Residential three phase power --------------------------------------

[KE6DF]

Does anyone have three phase power in their residence?

Will power companies supply it if you live in a residential zoned area if you ask?

The home I grew up in in Phoenix had three phase power. My father was an electrical contractor and, back in the 1950's put an AC unit in the house -- back when most people had swamp coolers.

It was a small commercial unit, water cooled with a water tower, and ran on three phase current.

I remember as a teenager helping him upgrade the service on the house to 200 amp three phase (the main power service disconnect had three ganged breakers).

My parents have passed on, but my sister and I still own the house, but I don't know if he ever downgraded to single phase after I moved out. I'll check next time I get there.

I know the original AC unit is long gone, in fact the house is on it's third AC system.

I'm wondering if this is common or rare in residences. None of the houses I've owned or any of my friends have owned had three phase power.

[AB3FL]

Wow!     3 phase residential.   MY house was built in 1958 and when I moved in, it had the original Carrier A/C.  It hardly worked and ran on 240....Needless to say, I had it replaced with a new carrier unit.  The compressor unit was in the back of the garage and it was about 5' long X 2 1/2' high X 2 1/2' deep........I think 40A

Tom - AB3FL

[WA1HZK]

Three Phase
Your making me all fuzzy feeling.
No more problems running 1.2 Gigawatts
Time for a BC Rig!!!

[flintstone mop]

PHIL K2PG has three phase power at his residence for his Coillins AM transmitter. It is running at legal limit, he didn't want to convert anything to single phase.
IF you really need 3 phase for that special transmitter project, you can buy motor converters to make three phase from single phase. A real light dimmer when it starts up.

Fred

[Opcom]

If the motor-generator was connected to power only the plate section, it would have the property of "kerchunkery" (tm).

[WB2YGF]

Does anyone have three phase power in their residence?

Will power companies supply it if you live in a residential zoned area if you ask?

I suspect many residential areas don't have 3 phase going down the street so that would be a deal breaker right there.  Moreover, I believe our 3 phase service at work has 3 transformers.  Pretty expensive to provide for one residence.

[W3SLK]

Mopman Fred said:

PHIL K2PG has three phase power at his residence for his Coillins AM transmitter.

That's because a lot of farms utilize 3Ø to run heaters and blowers in their grain silos. Of course, it helps that the power plant is about 3 miles from Phil's QTH.

[k7yoo]

I have a 200 A 3 phase service --only because I live in an old building that used to be a blacksmith/welding shop. It sure makes HV filtering easier if you run 3 phase generated B+. Uses a lot of rectifiers though.
Skip

[W3RSW]

Right on the three phase complexity remarks.

I think for new three phase service, at least around here, you have to sign up for commercial Demand service, i.e. in order for the power company to go to the expense of installing such service your power bill will be higher reflecting the ultimate demand of the service.

I'd look up the rates and rate structure before planning.  Most times three phase contracts are handled by a pwr. co'.s engineering dept, not the 'sales' dept.

"... Uh, Mon Power?..   
 "Ok, yeah, I'll hold.. " 
 "damn touch tone.. "
 "<6, ,3, 1,>.."
" uh hi,"  "yeah, well I gotta 50kw vapour phase cooled reactor here... "

"Say What!"   
 "you say minimum $300/mo,? .. "   " AND 50 Cents/Kwh?...  " 
 "Click."

[WBear2GCR]

If you only have one wire on the pole then there is no way to get 3 phase from the power company.

One does not need a "motor generator" (actually motor alternator) set up to run 3 phase stuff off single phase.

You can check the web and find that you can make a good 3 phase power using a 3 phase motor of greater HP than the thing you want to run via what is basically some switches and a few well placed oil caps.

If the power requirement is low enough you don't even need the switches, just the caps.

I do this trick all the time to run my milling machine. Works fine.

My neighbor used to run his on single phase (reduced torque) by using the cap start trick on his three phase motor...

Works like a charm. Makes some noise though.

            _-_-bear

[W7TFO]

If you have poles & wires feeding your place, you may be in luck.  There need to be three wires up on the high tension side, and make sure you get a wye hookup as an open delta (two pig service) does not give true 3ph.

We have 480V 3PH here at the Arizona acreage. It is within the bounds of a small co-op (Electrical District 3), and I inquired how to go about it.  They subsidized $5K of it, I had to pay $2K towards the upgrade.

There are three 50 kVa pigs outside now.  I worked commercial power in my broadcast job for years, so the hookup after the meter was old hat.

Our KWH cost is just a plain residential rate, so it doesn't hurt too badly.  I hope to recoup the investment by using 3ph in most motor areas.

Now that 1940 water-cooled WECo 405B in storage has a reason to live on 160....

[KM1H]

Ive been using a 7.5 HP 3 phase motor and a phasing cap for a few decades to run machine tools and a 5 HP 2 stage compressor in the garage.

I havent reached the level yet to need similar in the basement but this latest acquisition just might force it

Carl
KM1H

[N3DRB The Derb]

carl,

LUV teh 1920's breadboard construction!    ....qth to send flowers and card pse?

(assuming thats just a picture pose)

I shouldnt joke, my hb rig had full B+ on the tank coil and no shielding or safety features at all.  It was death personified.

[w4bfs]

3CW20000A7-1-1.jpg


right out of Better Homes and Gardens ... a great center piece !  ...73 ....John

[KE6DF]

You could use it as combination transmitter and tankless water heater for your house.

[flintstone mop]

The Bear is right on!!!
I also know a fella who has a machine shop with a motor generator to make three-phase and it is definitley a light dimmer when first turned on.

It's strange that Allan Weiner didn't try a "Commercial Demand" with his electric company to get three-phase for WBCQ. It's an electrical nighmare $$ over there sucking on single phase power for several 50KW transmitters.

Fred

[W7TFO]

All fine & well, but all a 'phase trick' does is run a motor.  Not much for the power supply in a transmitter there.

[KM1H]

carl,

LUV teh 1920's breadboard construction!    ....qth to send flowers and card pse?

(assuming thats just a picture pose)

I shouldnt joke, my hb rig had full B+ on the tank coil and no shielding or safety features at all.  It was death personified.

Thats just the way I picked that Eimac Steamer up a few weeks ago at the local surplus place. The tube looks brand new, or at least it hasnt had any serious dissipation. It has a 1995 date code.

Filament transformer and filament seal blower are Italian. It also came with a lab quality conductivity meter and several liquid conductivity standards. Im wondering if it wasnt some some of university lab demo for heat transfer.

Anyway the price was too good to pass up, they had no idea what it was. It could sure make a loafing linear to keep 3885 clear . Ill bet even Patrick could hear it.

Carl
KM1H

[KM1H]

All fine & well, but all a 'phase trick' does is run a motor.  Not much for the power supply in a transmitter there.

Why not?  It runs my welder just fine.

Carl

[KA2QFX]

Hey Carl,

N1HCI and I saw that at ESS too.  I decided I couldn't afford to run that 100 Amp filament, let alone the plate transformer for that thing.  Will you be drilling a geothermal well to dump the heat?  Man, let me know when you fire up so I can disconnect my antennas.  Frankly, I'd love to play with that thing too.
73,
Mark
Concord, NH

[KM1H]

Hey Carl,

N1HCI and I saw that at ESS too.  I decided I couldn't afford to run that 100 Amp filament, let alone the plate transformer for that thing.  Will you be drilling a geothermal well to dump the heat?  Man, let me know when you fire up so I can disconnect my antennas.  Frankly, I'd love to play with that thing too.
73,
Mark
Concord, NH

I drop in there once a week and I think he got tired of me fondling it and dropped the price in half. The filament is ony 700W and the xfmr is included. Thats not much on the electric bill as long as its only on when needed

I doubt if I'll ever use it but its a great conversation piece. Its in the kitchen eating area window for now.

Carl
KM1H

[KE6DF]

Well, I finally got back to our Phoenix house, and it does still have three phase power.

There are four lines coming in from the pole-pig up on the pole in the alley.

Three insulated hot wires and a very thick uninsulated common wire.

The house has three sub panels. Two are fed off two of the hot lines with two ganged breakers from the main panel on the back of the house near the meter. I assume these panels are only for 240 volts and the 120 volt curcuits between one of the hot lines and ground.

The third sub panel, which goes to the utility, furnace, and AC room is fed by three phase with a tripple ganged 50 amp set of breakers. I'm pretty sure nothing in the house needs three phase power any more since that original three phase AC unit was replaced years ago.

The service is 200 amp three phase.

I wonder if the current AC unit runs off 208V. I'll have to check that before I leave Phoenix.

The whole thing seems like overkill for a ordinary 2000 sq ft 1955 tract home.

I wonder if we are paying more per KWH than the neighbors. Probably not, since knowing my dad he never would have put up with that.

[W2VW]

Sounds like 208 wye 4 wire.

[W2PFY]

Lots of people think you need three transformers to make three phase. If you power company says that, tell them you want a Scott T configuration. It uses two transformers but I don't know if it would work in a Y configuration to give you 208/120 volts. You may need a separate indoor step down transformer for your 120 volts. Can anyone enlighten me here?   

[N4LTA]

Three phase is tough in new residential areas. If you have underground service with pad mounted transformer you are probably out of luck. If you have overhead lines you may have a chance, but many residential areas are fed with single phase overhead lines.

Some older house have three phase lines because when air conditioning was a new thing, many system required three phase power. This dates to the 50's and earlier.

Most power companies have discontinued the old three phase open delta  services that used two high voltage phase wire and two transformers. The services has a "high leg" that caused lots of problems. One of the transformers was a 240 /120 volt secondary. From two points in the delta, you got 120 volts but from the other you got 190 volts. That burned lots of things up when someone used the high leg  breaker space.

Almost all three phase is now delivered using three phase transformers and delivered at 208/120 wye and 480/277 wye except speciality industrial services that sign a long term contract.

If you don't have a three phase primary in your area, you are out of luck on getting three phase from the power company. The three phase converters will work with motors but are not much use when trying to deliver power to a non motor load. The whole purpose in three phase power delivery is to get more power with less conductor.

The rotary converter are less efficient than just designing a single phase solution They work fine when you have a three phase motor and only have a single phase power source, but the power transfer is not efficient.

Pat
N4LTA