Common practice for well casings?

[realolman]

By the NEC, it's not unless you decide to use it as such. Do you agree with that statement?

I think it is the exact same well casing with the exact same electrical characteristics relative to earth.... NEC or no NEC. Because of the relative sizes, the well casing has at least 25 times more contact with the earth than a ground rod.

As a grounding electrode it has a # 6 cu GEC ...or as in the OP a #4

As a metallic part likely to become energized it has a #12 cu or maybe #10 EGC.

What is the safety advantage to personnel being shocked by a fault to the casing in the pump circuit with a #12 EGC over a #6 GEC?

Think of the impedance created by the #12 that is only accessible to the lightning by way of the feeder EGC, to the branch circuit EGC, out an average 150' of overall wire length to get to the casing.

1. You think lightning is going to prefer that path over the rod?

2. Can you imagine the collateral damage throughout the home to all the other paths that are equally attractive?

I don't understand your point. "preferences" of lightning???

I started off my earlier post admitting that I don't know what to do with a well casing. I'm trying to understand and apply logic , common sense, and maybe a few electrical principles to the situation. The lightning doesn't know whether I decided to use the casing as a Grounding electrode or not. Would it burn off the smaller EGC with it's higher impedance more readily than if it were a # 6? I don't know.

How does the lightning get to the rod? Because of the considerably greater earth contact, would the lightning "prefer" the well casing over the ground rod? I don't know that either.


Most people do not put the well that far from the house ...the closer the cheaper. The well has to be 100 ft from the sewage disposal and the neighbors' sewage also has to be taken into account. Lots are expensive. the closer to the house the better.

Except for the difference in impedance of the # 10 or 12 and the #6, you're hooking them up the same way one way or another...

It's the same well casing. It's not a metal box hanging in a wooden stud wall. NEC or not, It's a grounding electrode with a #6 one way, and a grounding electrode with a #12 the other. I think the well casing should have the #6 cu . The OP is talking about someone running a #4.

 

[realolman]

If you own a copy of the NEC....try [250.53(A)(2)] (well casing as a pipe or rod electrode) the H2O pipe shall be supplemented. Exc. 25 ohm compliance in this instance.
An EGC bonding for a well casing is what was originally referred to for the OP's question and your wanting to understand why the casing is not a superior ground electrode in true code terms.

Yes. I own a copy of the NEC..... that is not what you said in your post... you said as a structure, the well casing needs a ground rod.

Originally Posted by gndrod

Unless you do this for a living and have good reason to deviate from an EGC, the questions asked are understandable. In some instances the well casing, under code within a structure would require a grounding electrode.

 

[gndrod]

Yes. I own a copy of the NEC..... that is not what you said in your post... you said as a structure, the well casing needs a ground rod.

Please read what was said carefully. "In some instances...." I may ask, have you ever installed or set a well system? Quite a few installations are in a well house structure that is a stand alone hookup to an agri service.

 

[George Stolz]

I started off my earlier post admitting that I don't know what to do with a well casing. I'm trying to understand and apply logic , common sense, and maybe a few electrical principles to the situation.

If we can't use the NEC requirements as a starting point, then this has the potential to be a stunted, painful conversation.

 

[LEO2854]

If we can't use the NEC requirements as a starting point, then this has the potential to be a stunted, painful conversation.

Sorry George but what post are you replying to?

 

[realolman]

How about electrical theory and, logic, and common sense?

Seems to me being unwilling to discuss anything beyond the letter of the NEC law is the stunted, painful approach.

I think the NEC starting points have been well made. Even I understand them.

My problem is that they don't seem to be logical . There again... I understand that NEC compliance is not necessarily logical, but I don't see why logic and common sense should be disdained in a forum discussion.

Reading other threads in the past, it seems to me that some of the NEC logic(?) of grounding to water system pipes is lost on members of this forum with less stunted knowledge than I.

 

[iwire]

There again... I understand that NEC compliance is not necessarily logical, but I don't see why logic and common sense should be disdained in a forum discussion.

Well for one thing you confuse the heck out of folks that don't understand the NEC requirements and this is primarily an NEC forum.

I understand your point, but try to write an understandable and concise code section to cover this odd instance of EGC vs GEC sizing?

Also can you present any evidence at all the rules as they are create an unsafe condition and a change would increase safety?

 

[George Stolz]

Realolman, I simply was trying to verify that you agreed with us about what the NEC required before we dive off into other parts. You hadn't said as much yet, and it is the proper thing to iron out before a digression.

Deep breaths. I'm not trying to get personal.

 

[kwired]

IMO if the well casing is to be used as a grounding electrode for a dwelling (or other building) it needs to be pretty close to the building to serve this purpose, not 100' or more away, and more realistically not more than maybe 20 feet away.

 

[kwired]

It is ideal to put well near the house. There are times it is more practical to put is farther away because putting it near the house is more expensive, lower quality water, or some other problem comes up, so they do end up away from the house sometimes.

Seen many times where irrigation well had to go anywhere from 200-1500 feet away from the center pivot because there was not enough/ good enough water at the center pivot location. Underground geology is not always what you want it to be.

 

[Dennis Alwon]

Placement of the well can be more difficult when there is a septic field involved. It used to be that the well had to be 100' from the field so depending on the size of the lot you may not have much choice as to how close you want it. Mine is within 50' of the house.

 

[gndrod]

Stunting

Stunting

How about electrical theory and, logic, and common sense?

Reading other threads in the past, it seems to me that some of the NEC logic(?) of grounding to water system pipes is lost on members of this forum with less stunted knowledge than I.

I truly understand your lament in seeking out the logic and common sense in this forum...but it is not going to happen because there is too much interfacing knowledge that affects an accurate electrical closure. Unfortunately the CMP's are not making electrical rules for the aspects of well equipment with structure electrodes and safety.

The Articles are all written to cover water fountains, swimming pools, ponds and hydro-massage equipment. I do not sympathize with the CMP, for they are setting electrical rules without consulting outside trade expertise.

The only way you are going to understand deep submersible well installations is by brute experience rather than following a string of NEC code requirements that need better condition descriptions surrounding compliant well installations. The two facets of electrical safety for a well system come down to mainly EGC and secondarily GEC constraints.

I wish I had the time to explain the considerations needed to help understand the variations in well construction. The NFPA does not pay any of us to make sense or logic for simplifying codes. Agendas $$$ from the corporate voting members kind of put the perspective on where all of us as a group need to be creative and stick together.

 

[kwired]

I truly understand your lament in seeking out the logic and common sense in this forum...but it is not going to happen because there is too much interfacing knowledge that affects an accurate electrical closure. Unfortunately the CMP's are not making electrical rules for the aspects of well equipment with structure electrodes and safety.

The Articles are all written to cover water fountains, swimming pools, ponds and hydro-massage equipment. I do not sympathize with the CMP, for they are setting electrical rules without consulting outside trade expertise.

The only way you are going to understand deep submersible well installations is by brute experience rather than following a string of NEC code requirements that need better condition descriptions surrounding compliant well installations. The two facets of electrical safety for a well system come down to mainly EGC and secondarily GEC constraints.

I wish I had the time to explain the considerations needed to help understand the variations in well construction. The NFPA does not pay any of us to make sense or logic for simplifying codes. Agendas $$$ from the corporate voting members kind of put the perspective on where all of us as a group need to be creative and stick together.

What more is there to a submersible well as far as NEC is concerned other than the fact there is a motor, a cable/conductors, a casing that they are installed in, and transition to other wiring methods covered in Ch 1-4 to supply it? And then add the grounding of a metal casing if it exists? Most of these items are usually listed for purpose and need not be covered by NEC - just install according to listing instructions. That leaves us with grounding the case if that applies and following listing instructions for the NEC to deal with, doesn't seem too big of a challenge for CMP's

 

[gndrod]

What more is there to a submersible well as far as NEC is concerned other than the fact there is a motor, a cable/conductors, a casing that they are installed in, and transition to other wiring methods covered in Ch 1-4 to supply it? And then add the grounding of a metal casing if it exists? Most of these items are usually listed for purpose and need not be covered by NEC - just install according to listing instructions. That leaves us with grounding the case if that applies and following listing instructions for the NEC to deal with, doesn't seem too big of a challenge for CMP's

For you and I, it's a walk in the park. Obviously this forum segment indicates there are confused questions of not easily understood concepts. The facets of well setting I believe, needs better code interface in more precise context. Let's start with VFD's and GFCI uses together or the associated vertical wire and cable support details. Not in Ch 1-4.

Disconnects not within sight for well motor locations could be another definitive rule to be explained under a common Article that helps focus on deep well wiring installations.

Compartmentalizing by technology is necessary for an easier understanding wouldn't you think? Just explaining grounding a well case with a ground rod seems to confuse experienced inquiring minds...and I had to take a lot of time to do so.

 

[iwire]

Wow, what a concept, try to make things less confusing by adding redundant code pages.


I dont think there is anything at all special about well pump wiring.

 

[ActionDave]

.....I dont think there is anything at all special about well pump wiring.

There sure is if the well pump guys are doing the wiring!

 

[gndrod]

Wow, what a concept, try to make things less confusing by adding redundant code pages.


I dont think there is anything at all special about well pump wiring.

Yer up a bit late, thanks for the positive reply. Nothing to it after doing a few. A quick question...why would anyone use a 3-wire instead of a 2-wire hookup on a deep submersible about 200 ft down? For ducks, 230V, 1 ph as a constant.

 

[kwired]

For you and I, it's a walk in the park. Obviously this forum segment indicates there are confused questions of not easily understood concepts. The facets of well setting I believe, needs better code interface in more precise context. Let's start with VFD's and GFCI uses together or the associated vertical wire and cable support details. Not in Ch 1-4.

Disconnects not within sight for well motor locations could be another definitive rule to be explained under a common Article that helps focus on deep well wiring installations.

Compartmentalizing by technology is necessary for an easier understanding wouldn't you think? Just explaining grounding a well case with a ground rod seems to confuse experienced inquiring minds...and I had to take a lot of time to do so.

Never seen GFCI used on a well and don't know why one would need it. But if it is used it is covered in Ch 1-4 as well as VFD's and vertical wire and cable support. Disconnect not within site of motor is covered in 430.102(B)(1) & (2) exception.

Why do we need a section for this application? Everything is already covered someplace.

 

[kwired]

Yer up a bit late, thanks for the positive reply. Nothing to it after doing a few. A quick question...why would anyone use a 3-wire instead of a 2-wire hookup on a deep submersible about 200 ft down? For ducks, 230V, 1 ph as a constant.

Because a capacitor or control device may not last long in the environment that is 200 feet down, or it is at least much easier to change when it is not 200 feet down. They also mount them outside of hermetic refrigerant compressors and have no internal controls for similar reasons.

 

[gndrod]

Because a capacitor or control device may not last long in the environment that is 200 feet down, or it is at least much easier to change when it is not 200 feet down. They also mount them outside of hermetic refrigerant compressors and have no internal controls for similar reasons.

How many pumps have you set like that? Not even close to a good answer.