Electricity 101

[chancer]

And why does using the higher voltage/ amperage cord work better?????

They rate the amperage of an extension cord based on wire size. With the larger wire you get less amperage drop, especially on longer extensions.
Also extension cords use stranded wire. For two reasons.
A. so you can roll them up easier and
B. The actual electrons or current flow along the edge of the wire. So more strands mean better electron flow.
That's why romex is solid only up to 10g then 8g and 6g you get stranded wire. More amps need better flow.

 

[Poboy kartman]

Keep in mind....I am talking about 10 guage cords for both the 110 and 220 cords....the amperage drop with the 110 is apparent only running one tool...whereas the 220 will allow. me to run several high amperage demand tools at once.....

 

[Poboy kartman]

The more I think about this the more confused I get....but I might have a few things figured out......I made my own 220 cords...I'll have to take a closer look at that wire later today...this was many years ago and the wire cost $1 a foot..

The 110 cord was purchased...so perhaps the wire itself is just that much better to start with.....

So I mounted a bunch of gang boxes to a short 2×6 with a short 12 guage piece of extension cord with a 220 plug.....All the boxes had 15amp 110 outlines w/ground wired with wires removed from 12 guage Romex for 110v..

So....if I unplugged that box, and plugged in any 220v tool...there is no doubt I had 30 amps of 220v current...

But.....with that box plugged in....I believe I was only getting 15 amps of 110v current....basically 2 110v extension cords with a shared neutral/ground in the same sheath.....

I only made 50' cords because they were heavy and bulky at that length....which got me to thinking where I might also be getting less amperage drop: Starting at the temporary pole...Even though short.the wires from the breaker and ground bar were heavier to the outlet which was rated for more amps.....So were every male and female plug on the extension cords....

 

[Poboy kartman]

Normal breakers trip from too many amps. GFCIs trip from current going to the wrong place. They have completely different jobs with no overlap.

GFCIs absolutely can be overloaded and should always be run downstream of standard breakers. GFCIs are used in places where an alternate path to ground is likely such as outdoors or wet areas like bathrooms and kitchens. If you get electrocuted on a circuit with a standard breaker only, it will not stop electrocuting you unless the circuit becomes overloaded.

Also worth noting, if your body becomes the bridge between hot and neutral of the outlet and you are not grounded, a GFCI will not trip.

I forgot to mention something .....this was.a while back....in later years....either the code changed...or they started cracking down....and the 220 breakers went to GFCI.....so my split cord no longer worked....

 

[Badot]

GFCIs can be a pain sometimes. Anything conductive can potentially pull current from magnetic fields (off of transformers, motors, inductors, coiled wire, etc.) and trip them.

Even then, long straight runs after the GFCI can also act as antennas and pick up radio noise in the air and trip them.

In both cases you can try either shielded wire or using a twisted core wire.

Also, as for getting 15A max... does your 220v dual pole breaker have 15s on the breaker or 30s? I mean what's physically printed on it, not doubling or anything.

 

[Poboy kartman]

Well....it's not my pole...and this was a while back....but generally they were 30 amp circuits....so yeah....15 on the two breakers.....

Occasionally, we would run across a problem breaker or situation, and we would swap out whatever was there for a dual 20 amp breaker....and at first...for a while...we swapped out the GFCIs.....but I finally gave up and just changed the male on one cord to a 110 plug....and wired up a pigtail and used traditionally wired power centers.....

Also....a lot of the builders got smart and ran a power center into the house......

 

[mckutzy]

For me, they were dual 15amp's at the source breaker panel. They have a bar connecting the two individual switches actuating together.. The working end, has 2 seperate breaker switches of 15amps, also with seperate receptical plugs.

 

[Badot]

So you don't have a 30A 220 volt line... it's a 15 amp. Think of it like putting batteries together... you have two 110v15a lines. When you combine two in series (which is what a 220v appliance does) you get double the voltage with the same amperage.

That means that when you 'convert' it to 110v and a single one of those lines pulls over 15A it'll trip both lines. It also means when the total draw of both circuits is over 15A (say you're running a 10A tool on each line) the breakers will not trip but you'll be overloading your neutral/ground by 5A.

 

[Poboy kartman]

So you don't have a 30A 220 volt line... it's a 15 amp. Think of it like putting batteries together... you have two 110v15a lines. When you combine two in series (which is what a 220v appliance does) you get double the voltage with the same amperage.

That means that when you 'convert' it to 110v and a single one of those lines pulls over 15A it'll trip both lines. It also means when the total draw of both circuits is over 15A (say you're running a 10A tool on each line) the breakers will not trip but you'll be overloading your neutral/ground by 5A.

Ok....Thanks! !!! Actually......I was going by memory on what might have been in those temporary poles 10 years ago..My breaker box is partially behind my freezer.....I can open it enough to reset the breakers but not really. see them.sp I moved my freezer to take a better look...I have two 30 amp and one 50 amp breakers....

So....If those were 30 amp breakers back then.(who knows)....then I was indeed running two 30 amp 110 v circuits.....which is why I always had all the amperage I needed......

See....I learned something! !!!!

I also had some funky things happen a couple of times: once I had a brain fart replacing a plug on one of the cords and hooked it up wrong....I pulled the trigger on my 15" Hitachi miter saw and ran it for maybe two seconds max before I realized it was on 220....the blade began to wobble due to the extreme rpms....it was pretty hairy.....

Another time...when I pulled the trigger on the miter saw, the compressor would come on....when I let off, the compressor would stop....I really don't remember exactly what was happening, but IIRC I traced it down to a faulty ground in the temp box receptacle....the theory being that there wasn't enough ground/ neutral contact to run one circuit but with both feeding the neutral line there was enough juice there to complete the circuit.....

And while I understand in theory I am overloading the neutral /ground line....I'm really not...unless I'm maxing out both circuits....(and I couldn't check that wire...it rained all day) ...but I'm pretty sure that cord can handle more than 30 amps....and I seldom ran that many tools at once.

 

[Badot]

And while I understand in theory I am overloading the neutral /ground line....I'm really not...unless I'm maxing out both circuits....(and I couldn't check that wire...it rained all day) ...but I'm pretty sure that cord can handle more than 30 amps....and I seldom ran that many tools at once.....

EDIT: So...in the scenario using two 15 amp breakers....wouldn't the same thing hold true??

Running two 110V15A lines off of a 220V30A (dual pole with 30A marked on each individual breaker) line shouldn't ever overload your neutral/ground and should be as safe as any other hookup. 15 amps on each line totals 30 amps, and that's what your 220V neutral/ground wire are sized for (if not a bit more).

Again, not sure if it's up to code, but it's not really any different from how it comes into your main breaker in the first place.

The problem comes in if, for example, you install two 30A110V breakers. With the 30A dual pole breaker on the 220V, each hot line can carry 30A on its own for a total of 60A drawable before the breaker trips, but the single neutral/ground from the original 220V circuit can still only handle 30A which has to be shared between your two 110V circuits.

 

[Poboy kartman]

Yeah....you were too quick...you quoted before I deleted that....I realized that it couldn't overload the neutral with the breakers.....

 

[chancer]

"So....If those were 30 amp breakers back then.(who knows)....then I was indeed running two 30 amp 110 v circuits.....which is why I always had all the amperage I needed......

See....I learned something! !!!!"

And that's what I was thinking and sayin Yesterday.

 

[Poboy kartman]

Now....I installed a 30 amp breaker for my drier....don't remember what wire I used....but it's only about 15' from the panel....then I added another box next. to it..and run one of those 50' cords to my shop..I have one 220 outlet that never gets used....but about 15 110v outlets pretty much like what I described before and never gave it much thought . I typically run two 300watt halogen lights, an amperage hungry compressor and often my table saw while its running.....and without thinking about it...ran the drier at the same time.....

I think I'll refrain from using the drier and shop simultaneously in the future....

 

[Poboy kartman]

"So....If those were 30 amp breakers back then.(who knows)....then I was indeed running two 30 amp 110 v circuits.....which is why I always had all the amperage I needed......

See....I learned something! !!!!"

And that's what I was thinking and sayin Yesterday.

And that's why I said I didn't care about being right and I might learn something... and we all might..

I would much rather be wrong and learn something.....than to be mistakenly convinced I'm right and remain ignorant of the truth.....

 

[Poboy kartman]

Ok...let's review: Splitting a 220v circuit into 2 110v circuits results in 2 110v circuits with the same amperage as the original 220v breakers and is against code and potentially dangerous as well..so don't do it!!!!
I do....but as many of you already know....I'm an idiot....and still have space on my shelves for a Darwin award.....

Now... Splitting them with breakers may or may not be code worthy depending on how and where it's done..but it's safe....as long as the 110v breakers don't exceed 1/2 of the amperage of the 220 breakers....then they can't send more amperage back through the neutral / ground...

So...I think we're done with that...

The other thing I hear all the time is your wires are going to get hot and you'll burn your house down......not likely....not impossible....but what would it take to make it happen?

 

[ML-TOYS]

The other thing I hear all the time is your wires are going to get hot and you'll burn your house down......not likely....not impossible....but what would it take to make it happen?

Sh** wiring like whats in my house, aluminum that will get hot.

 

[Poboy kartman]

Sh** wiring like whats in my house, aluminum that will get hot.

True...now illegal....and outdated wiring and breaker systems (especially with those 1 cent fuses)....

 

[Badot]

Once you throw properly sized amperage-based breakers on it becomes pretty safe. So long as the wiring job is good and the wire itself dissipates heat fast enough to keep up with the amps from the breaker, it's nearly impossible to have problems.

On the other hand, you can still have problems with long runs where you get reduced voltage at the outlet when under load. With some electronics, when the voltage drops they draw more amps to compensate. The problem then is that the wiring/breakers may be capable of handling the amperage but the device isn't, and that can very easily overheat and start a fire.

Having undersized wire will A: give you more voltage drop, B: make your wiring heat up more per amps drawn, and C: Have less surface area to dissipate heat from. A little size difference can make a big current capacity difference.

 

[Poboy kartman]

That's my thinking as well....the incident of a house fire due to wires overheating is very small in code compliant installations.....

Most home electrical fires are caused by something plugged in.....of the small percentage of fires caused by the wiring system itself are mainly caused by faulty switches, outlets, or connections.....not from the heat of the wire..

And I've heard that the rule not to use 14 gauge wire on a 20 amp breaker is an extra safety measure and that 14 gauge can handle 20 amps.....

I've heard too that welders will heat circuit wires....but I don't know how or why....or even if it's true.....

I know less about welders than I do electrical wiring....and almost zero about 220 welders.....