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Very tight bend/crimp at CSST fitting


Neal Lewis

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I'm still unable to understand how the extra fancy bonding (#6 copper) is better than the regular bonding that's been required for this stuff since day one (bonding wire that's the same size as the wire that might energize pipe).

Lightning currents are a different animal.

Marc

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I'm still unable to understand how the extra fancy bonding (#6 copper) is better than the regular bonding that's been required for this stuff since day one (bonding wire that's the same size as the wire that might energize pipe).

Lightning currents are a different animal.

Marc

Clearly so. But that doesn't explain why the #6 would be any more effective than, say, a #14. Both will do pretty much the same job of reducing the chance of potentials that might cause arcing - even from nearby lightning strikes. (Which is to say that neither will do much.)

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I agree that these code changes relating to the bonding of CSST are little more than a stab in the dark.

One of the smartest moves the code forming guys could have done is to require robust lightning bypass systems on houses that have such products as CSST and radiant roof decking installed within them. Either that or remove the stuff.

The current CSST bonding requirements are a mess.

They should eventually also set specs for new building products that have conductive surfaces or planes that can span large areas or dimensions of the house.

Marc

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I thought that the main problem or issue with CSST was that a lightning strike would punch a hole in the thin wall of the CSST instead of being dissipated by thicker walled black steel pipe. I'm with Jim, I don't see how #6 copper wire is going to do more than #14.

The lightning current overheats the stainless on the CSST and melts a hole in it. It's not unlike a wire too small to carry the current flowing through it. It overheats. Steel pipe is thick enough to carry it without fail.

I've known something similar to happen on a house that I had previously inspected for an HI client. He had not yet closed on it when lightning struck it. He asked me to return to assess the damage. I traced the various paths of the lightning currents attempting to reach the earth. One of them began with the water heater flue, progressed to the water heater itself and the steel gas lines then to the earth but also from the water heater through one of the two flexible copper water connectors, copper distribution lines then the earth. In the process, it blew a pinhole in the corrugations of one of the connectors. The Fire Marshal was the first responder and noticed it. It wasn't CSST that blew, but it's the same type of failure. The corrugations may be a factor. Lightning currents include extreme frequencies and the electro-magnetics of such frequencies in a corrugated linear conductor could end up being very complicated, like way over my head complicated.

Marc

EDIT: Grammar

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I thought that the main problem or issue with CSST was that a lightning strike would punch a hole in the thin wall of the CSST instead of being dissipated by thicker walled black steel pipe. I'm with Jim, I don't see how #6 copper wire is going to do more than #14.

The lightning current overheats the stainless on the CSST and melts a hole in it. It's not unlike a wire too small to carry the current flowing through it. It overheats. Steel pipe is thick enough to carry it without fail.

I've known something similar to happen on a house that I had previously inspected for an HI client. He had not yet closed on it when lightning struck it. He asked me to return to assess the damage. I traced the various paths of the lightning currents attempting to reach the earth. One of them began with the water heater flue, progressed to the water heater itself and the steel gas lines then to the earth but also from the water heater through one of the two flexible copper water connectors, copper distribution lines then the earth. In the process, it blew a pinhole in the corrugations of one of the connectors. The Fire Marshal was the first responder and noticed it. It wasn't CSST that blew, but it's the same type of failure. The corrugations may be a factor. Lightning currents include extreme frequencies and the electro-magnetics of such frequencies in a corrugated linear conductor could end up being very complicated, like way over my head complicated.

Marc

EDIT: Grammar

What is interesting is the focus on the CSST product and seldom is anything mentioned about the corrugated appliance connector that is pretty much the same thing. Marc's experience shows that connector is just as much of a target as CSST is.

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I'm still unable to understand how the extra fancy bonding (#6 copper) is better than the regular bonding that's been required for this stuff since day one (bonding wire that's the same size as the wire that might energize pipe).

Every now and then, "'cause the rules say so".

I've heard you say it before.

I make recommendations "because they say so," but I don't achieve understanding because they say so.

I'm just trying to understand the rationalization behind what seems to be a stupid requirement.

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I'm still unable to understand how the extra fancy bonding (#6 copper) is better than the regular bonding that's been required for this stuff since day one (bonding wire that's the same size as the wire that might energize pipe).

Every now and then, "'cause the rules say so".

I've heard you say it before.

I make recommendations "because they say so," but I don't achieve understanding because they say so.

I'm just trying to understand the rationalization behind what seems to be a stupid requirement.

I think it's partially to do with litigation and the argument over whether the product is deficient or not. The expanded bonding requirements were born out of that situation. The manufacturers are saying, "do this and it's safe". It's then a claim they can make that the product was not installed correctly when a problem happens.

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When you bond a metal pipe system with a ground wire sized by the circuit likely to energize it, a ground for a 20 amp circuit is plenty. If the 20 amp circuit is attached to the metal pipe, the properly sized ground for that circuit makes a path back from whence it came and trips the breaker.

Following the same logic, what is the amperage of a lightening bolt or an induced charge from a nearby strike? Since there is no readily obtainable answer short of a swag, use the size of the largest conductor in the system, the GEC that goes to the ground rod, typically a #6 bare copper wire. Anything smaller and it might not be enough, anything larger and the rest o the GEC and GE may fail. You don't want the bonding conductor to be the weak link. The theory as I understand it is to get the charge into the ground and off of the CSST as quickly and easily as possible. It might not work, but it is worth a shot and there are some studies that have been done on the subject that might shed more light.

http://www.nfpa.org/~/media/Files/Resea ... report.pdf

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I think it's partially to do with litigation and the argument over whether the product is deficient or not. ..........The manufacturers are saying, "do this and it's safe". It's then a claim they can make that the product was not installed correctly when a problem happens.

That's an astute observation that applies to a lot of the silly stuff in this gig. The rationalizations are not performance or logic based; it's corporate legal covering asses.

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When you bond a metal pipe system with a ground wire sized by the circuit likely to energize it, a ground for a 20 amp circuit is plenty. If the 20 amp circuit is attached to the metal pipe, the properly sized ground for that circuit makes a path back from whence it came and trips the breaker.

Following the same logic, what is the amperage of a lightening bolt or an induced charge from a nearby strike? Since there is no readily obtainable answer short of a swag, use the size of the largest conductor in the system, the GEC that goes to the ground rod, typically a #6 bare copper wire. Anything smaller and it might not be enough, anything larger and the rest o the GEC and GE may fail. You don't want the bonding conductor to be the weak link. The theory as I understand it is to get the charge into the ground and off of the CSST as quickly and easily as possible. It might not work, but it is worth a shot and there are some studies that have been done on the subject that might shed more light.

http://www.nfpa.org/~/media/Files/Resea ... report.pdf

I don't see the logic in that. Lightning doesn't yet succumb to calculation because it isn't understood. It's an unknown. The only thing that makes sense is to use lightning protection concepts that experience has shown to work. They've been in use for decades. Bypass the strike to the earth so it doesn't go through the house.

Marc

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When you bond a metal pipe system with a ground wire sized by the circuit likely to energize it, a ground for a 20 amp circuit is plenty. If the 20 amp circuit is attached to the metal pipe, the properly sized ground for that circuit makes a path back from whence it came and trips the breaker.

Following the same logic, what is the amperage of a lightening bolt or an induced charge from a nearby strike? Since there is no readily obtainable answer short of a swag, use the size of the largest conductor in the system, the GEC that goes to the ground rod, typically a #6 bare copper wire. Anything smaller and it might not be enough, anything larger and the rest o the GEC and GE may fail. You don't want the bonding conductor to be the weak link. The theory as I understand it is to get the charge into the ground and off of the CSST as quickly and easily as possible. It might not work, but it is worth a shot and there are some studies that have been done on the subject that might shed more light.

http://www.nfpa.org/~/media/Files/Resea ... report.pdf

Makes no sense. As I understand it, the problem is not too much current, but, rather, differences in voltage potential that can cause arcing between conductive materials. A fat wire isn't going to be any different than a skinny wire in that regard. The real solution is some kind of conductive shield, like what they use in modern-day CSST.

The fat wire is an illusory solution of the type used by sleight-of-hand artists.

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When you bond a metal pipe system with a ground wire sized by the circuit likely to energize it, a ground for a 20 amp circuit is plenty. If the 20 amp circuit is attached to the metal pipe, the properly sized ground for that circuit makes a path back from whence it came and trips the breaker.

Following the same logic, what is the amperage of a lightening bolt or an induced charge from a nearby strike? Since there is no readily obtainable answer short of a swag, use the size of the largest conductor in the system, the GEC that goes to the ground rod, typically a #6 bare copper wire. Anything smaller and it might not be enough, anything larger and the rest o the GEC and GE may fail. You don't want the bonding conductor to be the weak link. The theory as I understand it is to get the charge into the ground and off of the CSST as quickly and easily as possible. It might not work, but it is worth a shot and there are some studies that have been done on the subject that might shed more light.

http://www.nfpa.org/~/media/Files/Resea ... report.pdf

Makes no sense. As I understand it, the problem is not too much current, but, rather, differences in voltage potential that can cause arcing between conductive materials. A fat wire isn't going to be any different than a skinny wire in that regard. The real solution is some kind of conductive shield, like what they use in modern-day CSST.

The fat wire is an illusory solution of the type used by sleight-of-hand artists.

Interesting. I don't see the punctures in CSST as arc related.

Marc

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