Booster pump at a distance, what size wire?

[Slimmons]

Hey, I have a booster pump that I'm about to wire at the bottom of a hill. I've got to run the wire about 350ft. Its plug in is a standard 110 volt 3 prong, and all I want to power at the bottom of the hill is maybe some minimal lighting (probably low draw LED), and during winter I'd like to run a small bulb in the pump house to keep it above freezing. I am in the US, and I have a 200 amp breaker box with plenty of space available. Wire is so expensive at that length, that I don't want to over build this too much, but I also don't want anything to burn up.


The specs for the pump are at max:
115 volts,
1250 watts

Which assuming my math is not awful, is 10.87 amps


I have little to no experience in electrical, and just about every "wire gauge calculator" I'm using is spitting out a different answer.
I have a friend who does more electrical work than me, who said a 30 amp breaker with 10 gauge wire should be fine. But, I've got enough problems without me also destroying a pump. I don't have a huge preference on which size breaker I use, as I have a ton of breakers laying around now ranging from 15-50amp. Thanks again hive mind.

 

[Innovate1]

Number 10 copper at that length gives 6.65% drop. Pretty high and given the startup current the pump may not start. #8 give 4.4%, #6 gives 2.8% which I would guess would be fine. I'd give serious thought to a 240V pump - if yours can't be changed you could get one that can. And you could go with aluminum wire to save some money. Conduit isn't cheap either so maybe some direct burial cable. Not much available in smaller sizes. Triplex URD is available from wireandcableyourway.com so you could consider that.

 

[mike93lx]

Almost hate to say it, but #2 MHF and a little sub to facilitate connections if probably prudent. You'd have to at least pigtail with #8 or 6 anyway and having a breaker and gfci at the device instead of 350ft away wouldn't ****

 

[micromind]

Since the motor is listed in watts and not amps, it's most likely of poor quality and won't hold up very well with low voltage so you'd need at least #8 copper.

I like the idea of a larger aluminum wire with a sub panel, as noted above. It's more $$$ now but it's way more versatile for the future.

 

[LopezBart]

Since the motor is listed in watts and not amps, it's most likely of poor quality and won't hold up very well with low voltage so you'd need at least #8 copper.

That's a Grundfos pump. I would not call those as being of poor quality. Here's a picture of some of their technical info provided on that site. Since their pumps are available in both 120 and 240V versions, representing the power level in watts makes perfect sense.
I would definitely try to get a 240V pump. Failing that, a step-down transformer at the booster pump would allow you to run 220 down the hill and save on wire.

 

[micromind]

You're right, Grundfoss is high quality.

There are a ton of chintzy pumps out there that use watts rather than amps or HP.

My mistake.

 

[chinboys]

Exchange the 120V pump for a 220-240V one thus halving the amperage and sizing of wiring for the same run length

 

[Slimmons]

At this point, exchanging the pump for a 240v pump won't make sense. I've been using the pump for several months, just near the top of my hill. It isn't getting as much water as it needs, so I'm lowering it down the hill. @LopezBart thanks for the suggestion. I'm guessing switching to 240V and getting a step down would save me money because I can use a smaller gauge wire. What size wire would that need to be? Could I do something like a 12/2, and get the step down once I'm there?

 

[chinboys]

I took a quick look at this model of pump and perhaps there might be a way to rewire your pump to work on 220V and a changing of the male plug.
It would be worthwhile to ask the place where you purchased the pump if Grundfos has such documentation or there is a voltage setup illustrated on the case of the motor.

 

[wyliesdiesels]

At this point, exchanging the pump for a 240v pump won't make sense. I've been using the pump for several months, just near the top of my hill. It isn't getting as much water as it needs, so I'm lowering it down the hill. @LopezBart thanks for the suggestion. I'm guessing switching to 240V and getting a step down would save me money because I can use a smaller gauge wire. What size wire would that need to be? Could I do something like a 12/2, and get the step down once I'm there?

which model pump do you have? really need specs to calc these things

also the formula for voltage drop calcs is in the electrical FAQs sticky in post # 29, so you can calc the sizes yourself.

Electrical FAQs

Welcome All I have started this sticky as an FAQ thread for info on the basics that are encountered countless times every week on here. Hopefully this will help some. If u have a topic request, go ahead and post it. And if you have an FAQ you would like covered let me know.... Or if you...

www.garagejournal.com

 

[Innovate1]

Or use an on line calculator like this one:
https://www.southwire.com/calculator-vdrop
going to 240V will roughly cut your current in half.
Changing wire gauge 3 sizes will change the cross sectional area by 2. Since odd wire gauges are not common you could change wire gauge by 2. You still aren't going to be able to use #12. I suppose you could boost the voltage to 480 and use #12 but the cost of transformers at both ends is likely to be more than the cost of larger wire.

 

[Slimmons]

Ok, so update to this. I decided since I had the materials, I'd try running 10/2 wire down the 350ft. I wired a gfci 110v outlet at the bottom of the hill, and at the top of the hill I used a single leg of a gfci 220v breaker. Basically, I had most of the material to do this handy, so I decided to test it out......it did not work.
Also, I switched to a larger pump (Grundfos CMBE 1-44) I called and visited every plumbing and pump store around me, and no one had any 220v/240v pumps, and everything was on back order. I didn't think it would be a big deal sticking with 110......but this has turned into quite the headache.
The gfci outlet at the bottom of the hill trips a couple of times a day. Once again, I'm not an electrician (but neither are most electricians I've met recently) but I'm guessing it's worth it for me to go ahead and wire up both legs of the 220v breaker I have, buy some 10/3, and run it down the hill. But I still have the issue, of the pump being 110. @LopezBart mentioned a step down, but I can't seem to find one that takes bare wire. Is there some product I'm missing? Links to products would be useful. Or other ideas that I'm missing.
Ideally, I'd like to not have to buy the 10/3 wire, but at this point I'm willing to spend some money to make this problem go away. I just can't wait 3 months for a 240v pump.

 

[PCustoms]

Ok, so update to this. I decided since I had the materials, I'd try running 10/2 wire down the 350ft. I wired a gfci 110v outlet at the bottom of the hill, and at the top of the hill I used a single leg of a gfci 220v breaker. Basically, I had most of the material to do this handy, so I decided to test it out......it did not work.
Also, I switched to a larger pump (Grundfos CMBE 1-44) I called and visited every plumbing and pump store around me, and no one had any 220v/240v pumps, and everything was on back order. I didn't think it would be a big deal sticking with 110......but this has turned into quite the headache.
The gfci outlet at the bottom of the hill trips a couple of times a day. Once again, I'm not an electrician (but neither are most electricians I've met recently) but I'm guessing it's worth it for me to go ahead and wire up both legs of the 220v breaker I have, buy some 10/3, and run it down the hill. But I still have the issue, of the pump being 110. @LopezBart mentioned a step down, but I can't seem to find one that takes bare wire. Is there some product I'm missing? Links to products would be useful. Or other ideas that I'm missing.
Ideally, I'd like to not have to buy the 10/3 wire, but at this point I'm willing to spend some money to make this problem go away. I just can't wait 3 months for a 240v pump.

What didn't work with your setup using the 10/2?

Did you measure voltage at the end?

We're the GFCI tripping?

Is suspect a 240v GFCI isn't going to like only one leg connected, I may be wrong though.

 

[Slimmons]

@PCustoms I'm guessing (emphasis on guess) that the pump is trying to draw too much power, and that's what's causing the gfci at the bottom of the hill to go off. Having said that, I'm guessing at this point.

 

[PCustoms]

@PCustoms I'm guessing (emphasis on guess) that the pump is trying to draw too much power, and that's what's causing the gfci at the bottom of the hill to go off. Having said that, I'm guessing at this point.

A GFCI outlet will not trip due to current.

You have another issue.

Can you bring the pump inside and test it on a know GFCI outlet?

 

[Slimmons]

@PCustoms Unfortunately no. This pump is the only source of water to my house, so I wouldn't be able to test the pump anywhere but where it's at. BUT, I can tell you that there's no water coming in contact with the outlet. It's inside of two water proof containers, and I keep checking it. Everything has been bone dry.

Also, I'm not saying you're wrong. BUT, for every website I find that says a GFCI outlet won't trip due to current, I find another that says it's THE MOST common reason they trip.
I'm going to assume you're right, and troubleshoot it assuming that current is not the reason. I'll double check all of my wiring and make sure I haven't inadvertently done something wrong there. But, I'm kind of doubting that's the issue either, as there's no movement inside the waterproof containers, and it's working for more than half a day at a time.
Also, since I'm running this bare wire over ground, I'll trace the whole thing and make sure no animal has tried to eat it. Other than that, I'm out of troubleshooting steps.

 

[PCustoms]

@PCustoms Unfortunately no. This pump is the only source of water to my house, so I wouldn't be able to test the pump anywhere but where it's at. BUT, I can tell you that there's no water coming in contact with the outlet. It's inside of two water proof containers, and I keep checking it. Everything has been bone dry.

Also, I'm not saying you're wrong. BUT, for every website I find that says a GFCI outlet won't trip due to current, I find another that says it's THE MOST common reason they trip.
I'm going to assume you're right, and troubleshoot it assuming that current is not the reason. I'll double check all of my wiring and make sure I haven't inadvertently done something wrong there. But, I'm kind of doubting that's the issue either, as there's no movement inside the waterproof containers, and it's working for more than half a day at a time.
Also, since I'm running this bare wire over ground, I'll trace the whole thing and make sure no animal has tried to eat it. Other than that, I'm out of troubleshooting steps.

I forgot if you mentioned, is the pump new? How long has it run? Is it running now?

You say it's your only water source, but I thought this was new, so it's throwing me off.

GFCI outlet don't trip for current. Period.

Do you have a meter?

Do you have another grounded device you can try at the end of the wire run?

 

[Slimmons]

I forgot if you mentioned, is the pump new? How long has it run? Is it running now?

You say it's your only water source, but I thought this was new, so it's throwing me off.

GFCI outlet don't trip for current. Period.

Do you have a meter?

Do you have another grounded device you can try at the end of the wire run?

It's a brand new pump that I just got. Straight out of the box. It is my only source of water, but I had a different pump before that died due to manufacturer defect.

I do have a meter, and I do have some other devices I can try and test at the end of the wire run. I'm not great with a meter, but I have one.

 

[PCustoms]

It's a brand new pump that I just got. Straight out of the box. It is my only source of water, but I had a different pump before that died due to manufacturer defect.

I'm still it following, is it working, or are you without water?

I do have a meter, and I do have some other devices I can try and test at the end of the wire run. I'm not great with a meter, but I have one.

I would check the outlet first, you can either plug something in, probe it with the meter or these are like $15 and well worth it:



Assuming no issues there, then I would verify there is NO continuity between the ground pin and either terminal on the pump plug.

 

[LopezBart]

I'll echo what others have said: A tripping GFCI outlet isn't due to overcurrent. They do fail however, and they're cheap enough to replace.
There are various auto-transformers around; this one is likely not very good but it's inexpensive compared to 350 feet of fat copper wire: https://www.homedepot.com/p/VEVOR-V...rt-CE-Certified-DYZHQ110V230VQLPQV1/327190581.

 

[Slimmons]

I'm still it following, is it working, or are you without water?



I would check the outlet first, you can either plug something in, probe it with the meter or these are like $15 and well worth it:



Assuming no issues there, then I would verify there is NO continuity between the ground pin and either terminal on the pump plug.

Sorry, I re-read what I wrote and it's not clear. The pump is working fine, until the GFCI trips. It's tripping like once every 1-5 hours. So, I have water.....until I don't. Then I have to drive down my hill and reset the GFCI. Then I have water for another 1-5 hours.
Thanks, I'll check the wiring, and I'll probably buy the extra tool. Easily worth $15. Thanks again.

 

[micromind]

Does the GFI trip only when the pump runs? or does it still trip when there's no water demand?

If it trips during the night when there's no water demand, I'd unplug the pump for a night and see if it still trips.

That'll help a lot with trouble shooting.

 

[PCustoms]

Sorry, I re-read what I wrote and it's not clear. The pump is working fine, until the GFCI trips. It's tripping like once every 1-5 hours. So, I have water.....until I don't. Then I have to drive down my hill and reset the GFCI. Then I have water for another 1-5 hours.
Thanks, I'll check the wiring, and I'll probably buy the extra tool. Easily worth $15. Thanks again.

Get the GFCI tester.

Replace the outlet at the pump with a standard outlet.

Put GFCI tester in outlet, verify outlet is wired OK.

Hit GFCI test button on tester. Outlet should now be dead. Plug pump in, drive back uphill. Reset GFCI in panel. Enjoy water.

If you have more issues you can diagnose from there. Part of the issue may be the redundant GFCI. You'll get differing opinions on this, but they aren't required, don't really have a benefit here, and don't always seem to play nice.

 

[Innovate1]

You said you tried a GFCI breaker in the panel using one leg of a 240V one. Unless that breaker also has a neutral feed through for the load it isn't going to work with one leg connected. They detect current DIFFERENCE so both (all) load conductors must go through whatever GFCI device you have. I didn't see it noted but you must be feeding this with a different breaker now?

 

[dave*99]

Ok, so update to this. I decided since I had the materials, I'd try running 10/2 wire down the 350ft. I wired a gfci 110v outlet at the bottom of the hill, and at the top of the hill I used a single leg of a gfci 220v breaker. Basically, I had most of the material to do this handy, so I decided to test it out......it did not work.
Also, I switched to a larger pump (Grundfos CMBE 1-44) I called and visited every plumbing and pump store around me, and no one had any 220v/240v pumps, and everything was on back order. I didn't think it would be a big deal sticking with 110......but this has turned into quite the headache.
The gfci outlet at the bottom of the hill trips a couple of times a day. Once again, I'm not an electrician (but neither are most electricians I've met recently) but I'm guessing it's worth it for me to go ahead and wire up both legs of the 220v breaker I have, buy some 10/3, and run it down the hill. But I still have the issue, of the pump being 110. @LopezBart mentioned a step down, but I can't seem to find one that takes bare wire. Is there some product I'm missing? Links to products would be useful. Or other ideas that I'm missing.
Ideally, I'd like to not have to buy the 10/3 wire, but at this point I'm willing to spend some money to make this problem go away. I just can't wait 3 months for a 240v pump.

Not good. Use 1 GFCi not 2. Don't feed one GFCI from another.

If using 1 leg of the 2 pole breaker, you must connect the breaker pigtail to the neutral bus in the panel. And you must connect the neutral from your 350' run to the neutral terminal on the 2 pole breaker.

Ultimately if you can't find a 240V pump, I'd remove the 2 pole GFCI breaker in favor of a standard 1 pole breaker and use only the GFCI outlet as protection.

 

[larry_g]

Me personally I would FOR TESTING PURPOSES get rid of the gfci outlet and go with a standard one. If that works then proceed to testing on what is blowing the gfci.

lg
no neat sig line

 

[Sumboodie]

Ok, so update to this. I decided since I had the materials, I'd try running 10/2 wire down the 350ft. I wired a gfci 120v outlet at the bottom of the hill, and at the top of the hill I used a single leg of a gfci 240v breaker.

No... WTH?! Use a 120v breaker, or run 240v to the shed and setup a small subpanel.
Why would a person use half a GFCI breaker and a GFCI outlet? Makes no sense.

It's 240v/120v, 110 hasn't been a thing since ~ww2

Basically, I had most of the material to do this handy, so I decided to test it out......it did not work.
Also, I switched to a larger pump (Grundfos CMBE 1-44) I called and visited every plumbing and pump store around me, and no one had any 240v pumps, and everything was on back order. I didn't think it would be a big deal sticking with 120......but this has turned into quite the headache.
The gfci outlet at the bottom of the hill trips a couple of times a day. Once again, I'm not an electrician (but neither are most electricians I've met recently) but I'm guessing it's worth it for me to go ahead and wire up both legs of the 220v breaker I have, buy some 10/3, and run it down the hill. But I still have the issue, of the pump being 120. @LopezBart mentioned a step down, but I can't seem to find one that takes bare wire. Is there some product I'm missing? Links to products would be useful. Or other ideas that I'm missing.
Ideally, I'd like to not have to buy the 10/3 wire, but at this point I'm willing to spend some money to make this problem go away. I just can't wait 3 months for a 240v pump.

 

[Slimmons]

Get the GFCI tester.

Replace the outlet at the pump with a standard outlet.

Put GFCI tester in outlet, verify outlet is wired OK.

Hit GFCI test button on tester. Outlet should now be dead. Plug pump in, drive back uphill. Reset GFCI in panel. Enjoy water.

If you have more issues you can diagnose from there. Part of the issue may be the redundant GFCI. You'll get differing opinions on this, but they aren't required, don't really have a benefit here, and don't always seem to play nice.

Looks like the issue was in fact having double GFCI. As a quick test, I removed the GFCI outlet at the bottom of the hill by the pump. It's been running now for 7 hours without knocking itself out. I'll wait longer before I make further changes, but long term I'll get rid of the GFCI breaker, and put the GFCI outlet back in at the bottom. I'm glad this was the issue. I wasn't looking forward to running a lot of expensive cable, and buying a step down. I did buy some testers and will be using them.


@dave*99 Thanks, that is how it's set up. Before I used that double breaker I had an actual electrician make sure what I was doing was correct. And yes, I he did advise me to get a single pole, but like I said, I was using what I had, and it appears to be working fine now. But, like I said, I'll be removing it anyway and adding back the GFCI outlet.
Thanks for the help everyone, and I'll let you know if I hit further issues.

 

[PCustoms]

Looks like the issue was in fact having double GFCI. As a quick test, I removed the GFCI outlet at the bottom of the hill by the pump. It's been running now for 7 hours without knocking itself out. I'll wait longer before I make further changes, but long term I'll get rid of the GFCI breaker, and put the GFCI outlet back in at the bottom. I'm glad this was the issue. I wasn't looking forward to running a lot of expensive cable, and buying a step down. I did buy some testers and will be using them.


@dave*99 Thanks, that is how it's set up. Before I used that double breaker I had an actual electrician make sure what I was doing was correct. And yes, I he did advise me to get a single pole, but like I said, I was using what I had, and it appears to be working fine now. But, like I said, I'll be removing it anyway and adding back the GFCI outlet.
Thanks for the help everyone, and I'll let you know if I hit further issues.

I'd personally run this on a GFCI breaker, that way you 350' of wire plus the pump is protected.

With an outlet at the bottom, just the pump is protected.

Is the wire in conduit? Buried? How deep?

 

[Slimmons]

I'd personally run this on a GFCI breaker, that way you 350' of wire plus the pump is protected.

With an outlet at the bottom, just the pump is protected.

Is the wire in conduit? Buried? How deep?

It's not buried yet. I won't be able to bury it more than a couple to a few inches unfortunately. No conduit, it's just the grey outdoor wire.

The reason I used the double pole originally is because it's hard to find a single pole 30 amp gfci breaker for square D home line. I was told before a 30 amp would be best for this, but if there's no reason I can't go down to 20, then it's simple to find one.

 

[PCustoms]

It's not buried yet. I won't be able to bury it more than a couple to a few inches unfortunately. No conduit, it's just the grey outdoor wire.

You really should bury that deeper, per code, but I get it.

The GFCI needs to be at the panel in this case. Period. This protects if the wire gets damaged and "leaks" current to ground.

Forget the GFCI outlet, it does nothing in this situation.

The reason I used the double pole originally is because it's hard to find a single pole 30 amp gfci breaker for square D home line. I was told before a 30 amp would be best for this, but if there's no reason I can't go down to 20, then it's simple to find one.

Not sure why you'd want a 30.

Put a 20A 120v GFCI in the ones and be done with all this.

 

[wyliesdiesels]

I'd personally run this on a GFCI breaker, that way your 350' of wire plus the pump is protected.

With an outlet at the bottom, just the pump is protected.

Is the wire in conduit? Buried? How deep?

A GFCI doesnt protect wire or equipment.

 

[PCustoms]

A GFCI doesnt protect wire or equipment.

This entire thread, and that's what you commented on?

I know the GFCI isn't protecting the wire or the equipment. But it is protecting people who touch the wire and the equipment, hence why I said the whole length is "protected". Guess I should have used "safe", I apologize.

 

[wyliesdiesels]

This entire thread, and that's what you commented on?

I know the GFCI isn't protecting the wire or the equipment. But it is protecting people who touch the wire and the equipment, hence why I said the whole length is "protected". Guess I should have used "safe", I apologize.

yes because it can mislead people into thinking a GFCI in this application will protect wire and motors. There are GFCI breakers in industrial panels that protect equipment but that is a different situation.

in this case, GFCIs are for protecting life.

 

[Slimmons]

As an update to this, in case anyone is interested, or for future people who find this. I ended up measuring the voltage drop at the bottom of the hill and it was negligible. I don't remember exactly what it was but if I remember correctly it was around 2%. If that number sounds crazy, maybe I'm wrong. But I ended up ditching the weird single pole of the 220 and used a single 20amp single pole breaker down to the gfci outlet. This has worked for over a year now. It only trips when I use a lot of water at the top of the hill. I'm guessing (and based on googling) the continued tripping seems to be leakage related (electrical, not water) related to ground leak associated with this kind of VHD. I've done a lot of reading and learning since the time I originally posted this (due to a lot of failures/retries).
@PCustoms already gave me the answer, but I don't think I understood it at the time.

The GFCI needs to be at the panel in this case. Period. This protects if the wire gets damaged and "leaks" current to ground.

Forget the GFCI outlet, it does nothing in this situation.

So, I'm going to put a normal outlet at the bottom of the hill, and replace the current breaker with a a single pole 20 amp gfci breaker.

specifically this one.

Square D Homeline 20 Amp Single-Pole GFCI Circuit Breaker HOM120GFICP - The Home Depot

Get the Homeline 20 amp 1 in. Single-Pole Ground Fault Circuit Breaker 07110, GFCI for overload and short-circuit protection of wiring at The Home Depot

www.homedepot.com

Thanks again for the help everyone. Trying to catch up to you guys

 

[willf650]

I read a lot of this thread and there are different gfci trip ratings for equipment versus personal protection. I'm not going to dig through the code but to see what is what at this moment but when I used to do a lot of heat trace work I used a GFCI with a higher trip threshold.

If the conditions matches the code requirements could you get a higher trip class breaker or stand alone GFCI unit and swap your pump outlet to a single dedicated outlet. This would not be personal protection at this point and the higher threshold trip unit may stop your issues.

I used to use the stand alone GFCI units regularly for this purpose. It looks like an outlet with no actual outlet prongs. Take this with a grain of salt as I haven't done this or looked over this section of the code in 12 years or more and a lot has changed in regards to GFCI and AFCI.

Also to measure voltage drop you would have to do it while the motor is running. I'm not sure if you did that or not but the drop is based upon the current across the resistance of the wire. If the motor wasn't running you aren't really getting an accurate reading of the voltage drop.

 

[dave*99]

I read a lot of this thread and there are different gfci trip ratings for equipment versus personal protection. I'm not going to dig through the code but to see what is what at this moment but when I used to do a lot of heat trace work I used a GFCI with a higher trip threshold.

I believe you are referring to GFPE Ground Fault Protection of Equipment. Often used in marina and heat trace circuits. 30mA is a common trip level for some of these devices. I don't think they are permitted for a well pump.

 

[justsam]

As an update to this, in case anyone is interested, or for future people who find this. I ended up measuring the voltage drop at the bottom of the hill and it was negligible. I don't remember exactly what it was but if I remember correctly it was around 2%. If that number sounds crazy, maybe I'm wrong. But I ended up ditching the weird single pole of the 220 and used a single 20amp single pole breaker down to the gfci outlet. This has worked for over a year now. It only trips when I use a lot of water at the top of the hill. I'm guessing (and based on googling) the continued tripping seems to be leakage related (electrical, not water) related to ground leak associated with this kind of VHD. I've done a lot of reading and learning since the time I originally posted this (due to a lot of failures/retries).
@PCustoms already gave me the answer, but I don't think I understood it at the time.

So, I'm going to put a normal outlet at the bottom of the hill, and replace the current breaker with a a single pole 20 amp gfci breaker.

specifically this one.

Square D Homeline 20 Amp Single-Pole GFCI Circuit Breaker HOM120GFICP - The Home Depot

Get the Homeline 20 amp 1 in. Single-Pole Ground Fault Circuit Breaker 07110, GFCI for overload and short-circuit protection of wiring at The Home Depot

www.homedepot.com

Thanks again for the help everyone. Trying to catch up to you guys

Did you measure the voltage with the pump running and pumping water? After reviewing your postings I noticed that you are using a Grundfos CMBE 1-44 pump as opposed to the earlier one mentioned. That pump draws 8 Amps at 120VAC. Using your 10ga wire at 350 feet gives you a voltage drop of 5.6 Volts, or 4.6%. I would be OK with these numbers as the pump has a variable drive and tends to buffer inrush currents. Grundfos is also a quality pump with built in protection from voltage sag. You did mention that during winter you may want to add a light in the pump house to generate heat. To generate heat that means it will be incandescent so do not over due this as a 100 Watt incandescent can add almost another Amp to the circuit.