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Tig welder extension cord
The business had a little extra cash before tax
time so my wife let me buy a Thermal Arc 185 TIG welder. I sorted out the plug/socket and installed an outlet for the unit. I also want to fabricate a 20' extension cord for the unit, and that's where I got confused. The welder specs call out 38 amps/240 volts as the max current draw. The welder comes with a line cord with 12 gauge conductors with a 50 ampere plug on the end. Anyone see the apparent contradiction here? I installed a 50 ampere breaker, the called-out 50 ampere socket, and 50 ampere-rated conductors between the two. Should be no issue there. The problem is the 20 foot extension cord. 8 or even 10 gauge portable cordage would seem to be a waste given the 12 gauge cord on the unit. OTOH, there's just something wrong about putting a 25 amp cable on a 50 amp breaker running to a 38 amp load. |
Tig welder extension cord
On Sep 4, 2:24 pm, Jim Stewart wrote:
The business had a little extra cash before tax time so my wife let me buy a Thermal Arc 185 TIG welder. I sorted out the plug/socket and installed an outlet for the unit. I also want to fabricate a 20' extension cord for the unit, and that's where I got confused. The welder specs call out 38 amps/240 volts as the max current draw. The welder comes with a line cord with 12 gauge conductors with a 50 ampere plug on the end. Anyone see the apparent contradiction here? I installed a 50 ampere breaker, the called-out 50 ampere socket, and 50 ampere-rated conductors between the two. Should be no issue there. The problem is the 20 foot extension cord. 8 or even 10 gauge portable cordage would seem to be a waste given the 12 gauge cord on the unit. OTOH, there's just something wrong about putting a 25 amp cable on a 50 amp breaker running to a 38 amp load. what was the duty cycle of the unit at max? probably 20% so for 2 minutes out of 10 the 12 gauge cord has to carry a 38 amp load then the cable has eight minutes to cool down What is the cost of the cable compared to the cost of the machine? is it really worth saving the 20 dollars on the length of the extension cord to use 12 instead of 8 Gauge? comapred to the 1500 to 2000 dollar machine and the even remote chance of a fire hazard? In fact if youre feeling extra cautious cut the breaker down to 40 amps and you should still never manage to pop it. For what youre saving on cable the safety seems a better choice |
Tig welder extension cord
Jim Stewart wrote:
The business had a little extra cash before tax time so my wife let me buy a Thermal Arc 185 TIG welder. I sorted out the plug/socket and installed an outlet for the unit. I also want to fabricate a 20' extension cord for the unit, and that's where I got confused. The welder specs call out 38 amps/240 volts as the max current draw. The welder comes with a line cord with 12 gauge conductors with a 50 ampere plug on the end. Anyone see the apparent contradiction here? I installed a 50 ampere breaker, the called-out 50 ampere socket, and 50 ampere-rated conductors between the two. Should be no issue there. The problem is the 20 foot extension cord. 8 or even 10 gauge portable cordage would seem to be a waste given the 12 gauge cord on the unit. OTOH, there's just something wrong about putting a 25 amp cable on a 50 amp breaker running to a 38 amp load. The national electric code allows the conductors supplying an electric welder to be reduced according to the duty cycle. You didn't really need to use #6 conductors to wire in the circuit -- but if you ever replaced the welder with one that had a much higher duty cycle machine you might have to put in heavier wiring, and with what you used you'll never have to do that. I'd probably make the extension cord out of #10 SE cable unless I just really needed something more flexible. (I think it's available in 10 gauge.) There would be nothing wrong with using #12 SJO (etc) cord here. HTH, :-) Bob |
Tig welder extension cord
Ratings for power cords are not the same as ratings for in the wall
cables in conduits. The cable has more of a chance to cool from ambient air and dissipate the heat. There is also a good point made by posters who mentioned duty cycle. I am also not sure why there is a need for an extension cord. I would go with 10 gauge for the extension cord. i |
Tig welder extension cord
Jim Stewart wrote:
The business had a little extra cash before tax time so my wife let me buy a Thermal Arc 185 TIG welder. I sorted out the plug/socket and installed an outlet for the unit. I also want to fabricate a 20' extension cord for the unit, and that's where I got confused. The welder specs call out 38 amps/240 volts as the max current draw. The welder comes with a line cord with 12 gauge conductors with a 50 ampere plug on the end. Anyone see the apparent contradiction here? I installed a 50 ampere breaker, the called-out 50 ampere socket, and 50 ampere-rated conductors between the two. Should be no issue there. The problem is the 20 foot extension cord. 8 or even 10 gauge portable cordage would seem to be a waste given the 12 gauge cord on the unit. OTOH, there's just something wrong about putting a 25 amp cable on a 50 amp breaker running to a 38 amp load. As has been noted, the NEC allows the use of undersized conductors on circuits feeding welders. This is ok in a commercial environment, but not so good in a residential environment. If there is a 50A outlet on the wall, someone will eventually try to connect a 50A load to it in a residential environment, so everything up to it really ought to be appropriately rated even if code doesn't require it. On the same idea, I would make my extension properly rated as well to allow for other uses in the future. Perhaps you'll get a kiln or heat treat furnace or something. Pete C. |
Tig welder extension cord
Besides worrying about the cord heating up, you should consider voltage
drop. You don't want to have a sagging voltage characteristic when you are running the welder at maximum output. I haven't done the math, but you should. (And, of course, this has nothing to do with duty cycle,) |
Tig welder extension cord
OTOH, there's just something wrong about putting a 25 amp cable on a 50 amp breaker running to a 38 amp load. Actually you do this kind of thing every time you plug a table lamp wired with 18 gauge wire into a wall outlet protected by a 20 amp breaker. As others have mentioned, this is allowed by the NEC under certain circumstances. My only concern in your case would be voltage drop if your extension cord was too long. I also have a T/A 185 tig. It's on a cart along with a Thermal Dynamics 51 plasma cutter. The cart has a 30' 10 gauge cord that powers both the tig and the plasma cutter ( but not at the same time ). I've never had any problems with this setup. The 10 gauge cord never even gets warm, and neither unit seems to suffer from low voltage due to a voltage drop in the supply cord. Enjoy your new welder 42 -- Posted via a free Usenet account from http://www.teranews.com |
Tig welder extension cord
On Tue, 4 Sep 2007 13:40:14 -0700, 42etus wrote:
OTOH, there's just something wrong about putting a 25 amp cable on a 50 amp breaker running to a 38 amp load. Actually you do this kind of thing every time you plug a table lamp wired with 18 gauge wire into a wall outlet protected by a 20 amp breaker. That is not a very good analogy. i |
Tig welder extension cord
On Tue, 4 Sep 2007 13:40:14 -0700, with neither quill nor qualm,
"42etus" quickly quoth: OTOH, there's just something wrong about putting a 25 amp cable on a 50 amp breaker running to a 38 amp load. Actually you do this kind of thing every time you plug a table lamp wired with 18 gauge wire into a wall outlet protected by a 20 amp breaker. Huh? A table lamp isn't drawing 152% of the cable's current rating when it's in use. A 150W bulb draws only 1.25A @ 120V. Standard current carrying capacity of an 18ga zip cord is 7A (16 in chassis use.) If a cord gets hot in use, it's definitely overloaded and I'd install a larger gauge cable in its place before I'd use it again. So far, I've had no electrical fires in this lifetime. ================================================== ========= Save the Endangered Bouillons from being cubed! ================================================== ========= |
Tig welder extension cord
I had a similar problem and I put in about 25 feet of 8x3.
I must admit that I had to breathe rather deeply when I saw how much it was going to cost. But now the weakest link in the chain is the guy doing the work! :-)oo DOC Jim Stewart wrote: The business had a little extra cash before tax time so my wife let me buy a Thermal Arc 185 TIG welder. I sorted out the plug/socket and installed an outlet for the unit. I also want to fabricate a 20' extension cord for the unit, and that's where I got confused. The welder specs call out 38 amps/240 volts as the max current draw. The welder comes with a line cord with 12 gauge conductors with a 50 ampere plug on the end. Anyone see the apparent contradiction here? I installed a 50 ampere breaker, the called-out 50 ampere socket, and 50 ampere-rated conductors between the two. Should be no issue there. The problem is the 20 foot extension cord. 8 or even 10 gauge portable cordage would seem to be a waste given the 12 gauge cord on the unit. OTOH, there's just something wrong about putting a 25 amp cable on a 50 amp breaker running to a 38 amp load. |
Tig welder extension cord
On Sep 4, 11:24 am, Jim Stewart wrote:
The business had a little extra cash before tax time so my wife let me buy a Thermal Arc 185 TIG welder. I sorted out the plug/socket and installed an outlet for the unit. I also want to fabricate a 20' extension cord for the unit, and that's where I got confused. The welder specs call out 38 amps/240 volts as the max current draw. The welder comes with a line cord with 12 gauge conductors with a 50 ampere plug on the end. Anyone see the apparent contradiction here? I installed a 50 ampere breaker, the called-out 50 ampere socket, and 50 ampere-rated conductors between the two. Should be no issue there. The problem is the 20 foot extension cord. 8 or even 10 gauge portable cordage would seem to be a waste given the 12 gauge cord on the unit. OTOH, there's just something wrong about putting a 25 amp cable on a 50 amp breaker running to a 38 amp load. Jim -- Are you near water? Any decent-sized town with a boating presence will have a used marine equipment store and they just about always have shore power cables available. A 50A marine shore power cable will be just the ticket for your welder, and likely cost less at the boat surplus shop than it would to buy the parts new. Regards, Bob |
Tig welder extension cord
Bob wrote:
On Sep 4, 11:24 am, Jim Stewart wrote: The business had a little extra cash before tax time so my wife let me buy a Thermal Arc 185 TIG welder. I sorted out the plug/socket and installed an outlet for the unit. I also want to fabricate a 20' extension cord for the unit, and that's where I got confused. The welder specs call out 38 amps/240 volts as the max current draw. The welder comes with a line cord with 12 gauge conductors with a 50 ampere plug on the end. Anyone see the apparent contradiction here? I installed a 50 ampere breaker, the called-out 50 ampere socket, and 50 ampere-rated conductors between the two. Should be no issue there. The problem is the 20 foot extension cord. 8 or even 10 gauge portable cordage would seem to be a waste given the 12 gauge cord on the unit. OTOH, there's just something wrong about putting a 25 amp cable on a 50 amp breaker running to a 38 amp load. Jim -- Are you near water? Any decent-sized town with a boating presence will have a used marine equipment store and they just about always have shore power cables available. A 50A marine shore power cable will be just the ticket for your welder, and likely cost less at the boat surplus shop than it would to buy the parts new. Great suggestion. I'll check it out. |
Tig welder extension cord
On Tue, 04 Sep 2007 16:08:17 -0500, Ignoramus15584
wrote: On Tue, 4 Sep 2007 13:40:14 -0700, 42etus wrote: OTOH, there's just something wrong about putting a 25 amp cable on a 50 amp breaker running to a 38 amp load. Actually you do this kind of thing every time you plug a table lamp wired with 18 gauge wire into a wall outlet protected by a 20 amp breaker. That is not a very good analogy. i Sure isn't, because the 1 amp table lamp is on a 7 amp cord in a 15 amp circuit. However, when running a welder on an extention cord, you want a cord capable of handling AT LEAST 120% of the expected load to reduce voltage drop. I like a good tec table 4-3 or 12-3 extention cord (15 or 20 amp capacity) to run things like table saws, light duty welders,pressure washers, etc. A lighter cord can sometimes prevent popping a fuse on startup because it limits the load - but not a good idea. My old repulsion start table saw would occaisionally pop a standard 15 amp fuse when started plegged into the wall. When on a 16 gauge cord 25 feet long it took longer to come up to speed but never popped a fuse. Went to using "slo-blow_ fusetrons - no more blown fuses. -- Posted via a free Usenet account from http://www.teranews.com |
Tig welder extension cord
"42etus" writes:
OTOH, there's just something wrong about putting a 25 amp cable on a 50 amp breaker running to a 38 amp load. Actually you do this kind of thing every time you plug a table lamp wired with 18 gauge wire into a wall outlet protected by a 20 amp breaker. Only if the lamp is running between 17 and 19 amps (just did a quick google and found a claim that 18ga is good for 16A -- what I'm saying here is based on the assumption that the info I found was accurate). If the lamp is rated for a 100W bulb, you're fine. As others have mentioned, this is allowed by the NEC under certain circumstances. I'll have to look that one up... |
Tig welder extension cord
On Tue, 04 Sep 2007 18:48:18 -0400, clare at snyder.on.ca wrote:
On Tue, 04 Sep 2007 16:08:17 -0500, Ignoramus15584 wrote: On Tue, 4 Sep 2007 13:40:14 -0700, 42etus wrote: OTOH, there's just something wrong about putting a 25 amp cable on a 50 amp breaker running to a 38 amp load. Actually you do this kind of thing every time you plug a table lamp wired with 18 gauge wire into a wall outlet protected by a 20 amp breaker. That is not a very good analogy. i Sure isn't, because the 1 amp table lamp is on a 7 amp cord in a 15 amp circuit. Seems like a perfectly good analogy to me. The cord is sized considering the nature of the load, not the capacity of the circuit that's feeding it. The welder in question draws about 30A @ 30% duty cycle. However, when running a welder on an extention cord, you want a cord capable of handling AT LEAST 120% of the expected load to reduce voltage drop. Unlike induction motors, most welders are tolerant of low input voltage. The 185T will operate on 208V circuits, so if it's being supplied by a typical 240V feed there'd have to be an awfully big drop to bother it. -- Ned Simmons |
Tig welder extension cord
On Tue, 04 Sep 2007 18:48:18 -0400, clare at snyder.on.ca clare wrote:
On Tue, 04 Sep 2007 16:08:17 -0500, Ignoramus15584 wrote: On Tue, 4 Sep 2007 13:40:14 -0700, 42etus wrote: OTOH, there's just something wrong about putting a 25 amp cable on a 50 amp breaker running to a 38 amp load. Actually you do this kind of thing every time you plug a table lamp wired with 18 gauge wire into a wall outlet protected by a 20 amp breaker. That is not a very good analogy. i Sure isn't, because the 1 amp table lamp is on a 7 amp cord in a 15 amp circuit. exactly. However, when running a welder on an extention cord, you want a cord capable of handling AT LEAST 120% of the expected load to reduce voltage drop. I like a good tec table 4-3 or 12-3 extention cord (15 or 20 amp capacity) to run things like table saws, light duty welders,pressure washers, etc. A lighter cord can sometimes prevent popping a fuse on startup because it limits the load - but not a good idea. My old repulsion start table saw would occaisionally pop a standard 15 amp fuse when started plegged into the wall. When on a 16 gauge cord 25 feet long it took longer to come up to speed but never popped a fuse. Went to using "slo-blow_ fusetrons - no more blown fuses. A welder does not have such startup issues. i |
Tig welder extension cord
I think you guys missed my point. The OP seemed to be concerned that he was
going to have a cord rated at 25 amps protected by a 50 amp breaker. What I meant to point out is that it is very common and allowed by the NEC to have cords supplying appliances that are rated less than the breaker supplying the circuit. Most household appliances, toasters, lamps, radios, computers etc all have power supply cords that are not rated for the 20 amps that wall outlets are capable of supplying. Can you imagine your electric razor having a 12/3 SJO cord just because your outlet in the bathroom was on a circuit protected by a 20 amp breaker? That would make shaving each morning a real PITA. 42 "Ignoramus15584" wrote in message ... On Tue, 04 Sep 2007 18:48:18 -0400, clare at snyder.on.ca clare wrote: On Tue, 04 Sep 2007 16:08:17 -0500, Ignoramus15584 wrote: On Tue, 4 Sep 2007 13:40:14 -0700, 42etus wrote: OTOH, there's just something wrong about putting a 25 amp cable on a 50 amp breaker running to a 38 amp load. Actually you do this kind of thing every time you plug a table lamp wired with 18 gauge wire into a wall outlet protected by a 20 amp breaker. That is not a very good analogy. i Sure isn't, because the 1 amp table lamp is on a 7 amp cord in a 15 amp circuit. exactly. However, when running a welder on an extention cord, you want a cord capable of handling AT LEAST 120% of the expected load to reduce voltage drop. I like a good tec table 4-3 or 12-3 extention cord (15 or 20 amp capacity) to run things like table saws, light duty welders,pressure washers, etc. A lighter cord can sometimes prevent popping a fuse on startup because it limits the load - but not a good idea. My old repulsion start table saw would occaisionally pop a standard 15 amp fuse when started plegged into the wall. When on a 16 gauge cord 25 feet long it took longer to come up to speed but never popped a fuse. Went to using "slo-blow_ fusetrons - no more blown fuses. A welder does not have such startup issues. i -- Posted via a free Usenet account from http://www.teranews.com |
Tig welder extension cord
On Tue, 04 Sep 2007 20:00:07 -0400, Ned Simmons
wrote: On Tue, 04 Sep 2007 18:48:18 -0400, clare at snyder.on.ca wrote: On Tue, 04 Sep 2007 16:08:17 -0500, Ignoramus15584 wrote: On Tue, 4 Sep 2007 13:40:14 -0700, 42etus wrote: OTOH, there's just something wrong about putting a 25 amp cable on a 50 amp breaker running to a 38 amp load. Actually you do this kind of thing every time you plug a table lamp wired with 18 gauge wire into a wall outlet protected by a 20 amp breaker. That is not a very good analogy. i Sure isn't, because the 1 amp table lamp is on a 7 amp cord in a 15 amp circuit. Seems like a perfectly good analogy to me. The cord is sized considering the nature of the load, not the capacity of the circuit that's feeding it. The welder in question draws about 30A @ 30% duty cycle. However, when running a welder on an extention cord, you want a cord capable of handling AT LEAST 120% of the expected load to reduce voltage drop. Unlike induction motors, most welders are tolerant of low input voltage. The 185T will operate on 208V circuits, so if it's being supplied by a typical 240V feed there'd have to be an awfully big drop to bother it. My little "MIG" welder runs on a 15 amp circuit on 110 volts. On a 50 foot 16 guage cord at full output the voltage drops to about 96 volts. That reduces the maximum current of an already borderline welder significantly.(14% voltage drop roughly 28% power drop?????) -- Posted via a free Usenet account from http://www.teranews.com |
Tig welder extension cord
Ned Simmons writes:
On Tue, 04 Sep 2007 18:48:18 -0400, clare at snyder.on.ca wrote: On Tue, 04 Sep 2007 16:08:17 -0500, Ignoramus15584 On Tue, 4 Sep 2007 13:40:14 -0700, 42etus wrote: OTOH, there's just something wrong about putting a 25 amp cable on a 50 amp breaker running to a 38 amp load. Actually you do this kind of thing every time you plug a table lamp wired with 18 gauge wire into a wall outlet protected by a 20 amp breaker. That is not a very good analogy. Sure isn't, because the 1 amp table lamp is on a 7 amp cord in a 15 amp circuit. Seems like a perfectly good analogy to me. The cord is sized considering the nature of the load, not the capacity of the circuit that's feeding it. The welder in question draws about 30A @ 30% duty cycle. You're assuming the conditions of setting the duty cycle of the welder also apply to the duty cycle of the cord. I don't see *any* reason to believe that's going to be the case. When I see a duty cycle rating for an extension cord, I'll believe that it applies to it. In the mean time, I'll use a cord rated for the peak load that it will be called on to handle. However, when running a welder on an extention cord, you want a cord capable of handling AT LEAST 120% of the expected load to reduce voltage drop. Unlike induction motors, most welders are tolerant of low input voltage. The 185T will operate on 208V circuits, so if it's being supplied by a typical 240V feed there'd have to be an awfully big drop to bother it. I'll agree that this is a different, and almost unrelated, question. |
Tig welder extension cord
On Tue, 04 Sep 2007 11:24:09 -0700, Jim Stewart
wrote: The business had a little extra cash before tax time so my wife let me buy a Thermal Arc 185 TIG welder. I sorted out the plug/socket and installed an outlet for the unit. I also want to fabricate a 20' extension cord for the unit, and that's where I got confused. The welder specs call out 38 amps/240 volts as the max current draw. The welder comes with a line cord with 12 gauge conductors with a 50 ampere plug on the end. Anyone see the apparent contradiction here? I installed a 50 ampere breaker, the called-out 50 ampere socket, and 50 ampere-rated conductors between the two. Should be no issue there. The problem is the 20 foot extension cord. 8 or even 10 gauge portable cordage would seem to be a waste given the 12 gauge cord on the unit. OTOH, there's just something wrong about putting a 25 amp cable on a 50 amp breaker running to a 38 amp load. Duty cycle. The same reason the wiring codes allow you to use smaller wire than indicated for welders. Gunner |
Tig welder extension cord
On Tue, 04 Sep 2007 20:00:07 -0400, Ned Simmons
wrote: i Sure isn't, because the 1 amp table lamp is on a 7 amp cord in a 15 amp circuit. Seems like a perfectly good analogy to me. The cord is sized considering the nature of the load, not the capacity of the circuit that's feeding it. The welder in question draws about 30A @ 30% duty cycle. Then there is the standard practice among professional welders to put a 10' whip of much lighter, more flexible cable on the end of a welding lead. Gunner |
Tig welder extension cord
|
Tig welder extension cord
On Tue, 4 Sep 2007 20:03:48 -0700, "42etus"
wrote: I think you guys missed my point. The OP seemed to be concerned that he was going to have a cord rated at 25 amps protected by a 50 amp breaker. What I meant to point out is that it is very common and allowed by the NEC to have cords supplying appliances that are rated less than the breaker supplying the circuit. Most household appliances, toasters, lamps, radios, computers etc all have power supply cords that are not rated for the 20 amps that wall outlets are capable of supplying. Can you imagine your electric razor having a 12/3 SJO cord just because your outlet in the bathroom was on a circuit protected by a 20 amp breaker? That would make shaving each morning a real PITA. 42 And where do you have 20 amp breaker protection on domestic circuits????? In North America????? Virtually all domestic branch circuits are 15 amp fused(or breaker protected) 14 AWG copper or 12 awg Aluminum cable. Virtually all computer power cords are 18AWG fine stranded copper, as are MOST lamp cords and many light duty extention cords. Virtually all domestic 110 volt receptacles are 15 amp and it is AGAINST CODE to install 20 amp receptacles on a 14 guage 15 amp circuit. The OCCAISIONAL dedicated circuit for things like room air conditioners are wired with 12awg and protected to 20 amp - using 20 amp receptacles and the odd "T" type power plugs - | u -- Posted via a free Usenet account from http://www.teranews.com |
Tig welder extension cord
On Tue, 4 Sep 2007 20:03:48 -0700, "42etus"
wrote: I think you guys missed my point. The OP seemed to be concerned that he was going to have a cord rated at 25 amps protected by a 50 amp breaker. What I meant to point out is that it is very common and allowed by the NEC to have cords supplying appliances that are rated less than the breaker supplying the circuit. Exactly. The welder has 12-3 SO Cable on it, and you have to remember that the "20 Amps for 12-AWG wire" rule is artificially imposed - in reality it's good for quite a bit more depending on the temperature rating of the cable insulation and the ambient temperature around it, especially in free air. The reason you would not use 12-3 for the welder extension cord is voltage drop. 10-3 would work fine for a 25' to 50' welder or plasma cutter extension cord - that's what I use. If you want that cord to go 100' or more, when you run across a coil of 8-3 or 8-4 SO cord at a good price, grab it. Most household appliances, toasters, lamps, radios, computers etc all have power supply cords that are not rated for the 20 amps that wall outlets are capable of supplying. Can you imagine your electric razor having a 12/3 SJO cord just because your outlet in the bathroom was on a circuit protected by a 20 amp breaker? That would make shaving each morning a real PITA. That was why they invented the cordless razor. Of course, you had to hold it upright so the battery acid from the open tank cells didn't get spilled in your beard... ;-P But this kind of stupidity still exists in certain instances - they have a rule for Commercial Track Lighting that if the track and the dimmer are rated for 20A (2400W), they have to figure the actual load at 2400W - even if you are only going to connect 400W of lights... To get around this, they came up with permanent small breakers between the power source and track to "derate" the track to 4A (480W), thus allowing them to reduce the overall building load calculations. -- Bruce -- |
Tig welder extension cord
clare at snyder.on.ca wrote:
On Tue, 4 Sep 2007 20:03:48 -0700, "42etus" wrote: I think you guys missed my point. The OP seemed to be concerned that he was going to have a cord rated at 25 amps protected by a 50 amp breaker. What I meant to point out is that it is very common and allowed by the NEC to have cords supplying appliances that are rated less than the breaker supplying the circuit. Most household appliances, toasters, lamps, radios, computers etc all have power supply cords that are not rated for the 20 amps that wall outlets are capable of supplying. Can you imagine your electric razor having a 12/3 SJO cord just because your outlet in the bathroom was on a circuit protected by a 20 amp breaker? That would make shaving each morning a real PITA. 42 And where do you have 20 amp breaker protection on domestic circuits????? In North America????? Virtually all domestic branch circuits are 15 amp fused(or breaker protected) 14 AWG copper or 12 awg Aluminum cable. Virtually all computer power cords are 18AWG fine stranded copper, as are MOST lamp cords and many light duty extention cords. Virtually all domestic 110 volt receptacles are 15 amp and it is AGAINST CODE to install 20 amp receptacles on a 14 guage 15 amp circuit. The OCCAISIONAL dedicated circuit for things like room air conditioners are wired with 12awg and protected to 20 amp - using 20 amp receptacles and the odd "T" type power plugs - | u That's Canada. The USA uses a mixture of 20A circuits with 15A duplex receptacles and 12 AWG copper wire, and 15A circuits w/ 14 AWG copper wire. Aluminum wiring is only used for 30A and larger circuits. (there was an experiment that went terribly wrong during the 1970's with using AL wiring for 15 and 20A circuits.) Bob |
Tig welder extension cord
clare at snyder.on.ca wrote:
On Tue, 04 Sep 2007 20:00:07 -0400, Ned Simmons wrote: On Tue, 04 Sep 2007 18:48:18 -0400, clare at snyder.on.ca wrote: On Tue, 04 Sep 2007 16:08:17 -0500, Ignoramus15584 wrote: On Tue, 4 Sep 2007 13:40:14 -0700, 42etus wrote: OTOH, there's just something wrong about putting a 25 amp cable on a 50 amp breaker running to a 38 amp load. Actually you do this kind of thing every time you plug a table lamp wired with 18 gauge wire into a wall outlet protected by a 20 amp breaker. That is not a very good analogy. i Sure isn't, because the 1 amp table lamp is on a 7 amp cord in a 15 amp circuit. Seems like a perfectly good analogy to me. The cord is sized considering the nature of the load, not the capacity of the circuit that's feeding it. The welder in question draws about 30A @ 30% duty cycle. However, when running a welder on an extention cord, you want a cord capable of handling AT LEAST 120% of the expected load to reduce voltage drop. Unlike induction motors, most welders are tolerant of low input voltage. The 185T will operate on 208V circuits, so if it's being supplied by a typical 240V feed there'd have to be an awfully big drop to bother it. My little "MIG" welder runs on a 15 amp circuit on 110 volts. On a 50 foot 16 guage cord at full output the voltage drops to about 96 volts. That reduces the maximum current of an already borderline welder significantly.(14% voltage drop roughly 28% power drop?????) A TIG welder uses a constant-current power supply. It's much less susceptible to voltage drop in the power feed than a MIG welder (which uses a constant voltage supply). Bob |
Tig welder extension cord
And where do you have 20 amp breaker protection on domestic circuits????? In North America????? It has been commonplace, though not required, to wire outlets in homes on 20 amp circuits for years now, at least in the U.S. Virtually all domestic branch circuits are 15 amp fused(or breaker protected) 14 AWG copper or 12 awg Aluminum cable. Wrong! Typically residential wiring uses 12 AWG wire on 20 amp circuits for wall outlets. Aluminum wire is NOT allowed in residential wiring except as service entrance conductors and hasn't been for years. Virtually all computer power cords are 18AWG fine stranded copper, as are MOST lamp cords and many light duty extention cords. That is the point I was trying to make. Virtually all domestic 110 volt receptacles are 15 amp and it is AGAINST CODE to install 20 amp receptacles on a 14 guage 15 amp circuit. Yes, but FWIW it is NOT against the NEC to install 15 amp receptacles on 20 amp branch circuits. The OCCAISIONAL dedicated circuit for things like room air conditioners are wired with 12awg and protected to 20 amp - using 20 amp receptacles and the odd "T" type power plugs That would be a very small A/C unit indeed since the NEC requires that an appliance on a dedicated circuit draw no more than 75 % of the circuit's rating, or in the case of a 20 amp circuit, 15 amps. An appliance that draws 15 amps is not likely to have a NEMA 5-20P (odd T type) plug. 42 -- Posted via a free Usenet account from http://www.teranews.com |
Tig welder extension cord
Now I see from your header that you're in Canada. I don't know a thing about
the Canadian codes, my experience has all been in the USA. All my comments were intended to remain south of the 48th parallel.grin 42 clare at snyder.on.ca wrote in message ... On Tue, 4 Sep 2007 20:03:48 -0700, "42etus" wrote: I think you guys missed my point. The OP seemed to be concerned that he was going to have a cord rated at 25 amps protected by a 50 amp breaker. What I meant to point out is that it is very common and allowed by the NEC to have cords supplying appliances that are rated less than the breaker supplying the circuit. Most household appliances, toasters, lamps, radios, computers etc all have power supply cords that are not rated for the 20 amps that wall outlets are capable of supplying. Can you imagine your electric razor having a 12/3 SJO cord just because your outlet in the bathroom was on a circuit protected by a 20 amp breaker? That would make shaving each morning a real PITA. 42 And where do you have 20 amp breaker protection on domestic circuits????? In North America????? Virtually all domestic branch circuits are 15 amp fused(or breaker protected) 14 AWG copper or 12 awg Aluminum cable. Virtually all computer power cords are 18AWG fine stranded copper, as are MOST lamp cords and many light duty extention cords. Virtually all domestic 110 volt receptacles are 15 amp and it is AGAINST CODE to install 20 amp receptacles on a 14 guage 15 amp circuit. The OCCAISIONAL dedicated circuit for things like room air conditioners are wired with 12awg and protected to 20 amp - using 20 amp receptacles and the odd "T" type power plugs - | u -- Posted via a free Usenet account from http://www.teranews.com -- Posted via a free Usenet account from http://www.teranews.com |
Tig welder extension cord
"42etus" writes:
I think you guys missed my point. The OP seemed to be concerned that he was going to have a cord rated at 25 amps protected by a 50 amp breaker. What I I read the issue as having a cord rated at 25 amps feeding a load rated at 38. |
Tig welder extension cord
On Tue, 04 Sep 2007 23:21:46 -0500, zxcvbob
wrote: (there was an experiment that went terribly wrong during the 1970's with using AL wiring for 15 and 20A circuits.) Bob Indeed. They are still finding them when the house burns to the ground. Gunner |
Tig welder extension cord
On Wed, 05 Sep 2007 00:05:51 -0600, Joe Pfeiffer
wrote: "42etus" writes: I think you guys missed my point. The OP seemed to be concerned that he was going to have a cord rated at 25 amps protected by a 50 amp breaker. What I I read the issue as having a cord rated at 25 amps feeding a load rated at 38. True indeed. An intermitant load. Gunner |
Tig welder extension cord
On Tue, 04 Sep 2007 23:28:21 -0400, with neither quill nor qualm,
clare at snyder.on.ca quickly quoth: My little "MIG" welder runs on a 15 amp circuit on 110 volts. On a 50 foot 16 guage cord at full output the voltage drops to about 96 volts. That reduces the maximum current of an already borderline welder significantly.(14% voltage drop roughly 28% power drop?????) Time to bite the bullet and go buy a 12/3 contractor's extension cord. They're about $60 here in the States. Dunno 'bout Canuckistan. ================================================== ========= Save the Endangered Bouillons from being cubed! ================================================== ========= |
Tig welder extension cord
On Tue, 04 Sep 2007 21:34:16 -0600, Joe Pfeiffer
wrote: Ned Simmons writes: Seems like a perfectly good analogy to me. The cord is sized considering the nature of the load, not the capacity of the circuit that's feeding it. The welder in question draws about 30A @ 30% duty cycle. You're assuming the conditions of setting the duty cycle of the welder also apply to the duty cycle of the cord. I don't see *any* reason to believe that's going to be the case. When I see a duty cycle rating for an extension cord, I'll believe that it applies to it. In the mean time, I'll use a cord rated for the peak load that it will be called on to handle. See the NEC article on welders. It recognizes the intermittent nature of welding and allows conductors with an ampacity lower than the breaker on a welder circuit. There's a similar situation with motor branch circuits, though the rules for sizing the breaker and wiring are very different from than those for welders. -- Ned Simmons |
Tig welder extension cord
On Tue, 04 Sep 2007 21:34:16 -0600, Joe Pfeiffer
wrote: Ned Simmons writes: Seems like a perfectly good analogy to me. The cord is sized considering the nature of the load, not the capacity of the circuit that's feeding it. The welder in question draws about 30A @ 30% duty cycle. You're assuming the conditions of setting the duty cycle of the welder also apply to the duty cycle of the cord. I don't see *any* reason to believe that's going to be the case. When I see a duty cycle rating for an extension cord, I'll believe that it applies to it. In the mean time, I'll use a cord rated for the peak load that it will be called on to handle. I'm not assuming anything. See the NEC article on welders, which recognizes the intermittent nature of welding and allows for conductors with an ampacity lower than the breaker's setting on welder circuits. There's a similar situation for motor branch circuits that accomodates the starting current of induction motors. -- Ned Simmons |
Tig welder extension cord
On Tue, 04 Sep 2007 23:28:21 -0400, clare at snyder.on.ca wrote:
On Tue, 04 Sep 2007 20:00:07 -0400, Ned Simmons However, when running a welder on an extention cord, you want a cord capable of handling AT LEAST 120% of the expected load to reduce voltage drop. Unlike induction motors, most welders are tolerant of low input voltage. The 185T will operate on 208V circuits, so if it's being supplied by a typical 240V feed there'd have to be an awfully big drop to bother it. My little "MIG" welder runs on a 15 amp circuit on 110 volts. On a 50 foot 16 guage cord at full output the voltage drops to about 96 volts. That reduces the maximum current of an already borderline welder significantly.(14% voltage drop roughly 28% power drop?????) In this case, a 20 foot, 12 ga extension with a 38A load @ 240V results in a 2.5% drop, or 234V at the welder. Also note that the 185T is an inverter welder - it acts like a switching regulator and draws more current as the supply voltage drops, so I doubt you'd notice any difference at the output. I get about 30A running thru a 50ft, 16 ga extension for a 14V drop. Are you sure the whole loss is in the cord? -- Ned Simmons |
Tig welder extension cord
clare, at, snyder.on.ca wrote:
On Tue, 4 Sep 2007 20:03:48 -0700, "42etus" wrote: I think you guys missed my point. The OP seemed to be concerned that he was going to have a cord rated at 25 amps protected by a 50 amp breaker. What I meant to point out is that it is very common and allowed by the NEC to have cords supplying appliances that are rated less than the breaker supplying the circuit. Most household appliances, toasters, lamps, radios, computers etc all have power supply cords that are not rated for the 20 amps that wall outlets are capable of supplying. Can you imagine your electric razor having a 12/3 SJO cord just because your outlet in the bathroom was on a circuit protected by a 20 amp breaker? That would make shaving each morning a real PITA. 42 And where do you have 20 amp breaker protection on domestic circuits????? In North America????? Virtually all domestic branch circuits are 15 amp fused(or breaker protected) 14 AWG copper or 12 awg Aluminum cable. Virtually all computer power cords are 18AWG fine stranded copper, as are MOST lamp cords and many light duty extention cords. Virtually all domestic 110 volt receptacles are 15 amp and it is AGAINST CODE to install 20 amp receptacles on a 14 guage 15 amp circuit. The OCCAISIONAL dedicated circuit for things like room air conditioners are wired with 12awg and protected to 20 amp - using 20 amp receptacles and the odd "T" type power plugs - | u -- Posted via a free Usenet account from http://www.teranews.com Every single "domestic" circuit in my house is 20A. There is no 14ga wire anywhere in the house. It was even this way when I bought the house, before I replaced the main panel. Pete C. |
Tig welder extension cord
Pete C. wrote:
clare, at, snyder.on.ca wrote: On Tue, 4 Sep 2007 20:03:48 -0700, "42etus" wrote: I think you guys missed my point. The OP seemed to be concerned that he was going to have a cord rated at 25 amps protected by a 50 amp breaker. What I meant to point out is that it is very common and allowed by the NEC to have cords supplying appliances that are rated less than the breaker supplying the circuit. Most household appliances, toasters, lamps, radios, computers etc all have power supply cords that are not rated for the 20 amps that wall outlets are capable of supplying. Can you imagine your electric razor having a 12/3 SJO cord just because your outlet in the bathroom was on a circuit protected by a 20 amp breaker? That would make shaving each morning a real PITA. 42 And where do you have 20 amp breaker protection on domestic circuits????? In North America????? Virtually all domestic branch circuits are 15 amp fused(or breaker protected) 14 AWG copper or 12 awg Aluminum cable. Virtually all computer power cords are 18AWG fine stranded copper, as are MOST lamp cords and many light duty extention cords. Virtually all domestic 110 volt receptacles are 15 amp and it is AGAINST CODE to install 20 amp receptacles on a 14 guage 15 amp circuit. The OCCAISIONAL dedicated circuit for things like room air conditioners are wired with 12awg and protected to 20 amp - using 20 amp receptacles and the odd "T" type power plugs - | u -- Posted via a free Usenet account from http://www.teranews.com Every single "domestic" circuit in my house is 20A. There is no 14ga wire anywhere in the house. It was even this way when I bought the house, before I replaced the main panel. Pete C. I'm not really up on Canadian electric codes, but they are different than in the USA: Canada only recently changed to allow 20A receptacles that will accept a 15A plug. Previously, 15A circuits could only have 15A receptacles (just like USA) and 20A circuits could only have 20A-only receptacles (I'm not sure those even exist in the USA) Also they wire their kitchen countertop outlets different -- IIRC they use 15A duplex receptacles and split them, using an "edison circuit" (each pair of outlets has 240V available between them) That would come in really handy if you wanted to replace one with a 240V receptacle for one of those 3000W British electric kettles that will boil a quart of water in 10 seconds ;-) Bob |
Tig welder extension cord
On Wed, 05 Sep 2007 01:27:33 -0700, Gunner Asch wrote:
On Tue, 04 Sep 2007 23:21:46 -0500, zxcvbob wrote: (there was an experiment that went terribly wrong during the 1970's with using AL wiring for 15 and 20A circuits.) Indeed. They are still finding them when the house burns to the ground. More prevalent in mobile homes than stick-built houses, almost universally AL wiring in coaches from the late 60's through 80's. The mobile home industry always uses the rock bottom cheapest way to build coaches, so they pressed for the code change allowing it. And didn't stop until forced to by the code changing back because of the problems, they tried AL-COR "revised" devices that didn't help. Mobile homes burn a whole lot better. No drywall, all paneling. Usually the cheap brown phenolic boxes that couldn't enclose a sneeze, let alone a fire till it goes out on it's own. And cheap Federal Pacific breakers that won't trip when you need them to. And as the FD is snuffing out the embers the dummy homeowner goes "Gee, there was this one outlet circuit that blinked and flickered every time I ran my electric frying pan - was I supposed to call someone to check it?" -- Bruce -- |
Tig welder extension cord
"Bruce L. Bergman" wrote:
On Wed, 05 Sep 2007 01:27:33 -0700, Gunner Asch wrote: On Tue, 04 Sep 2007 23:21:46 -0500, zxcvbob wrote: (there was an experiment that went terribly wrong during the 1970's with using AL wiring for 15 and 20A circuits.) Indeed. They are still finding them when the house burns to the ground. More prevalent in mobile homes than stick-built houses, almost universally AL wiring in coaches from the late 60's through 80's. The mobile home industry always uses the rock bottom cheapest way to build coaches, so they pressed for the code change allowing it. And didn't stop until forced to by the code changing back because of the problems, they tried AL-COR "revised" devices that didn't help. Mobile homes burn a whole lot better. No drywall, all paneling. Usually the cheap brown phenolic boxes that couldn't enclose a sneeze, let alone a fire till it goes out on it's own. And cheap Federal Pacific breakers that won't trip when you need them to. And as the FD is snuffing out the embers the dummy homeowner goes "Gee, there was this one outlet circuit that blinked and flickered every time I ran my electric frying pan - was I supposed to call someone to check it?" -- Bruce -- Unfortunate how the lowest quality, least resilient housing tends to align with the least attentive and proactive occupants... |
Tig welder extension cord
You left off the MAX after the 38. If the welder has a 20% duty cycle
at max output then the average current is well below 25 amps. Dan On Sep 5, 7:05 am, Joe Pfeiffer wrote: I read the issue as having a cord rated at 25 amps feeding a load rated at 38. |
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