Electrian dad says GCFI is pointless?
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CodeRage
Death by Magumba!
A GFCI will work with out a neutral..... It's all about current in vs current out.
Hermit
fuddle
How do you differentiate current in vs out on a 240 circuit since both sides supply current? Many home appliances that use 240 also have 120 components. I've done amperage readings on dryers and there is a difference in current on the leg that has the motor. I can hardly wait for the people that build the GFCI's to get them mandated for all home appliances.
CodeRage
Death by Magumba!
How do you differentiate current in vs out on a 240 circuit since both sides supply current? Many home appliances that use 240 also have 120 components. I've done amperage readings on dryers and there is a difference in current on the leg that has the motor. I can hardly wait for the people that build the GFCI's to get them mandated for all home appliances.
in 120V current goes back and forth between neutral and 120V, hence alternating current. if the current leaving L1 is equal to the current flowing through N and vice versa there is no ground fault.
240V is the same thing. Current flows back and forth between L1 and L2, as long as #mA is measured leaving L1 and is flowing #mA into L2 there is no ground fault. When they are out of balance current is going somewhere else and the gfci pops.
They make 2 pole GFCIs that support split phase as well. You can identify them by the curly white pigtail attached to them. They monitor all three, L1, L2, and Neutral and if any current is unaccounted for it pops.
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mhermetz
Well-Known Member
.....crap I totally need to re-build my chiller.
I can slip it in the boilmaker easily but once the elements are in the chiller it will be sitting 2 inches above the wort level. Unless I can some how slip the chiller under the elements too.
Not entirely bad... but not as effecient as it could be.
I can slip it in the boilmaker easily but once the elements are in the chiller it will be sitting 2 inches above the wort level. Unless I can some how slip the chiller under the elements too.
Not entirely bad... but not as effecient as it could be.
CodeRage
Death by Magumba!
Thats why I went CFC. Or you could make a fixed mount IC in there that bends around the element.
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mhermetz
Well-Known Member
I could do that.... Think I would be able to roll out the copper tube without weakening or causes kinks? I assume you have to do that to make the CFC
abracadabra
Well-Known Member
Speaking of misconceptions "30+ amps of continuous peak current"
240v AC (Alternating Current ) goes from 0v to 120v back to 0v then to 120v in the opposite direction or polarity for a total swing of 240v. The current goes up and down with the voltage and the electrons changes the direction in which they flow as the voltage changes polarity.
DC (Direct Current) can offer a continuous peak current.
Or you'd need something like 3 phase AC to be close to a continuous peak current condition.
Residential electricity is single phase AC.
Interesting situation happened at work, that sorta applies to the Murphy's Law/GFCI thing..
On a job site, a extension cord (we call em stingers) was plugged into a 20amp GFCI outlet on a 20A circuit. A tech mistakely cut the plugged-in extension cord with his linemans pliers. POP! After making sure he was okay, we went to reset the GFCI - but it wasn't tripped. Went to the panel & the 20a breaker was what tripped.
Hmm. The GFCI was wired correctly: wires to panel feed the Line side. GFCI tests fine.
Our theory: as his pliers cut through the 12/3 cord, his cutter first severed the hot & ground first, cutting the neutal after the panel breaker popped. That's our theory, but in any case the GFCI, which is supposed to be sensitive, didn't do anything.
Anyway, moral of the story: Things sometimes don't go the way we want or expect. GFCI's are great things, even if they don't ALWAYS provide protection. Oh, and Murphy's Law is always in effect.
On a job site, a extension cord (we call em stingers) was plugged into a 20amp GFCI outlet on a 20A circuit. A tech mistakely cut the plugged-in extension cord with his linemans pliers. POP! After making sure he was okay, we went to reset the GFCI - but it wasn't tripped. Went to the panel & the 20a breaker was what tripped.
Hmm. The GFCI was wired correctly: wires to panel feed the Line side. GFCI tests fine.
Our theory: as his pliers cut through the 12/3 cord, his cutter first severed the hot & ground first, cutting the neutal after the panel breaker popped. That's our theory, but in any case the GFCI, which is supposed to be sensitive, didn't do anything.
Anyway, moral of the story: Things sometimes don't go the way we want or expect. GFCI's are great things, even if they don't ALWAYS provide protection. Oh, and Murphy's Law is always in effect.
CodeRage
Death by Magumba!
Speaking of misconceptions "30+ amps of continuous peak current"
240v AC (Alternating Current ) goes from 0v to 120v back to 0v then to 120v in the opposite direction or polarity for a total swing of 240v. The current goes up and down with the voltage and the electrons changes the direction of it flows or with the change of voltage polarity.
DC (Direct Current) can offer a continuous peak current.
Or you'd need something like 3 phase AC to be close to a continuous peak current condition.
Since the voltage is rated at RMS saying the current is continuous peak at I RMS is perfectly acceptable...
abracadabra
Well-Known Member
edit see below
abracadabra
Well-Known Member
RMS or Root Mean Square is the average electrical power. Current rises and falls as the voltage rises and falls.
It may be considered accetable but it's factually incorrect.
Cpt_Kirks
Well-Known Member
Maybe I am just a spendthrift, but to me, my little white hiney is worth the $20 I spent on a 20A GFCI.
Hermit
fuddle
Speaking of misconceptions "30+ amps of continuous peak current"
240v AC (Alternating Current ) goes from 0v to 120v back to 0v then to 120v in the opposite direction or polarity for a total swing of 240v. The current goes up and down with the voltage and the electrons changes the direction in which they flow as the voltage changes polarity.
DC (Direct Current) can offer a continuous peak current.
Or you'd need something like 3 phase AC to be close to a continuous peak current condition.
Residential electricity is single phase AC.
Been a while, but since it is RMS isn't PEAK for 120 around 177 or so? Long time since I did the calculations....
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I used my old IC. I uncoiled it, fed it through the hose, the recoiled it for my CFC. So far so good.
- Wrong, sorry. RMS values are not the same as "average" values for sine waves. The RMS value is the DC equivalent, so it is the perfect way to know the heating potential or work potential of AC power.
- RMS is not only an acceptable way of describing AC electricity, it is the standard way in which most AC components are rated.
abracadabra
Well-Known Member
http://en.wikipedia.org/wiki/Root_m...he_arithmetic_mean_and_the_standard_deviation
below is a quote from the web page listed at the top of this post.
"So, the RMS value, IRMS, of the function I(t) is the constant signal that yields the same average power dissipation". Where (t) equals time.
Perhaps in trying to explain this in laymans terms I over simplified. But if you'll read the web page at the top of this post you'll see RMS is indeed average power.
And yes RMS is an expression of what average continuous power would be if it was actually continuous but since it is not it is merely expressed in a calculation as if it was continuous.
below is a quote from the web page listed at the top of this post.
"So, the RMS value, IRMS, of the function I(t) is the constant signal that yields the same average power dissipation". Where (t) equals time.
Perhaps in trying to explain this in laymans terms I over simplified. But if you'll read the web page at the top of this post you'll see RMS is indeed average power.
And yes RMS is an expression of what average continuous power would be if it was actually continuous but since it is not it is merely expressed in a calculation as if it was continuous.
sparkyaber
Well-Known Member
Nobody explained this to you so: GFCI detects a leak of current- They do not protect against short circuits. That is the breakers job. This played out exactly as was supposed to. Your theory maybe correct as the gfci monitors the current between the hot and neutral.
CodeRage
Death by Magumba!
Huh?
If when he had cut the cord and he bridged 110 and neutral ONLY and was 100% insulated the gfci would not have popped but the breaker would have.
Had he made contact with ground and 110 first or if he himself started to conduct current to ground, the gfci would have popped.
When you press the test button on a gfci, it leaks current from the line to ground.
kryolla
Well-Known Member
I didn't read through all this but my take on it is that GFCI does work. I had a saltwater reef tank plugged into an external GFCI/extenstion cord. I was hooking up my new lights and the whole thing fell into the tank, my first reaction was to grab it then I realize what I was doing and pulled my hand out. The GFCI popped and I didn't feel a thing so I am a firm believer in GFCI. I did have to buy a new ballast.
You should have a titanium rod in the tank, tied to earth gnd. Maybe you do already.
VHO or MH?
kryolla
Well-Known Member
You should have a titanium rod in the tank, tied to earth gnd. Maybe you do already.
T5 it was the new thing back then, the funny thing is you would think I learned my lesson the first time and not reach in but it saved my arse a few times
sparkyaber
Well-Known Member
Really, then why is the only legal way to replace old two wire receptacles with three wires is by way of a gfci? There is no ground involved. They monitor the current between ungrounded and grounded conductors. It is amazing how many electricians think the ground is involved. Wouldn't you have to run the ground through the receptacle?
http://ecmweb.com/mag/electric_gfcis_work/
I didn't erase the above for other peoples benefit.
I just reread what you wrote, I think I may have mis-read it. I thought you were saying that the ground and ungrounded conductor were monitored.
But, I was replacing a switch that was on the load side of a GFCI, I thought the cirucit was off, and while cutting the hot, my strippers were touching the swich and boom, now a #14 hole right in the middle of the cutters on my strippers. GFCI did not trip, breaker did, and after I finished, I used my tester and the GFCI was working correctly??
All I was trying to point out that it is not the GFCI's job to protect against short circuits, at least not at the residential level.
How do you differentiate current in vs out on a 240 circuit since both sides supply current? Many home appliances that use 240 also have 120 components. I've done amperage readings on dryers and there is a difference in current on the leg that has the motor. I can hardly wait for the people that build the GFCI's to get them mandated for all home appliances.
i think in the 2011 nec all standard receps in a kitchen have to be gfci protected
Fingers
Well-Known Member
GFCI detects leak current. Going to ground is the most common leak, but it's no different to a GFCI than going somewhere else. As long as what goes out on one hot comes back on the other, the GFCI will not trip. That's why you can use it where there is no ground.
Just to jump in here on the original issue, I would never consider not using GFCI on my electric build. I can think of several scenarios out of my control that would trip one. The best state,ement I heard here was that current will not only take the path of least resistance, but it will take all paths that it can find. If you're a high impedance short, you'll get the poke without tripping the breaker.
Just to jump in here on the original issue, I would never consider not using GFCI on my electric build. I can think of several scenarios out of my control that would trip one. The best state,ement I heard here was that current will not only take the path of least resistance, but it will take all paths that it can find. If you're a high impedance short, you'll get the poke without tripping the breaker.
They are now if I recall. SA(small appliance circuits). I don't think they will require GFCI for appliances that do not get unplugged often or ever. It would be hard to pull the stove out and dunk it into the sink. They want to protect people from things like blenders and toaster ovens because they can be moved into wet situations. Microwaves don't need them. Bathrooms do again SA.
Washers/Dryers, Stoves, Hot Water heaters, boilers, and other permanant appliances are usually exempt from the GFCI codes.
Hermit
fuddle
I've seen brand new functional appliances trip these things. No sign of leakage current though I didn't have a triggered scope to find out for sure. But plug them into another non GFCI outlet and test, they worked fine, still no sign of any voltage to ground.
illin8
Well-Known Member
I've got a sump that, all of a sudden, is tripping the 20-amp GFCI plug that powers it. Never did it before. It's fine when connected to a non-gfci plug...makes me wonder if there is any harm in connecting it to a non-gfci recepticle. The sump pumps wastewater from my utility sink up 4' to the wastewater pipe in my basement.
CodeRage
Death by Magumba!
The most likely culprit is the windings are starting to loose their insulation and leaking small amounts of current somewhere. the pump is more than likely fine but won't work with the gfci attached.
gfci's are only meant to protect people, not equipment. you won't harm the pump by putting it on a non-gfci
Bernie Brewer
Grouchy Old Fart
You won't harm the pump, but GFCIs are required in basements by the NEC, and there is no longer an exception for sump pumps. Personally, I think that this rule is absolutely insane, but code is code. To do it legally, you are going to need a new pump.
Hermit
fuddle
Or a new GFCI. They do go bad too.
yeah i agree it's insane. given the choice between a new ejector pump or an extension cord/non gfci recep, i think most people will end up picking the latter
BrewBeemer
Well-Known Member
Wow is this an old requirement like 10 years ago.
CodeRage
Death by Magumba!
So YOU were the tech
I ruined a brand new pair of klein strippers doing the same thing. I use a voltage wand and/or meter on EVERYTHING now and don't trust what any one says unless my lockout is on the breaker.Glad you picked up what I was putting down, sorry if I wasn't clear.
The only reason why I could think the gfci didn't break is because you could have shorted neutral and line together. this way the current on the neutral and line would still be balanced. Thats like a 1 in a million shot though.
If it was an AFCI and it didn't trip, then I would be really concerned
Happy to hear you are okay, nothing like playing dr. arc and spark to get you going in the morning.
Bernie Brewer
Grouchy Old Fart
True.........
Or you could move to WI. We have an exception-sort of. As long as the pump is plugged into a single receptacle, and there is a GFCI within 3 feet, we can go without GFCI.:cross:
BrewBeemer
Well-Known Member
So YOU were the tech
Glad you picked up what I was putting down, sorry if I wasn't clear.
The only reason why I could think the gfci didn't break is because you could have shorted neutral and line together. this way the current on the neutral and line would still be balanced. Thats like a 1 in a million shot though.
If it was an AFCI and it didn't trip, then I would be really concerned
Happy to hear you are okay, nothing like playing dr. arc and spark to get you going in the morning.
Code; I would rather replace strippers blown away than a pair of 9' side cutters. Tic Trace or Knopp are your best friends. Side cutters have gone up times five in price vs back in 75.
BrewBeemer
Well-Known Member
They have electricity now in WI.? I thought they still ran off 32 volts of battery banks with a Chicago AeroMotor Windmill Generators for lighting. I recall some states even in the late 40's early 50's still had battery / generator lighting in the mid west. Way past the time of Hit & Miss powered generators. I had to pick on ya bro.
I like this thread. If there is one thing to take from it...USE A GFI on your brew rig!
A GFCI device will monitor current leaving the breaker or receptacle and not returning along the proper path (grounded or neutral conductor). If current somehow leaks to ground via another path (through a person for example) the device trips.
A standard circuit breaker will trip with a direct short to ground or overcurrent. I have all metal parts of my brew rig bonded (attached together forming a common electrical point which is then tied to ground). I feel quite confident that a live wire that comes into contact with any metal parts of my brew rig will trip a standard breaker. I see this as my primary protection. But if somehow I should loose my bonding/grounding to any piece of metal on my rig and it becomes energized, and I shoud happen to touch it, I would be at risk with a standard breaker. A GFI would sense a leak of current along an improper path and trip.
My point: If you have a properly bonded/grounded set up to begin with and can guarantee that bonding/grounding, you should feel quite safe. If you have that with added GFCI protection there is not much that can go wrong.
A GFCI device will monitor current leaving the breaker or receptacle and not returning along the proper path (grounded or neutral conductor). If current somehow leaks to ground via another path (through a person for example) the device trips.
A standard circuit breaker will trip with a direct short to ground or overcurrent. I have all metal parts of my brew rig bonded (attached together forming a common electrical point which is then tied to ground). I feel quite confident that a live wire that comes into contact with any metal parts of my brew rig will trip a standard breaker. I see this as my primary protection. But if somehow I should loose my bonding/grounding to any piece of metal on my rig and it becomes energized, and I shoud happen to touch it, I would be at risk with a standard breaker. A GFI would sense a leak of current along an improper path and trip.
My point: If you have a properly bonded/grounded set up to begin with and can guarantee that bonding/grounding, you should feel quite safe. If you have that with added GFCI protection there is not much that can go wrong.
CodeRage
Death by Magumba!
Doesn't monitor the ground, just neutral and line. If anything leaks onto THE ground it will trip.
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