Can someone explain to me why I have used 6 ft 12ga cords on 5500 watt elements and internal short wires. And have no problems with wire over heating. Wire must be rated for amps at long runs. I know I need to run heaver gauge on long runs. But it doesn't seem so on short runs.
5500 watt 12ga wire?
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NoahBeach
Well-Known Member
5500w = ~22 amps at 240v
12g wire = rated for safe use with 20amp over current protection device (breaker)
You're just above the safe rated current protection required for that wire, which is the rating at which the wire is determined to not catch fire when installed properly. The current rating is going to have some safety factor built in (no idea as to the value of that), you're just under it.
Is it code? No, but unless your stand is permanently wired into your house that doesn't "apply".
Is it safe? Maybe, maybe not. Distance, quality of wire, insulation of wire, etc all come into play.
Should you just get some 10g wire? Yes.
Is it your prerogative to do whatever you want? Yes.
Have fun, be safe!
12g wire = rated for safe use with 20amp over current protection device (breaker)
You're just above the safe rated current protection required for that wire, which is the rating at which the wire is determined to not catch fire when installed properly. The current rating is going to have some safety factor built in (no idea as to the value of that), you're just under it.
Is it code? No, but unless your stand is permanently wired into your house that doesn't "apply".
Is it safe? Maybe, maybe not. Distance, quality of wire, insulation of wire, etc all come into play.
Should you just get some 10g wire? Yes.
Is it your prerogative to do whatever you want? Yes.
Have fun, be safe!
PlexVector
Mellow Goose Brewing
PlexVector
Mellow Goose Brewing
They verified all the math and UL tested it? I'd have to look at a unit and see what they did and then reverse engineer it to know for sure. I've not designed one myself.
I found this on internet and the internet doesn't lie. It seem internal chassis wiring you could use 12ga for 41 amps. I might not be reading it correctly.
http://www.powerstream.com/Wire_Size.htm
http://www.powerstream.com/Wire_Size.htm
Gr3:
Check the wattage of your toaster or tea kettle. Then look at the gauge of wire.
You are correct that a temporary cable in free air is a different situation than permanent cable inside the wall. But you are best to keep that to yourself, there are a lot of electrical bashers here.
Tom
Check the wattage of your toaster or tea kettle. Then look at the gauge of wire.
You are correct that a temporary cable in free air is a different situation than permanent cable inside the wall. But you are best to keep that to yourself, there are a lot of electrical bashers here.
Tom
PlexVector
Mellow Goose Brewing
Also the type of insulation will define the overall diameter of the wire.
Inside the device the insulation thickness may be thin because it is Teflon
that can handle higher temperatures as opposed to externally the more
common wire insulation thickness used is thicker for safety and cost since
it is not in a protective enclosure. I've simplified the explanation. There
are many factors that define the type of wire required based on safety
and performance.
Inside the device the insulation thickness may be thin because it is Teflon
that can handle higher temperatures as opposed to externally the more
common wire insulation thickness used is thicker for safety and cost since
it is not in a protective enclosure. I've simplified the explanation. There
are many factors that define the type of wire required based on safety
and performance.
No, sorry. I know what you're trying to say, but the voltage drop per inch is the same regardless of the length. Thus, the heating is the same per inch.
PlexVector
Mellow Goose Brewing
Correct, less inches-less heat, and more power available to the heater and less heat dissipated by the lead wire.
I think you can use the chassis wiring column in those tables. I did for my first build.
Chassis wiring is wiring that has open, convective cooling. That is, the load-carrying wires aren't bundled with a lot of other wires carrying similar loads. So, in a chassis application the heat from the wire can dissipate into the enclosure. If the wire is bundled with a bunch of other wire, as in a overhead raceway, there is less (or no) cooling, and thus the lower current rating.
However, I did end up buying a bunch of SJOOW-10/3 at Home Depot and using that for both the power cord and the chassis wiring in my box.
Chassis wiring is wiring that has open, convective cooling. That is, the load-carrying wires aren't bundled with a lot of other wires carrying similar loads. So, in a chassis application the heat from the wire can dissipate into the enclosure. If the wire is bundled with a bunch of other wire, as in a overhead raceway, there is less (or no) cooling, and thus the lower current rating.
However, I did end up buying a bunch of SJOOW-10/3 at Home Depot and using that for both the power cord and the chassis wiring in my box.
Er... right. You're right there.
But I don't want anybody to think that for a very short run, say a couple of inches, they can use 22AWG for 20 amps. Though the run is quite short, it will burn up quickly.
PlexVector
Mellow Goose Brewing
I would bet that code requires larger diameter wire as the run gets longer. Or at least the manufacturer of the furnace would to prevent voltage drop, which would effect performance. The toaster's performance is not that critical.
We want to minimize voltage drops because the power drops 4x for every 1x of voltage. Could make the difference in how long it takes to get to boil on a windy day.
We want to minimize voltage drops because the power drops 4x for every 1x of voltage. Could make the difference in how long it takes to get to boil on a windy day.
PlexVector
Mellow Goose Brewing
I fully agree with you on that one! They would have a cabinet full of smelly dangerous fuses.
augiedoggy
Well-Known Member
I havent read the thread since its surely a debate based on opinions with a few facts thrown in to make it confusing, plus if I read it I will end up off topic like the thread has likely gone but my advice it just pay attention to the application of the cord and what its rated for..
A 5500w element can draw up to 23amps max (usually 22). There is 12/3 SJ wire thats rated for 25a at 250v.... This is perfectly safe to use for an element cord especially at lengths shorter than 10 ft. I use it for my 4500w elements and it does not even get warm. if the cable is rated for 25a at a certain voltage that means it is safe and capable to handle up to that much in its intended application.
people on forums often just like to argue... and overdue things due to the fact that they might feel out of thier element with electrical work... if many havent already they will suggest the thicker, more expensive and less flexible 10 gauge even though from a practical standpoint it has no advantage here...
A 5500w element can draw up to 23amps max (usually 22). There is 12/3 SJ wire thats rated for 25a at 250v.... This is perfectly safe to use for an element cord especially at lengths shorter than 10 ft. I use it for my 4500w elements and it does not even get warm. if the cable is rated for 25a at a certain voltage that means it is safe and capable to handle up to that much in its intended application.
people on forums often just like to argue... and overdue things due to the fact that they might feel out of thier element with electrical work... if many havent already they will suggest the thicker, more expensive and less flexible 10 gauge even though from a practical standpoint it has no advantage here...
PlexVector
Mellow Goose Brewing
Not so much a debate as is obfuscation through unintended agreement.
Any time NEC is mentioned, there's a debate. 3... 2... 1...
(the real problem is people like me just post stuff without any reference to the real electrical code, so it's conjecture; eventually, somebody will come along with the book in front of them and give the straight dope, but then there're multiple "interpretations" of that code, and it's circular until we all get tired; I've been through this exact discussion before, and looked up the code, but I don't have the energy to do that this time).
PlexVector
Mellow Goose Brewing
LOL. NEC is not the first thing I think, but as a design engineer what do I want the performance to be, do the math and start looking up component specifications until I find what fits plus buffer. It would probably easier to just look it up in NEC.
azazel1024
Well-Known Member
It is because the safety factor for all in-wall wiring is assuming a worst case. Effectively the wire running through insulation so that it's heat dissipation is impaired. Also at reasonably high temperatures (possibly 40-45C ambient, and insulated and that high a current).
10awg should probably be used, but it isn't the end of the world. A long run is "required" in large part because the smaller the wire, the larger the Vdrop you experience. 6ft with a bit of internal wire all at 12awg might be, dunno, a 5v Vdrop on a 22amp load, or about a 3-4% loss of power to the element. If you have 50ft of 12awg wire and that same 22amp load you might have a 20v Vdrop, which would be closer to a 15% loss of power to the element.
Numbers are extremely rough, because I am lazy and won't look up a Vdrop calculator to do the actual math.
That loss isn't really a loss in that you are using less power, that is a loss because all of that energy is being dumped in to the wiring, heating it up.
So for just a handful of feet, it isn't that big a deal, but for a long run, you are losing a lot of heating power, plus it is extra cost to run your element, because it is using the same power, but delivering less.
For high amperage loads, especially if they are used often, you can recoup the cost of heavier wiring over time. In something you are running a few hours every week or two, you'll never recoup the cost of moving from 12awg to 10awg wiring...but it DOES increase the safety factor significantly and also can save you time and effort because your element is putting out a lot more heat.
azazel1024
Well-Known Member
I would bet that code requires larger diameter wire as the run gets longer. Or at least the manufacturer of the furnace would to prevent voltage drop, which would effect performance. The toaster's performance is not that critical.
We want to minimize voltage drops because the power drops 4x for every 1x of voltage. Could make the difference in how long it takes to get to boil on a windy day.
Yes, as for why code requires higher diameter wiring for longer runs. The diameter of wiring is chosen for different circuit amperages based both on worst case (to code) installation heat dissipation combined with voltage drop caused by the run at the circuit's rated amperage. I forget off the top of my head what the maximum Vdrop is allowed, but I want to say it has to be within 10% to be to code? So a 100ft long 14awg circuit might be fine since it has a 15A max current, but if you were to run it 150ft, you might need 12awg wire, not because the wire is dissipating more heat per inch, but because your Vdrop would exceed "allowances" at the longer circuit path length.
I was looking at those tables not too long ago trying to figure out what I needed to run to a garage I was looking at building. I was planning on a 240v/20A supply to a subpanel in the garage, running a 240v, 1500w heater (because 120v heaters are rare as hen's teeth and often huge, especially at 1500w output, and I don't want to install 4x the size of 240v heaters, just to get the same heat output) as well as supplying a couple of 120v 15a circuits (one for lighting, one for outlets). IIRC I was right near the upper range of 12awg capacity for Vdrop. Like within 20ft, depending on what the circuit length would actually be within the garage. So I'll probably run 10AWG, despite the extra cost of the wiring (it is like 100ft or somewhat more, just to get it out there), because it'll put it safely within the Vdrop limits.
PlexVector
Mellow Goose Brewing
And what if a motor is involved? Does that have an effect on any of the above. Probably the breaker size is affected and then wire size and length would have to be recalculated?
azazel1024
Well-Known Member
not really. The start-up surge is part of breaker type and size determination as well as Vdrop acceptability already. An 1800w motor can be run on a 120v 15A circuit just fine, unless it, for some reason, has well above a normal start-up surge. Residential breakers are designed to carry something like 125% above rated current for a couple of minutes before tripping about 150% load for something in the range of a minute before tripping (or maybe it is something a little less) and something in the range of 200% load for a few seconds before tripping. This is more than sufficient for running a motor up to basically the rating of the breaker as most motors have a start-up surge of about 150% of their rated power consumption for only a few seconds before it settles down. Much over 200% load (open short) and the breaker will trip in milliseconds due to the magnetic inductance in the breaker (dual type, thermal and magnetic).
Certain load types require magnetic only type breakers and some thermal only breakers, but all you'll find in a residence are dual type.
It is why residential breakers are dual type breakers.
Obviously this doesn't speak to a commercial/industrial setting with BIG motors.
Will there ever come a time when the moderators ban any electrical talk on a beer board?
It does seem like the most controversial talk, most myths and misinformation and "do or die" comes from a simple electrical question.
I have decided to just enjoy the comedy of it.
Tom
It does seem like the most controversial talk, most myths and misinformation and "do or die" comes from a simple electrical question.
I have decided to just enjoy the comedy of it.
Tom
The10mmKid
Well-Known Member
One item I've missed seeing in these wire size debates is construction of the wire/cable.
Insulation rating is a huge factor.
We are mandated to use 90°C wire in our facility until it's terminated in cabinets, machines, fixtures, etc.
Once inside, I've seen soft 60°C control wires and bad-ass tinned Teflon w/fiberglass 150°C heater lead wires.
Another missed factor is stranded verses solid.
Electrons travel the exterior of the copper wire. Stranded has a lot more surface area verses residential solid wire. aka Romex
'da Kid
Insulation rating is a huge factor.
We are mandated to use 90°C wire in our facility until it's terminated in cabinets, machines, fixtures, etc.
Once inside, I've seen soft 60°C control wires and bad-ass tinned Teflon w/fiberglass 150°C heater lead wires.
Another missed factor is stranded verses solid.
Electrons travel the exterior of the copper wire. Stranded has a lot more surface area verses residential solid wire. aka Romex
'da Kid
The10mmKid
Well-Known Member
OP
Can you get your hands on an 'Amp Clamp' meter?
You may be surprised!
We throw around the 5500/240 = 22A math all the time.
In reality, we are probably dealing with a 5425W divided by 232V or some variation.
Amp clamp it and you'll know for sure.
P.S. As the voltage drops across a resistance, the current will drop.
'da Kid
Can you get your hands on an 'Amp Clamp' meter?
You may be surprised!
We throw around the 5500/240 = 22A math all the time.
In reality, we are probably dealing with a 5425W divided by 232V or some variation.
Amp clamp it and you'll know for sure.
P.S. As the voltage drops across a resistance, the current will drop.
'da Kid
RufusBrewer
Well-Known Member
We are talking about people spending time and money to construct elaborate systems that make beer. Beer you can easily purchase, at a cost at least competitive with what it costs for you to brew it.
Regarding this topic, for design and installation purposes I start off and use worse case scenario. Use 240 VAC & published power consumption calculate current and round up to the next larger of conductor. As a starting point.
Of course there are real world considerations. Availability of materials and components and/or ease or ability to install the hypothetical optimum design.
If 10 gauge wire is a available as as 12 gauge. If the cost is not a barrier. If it is not difficult to properly install and terminate the larger cable, what the heck, use 10 gauge, it will not hurt anything.
Sure it is overkill, but then again, you could say the same thing about homebrewing.
PlexVector
Mellow Goose Brewing
augiedoggy
Well-Known Member
Its easier if I just link the correct cable since too many keep jumping off topic and discussing other codes and types of wiring that DO NOT pertain to the OP's situation or use...
again for those of you that are bad with math...22amps is less than 25a how we got to 4 pages of debate over this simple equation baffles me..
here is the correct 12/3 wire for your use...SJ or SOOW cable will do.
http://www.zoro.com/carol-portable-...2_QFdoK6GpCTUB0SbwTBkaAopb8P8HAQ&gclsrc=aw.ds
http://www.grainger.com/product/CAROL-Portable-Cord-2W378
http://www.ebay.com/itm/18-SJOOW-12-3-CABLE-PORTABLE-INDOOR-OUTDOOR-WIRE-300V-/181773672571
http://www.ebay.com/itm/1000-SJOOW-12-3-300V-Indoor-Outdoor-Portable-Power-Cable-/371329008616
again for those of you that are bad with math...22amps is less than 25a
how we got to 4 pages of debate over this simple equation baffles me..here is the correct 12/3 wire for your use...SJ or SOOW cable will do.
http://www.zoro.com/carol-portable-...2_QFdoK6GpCTUB0SbwTBkaAopb8P8HAQ&gclsrc=aw.ds
http://www.grainger.com/product/CAROL-Portable-Cord-2W378
http://www.ebay.com/itm/18-SJOOW-12-3-CABLE-PORTABLE-INDOOR-OUTDOOR-WIRE-300V-/181773672571
http://www.ebay.com/itm/1000-SJOOW-12-3-300V-Indoor-Outdoor-Portable-Power-Cable-/371329008616
PlexVector
Mellow Goose Brewing
azazel1024
Well-Known Member
Err, keep in mind, stranded wire has very slightly higher resistance per meter. It is twisted, so 1 meter of stranded, if all of the strands were straightened out would likely be more like 1.2 or so meters in actual length, even if skin effect means it has slightly less resistance. Anyway, it adds and subtracts and means that stranded wire tends to have around 3-6% more resistance per meter of actual wire run.
RufusBrewer
Well-Known Member
I was under the impression that skin affect was more of a factor as you go higher in frequency. I.e. DC = no skin affect and as you go up in frequency, skin affect has - well... more affect. 60 hertz is close enough to DC that skin affect is not a factor.
Not picking a fight, just saying what I remember. and I could be remembering incorrectly
augiedoggy
Well-Known Member
Again all totally off topic discussion which does more to confuse people than help.
There are codes and ratings already in place to make the OPs question simple to answer.
I think we get that there are some smart people in this forum but,
all this rambling does is scare people away from wanting to brew beer with electric
There are codes and ratings already in place to make the OPs question simple to answer.
I think we get that there are some smart people in this forum but,
all this rambling does is scare people away from wanting to brew beer with electric
Exactly!
Electrical is not rocket science. Be careful and use common sense. Test everything and if it gets too hot or tingles you need to rethink.
Tom
Not sure the debate... Use properly/safely oversized wire and worry not.
-BD
-BD
augiedoggy
Well-Known Member
Correct and a 25a rated 12g cable would be perfectly safe for the application without worry. Especially when dealing with the short length in question. Just as most homes are not wired with 20a rated Romex for 15a circuits.. if it was a real issue to use the wire size rated for the application then the ratings and codes wouldn't be worth the time it takes to read them... there's no harm in overdoing it except cost and ease of use and that its not as practical.
Either I missed it or nobody explained the important factor here to the original poster here. It's NOT how much current you draw during normal use. It's the current that the circuit breaker will trip at.
It's all about fire safety and wire size. If there is a partial short, and you have a 50 amp breaker, then you could technically heat up that 12 gauge wire before the breaker trips. If you have a 30 amp fuse/breaker using wiring rated to 41 amps in open air, different story.
It's all about fire safety and wire size. If there is a partial short, and you have a 50 amp breaker, then you could technically heat up that 12 gauge wire before the breaker trips. If you have a 30 amp fuse/breaker using wiring rated to 41 amps in open air, different story.
