Well guy says "Dead Short", Steel Drop Pipe has weird pock marks on it

[Gangwars Web]

Type of pump?
Submersible__YES______
Three wire (control box)___YES___
One or two pipes down the well_ONE___

Size of Pump?
Motor Horsepower?___1HP_______
Pump Model #___STA-RITE S20P4HS10231___________
Date Pump Installed___2/6/09_______

Pumping from?
Water Well_____YES_______
Depth of well___45ft_______
Depth to water__10-20ft_______
Pipe Size_____2?____"
Drop Pipe Material
Steel__YES_____

Well Casing Diameter___4____”
Rock Well____YES______

Well Casing Material
Steel____YES_____


Pressure Tank? NO


Pump Control Method?
Pump Start Relay (sprinkler timer, no tank)___YES_______


Water Used For?
Irrigation with timers___YES_____

Problems Experienced
No Water_____YES____________

No Sounds____YES_________

Do you have, and know how to use
an Ampmeter and Voltmeter_____YES_____________

Location: We are in the Tampa FL area

Describe Problem:

We live on an acre of property that is mostly irrigated. The other day I doing some yard pickup as the sprinklers cycled. At some point I noticed that they had stopped, and not finished.

I check the well, the pump is off (you can hear/feel it hum when its on). I check the timer, it still thinks the pump is on. I check the breaker, its fine. I manually turn it off, and I hear the control relays shut off. I manually turn it back on, I hear the relays... but nothing. I manually turned it off again and open the relax box to see if anything was obviously fried in there and all looked good.

I call the well guy that installed the current pump setup back in 2009. He comes out, and does testing and says its a "DEAD SHORT" in the pump. Its out of warranty (of course) but he says he wants to try and send it in anyways because he buys so many, etc etc....but he says if it got iron all over it, he knows they won't cover it. We do have iron in the water as you can see some stains the sprinklers have left.

Today he pulled the pump. The first 10 feet of the drop pipe were clean and shiny. The next 12 feet were black like chimney soot black. The next 12 feet were dark metal colored, not sooty black nor shiny, but have weird pock marks on them. I can't explain them, but I'm attaching a picture... I mean its REALLY weird. The last 10 feet were totally duct taped to the wire, so all you see is duct tape.... Then the pump is pretty black as well.

The guy said the well was causing the black soot and the pock marks/pitting. He said the pock/pitting was very unusal, and he'd only seen that in like 50 wells over several thousand that he's worked on over the years. His opinion is that the well will continue to ruin pumps and should ultimately be replaced.

He said they would be back in the morning, so I took the opportunity to take some pictures. Here are some pictures from what was pulled.







Does this guy have any idea what he is talking about? Is my well really killing pumps in 2 years? What are these pock marks? Any help at all would be appreciated...

Thanks,

AJ

[Texas Wellman]

Looks like you've got some electrolysis going on there. Why not go back with sch 80 pvc with stainless or brass collars, it would eliminate that problem (the soon to be holes in the pipe).

I would find the cause of the electrolysis, could be a nearby wire or bad ground somewhere causing the problem.

[cacher_chick]

Those are burn marks which could be from wires shorting together.
They also could have been there when they set the pump in the first place.

I hope you inspected every inch of the wire going down the hole.

[LLigetfa]

Looks like you've got some electrolysis going on there...

Agreed. I would suspect a poor neutral and ground on the service feed to the property resulting in the well plumbing/pump being the better ground. Is the service grounded to your well casing?

[cacher_chick]

I've not seen electrolysis do that, but there are a lot of things I have not seen.

[Gangwars Web]

Agreed. I would suspect a poor neutral and ground on the service feed to the property resulting in the well plumbing/pump being the better ground. Is the service grounded to your well casing?

The service ground seems ok as far everything else on the rest of the property works properly. I don't know if the well casing is grounded to the service or not... Should it be? I'll check first thing in the morning...

[Gangwars Web]

Do any of you guys know about galvanic corrosion? I was doing a bit more reading and it seems this possibly could be whats going on with the pock marks, if the drop pipe is two different metals.... but I'm still pretty clueless.

I'd like to add, that the drop pipe is 4 total sections, but right now taken apart into 2. One half has 2 sections that have the same part number and match exactly and are either sooty black or not underwater. In the other half, the next two sections have the same part number as each other, yet it's a different part number than on the sections on the other half and they have no black sooty mess on them at all, but are covered in these pock marks.

The sooty black stops and pock marks start exactly at this union between the two halves...

[LLigetfa]

So, we know your casing is steel and the drop pipe is steel. What piping material runs to the house and if metal, is the pipe bonded to the service ground? It looks like four wires going to the pump so presumably the green one is bonded to the service ground.

Some debate as to whether or not to bond the casing to the service. Some say that bonding to it causes corrosion but IMHO better for the casing to take the hit than the pump.

Have you determined that it is the pump motor that is shorted to ground and not the wire?

[LLigetfa]

Unless the pump motor casing failed from electrically induced corrosion it is more likely that lightning hits led to the eventual pump failure.

Based on the depth of the pump being in the rock bore hole, did the water flow upward across the motor to cool it? Some pumps require a sleeve to cool it if the water does not flow past the motor.

The sections of pipe with the difference in colour and corrosion might align with where the metal casing ends and the rock bore begins.

[Gangwars Web]

So, we know your casing is steel and the drop pipe is steel. What piping material runs to the house and if metal, is the pipe bonded to the service ground? It looks like four wires going to the pump so presumably the green one is bonded to the service ground.

Have you determined that it is the pump motor that is shorted to ground and not the wire?

The well is for irrigation only... Right at the top of the well it switches to PVC.... it stays PVC and never actually goes the the house. I asked the well guy the same question, and he said that he was able to tell from his testing with the amp meter before he even pulled the pump. Does that sound right? My train of though would be to hook up the pump with a short test lead to double check...

I assumed the casing is steel.... 2 years ago when the pump failed, the part of the casing that stuck out of the round was pretty rusty looking, and had a small hole in it... Well guy said that it was bad for dirt, etc to fall in there so it should be cleaned up. He cut off the top that was rusty and put a pcv top on it. Could the casing be of some other metal and then be reacting with the galvanized steel drop pipe? What metals are usually used for deep well casings?

[Gangwars Web]

Based on the depth of the pump being in the rock bore hole, did the water flow upward across the motor to cool it? Some pumps require a sleeve to cool it if the water does not flow past the motor.

The sections of pipe with the difference in colour and corrosion might align with where the metal casing ends and the rock bore begins.

The pump is at 42 feet. Based on the water lines on the drop pipe, water starts at about 10 feet.... We are in an area with no water supply issues... If you dig 8 - 10 feet down you hit water. I guess that's what you get at 10 ft above sea level. :|

I follow what your saying about the casing ending and the rock bore beginning.... But I think it a bit odd that there is this line almost exactly 1/2 down the drop pipe, denoted by a pipe junction where everything above it is black super dirty and everything below it is clean and has got electrolysis pock marks all over it....and the above junction is one type of pipe, below junction is another... Is it just me or is this worth asking the guy about? The drop pipes were all shinny and pretty when they went down, and the one that was previously removed, was dirty and nasty, but didn't have these electrolysis marks on it.

[Texas Wellman]

I can tell you several things from looking at the pictures. You're well is high in sulfur (the black "sooty" material), and your pH is low. The reason the bottom two pipes were different is because this well has had this problem in the past and the two lower sections were replaced once before, thus the reason why you have two different sets of pipe in one string. The newer pipe is probably not as good a grade as the older pipe, which makes it that much more vulnerable to corrosion.

The electrolysis could be caused by stray current, bad ground, or several other things. I'm not sure whether your bad pipe has anything to do with the bad motor, they may be separate issues.

Here's what I suggest. Replace all the galv. pipe with sch 80 pvc with stainless couplings. Replace the wire with new wire, and double check to make sure your ground is properly installed both at the pump and the C-Box. Then make sure your c-box ground is continued all the way to the service panel.

Any other questions call 813-677-PUMP (7867).

Good luck.

[LLigetfa]

What if the 4 inch pump in a 4 inch rock bore is top fed? What will cool the pump? Obviously there is no room for a sleeve.

[Porky]

I suspect that the system didn't have a Relief Valve which on a pump start relay, the irrigation controller could have turned the pump on but not turned on any zones deadheading the pump burning out the pump. I always recommend an irrigation pump system to be on a small tank, a pressure switch, a relief valve and a constant pressure valve (like a cycle stop valve). The relief valve will prevent your pump from deadheading and the cycle stop valve www.cyclestopvalves.com will prevent your pump from cycling and wearing out the pump system components prematurely. Your pump installer didn't install a relief valve, I'd say they aren't a qualified installer. They are cutting corners to make a few more dollars at the expense of the customers protection. When you contract a certified state licensed installer, you have some recourse because their license is at risk if they don't do a proper job!

[ballvalve]

go all plastic and drive a ground at the well too. Looks like Iron bacteria, the black. Might want to chlorinate this hole heavily and anything that goes back into it..

I have always wondered if strapping a few water heater anodes to galvanized drop pipe would give it many more years of service.