pool bonding

[russ__20000]

Can anyone tell me the safty reason behind this bond and what year was it added to the code?
The reason I am asking is cause the VD that this bond causes is a pain to deal with.
The utlity doesn't want to help and I can't climp up on their poles or go into everyones house and check their netrual connections or if someone has a ground short.
It seems to me, if all circuits were GFI protected, this bond would not be needed and the "stray voltage" would go away. The code will not even recognize stary voltage , as it relates to pools.
Does anyone know of some sort of "ronk blocker" that can be put in the bond to stop current from flowing, under 1 or 2 amps. This would stop it, but would this violate the pool bond code?
Any comments?

 

[petersonra]

Can anyone tell me the safty reason behind this bond and what year was it added to the code?

Fairly recent IIRC.

The reason I am asking is cause the VD that this bond causes is a pain to deal with.

Pool bonding has no effect whatsoever on VD if the electrical installation is done correctly since there should be no current flow through the pool bonding system.

It seems to me, if all circuits were GFI protected, this bond would not be needed and the "stray voltage" would go away. The code will not even recognize stary voltage , as it relates to pools.

The code may not call it stray voltage, but pool bonding in effect does deal with what some call stray voltage. The bonding creates an area around the pool where there is no potential voltage difference caused by current flow through the earth. Most times this current flow would be from the neutral/earth bond at the service point and GFIs would do nothing to prevent it since GFIs are only installed downstream of the service point.

 

[russ__20000]

Mostly I am talking about pools that where installed before the equipotential plain was introduced. In this case "pool bonding" has everything to do with voltage drop, cause the stray current or "stray voltage" is using the ground, any ground as a path back to the primary netrual cause its bonded to every secondary netrual and if I have 1 or many high resistance netrual connections it wants to use this path.

I asked about the GFI cause I would like to remove the ACEGs and the pool bond(the 8awg). An GFI protected circuit would trip in the cause of a ground fault and protect persons.
With GFIs I dont see a need for and equipotential plain bond. And without the equipotential plain bond or an ACEG connect the path that the stary current is taking back to the muilty connected netrual, via the pool area, will be gone.


If you had a service call and the persons are feeling a shock when they are getting out of the pool and you measure 3.4 volts from concrete to the water and you find .05 amps flowing on the pool bond wire and with the power off to the house you get the same reading, what would you do? The utily said drive another ground rod. I could drive 50 thousand ground rods and it wouldn't change a thing, so no help there. I left the bond wire, voltage goes away.

 

[petersonra]

You are making the assumption that ther "stray" current is coming from a circuit you can put a GFI on. In most cases it is not. It is coming from the service earth/neutral bond point and there is no GFI on the line side of the service point.

 

[haskindm]

Remember that GFCI protects against electrocution not electrical shock. A person may still experience electrical shock on a GFCI protected circuit, but it should not be lethal. Also remember that GFCI does nothing to protect from voltage leaking from line to neutral, the GFCI sees this as just additional load. GFCI is not, and never will be, a substitute for proper bonding and grounding.
In a properly bonded pool, all conducting surfaces would be at the same potential so it would not matter how much voltage was actually on the surface; since there would be no potential difference, there would be no current flow. In the scenario that you described there must have been a problem with the bonding, or there were areas that were not bonded. I cannot see any way that GFCI would help in that situation.

 

[PATELECTRIC]

The purpose of bonding a swimming pool is to bond all conductive surfaces and prevent any diference in potential that might occur. This potential does not have to come from the pool it may come from something else. Heater, metal fence, metal shed etc. There is no direct connection per say to ground, although ultimately it should get make its path through the pump which is protected via the gfci. If someone were to touch a metal bldg that had become energized due to a fault condition and touched the metal wall of the pool the potential diference could result in a serious shock. I hope I am on the mark with this and was a help.

Patrick

 

[weisengle]

Proper Bonding of hot tubs???

Proper Bonding of hot tubs???

This post illustrates a dilemma I have right now. I am installing a hot tub. The electrical source is a four wire 220 feed from the house. Yet within 8 feet there is an underground service entrance. I am very aware of how parrallel paths to ground can result in the exact situation this gentleman is complaining about.
My question is this. Should the sub panel be bonded to the main panel in the house or to the service entrance or both? If I bond the sub panel to both, and the subpanel must be bonded, then wouldn't I create a parrallel path for stray voltage drops. If so then wouldn't I be better off bonding the sub panel to the service entrance? Yet if I do not bond the sub panel to the house will the breaker supplying the feeders work? By bonding to the service is it possible that I will disable the feeder breaker?
Also our friend may have stumbled across the true answer. Is it possible that actually his problem is not multiple neutrals, but multiple grounding electrode conductors. It may be that in reality our friend has simply cured the problem by removing a grounding electrode conductor that is providing a parrallel path for stray voltages.

 

[George Stolz]

Your post is a bit confusing to follow, I'm going to focus on one sentence.

Should the sub panel be bonded to the main panel in the house or to the service entrance or both?

Typically, the bonding of neutral to the EGC's of the house should take place once, at the service, and never again.

One exception to this is in 250.32(B)(2) to detached structures (which will die in 2008). In that particular case, there is no EGC in the feeder to the detached structure, so the breaker-kicking return path in the event of a fault is the neutral, in that scenario.

Does that help?