Wire size for a pump?

   #1  

EddieWalker

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One day, probably years from now, I hope to have a pump that I can get water from my pond to water my gardens. I don't know how big this pump will be, or if I will put it next to my house and run a thousand feet of pipe to the pond, or run the wire to the pond and put the pump in the pond. It might not even happen, but I'm at a stage in my house remodel that I want to run the wire from my breaker box to the side of my house. It will be super easy to do it now, and not so much if I have to do it years from now.

There is also a good chance that I will have the power company put in a couple more poles and set a meter close to the pond, and have power down there that will make all of this meaningless.

Since I don't have the pump, and I'm driving myself crazy looking at pumps online to see what their power needs are, I'm curious what some of you would run for wire?

I was leaning towards 8/3. I only need about 40 feet, so I'm hoping that I can buy a 50 foot roll. I found some direct bury 6/3 on my shelf of scrap wire, but it's too short, but might work great in the future to go from the junction box that I will put on my outside wall, to the pump if I put it next to my house.

Which just reminded me that I need to put a 110 outlet out there too so I can have power to turn the sprinklers on and off!!!! I didn't even think of that until just now.
 
   #2  

fried1765

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One day, probably years from now, I hope to have a pump that I can get water from my pond to water my gardens. I don't know how big this pump will be, or if I will put it next to my house and run a thousand feet of pipe to the pond, or run the wire to the pond and put the pump in the pond. It might not even happen, but I'm at a stage in my house remodel that I want to run the wire from my breaker box to the side of my house. It will be super easy to do it now, and not so much if I have to do it years from now.

There is also a good chance that I will have the power company put in a couple more poles and set a meter close to the pond, and have power down there that will make all of this meaningless.

Since I don't have the pump, and I'm driving myself crazy looking at pumps online to see what their power needs are, I'm curious what some of you would run for wire?

I was leaning towards 8/3. I only need about 40 feet, so I'm hoping that I can buy a 50 foot roll. I found some direct bury 6/3 on my shelf of scrap wire, but it's too short, but might work great in the future to go from the junction box that I will put on my outside wall, to the pump if I put it next to my house.

Which just reminded me that I need to put a 110 outlet out there too so I can have power to turn the sprinklers on and off!!!! I didn't even think of that until just now.

Get a longer piece of 6/3.
Bigger is better in everything except P***ey
 
   #3  

BertZegers

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The distance from the house to the pond is the important factor because of the voltage drop. The higher the length, amps, the smaller the sq mm, the higher the voltage drop. The cable length in the house is probably short compared to the length outside, and would have not much voltage drop, you can compensate for voltage drop by choosing a heavier cable outside.

It doesn't mater of voltage drop occurs in-house or outside, it is the total voltage drop that matters.

In house, choose a 3 wire+ground so you have a neutral, ( maybe not needed but more possibilities, timer?). Choose the inside cable to the breaker Amps, you may need a special breaker for motors. Choose the outside cable so you stay within the permissible voltage loss for the pump. The pump should be 220 Volt for sure.

Without knowing the pump amps, voltage, cable lengths and their environment (in insulation or in conduit or in bare ground) it is impossible to calculate the square diameter of the wire, which than can be converted to the weird "gauge" size that is used on this continent, to make things more complicated than necessary.

In short: choose the in-house cable to mach the amps of the biggest pump your considering and the rest comes later.

I am a retired electrical contractor from Europe and I am not familiar with your local code. But voltage drop calculations are not different, except for the complication of that weird "gauge" thing. In Europe the square mm is printed on the cable. Plain and simple. No need to convert from "gauge".
 
   #4  

Mendonsy

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Here is a link to a handy wire size calculator. All you need to know is current and distance to find the required wire size.
wire size calculator
 
   #5  

BertZegers

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Here is a link to a handy wire size calculator. All you need to know is current and distance to find the required wire size.
wire size calculator

I think what Eddy is saying that he needs to run 40 feet from the main panel to the panel for the pump. From that panel 1000 feet to the pond, where the pump is.

I would not choose a 1000 feet long cable on an internet calculation that asks only 4 questions.
 
   #6  

mrmikey

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Which just reminded me that I need to put a 110 outlet out there too so I can have power to turn the sprinklers on and off!!!! I didn't even think of that until just now.
While you're installing things for the future, maybe low voltage wire for remote control of valves or motor control as well..................mike
 
   #7  

tmc_31

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Given what you know at this point, I think I would run a 1" or maybe a 1-1/2" conduit from your main panel out to a weather proof enclosure on an outside wall. Then when you decide on which pump you want to buy and where you want to put it you will only have to run the appropriate sized wire. You can put up to 3 #2thhn wires in a 1" conduit.

If you used a 1 hp pump 1040' away from your main (at (240v) , it would take #6 wire to stay under 3% voltage drop. If you want a bigger pump, you can run up to 3 -#2awg wires in a 1" conduit.
 
   #8  

BoylermanCT

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Eddie, what is the elevation change from the pond to the gardens? If the elevation change is only a few feet, you won't need a huge pump. My 1/2 hp well pump is rated for a well 200 feet deep. I am guessing you are not pumping the water uphill anywhere neat that, but I could be wrong. You could be pumping downhill for all we know!

I would definitely put the pump in the pond. The water will always flow if you do that. In our town, we have no fire hydrants so in the fire department we practice filling up 3000 gallon tanker trucks from local ponds and rivers, and it takes much more horsepower to suck water up an empty pipe that it does to push water up that same pipe. We are using 6" PVC dry hydrants that are sometimes 10-15 feet above the water level. We will back fill the empty pipe with water from the pumper engine and then reverse the flow to begin filling tankers. We can fill a 3000 gallon tanker in 2.5 minutes. We can pump water faster, but pushing it into the tanker at anything more that that can blow out the tank.
 
   #9  

Gator6x4

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I have never seen a pump with a thousand foot lift. Lift being the distance between the pump and the water source.
 

buickanddeere

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Pumps push, they don稚 pull worth a darn. About 15-20ft lift is about it with much reduced efficiency. Pump will hardly notice pushing 15-20ft of lift .
 
 
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