Thread: Hpw many AMPS is copper pipe rated for?

I have seen pics, but never saw it in person until now. They even fluxed the ends of the pipe, maybe they were going to solder them in.

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I have to admit that I have installed copper pipe fuses like that. But that was when I was growing up on a farm and didn't know any better.

paul

looks to me to be a little over a roll of pennys in height. so lets say theres 50 pennies to a roll. multiply that by 2 because there are two and i would say 100 amp, give or take a big fire or not

cvf

I believe it would be classified as "Slo-Blo" or perhaps "Never-Blo"

If you compare the size of the fusible link inside of a 100 amp fuse to the size of the copper pipe in the picture the copper pipe is probably good for 1000 amps or more. This is using the SWAG method of pipe sizing.

Bussman makes fuse jumpers so one does not need to use copper pipe for that purpose,now where they were used would make a huge difference such as a disco for a piece of equipment that has overcurrent protection upstream & did not require fuses at the equipment.

Originally Posted by Paul Kondzich

I have seen pics, but never saw it in person until now. They even fluxed the ends of the pipe, maybe they were going to solder them in.

How many amps depends on whether that's K, L, or M and what temperature rating you're targeting. I'm sure it can be calculated.

I agree about a 1,000 amps, the connections would certainly be the week link. It could easily carry 300 amps routinely. To bad they didn't leave the end caps off so there could be some internal cooling for efficiency sake.

But Corn is right you do need to know if it is K,L or M to calculate the cross sectional area correctly.

Personally I like the fact that they did not even care enough to use NEW pipe...
Geeze, if you are going to go to the trouble of using 100% copper "fuseable links", at least make sure to use 'solid, hollow wire' that has not been used, then recycled...
Or is this a case of recycling for LEED points???

I have a neighbor on my street that I am sure... uses the same method temporary each December.

He has one heck of a Christmas lite display...I tell ya' what!

Originally Posted by M. Slusar

Personally I like the fact that they did not even care enough to use NEW pipe...
Geeze, if you are going to go to the trouble of using 100% copper "fuseable links", at least make sure to use 'solid, hollow wire' that has not been used, then recycled...
Or is this a case of recycling for LEED points???

They should have used Monster Brand copper pipe so that their lights would put off pure light, their washer/dryer would do a better job cleaning clothes and their computers would run faster.

Let try put this more tehcnical for Poul and help litte bit to Corn Walker about how to calculate the size of overcurret protection that some bady use on this disconet; let sit a formula:
3" x ½" cu pipe + #8 THHN wire in a 60A disconect = 911 call for fire department or = to FBI call about "building bumb" intaled for a terrorist person.
I promece Poul that some bady will post another formula like this one on the current week,but for now you can figure out what could hapen if no one inpect this instalation.
Alex

You have to remember that electron flows primarily on the surface of metal structures. That's why stranded copper has better flow than solid core. So for those of you calculating flow, remember to use both the internal and external diameters. So you're absolutely correct in saying you need to know whether it's L,K, or M.

Originally Posted by James Foy

You have to remember that electron flows primarily on the surface of metal structures. That's why stranded copper has better flow than solid core. So for those of you calculating flow, remember to use both the internal and external diameters. So you're absolutely correct in saying you need to know whether it's L,K, or M.

This is only true of 60 Hz AC currents when you have solid conductors with a thickness of greater than 1/3". Stranded and hollow conductors do not exhibit the same skin effect tendencies. However stranded conductors have their own problems - proximity effect.

Because we can negate skin effect and proximity effect in our calculation (a hollow conductor is actually ideal in this situation), we can use the standard model for conductance for a given temperature rise. We need to know the cross-sectional area of the conductor and the resistance value of the material to determine how many amperes can be conducted at a given frequency before the temperature rise reaches our critical value.

Originally Posted by CHARLIE VAN FLEET

paul

looks to me to be a little over a roll of pennys in height. so lets say theres 50 pennies to a roll. multiply that by 2 because there are two and i would say 100 amp, give or take a big fire or not

cvf

Pennies have the ampere value stamped on them at the mint when they are made. It is directly over Lincolns head.

" In God We Trust"

Are they not two pieces soldered together? In which case it is the melting point of the solder that would determine the safety of the overload device, and that would depend on the mix of the solder. A genius could have put this together and we are calling this example of human engineering a disaster.

Of course I would tell the client to get a sparky.

I think the solder in the photo looks like it was already present on the piping--the piping is probably "repurposed"

Those are Time Delay fuses, time to get the marshmallows.

Everyone automatically assumes this installation will start a fire. No one has asked what this disconnect is for, what is feeding it, or what overcurrent protection is ahead of it.

I am not saying that the installation is in any way proper, but just pointing out that it may not be as much of a fire starter as all like to think.

for example : If it is for a residential heat pump, water heater, etc it is no different ( in theory) then using a non-rated breaker disconnect or one of those inexspensive pull out disconnects, neiother of which provide overcurrent protection but are legal to use.

Before you all try and hang me out - I am just playing devils advocate here

Ken makes a valid point! Not that I condone this in any way but if the wiring is protected by the proper size overcurrent device it is basically the same as a non-fused pull-out or safety switch. There was a time when any AC equipment installed had to have a fused disconnect by code because the equipment stated fuse, not circuit breaker for protection. Even if the wiring was properly sized and protected at the panel. It was very common to see copper pipe in the disconnects then and I still find it today! Nowadays almost all AC units state fuse OR circuit breaker so if you are protected in the panel you can use a non fused pull-out or safety switch at the unit.

Unanswered in the OP is: are fuses required in that location?

Fuse companies actually sell such things for use when you have a fusible disconnect, but there is a desire to not have any fuse there.

While is may be convenient to purchase such 'blanks' from the supply house, I do not see any code requirement that they be factory made or UL listed.

Originally Posted by Lou Romano

Ken makes a valid point! Not that I condone this in any way but if the wiring is protected by the proper size overcurrent device it is basically the same as a non-fused pull-out or safety switch. There was a time when any AC equipment installed had to have a fused disconnect by code because the equipment stated fuse, not circuit breaker for protection. Even if the wiring was properly sized and protected at the panel. It was very common to see copper pipe in the disconnects then and I still find it today! Nowadays almost all AC units state fuse OR circuit breaker so if you are protected in the panel you can use a non fused pull-out or safety switch at the unit.

OK, to answer a few questions, the pipe was re-used, they did'nt add the solder for any specific reason.

This was a A/C Condenser disconnect, with a circuit breaker at the panel, so it was protected.

My issue with this is that who knows how good the physical connection is at the pipe from the contacts at the box. Sure, there could be a pull out type switch, which is accomplishing the same thing, however thats what it was designed for, and was not field modified.

I also could not test to see if anything in this contraption was getting hot, because the condenser is sitting in some local scrap yard, and someone has a cheap 6 pack of beer, too bad they missed that ripe for the taking pieces of copper in the disconnect.

Originally Posted by Paul Kondzich

OK, to answer a few questions, the pipe was re-used, they did'nt add the solder for any specific reason.

This was a A/C Condenser disconnect, with a circuit breaker at the panel, so it was protected.

My issue with this is that who knows how good the physical connection is at the pipe from the contacts at the box. Sure, there could be a pull out type switch, which is accomplishing the same thing, however thats what it was designed for, and was not field modified.

I also could not test to see if anything in this contraption was getting hot, because the condenser is sitting in some local scrap yard, and someone has a cheap 6 pack of beer, too bad they missed that ripe for the taking pieces of copper in the disconnect.

This is a clear violation of NEC 110.3(b). The copper pipe is not listed an labeled. End of story. Also, I do not see a connector in the bottom of the disconnect.

Originally Posted by Paul Kondzich

My issue with this is that who knows how good the physical connection is at the pipe from the contacts at the box.

The issue should simply be that the fused disconnect was listed and labeled for use with fuses.

There is absolutely no need to try to determine whether or not the physical connection of the non-fuses are acceptable or not, the non-fuses are simply not acceptable in there ... regardless of all else.

If one was to use a dummy fuse this would be the best choice, I would prefer that a non-fusible model switch be used rather then use "site engineered" methods like CU pipe used in place of fuses, here is a link to the Bussman site.
http://www.cooperbussmann.com/pdf/ad...cbf467639c.pdf

Originally Posted by Bruce Breedlove

I have to admit that I have installed copper pipe fuses like that. But that was when I was growing up on a farm and didn't know any better.

Must admit I got a laugh ,seeing your avatar on this thread