Single phase vs. three phase air conditioning
 

I have a house with both single and three phase electric. I'm thinking of
adding air conditioning. Pros and cons of three phase?? It's a small house,
two tons should be enough.

Al

Single phase vs. three phase air conditioning
 

Your average residential HVAC technician will have a harder time working on
it, and parts may be harder to get.

"Big Al" wrote in message
...
I have a house with both single and three phase electric. I'm thinking of
adding air conditioning. Pros and cons of three phase?? It's a small
house,
two tons should be enough.

Al

Single phase vs. three phase air conditioning
 

Meant to say:
"Your average residential HVAC technician will have a harder time working on
3 Phase, and parts may be harder to get."

"Bob" wrote in message
...
Your average residential HVAC technician will have a harder time working
on
it, and parts may be harder to get.

"Big Al" wrote in message
...
I have a house with both single and three phase electric. I'm thinking
of
adding air conditioning. Pros and cons of three phase?? It's a small
house,
two tons should be enough.

Al

Single phase vs. three phase air conditioning
 

Al, I doubt you will find many 2-ton Three phase units available. Most
three phase units are 3 ton & up. Go single phase.


Stretch

Single phase vs. three phase air conditioning
 

Good point. I just looked at the Rheem/Ruud specs and 3 tons is the smallest
with 3 Phase. When you get into higher SEERs, there's nothing 3 Phase.

"Stretch" wrote in message
oups.com...
Al, I doubt you will find many 2-ton Three phase units available. Most
three phase units are 3 ton & up. Go single phase.


Stretch

Single phase vs. three phase air conditioning
 

"Bob" wrote in message
. ..
Good point. I just looked at the Rheem/Ruud specs and 3 tons is the
smallest
with 3 Phase. When you get into higher SEERs, there's nothing 3 Phase.

"Stretch" wrote in message
oups.com...
Al, I doubt you will find many 2-ton Three phase units available. Most
three phase units are 3 ton & up. Go single phase.


Stretch


I found a two and a two and a half ton. What about operating costs? Is three
phase more efficient or less expensive to run? My three phase is one cent a
KW more than single phase.

Al

Single phase vs. three phase air conditioning
 

"Big Al" wrote:


"Bob" wrote in message
...
Good point. I just looked at the Rheem/Ruud specs and 3 tons is the
smallest
with 3 Phase. When you get into higher SEERs, there's nothing 3 Phase.

"Stretch" wrote in message
oups.com...
Al, I doubt you will find many 2-ton Three phase units available. Most
three phase units are 3 ton & up. Go single phase.


Stretch


I found a two and a two and a half ton. What about operating costs? Is three
phase more efficient or less expensive to run? My three phase is one cent a
KW more than single phase.

Not enough to offset that over the life of the unit.

Single phase vs. three phase air conditioning
 

"Big Al" wrote in message
...
I have a house with both single and three phase electric. I'm thinking of
adding air conditioning. Pros and cons of three phase?? It's a small
house,
two tons should be enough.

Al

Let your contractor choose what is best after doing the manual calculations.
What voltage is the service?
Are you saying on a small house you have 2 services?
Check with your utility for rebates and deals offered. Mine has deals all of
the time.

I am unaware of any 3 phase units that small. The smallest I have ever seen
is 3 tons. No over is not a good idea.

Single phase vs. three phase air conditioning
 

If your 3 Phase "is one cent a KW MORE than single phase", why would you
want 3 Phase. If you have extra money you want to spend, PayPal me some.
What brand of 3 Phase comes in 2 ton?

"Big Al" wrote in message
...

"Bob" wrote in message
. ..
Good point. I just looked at the Rheem/Ruud specs and 3 tons is the
smallest
with 3 Phase. When you get into higher SEERs, there's nothing 3 Phase.

"Stretch" wrote in message
oups.com...
Al, I doubt you will find many 2-ton Three phase units available.
Most
three phase units are 3 ton & up. Go single phase.


Stretch


I found a two and a two and a half ton. What about operating costs? Is
three
phase more efficient or less expensive to run? My three phase is one cent
a
KW more than single phase.

Al

Single phase vs. three phase air conditioning
 

"SQLit" wrote in message
...

"Big Al" wrote in message
...
I have a house with both single and three phase electric. I'm thinking
of
adding air conditioning. Pros and cons of three phase?? It's a small
house,
two tons should be enough.

Al

Let your contractor choose what is best after doing the manual
calculations.
What voltage is the service?
Are you saying on a small house you have 2 services?
Check with your utility for rebates and deals offered. Mine has deals all
of
the time.

I am unaware of any 3 phase units that small. The smallest I have ever
seen
is 3 tons. No over is not a good idea.


The three phase is 200 Amp, 240 volt. I didn't look at the single phase to
see what current it is. Two separate meters, and two separate services but
billed on one account. I'm the only house with three phase power in the
neighborhood. That can't be good:(

Al

Single phase vs. three phase air conditioning
 

Big Al posted for all of us...
I don't top post - see either inline or at bottom.

I have a house with both single and three phase electric. I'm thinking of
adding air conditioning. Pros and cons of three phase?? It's a small house,
two tons should be enough.

Al



Are you SURE you have three phase? How many wires coming in the house?
--
My boss said I was dumb and apathetic.
I said I don't know and I don't care...

Tekkie

Single phase vs. three phase air conditioning
 

"Tekkie®" wrote in message
...
Big Al posted for all of us...
I don't top post - see either inline or at bottom.

I have a house with both single and three phase electric. I'm thinking
of
adding air conditioning. Pros and cons of three phase?? It's a small
house,
two tons should be enough.

Al



Are you SURE you have three phase? How many wires coming in the house?
--
My boss said I was dumb and apathetic.
I said I don't know and I don't care...

Tekkie

Yes I'm sure. Four wires come in.

Al

Single phase vs. three phase air conditioning
 

Bob wrote:
If your 3 Phase "is one cent a KW MORE than single phase", why would you
want 3 Phase. If you have extra money you want to spend, PayPal me some.
What brand of 3 Phase comes in 2 ton?

"Big Al" wrote in message
...

"Bob" wrote in message
m...

Good point. I just looked at the Rheem/Ruud specs and 3 tons is the

smallest

with 3 Phase. When you get into higher SEERs, there's nothing 3 Phase.

"Stretch" wrote in message
egroups.com...

Al, I doubt you will find many 2-ton Three phase units available.

Most

three phase units are 3 ton & up. Go single phase.


Stretch


I found a two and a two and a half ton. What about operating costs? Is

three

phase more efficient or less expensive to run? My three phase is one cent

a

KW more than single phase.

Al





I have work in commercial field. Many problems could have is a brownout
or other problem on one of the phases which when other phases still have
power could damage the compressor motor. We had to many time have phase
protection on the power to these units that if a problem happed as such
would kill power for all phases. The equipment can be costly and
therefore may not be worth it for residential use.

Single phase vs. three phase air conditioning
 

i seriously doubt he has 3 phase, more likely 3 wires coming in. unless
he lives in a commercial area.

yeah phase failure imbalance can cause all sorts of troubles, with wild
voltage swings. company I used to work for had that trouble, the
company copiers didnt like 30 volt changes:( We sold copiers and I was
one of the techs, it was a ongoing trouble finally sloved when the
company went out of business....

Single phase vs. three phase air conditioning
 

Big Al wrote:
"Tekkie®" wrote in message
...

Big Al posted for all of us...
I don't top post - see either inline or at bottom.


I have a house with both single and three phase electric. I'm thinking

of

adding air conditioning. Pros and cons of three phase?? It's a small

house,

two tons should be enough.

Al




Are you SURE you have three phase? How many wires coming in the house?
--
My boss said I was dumb and apathetic.
I said I don't know and I don't care...

Tekkie


Yes I'm sure. Four wires come in.

Al


I think that's pretty unusual, so I'm curious what you use it for (other
than considering using it for AC).

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form .

Single phase vs. three phase air conditioning
 

On 3 Feb 2006 04:15:35 -0800, "Stretch" wrote:

Al, I doubt you will find many 2-ton Three phase units available. Most
three phase units are 3 ton & up. Go single phase.


Stretch

Not with Copeland compressors.

I have built 2-ton DH's withe Copeland (coplemetec)
pumps, rated at 3 HP, R-12, 2 tons, medium-to-high temp.

Of course, that was many years ago, and these were salvaged from
commercial units.


But three phase exists all the way down to fractional horsepower, if
you need it. Price is the main stickler. Go with what is cheaper
(and cheaper to repair/replace, etc).

The reason you don't see too many residential 3-PH units under 5 tons,
is 3-PH power is rare in residential services, so there is little
call for it. But 3-PH motors and compressors are readily available,
all the way down to two tons or less. Fifteen to Thirty years ago,
3-PH motors were generally cheaper than single PH. Now, I dunno. I
don't do it no more.


Grab the latest Grainger catalog, and see what compressors are
available, and for what prices.



--
-john
wide-open at throttle dot info

Single phase vs. three phase air conditioning
 

On Sat, 04 Feb 2006 10:34:28 -0500, MC wrote:

We had to many time have phase
protection on the power to these units that if a problem happed as such
would kill power for all phases. The equipment can be costly and
therefore may not be worth it for residential use.

Nope. It's easily "hacked together" (for lack of a better term). Grab
an "artificial neutral", by connecting three equal resistors in a
WYE. Run the node of the WYE (the "artificial ground) through a
current sensor, to the real ground, or neutral. A preset unbalance
will develop a current offset from artificial neutral to real neutral
or ground, and trip the protective relay which will open the mag
(contactor)

A few bucks worth of Radio Shack parts, and a 16 year old nerd down
the street are all you need.

--
-john
wide-open at throttle dot info

Single phase vs. three phase air conditioning
 

~^Johnny^~ wrote:

On Sat, 04 Feb 2006 10:34:28 -0500, MC wrote:


We had to many time have phase
protection on the power to these units that if a problem happed as such
would kill power for all phases. The equipment can be costly and
therefore may not be worth it for residential use.


Nope. It's easily "hacked together" (for lack of a better term). Grab
an "artificial neutral", by connecting three equal resistors in a
WYE. Run the node of the WYE (the "artificial ground) through a
current sensor, to the real ground, or neutral. A preset unbalance
will develop a current offset from artificial neutral to real neutral
or ground, and trip the protective relay which will open the mag
(contactor)

A few bucks worth of Radio Shack parts, and a 16 year old nerd down
the street are all you need.

Or you could just buy one. All of our 3 phase units come with phase
protection consisting of a 2.5" x 2.5" card with very few components
mounted on it. Cost about 15 bucks apiece. How many do you need? BTW,
they will be marked up before you get them :)

Richard Perry

Single phase vs. three phase air conditioning
 

John Wrote

"Not with Copeland compressors.

I have built 2-ton DH's withe Copeland (coplemetec)
pumps, rated at 3 HP, R-12, 2 tons, medium-to-high temp.


Of course, that was many years ago, and these were salvaged from
commercial units.


But three phase exists all the way down to fractional horsepower, if
you need it. Price is the main stickler. Go with what is cheaper
(and cheaper to repair/replace, etc).


The reason you don't see too many residential 3-PH units under 5 tons,
is 3-PH power is rare in residential services, so there is little
call for it. But 3-PH motors and compressors are readily available,
all the way down to two tons or less. Fifteen to Thirty years ago,
3-PH motors were generally cheaper than single PH. Now, I dunno. I
don't do it no more.


Grab the latest Grainger catalog, and see what compressors are
available, and for what prices. "




John,

Yeah he could build his own air conditioner from parts he got at
Grainger. But he wants to BUY one that is already made, from Lennox or
Trane or Carrier, etc. THEY don't make many 3 phase units less than
three ton. THAT was the question. I realize it COULD be done, but a
homeowner isn't likely to do it, it would make no economic sense. I
don't make my own units either. cheaper and easier and better to buy
one from a major manufacturer.

Stretch

Single phase vs. three phase air conditioning
 

CJT wrote:
Big Al wrote:

"Tekkie®" wrote in message
...

Big Al posted for all of us...
I don't top post - see either inline or at bottom.


I have a house with both single and three phase electric. I'm thinking


of

adding air conditioning. Pros and cons of three phase?? It's a small


house,

two tons should be enough.

Al




Are you SURE you have three phase? How many wires coming in the house?
--
My boss said I was dumb and apathetic.
I said I don't know and I don't care...

Tekkie



Yes I'm sure. Four wires come in.

Al


I think that's pretty unusual, so I'm curious what you use it for (other
than considering using it for AC).

When my brother had his house built, he wanted 400 amp service which was
not as common then as now, Utility company had to use four wire entrance
as the only type they had that would suffice for that amperage. One of
the wires was not used.

Single phase vs. three phase air conditioning
 

In Myrtle Beach, SC, we have many older neighborhoods that have three
phase power. Most house in those neighborhoods (High End Houses) have
three phase service. The electric rate is the same. I have seen many
of them have three phase heat pumps and air conditioners. Newer
neighborhoods are mostly all single phase.

Stretch