fix the gas pump he has so it works properly.

Rescue

Re: How about if Ron used, lets say #10 or # 8 for the first 100' then downsized to #14 for the remaining 150' . Does that make the voltage drop alittle more acceptable at 220.

Certainly. The circuit breaker protecting the cable must be sized for the #14 (i.e., the smallest) cable. But, at 220 volts, the 2.7% loss or so that I calculated is within limits.

It is possible (I don't intend to do the calculation, atm), that 100' of #10 or # 8 wire would lower the resistance enough to work (i.e., avoid excessive voltage drop) at 120 volts.

But, the calculation is easy enough to do--for 100' of a different cable, get the resistance for 300' of #14 and add the resistance for 200' of #8 or 10, then multiply by the current at 120 volts (which, in this thread, has been assumed to be 9 amps). That is the voltage drop in volts, now divide by 120 (or 110) volts to see the voltage drop in percent (well, actually, that would be per unit, you need to multipy by 100 to get percent).

If it is less than, or not too far from 3%, it should be a workable solution, worth a try.

(Aside: it looks like that comment was my 1000th on CR4, so in celebration of that, I'm going to go the extra mile. ;-)

The resistance of #8 copper cable is 0.6401 ohms from Wire Resistance and Voltage Drop Calculator.

Thus, the resistance of 500' of #8 is 0.320 ohms, and the voltage drop for 9 amps is 2.88 volts, which, divided by 110 is 2.6% which means which is not far from 3%--thus, the vast majority of the cable would have to be #8 to achieve a 3% or less voltage drop.

Looking at it from the other direction, a 3% voltage drop of 110 volts is 3.3 volts. Still assuming 9 amps current, that means the maximum resistance of 500' of cable to achieve no more than a 3% voltage drop would be 3.3 / 9 which is 0.367 ohms.

So, we can create two equations (or one equation and one inequation ;-) in two unknowns.

use X as the length of #14 cable, Y as the length of #8 cable:

X + Y = 500

0.00257X + 0.0006401Y <= 0.367

Then:

X = 500 - Y

0.00257 (500 - Y) + 0.0006401Y = 0.367

1.285 - 0.00257Y + 0.0006401Y = 0.367

-0.00193Y = -0.918

Y = -0.918 / -0.00193Y

Y = 475'

X = 25'

So, you could use 12' of #14 cable and 238' of #8 cable (or more #8 and less #14).

How about installing a Windmill pump Like this

They seem to be a little pricey,but just think how much gas or power it might save you over time. This one is quite tall but I see there are ones that are small as 6 ft.

Rescue