Electrical Questions

[slnies]

No. Does that mean I'm not allowed to discuss and share what I know with others? My apologies. I'll shut up now...

{Long reply discussing the pros/cons of such installations deleted to make room for slnies to bless us with his wisdom}

YUP!!! The Name is Chairman MOU. Thank you very much. ROTGLOL!!!

 

[Philip1993]

No, by all means share with us your knowledge. Just make sure you have your facts straight when you talk about something as dangerous as electricity and the laws that are in place to protect us average joe's. I did not intend to be a prick

For not trying you sure did a fine job of it...

But since you feel the need to point out that I need to get my facts straight, how about you step up to the plate and enlighten the group with some good information about the proper way to wire a 220V circuit. That would certainly be a lot more useful than your little rants about which version of the electrical code mandated 4 wire 220v and the subtle differences between a "grounding conductor" and a "grounded conductor"...

Now, back to an intelligent discussion of 220v wiring that may be useful to someone out there trying to wire up their brewstand safely...

That's a myth. A GFCI doesn't need a ground to work properly. Never has. And a 240V GFCI breaker, while it has a neutral on it, doesn't need the neutral to work properly.

So you're saying that a 240v GFCI will work with no neutral and no ground (i.e. no grounded reference)? I could be wrong, but I believe that to be incorrect. Please explain.

Anyway, back to 220v vs. 120v. People who won't think twice about installing a ceiling fan or adding an outlet often fear 220v because they have never worked with it before. The outlets look different and the cables are often heavier. But 120v will kill you just as dead as 220v. And heavy cable is neccessary for high amp circuits whether they are 120v or 220v. Hence, there is no need to fear 220v if you aren't afraid of 120v. The plugs may be a little different, but the concepts are the same. If you already have the skills, knowledge, and comfort level to DIY the 120v wiring on your brewstand, with a little reading (or a few questions) you can do 220v just as easily. And since you can deliver twice the power to your boiler with the same gauge wiring, you will be happier with the results.

Here's a few *simple* diagrams that may help understand what's happening in a 120v vs. 220v circuit/heating element arrangement.

 

[MA_Brewer]

Here's a few *simple* diagrams that may help understand what's happening in a 120v vs. 220v circuit/heating element arrangement.

I don't get your first drawing- wouldn't each be 120v to ground/neutral, just off of differnt legs (phases?)

EDIT: Nevermind, I see it is trying to show which wires would be included in each type of wiring job 120v and 220v.


Also, I believe you can run a two-wire 240v circuit through a double pole GFCI just fine without the neutral traveling to your load. If you are using pure 240v (no 120v in use) you wouldn't use the neutral anyway.

 

[Philip1993]

Also, I believe you can run a two-wire 240v circuit through a double pole GFCI just fine without the neutral traveling to your load. If you are using pure 240v (no 120v in use) you wouldn't use the neutral anyway.

I don't know about a non-GFCI. For a non-GFCI you certainly can, and that's what I was trying to say originally about using "the same wiring". That said; unless you have no other choice, it's probably not a good idea to drop the neutral. The point of the later point of my post and I think that's what Sean was actually trying say when he was busy explaining that I didn't know what I was talking about.

Many devices designed for 240 actually make use of neutral. For example, a 240v dryer with a 240v element and a 120v motor. Also, I'm pretty sure that an inductive load like a 240v motor is wound in both phases and makes uses of neutral.

 

[z987k]

So you're saying that a 240v GFCI will work with no neutral and no ground (i.e. no grounded reference)? I could be wrong, but I believe that to be incorrect. Please explain.

240V works fine with no neutral and no ground. A GFCI also works with no neutral and no ground. A neutral on a 240 circuit is so you can also get 120 out of it. That is the only reason. A ground is for safety, but not the same as a GFCI. The GFCI measures the current going in and coming back out. If the difference is too great, it will trip the gfci. Therefore there is no need for a ground on the gfci (stupid but no need) ti work. The two hots are what is monitored.

I don't know about a non-GFCI. For a non-GFCI you certainly can, and that's what I was trying to say originally about using "the same wiring". That said; unless you have no other choice, it's probably not a good idea to drop the neutral. The point of the later point of my post and I think that's what Sean was actually trying say when he was busy explaining that I didn't know what I was talking about.

Many devices designed for 240 actually make use of neutral. For example, a 240v dryer with a 240v element and a 120v motor. Also, I'm pretty sure that an inductive load like a 240v motor is wound in both phases and makes uses of neutral.

You're right, if you wiring the thing up from nothing, just pull the neutral even if you don't use it for now.

Also, 240 is single phase. Not sure what you meant by the both phases. But no nothing 240V makes use of a neutral in the sense your thinking.

 

[slnies]

O.K. Pidoolittle,

Here is the deal with a neutral and 220v branch circuits. By all accounts 220 works fine with out a grounded conductor, but often times appliances require both 120V and 220V. This is often referred to as 120/250V circuit. So back in the not so past past. These appliances were wired with a regular 220v line with a ground. The manufactures in their wisdom, to save money use a different voltage for the control of the unit. Then they don't have to have equipment rated for the full voltage and amperage of the machine. Is this all clear, so far? So the ground was utilized as a neutral. Do you see where I am going? The ground would get damaged somewhere in the circuit leaving an open neutral when the device was trying to operate. This would in effect heat up the whole of the outside of the appliance. So the next time you or the wife went to try and use it you would end up with a nasty surprise, and a few people even died for cause. You see. the open neutral leaves the whole of the load on the line and when you go to touch the machine, you complete the ground. You end up receiving the full amount of amperage the the circuit carries to ground. And ... your dead or one unhappy mofo. either way, it sucks to be you. The same thing can happen in 220v by breaking one of the phases.

To get to Z's answer, you are correct. if you are going to pull a new line, then you might as well pull all four wires. That way you to can reap the savings of using lower voltage controls to control your prime movers. S.

 

[Philip1993]

240V works fine with no neutral and no ground. A GFCI also works with no neutral and no ground. A neutral on a 240 circuit is so you can also get 120 out of it. That is the only reason.

I'll have to take your word for it with the caveat that it still doesn't make sense to me. A 240 line is two hot wires 180deg out of phase with one another. If you take a "unplanned conductor" like a human and place it in circuit between either hot (or both) and ground, you have no ground reference voltage to compare it to. One of the phases is always non-zero...

A ground is for safety, but not the same as a GFCI. The GFCI measures the current going in and coming back out. If the difference is too great, it will trip the gfci.

So how does that differ from a run of the mill circuit breaker?

Also, 240 is single phase. Not sure what you meant by the both phases. But no nothing 240V makes use of a neutral in the sense your thinking.

You are right that "single phase" is the correct language. I often use the "other phase" or "Phase A / Phase B" to denote that both legs in a single phase installation are 180* out of phase. It's a habit I picked up from working with 3 phase. Much easier to keep everything straight if you just think of single phase as a 2 phase system.

 

[MA_Brewer]

I think we are all arguing about terminoligy here, and we all agree that it is best to run 4 wires for 220v use.

Can we argue now about how it isn't a good idea to use NM-B as the "extension cord" for this project?

 

[z987k]

So how does that differ from a run of the mill circuit breaker?

A circuit breaker trips when the amperage goes over it's rating (more or less) a gfi works by detecting an imbalance between the current going in and the current going out.

 

[pickles]

in columbus area your looking at $2000 average, but maybe more if the electric company has to install a larger drop to deliver 200+ amps, and depending on run

 

[John Beere]

My hot water heater is near my brew stand in the garage. It is already 220. I just cut the line to it and put a heavy duty 220v plug on the wall. Now all I have to do to turn on my electric HLT is unplug our hot water heater and plug in the HLT...

You can see my setup with electric HLT here: https://www.homebrewtalk.com/showthread.php?t=39422


<-- For the 3 year old munchkin in my lap --> :fro:

 

[Philip1993]

A circuit breaker trips when the amperage goes over it's rating (more or less) a gfi works by detecting an imbalance between the current going in and the current going out.

Ok so far. Refresh my memory. Let's use 120V and a pure resistive load for simplicity. When you place a load on hot-neu, the load drops the voltage. Given that V=IR, current must also drop. If you have an ideal load, voltage fully drops and Iout = 0. Good so far? So how does the GFCI differentiate between it's load and an "unplanned conductor"

Since, we're venturing a bit of topic and into theory. If you want send me to a site or to take this into a separate thread and/or email, that's cool.

 

[slnies]

I'll have to take your word for it with the caveat that it still doesn't make sense to me. A 240 line is two hot wires 180deg out of phase with one another. If you take a "unplanned conductor" like a human and place it in circuit between either hot (or both) and ground, you have no ground reference voltage to compare it to. One of the phases is always non-zero...



So how does that differ from a run of the mill circuit breaker?



You are right that "single phase" is the correct language. I often use the "other phase" or "Phase A / Phase B" to denote that both legs in a single phase installation are 180* out of phase. It's a habit I picked up from working with 3 phase. Much easier to keep everything straight if you just think of single phase as a 2 phase system.

Pidoolittle, Maybe this will make a little more sense for ya. Single phase is still transformed from three phase. That is to say at some point in the grid three phase energy that is created at the power plant is split in the residential grid to run off in different directions to support our power needs. This three phase is 120 degrees out of phase. This doesn't change when split off into separate parts of the grid. Single phase is actual dual phase or two phase because in order to have 220 you need two phases. These phases are still 120 degrees out of phase. When doing calculations for three phase you have to account for the third phase so you have to use a constant that represents the mathematical differences in the phases. When talking about single phase you don't have to use the constant because the third phase is not in use or available and by the numbers has no significance.

Now here is the clincher. 220v here in the US of A. is two hot wires, correct. Well if you put a load between them they complete a circuit between two different potentials. In D/C this would never work because of the need for a ground, D/C has no wave form because it is direct. In A/C the energy alternates, as long as the circuit is complete and there is a load everything is happy. The point of ground is fulfilled at the point of generation. Now I am sure this is a poor explanation but if you do the physics it is how it works. S.

 

[slnies]

Ok so far. Refresh my memory. Let's use 120V and a pure resistive load for simplicity. When you place a load on hot-neu, the load drops the voltage. Given that V=IR, current must also drop. If you have an ideal load, voltage fully drops and Iout = 0. Good so far? So how does the GFCI differentiate between it's load and an "unplanned conductor"

Since, we're venturing a bit of topic and into theory. If you want send me to a site or to take this into a separate thread and/or email, that's cool.

In you example you have a parallel circuit. So the voltage won't drop if the wire suppling the load is sized right. This is so the wire does not act like a resistor in series which will drop the voltage. And on the GFCI question the answer is you are right but not to neutral, but to the other phase. This is why your electrician will match load for load between phases in your panel. This is called load balancing. If done right, your mains coming in will have all of the load and the neutral will cary 5 or ten amps. as opposed to the 50 or 60 of the two phases. If there is a difference between the two, it will be reflected on the neutral as the neutral is to carry the un-balanced load. Clear as mud eh. S.

 

[LayMeister]

Ok so far. Refresh my memory. Let's use 120V and a pure resistive load for simplicity. When you place a load on hot-neu, the load drops the voltage. Given that V=IR, current must also drop. If you have an ideal load, voltage fully drops and Iout = 0. Good so far? So how does the GFCI differentiate between it's load and an "unplanned conductor"

Since, we're venturing a bit of topic and into theory. If you want send me to a site or to take this into a separate thread and/or email, that's cool.

It's really quite simple and whether the neutral is "hot" or not makes no difference. Your load (you suggest a resistor) is a two terminal device and according to circuit theory whatever current goes in one terminal comes out the other (Iin= Iout). The voltage drop across it is V=Iin R or V=Iout R. Now there is some resistance in the wiring in your house so Iin/Iout is determined by I=V/(R+Rneutral+Rhot)=120/(R+Rneutral+Rhot). Therefore the voltage drop across the resistor will be less than 120.

The NEMA code is setup to provide wire sizes that limit their resistance, but more importantly limit the power dissipated in them so that the insulation doesn't break down, since P=IV=I^2 R.

So now I guess you can see how you can make a GFI without a ground. All the GFI does is make sure that Iin = Iout. If they don't, then it knows right away that a 3rd terminal is involved, such as a short to ground that is taking some of the current from one of the terminals. Calling it a Ground Fault Interrupter is probably a source of confusion since it will detect other types of faults as well, such as a short to the hot side.

I hope this helps.

Paul

 

[BrewBeemer]

This I agree with at 120 degrees.

this I do not agree with, you should of said 180 degrees out of phase for single phase 220 volt for a normal residential service drop. Granted I know of two residences that have 3 phase service to their house. One is next to a commercial supermarket the service drop was 30' away. The other next to a firehouse and it feeds his Tig welders and house.

 

[Jaybird]

Guys
I have to tell you I have been a electrician for 14+ years, over 7 of them in the industrial field dealing w/ everything from power plant distribution @ 115KV to PLC and low voltage distribution @ 24VDC and you guys just made a simple 240VAC curcit sound like rocket science. Are you sure your not engineers?
JJ

 

[IrregularPulse]

Guys
I have to tell you I have been a electrician for 14+ years, over 7 of them in the industrial field dealing w/ everything from power plant distribution @ 115KV to PLC and low voltage distribution @ 24VDC and you guys just made a simple 240VAC curcit sound like rocket science. Are you sure your not engineers?
JJ

EXACTLY! I appreciate your guys knowledge base, but I hate when this happens in internet forums. The OP (myself) asked for help on Which heating elements are needed and CAN he get away with 120V and heat efficiently. From reading this it looks like the answer I recieved should have been, "Just go with a 220V line with a 4500W element, you will be much happier in the long run. If you are unsure how to wire this all up contact an electrician because just like 120V, 220V can kill you dead if you don't know what you're doing." Now this thread, had I been a complete noob with no idea of electricity, would have taken my thoughts of doing this/having it done, and totally discouraged me thinking i should go back to school and pick up that masters degree before attempting to plug in my alarm clock! (exaggeration ) .

 

[Philip1993]

it looks like the answer I recieved should have been, "Just go with a 220V line with a 4500W element, you will be much happier in the long run.

Yes.

If you are unsure how to wire this all up contact an electrician because just like 120V, 220V can kill you dead if you don't know what you're doing." Now this thread, had I been a complete noob with no idea of electricity, would have taken my thoughts of doing this/having it done, and totally discouraged me thinking i should go back to school and pick up that masters degree before attempting to plug in my alarm clock! (exaggeration ) .

What I was trying to say before the debate began was this:

If you're comfortable with 120v, don't fear 220. With 220v you can use a 4500W element (you will be much happier in the long run). Obviously, if you're not comfortable with 120v, I wouldn't recommend DIY with 120v or 220v.

 

[LayMeister]

Guys
I have to tell you I have been a electrician for 14+ years, over 7 of them in the industrial field dealing w/ everything from power plant distribution @ 115KV to PLC and low voltage distribution @ 24VDC and you guys just made a simple 240VAC curcit sound like rocket science. Are you sure your not engineers?
JJ

Do you have a problem with engineers?

Paul

 

[Chriso]

I'm scared now.
Signed,
The guy who gets nervous replacing his own light bulbs, much less one of those creepy screw-in fuses in the basement.

I'm not lying. I wear leather gloves to change a fuse because i'm so freaked out about getting electrocuted.

 

[slnies]

Sorry, did not mean to complicate the matter. Just got carried away.

 

[z987k]

Guys
I have to tell you I have been a electrician for 14+ years, over 7 of them in the industrial field dealing w/ everything from power plant distribution @ 115KV to PLC and low voltage distribution @ 24VDC and you guys just made a simple 240VAC curcit sound like rocket science. Are you sure your not engineers?
JJ

thats funny.

 

[Jaybird]

Do you have a problem with engineers?

Paul

Nah!!! They just complicate things....
JJ

 

[BrewBeemer]

I loaned out a spare 120 gallon 7 1/2 hp 1740 rpm 32 amp single phase two stage air compressor to a truck driver friend. It was for his home use sand blasting project. Instead he installed it at the truck tank wash (big rigs) and had the local greaseball wire it up to two legs of their 3 phase power. Was told it started so they went for coffee in another building. When they returned the motor had let the smoke out. Yes a difference between two legs at 180 degrees single phase vs two legs 120 degrees apart "single phasing off 3 phase power". Motor was bucking itself plus directly fed to an oversized breaker without any heater overload protection. Replacement for that motor is only around $706. What the heck was I thinking helping a friend? All I got was sorry want the compressor back?
And yes I hate most engineers but not all, having worked with them for over 31 years until a back injury forced me into retirement.
I wish not wanting this turned into a pissing contest, does not help our other brewers on this forum.

As far as screw in Edison base fuses there are resetable breakers that can replace those one shot fuses.
Fear of electricity is just not understanding and respecting it.

 

[Philip1993]

Fear of electricity is just not understanding and respecting it.

+1

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