Intermittent breaker tripping

[mmcjeeper]

So here is the issue I've been having: I bought the house 5.5 years ago, it was built about 6.5 years ago. My well is 76 feet, it had a 1/2HP 110V 8.5A continuous draw submersible pump without a control box. A few years ago, the 2oA 110V and the 30A on the main 220V panel would randomly trip (sometimes only 1, usually both). We had an electrician from a reputable company out who checked the wiring from the house to the well and then blamed the pump. The well installer came out and he blamed the electric cabling from the house to the well. The pump would occasionally draw 30A upon startup and trip the breakers (measured on an ammeter). Over the xmas holiday when I had some help, we replaced the well pump with a 1HP 110V 11A draw pump. It worked well for about 5 days and then the breaker tripped again. I haven't really gotten to do any more troubleshooting as I have gone out of town for business. Is it possible that a problem with wiring from the house to the well could cause the pump to draw more amps (a small intermittent short or exposed wiring)? The wire is about 18 inches down in the ground (which I found when I had to fix a line breakage where the well supply hose met the house piping), and I really don't want to replace it all, but I will (inside conduit this time). Just asking for ideas. This is pretty much the last thing I can think of since I've changed the breakers, the pressure switch and the pump. It just didn't seem to make any sense to me.

 

[VAWellDriller]

There should be only 1 breaker for the well pump; can you identify what it is, 20 amp or 30 and 1 pole (120volt) or 2 pole (240 volt)? Also, please clarify what pump/motor you have....if you have a 1HP submersible, it is not 110 volt. More useful information would be what size wire was used and the distance. I have seen this problem a lot with 1/2 hp 115 volt motors and undersized wire. The correct troubleshooting procedure for the wiring would be to unhook the wires from the pressure switch and also from the pump. Then use an ohm meter to measure resistance to ground of the wire run in the ground and the run from the top of the well to the pump. Do this and report back.

 

[Sponsor]

 

[WorthFlorida]

If your power cable is type UF, it's approved for direct burial at 12". Usually gray in color and it is extremely tough to strip back the jacket to get to the wires. Any other it must be replaced. As stated above only one breaker is required. The only time there are two breakers is the main panel is feeding a subpanel. Such as a 60 amp 220V breaker feeding a sub panel with one or more breakers.

Is the 20 amp breaker at or near the well? If it is replace it with a cutoff switch. It will allow to turn off power at the well for servicing the pump without having to go back and forth to the breaker panel.

It is possible as circuit breakers age and hit with thousands of surges such as a pump motor cycling, they can go out of tolerance. Changing it out for a new one will eliminate just one possible cause.

https://www.familyhandyman.com/electrical/wiring/how-to-bury-underground-cable/

 

[Reach4]

Your 1/2 hp 115 volt pump is usually powered via a 30 amp breaker.

The suggestion to replace the breakers sounds good. They are not that expensive.

 

[Reach4]

we replaced the well pump with a 1HP 110V 11A draw pump.

That would be a rare pump if it existed. You probably put in a 230 volt pump if it is 1 HP. Check your paperwork. Or maybe 1 HP was a typo.

 

[Valveman]

There are some pumps available now that have larger than 1/2HP in 115V. I think Hallmark makes 115V up to 1.5HP. Not saying that is a good thing as it takes so much more amperage to start a 115V pump than a 230V one. If a 1/2HP in 115V needs a 30 amp breaker, then a 1HP would need a 60 amp breaker. I don't think you can get more than a 30 amp breaker for 115V? GFI breakers won't work with pumps like that. Even a regular breaker could just be weak and need replacing. Problems like this are why I highly recommend 230V for anything larger than 1/2HP. And like VA says they didn't even use to be available.

 

[mmcjeeper]

OK I'm gonna try and answer all the question/comments from all the above replies. I am not at home right now and will check what I need to when I get home this weekend.

I DO have a ONE HP 110v submersible pump
( https://www.amazon.com/gp/product/B00NTT2JO4/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1) . I know it is 110v because of the way the power is run. I have a double pole 30A breaker on my 220 panel for the well which then goes to a 1 pole 20A breaker in a single breaker panel near the 220V panel (I'm not sure how this actually works but this is my setup). Power then runs underground to a 110V outlet at the well. The pressure switch has a normal 3 prong 110V plug which plugs into the outlet.

I'm not sure of the type/size of wiring running underground, I'll have to look when I get home.

The first thing I did after this started happening is replace the pressure switch and then the 20A breaker. It didn't effect the occurrence. The hardest part of this is that it is so intermittent. I can go a week or two without it happening and then it may happen 2x one day, then once the next then 3 days until it happens again then a week. If it happened regularly it might be easier to troubleshoot. It seems to happen more after it rains, but that may be mere coincidence. It doesn't always happen after it rains.

I appreciate all the attempted help and advice. I'm guessing I'm gonna be doing some digging this weekend. I was hoping to be filling in a hole and not making a bigger one. I'll post again after I get home.

Jay

 

[Valveman]

I would ohm the wires instead of digging. If there is a short then you have to dig. I would also put in at least a 30 amp breaker. No way a 20 amp will run that size of a pump. My book says a 30 is only good up to 1/2HP in 115V, so I don't think the 30 is even large enough. It is tripping intermittently because sometimes is stays in start mode just a bit too long, which is when it draws the most amperage.

 

[WorthFlorida]

When it does trip on you, is the ground damp or wet after a rain event? Possibly a varmint chewed at the wire and partially exposed the copper, however, what valveman and VA states is more likely the cause.

 

[mmcjeeper]

So I just got around to doing some more troubleshooting based on recommendations given before. My wires ohmed well for the most part. Everything was less than 1 ohm. The wires are 14 ga solid strand is my guess based on smaller than some 12 ga I have and not fitting through the 16 ga hole on my wire strippers. I'm guessing I need to change out the wires to 10 or 12 ga as well as my breakers.
Is there a difference in depth for wires run underground in conduit vs not in conduit? The wires running now are 18 inches or more underground at least where I know they are.

 

[WorthFlorida]

At 18” you are good for UF or conduit.

https://www.familyhandyman.com/electrical/wiring/how-to-bury-underground-cable/

 

[mmcjeeper]

I understand I'm good at 18 inches, I was just wondering if I can go shallower in conduit as I don't want to dig 18" deep and 30 feet long if I can help it.