On Thu, 23 Nov 2006 21:37:15 GMT, pyotr filipivich
It's a bit like getting Oxy Acelelene tanks. You are paying for the 3
phase line and transformer and its maintenance, which changes very
little between 100 wh per month and 500kwh per month. You could, of
cource, pay to have the line installed, and buy the transformer. Then
it might cost you $100 per month instead.
Posted via a free Usenet account from http://www.teranews.com
Nope..just lots of wheel spining and blinking.
A doctrine fostered by a delusional, illogical liberal minority and
rabidly promoted by an unscrupulous mainstream media,
which holds forth the proposition that it is entirely possible
to pick up a turd by the clean end.
The guy at REA told me it was because of the extra money needed to run and
'up keep' 3 phase lines. IIRC, he said one of the extra cost was the fact
that even if 3 phase was running near me I'd have to have more than one
transformer (3 pops into my mind) installed
That's partly a Red Herring - they send the main 'trunk feed; for
the area as 3-phase to keep the powerplant generator loads even on all
three phases - Power is almost always generated and transmitted as
If you live right along the main trunk-line feeder route, it's
already up there. Go out and look at the top arm of the pole right
outside your house, it will have either three or four conductors on
the top arm - if there are four, one is on smaller (often white)
insulators and that's the ground leg.
(There will be "butt plate grounds" and grounding risers spaced
every few poles.)
Now if you live on a branch to the main feeder, where they only
brought two hot legs down for a Delta-fed transformer (or one hot line
and a ground lead for a Wye-fed transformer) they *will* have to
extend all three hot lines to the pole outside your house or shop.
But that doesn't cost them all that much.
You can guesstimate the cost - drive out to the main road till you
see where they catch all three phases, and then watch your odometer on
the way back to get the distance, and count the poles along the way.
Your utility can give you the cost per mile figures.
You only need two transformers on the pole to get a 120/240V Open
Delta feed - The existing one stays for the regular loads and they add
a small can to get the Wild Leg. But it takes three transformers for
a full 120/240V Delta or 120/208V Wye.
The lower voltage 120/240V Open Delta feed can be a pain if you want
to run big motors - but it also allows them to feed your house and
other houses 120/240V single-phase loads off the same transformer set.
If you want 277/480V Delta they leave the original 120/240V 1ph
transformer and hang a new set of three above it for the 480V. And
you get stuck with the demand charges - it costs money simply to
energize the transformers even if they are not heavily loaded.
The Co-Op or Public Owned utilities price that work out simply to
break even, but for some strange reason the "For Profit" utilities
usually charge more...
(And don't sweat minor details that are "wrong" for your area - each
utility does their thing just a little different.)
--<< Bruce >>--
I live in the middle of no where, it took them almost 3 weeks before the
powers that be could even tell me what my mailing address would be. Does
that tell you how far it probably is to the main trunk line?
As it stands right now I can't afford to buy used equipment much less build
a shop to put it in so the cost of getting 3 phase is way down on my list.
<good stuff cut>
For three phase you will only need two hot lines on the pole.. the ones
at the top of the pole with the big insulators. They can give you open
delta but thats still better than a phase converter. In phase realtion
to groung the two hot wires are 120 degrees apart. The delta output
from the two transformers consists of three wires, the paired
connection of each winding and the other two ends of the two windings.
on Thu, 23 Nov 2006 18:16:26 GMT in rec.crafts.metalworking :
Makes a genset of your own a viable option. I mean $500 a month will
cover how big a generator? According to my catalogue here: 8kw 100 amp
standby generator for $3000 (plus shipping and handling, it costs to get
those fingerprints put on). Eight to nine months and you've got that paid
But I'm sure that Gunner can get you a "deal".
"Such a deal I got for you, I wouldn't give my own brother. But then he
knows where I live."
as an explaination for the decline in the US's tech edge, James
We used to rent warehouse space in an old furniture factory that had three
phase. The only thing it ran were a couple of fluorescent light (most of
the bulbs were burned out or broken ) for about 5 hours a month.
Every we got a bill for $80.00 with the description "In Lieu of Demand"
I miss the warehouse, but I sure don't miss that bill.
Paul K. Dickman
What a ripoff, my second house had 3 phase power at no extra cost
for the meter, the third cost an extra $200 for the 3 phase meter as
the peak draw was 25 kW, mainly electric stove & oven + 5 kW aircon.
Regret moving. Current house also has 3 phase, which I need to get
extended out to the shed. Long power cords are a PITA.
Residential does not attract a peak loading charge.
Cannot find latest account, it was about $120 for winter, (Aug/Sep)
last one for old house was $194.45 for 58 days, (Jan/Feb) aircon
running part of most days, but it was a cool summer.. Cost per unit
is 13.94 cents, receive account every 2 months. Just had 3 smaller
aircons installed instead of 1 large one, ready for summer. Warm
yesterday, about 95F, cooler today, only 85F.
Alan, in Gosnells, Western Oz.
VK6 YAB VKS 737 - W 6174
When you turn on an electric motor, its starting current is momentarily larger
than its running current, even loaded. All wire has resistance. The large
current running through the wire resistance causes a momentary droop of voltage,
which is what causes the lights to dim briefly.
You could go talk to your neighbors and explain to them that you're just turning
on an electric motor. If your relationship with them is good, and if you help
them fix things from time to time, maybe you can solve this problem politically;
i.e. just by talking.
You could also maybe switch to a rotary converter with power factor correction
capacitors installed. You can't do much about starting current in your mill's
motor, but at least this way you can reduce the reactive current in the line,
all of which contributes to the perceived voltage drop.
So call the power company and ask!
Since you have not supplied a location, or the name of the power
company, there is little chance of getting usefull information from any
You may get lucky and the Power Co will upgrade your supply for no
cost, as it appears they have already done with the transformer, or they
may tell you that you are getting as good as the supply line is capable
of, in which case I would be looking at three phase motors, Variable
Frequency Drives (aka VFD's), and programming in a soft start , so that
the surge does not take down the neighbors power.
In all probability that was supposed to be 15 kva. Remember also that
these utility grade transformers are rated to handle a 100% overload for
24 hours without damage.
If the OP is really out in the country the problem may be in the primary
distribution lines out to his area and not in the local transformer.
Indeed if a Bridgeport of what, 2 hp starting up is causing a noticeable
dip after the transformer was upgraded to 25 kva this is likely the
The utility isn't likely going to replace the miles of primary until
they are convinced it is old enough that's it's become more costly to
repair than replace, or some big customer comes into the area like a big
commercial building or a big housing developer.
I'm not an expert or anything but it should be pretty easy to rig up a
UPS unit to feed enough power to get past the initial current ramp on
those motors- I can't vouch for your area but I know around here almost
every junkyard has several large UPSs that you can buy by the pound.
The trick will be matching your discharge curve to that initial spike-
you'd need a much larger unit than rated for those motors because they
draw so much current cold. Beyond that though it shouldn't be a
problem- just make sure that you're primed before you turn the whole
My 10 HP idler motor draws about 120 amps of 240v at startup. That
adds to about 28 kVa. Very serious size for a UPS, it would weigh
about a ton. It would also have enough electronics to salvage to
afford to buy a small VFD for the bridgeport mill.
Right, you have to get a big (free) three phase online type UPS and
modify it to provide you with "real" three phase power for the shop
complete with starting surges, while drawing a nice constant load of
single phase from the utility and even keeping you from wrecking parts
you're working on when the utility power goes out.
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