LAvetteman

While a friend of mine and I where wiring our new house tonight he explained to me the principals of load balancing otherwise known as NEUTRAL BALANCING. What are your thoughts on this......

mrvette

I pay attention to load balancing, but the large heavy loads are all 220, and therefore not involving neutral much at all....
so it's not all THAT critical in most homes....
and most 110v appliance type loads are highly intermittant in nature, so will never load divide equally anyway....

now on 3 phase commercial, say for lighting a store....you betcha....

GENE

ddecart

Not a clue. But then again I'm a MECHANICAL engineer. What more do you need to know beyond "hot, common, ground" ? :D

I, for the most part, wired my own house. I've got a 200 amp panel with 40 spaces in it that are all filled, and a 50 amp 220 sub panel in my shop. Piece o' cake! TONS of lightly loaded circuits. :yesnod:

So what IS neutral balancing?

BudD

mrvette (GENE) pretty much said it. I would only add that the newer homes with 400 amp service entries can develop voltage problems if loading is not balanced between the to legs of service (120 volt). The service is 220 (240) volt with 110 (120) between neutral and phase bus.

Often more times than not the neutral connections become lose over time from loading, heating and cooling, to be more of a problem than balancing. If you utility uses 208/120 volt as a service voltage, Balancing becomes a real issue in residential services.

Edzred72

Yep.. I did mine years ago while installing ground fault outlets outside for all the Christmas decorations I put up. My panel was near balanced when I started, so it was a piece of cake. IMHO.. this procedure is realy not that critical, unless many excessive loads were added on. Just my .02 :cheers:

MikeC

In an industrial setting, balancing is critical, at home, it is not really that important

ddecart

Ok guys. So what IS it? :)

adam

Homes receive two phases (circuits) of the 3 phase electrical power system.
Your circuit box thus has two main circuits that you will 'hang' your
breakers on to connect power to your plugs, lamps, appliances, etc.

If you use more electricity from one phase than the other, then you are
not balancing the usage of the two phases. You will be charged at the usage
of the larger loaded phase. If you move breakers from one phase to the other
to balance the amount of current required, then your metered usage will be
lower than the unbalanced measurement.

That is why in an industrial setting where you use a LOT of current, you want
to balance the load between the 3 conductors.

Adam Krolnik
81 4sp RED
Electrical engineer, electrician's son.

Edzred72

You are correct. We do it where I work (industrial setting) everytime a new circut is added to a panel. :yesnod: :yesnod: :yesnod: :yesnod:

mrvette

Adam, I know that YOU know you are being somewhat simplistic in saying we get only 2 phases of a 3 phase system in our homes....in fact, the transofrmers give out only one phase, that is center tapped grounded on the output, so that gives in actuality ONE phase, split into two opposing 180* out phases, and acts like a two phase circuit....it's the differance between 208 and 220-240 line voltage....in how it was derived at the last splitting transformer.....so that all has nothing to do with a vette, except that the alternators are all 3 phase, and load balanced...of course....
thing is....who knows if they are delta or wye wound????

snicker......

Adam, I KNOW you just gotta know the answer, so lets's see what the rest of the guys say for fun... :D :D :D :cheers:

LAvetteman

My friend does mostly commercial service so balancing is second nature to him. I always knew it was good to balance the load of each HOT leg, but I had no clue that the power company charges a little bit more if you have one leg loaded more than the other. Nor did I know that the commons coming from each opposing circuit cancel each other out.
For those who think this has nothing to do with vettes, I disagree. If you move a couple of circuits around in your houses breaker box and it intern saves you X amount of $$$$ over time, thats money you could be spending on YOUR VETTE. Besides the fact that it lowers your chance of having a house fire or having an expensive electrical repair. Besides, whats wrong with us forum members having an intelligent discussion about other things sometimes?
:yesnod:

BudD

A little more explanation on the savings:

Residential single phase service will not see any savings by balancing the customer loading. Some Utilities provide Time Of Use (TOU) metering for residential to help control system loading. I don't know of any that provide Demand Billing for single phase service. .. Now on the other hand..

Commerial or industrial loads have many more options.. TOU, Real Time, Demand, and some have gone to KVA metering customers. Also customers at this level can be penalized for contributing (causing) a poor Power Factor. Demand is the oldest form of Load management Utilities use. Customers are billed at a Demand Rate once they exceed it. It is done by 15-minute interval peak reads in a 24 hour period over the course of a billing cycle. TOU has been around a long time also and is suppose to help shave the system loading during peak usage. In my opinion it just reshapes the system load profile to different times of the day..

Sorry I didn't mean to get so long winded here..

BudD

ddecart

'

Ummm..yeah. Black is still hot, white neutral and bare copper ground, right? :D

Desertdawg

Heck I just stick'em to my tongue for a second, then I know which ones have the lektricty :smash:

Dalannex

Alright guys, explain to me how we end up with 208. Keep it as simple as possible. I work at a large factory as a mechanic (not an electrician, we have one of those), and we have 208 in our older parts of the building. If I check it phase to ground, I get 110-120, if I check phase to phase I get 208, (I'm pretty sure that's what I came up with). How can that be? Sorry for being so stupid, but I fix mechanicals and Allen Bradley PLC's, i'm not an electrician.

R1234

Hot wire to stove, cold wire to refrigerator.
One wire hook up, two wire screw up, three wire drag up!:jester

So, anybody got any suggestions on my temperature gauge?
:smash:

mrvette

Dalannex, in a commercial power situation, they most often provide 3 phases, so to understand that, picture a two pole magnet rotating in a equilateral triangle built with 3 equal coils...all evenly spaced....
now as one pole passes in middle of a coil, it is generating max output voltage in that coil, but as other end of that magnet passes the ends of the other two coils just opposite, the output of the other two coils is nearly zero.....SO what that means is that as the magner rotates around it's axis,each coil in turn will generate voltages going positive and then negative....measured as one coil at a time.....

well in this scene, the differant outputs will only measure the sum of the voltages as apparent from the 3 coils in total....and since that 360* of rotation is divided equally, that means each coil is 120* out of 'phase'....or 'sequence' with the others......

now so given that phase differance the apparent voltage will measure slightly less, as i'ts not totally additive, just mostly....

now if you take just one of those generator phases, and feed it into a transformer, you will get a voltage on the output winding of that transformer......suppose we take that exact center of that output winding, and put a tap on it, and ground it.....??? what happens is our referance is now ground in center of two opposing voltages as they are now 180* apart with respect to the 'ground' we made, and not 120* apart as in your 3 phase generator....
so that means that with 180* out of phase (synch) they are additive, and the full voltage appears across the winding, as if the ground were not there....

beyond that, you need go to a library and get an elementary electrical book, they have diagrams....I can't draw that good anyway....

GENE

Dalannex

I have been thinking about going to check it out at the library. I don't really need to know, but it would be nice. I don't ever plan on being an electrician, but it is something that I need to know more and more about all the time. :cheers: