The heat has motivated me to have central air installed at my home. I am
trying to avoid getting ripped off on the electrical part of the job.

My understanding is that central air conditioning units generally pull
about 30 amps, depending on the size. At any rate, when I look at my
electrical service box, there are two 20 amp breakers that are unused.
Is it easy to somehow combine these two to support the needs of the
central air? Should the contractor that installs the AC be able to
handle this as a standard part of the job, or am I looking at additional
expenses?

Thanks.

probably OK.

what is the main breaker marked 200 amp your fine

100 amp probably OK

60 amp time for upgrade

the big issue is what is the overall capacity and how much are you
using?

"Andrew Taylor" wrote in message
. com...
The heat has motivated me to have central air installed at my home. I am
trying to avoid getting ripped off on the electrical part of the job.

My understanding is that central air conditioning units generally pull
about 30 amps, depending on the size. At any rate, when I look at my
electrical service box, there are two 20 amp breakers that are unused. Is
it easy to somehow combine these two to support the needs of the central
air? Should the contractor that installs the AC be able to handle this as
a standard part of the job, or am I looking at additional expenses?

Thanks.

They'll quote you a full price which includes the $500 the electrician will
charge them to run a ckt out to the unit. I had them back that out of
their bid and installed my own ckt. Before you try to figure out what
you're going to do in the panel, you need to get a hold of the spec sheet
for the A/C unit. Some need 30A. Some 40A, Some 50A, etc... The
literature should give you a minimum amperage for a breaker as well as a
maximum. It'll also tell you your full load amperage, RLA, etc... From
that, you can do some quick calcs on your panel to see if it'll support your
A/C or not. Before just automatically telling the HVAC guys to skip the
electrical, you really should find out what's going to be needed and price
it out. Copper wire has gone through the roof so it may not save you as
much as you think. That being said, I saved about $350 by doing it myself.
Good luck.
cc

It's a little more complicated than that. You have two unused breakers in
the panel, but unless you have a forced hot air heat system, you'll need
four spaces in the panel. A double pole for the condenser, and a double pole
for an air handler. You also must have enough service for the additional
load. Personally, I'd wait until September when AC guys aren't so busy, then
get a couple of prices


"Andrew Taylor" wrote in message
. com...
The heat has motivated me to have central air installed at my home. I am
trying to avoid getting ripped off on the electrical part of the job.

My understanding is that central air conditioning units generally pull
about 30 amps, depending on the size. At any rate, when I look at my
electrical service box, there are two 20 amp breakers that are unused. Is
it easy to somehow combine these two to support the needs of the central
air? Should the contractor that installs the AC be able to handle this as
a standard part of the job, or am I looking at additional expenses?

Thanks.

Andrew Taylor wrote:
The heat has motivated me to have central air installed at my home. I am
trying to avoid getting ripped off on the electrical part of the job.

My understanding is that central air conditioning units generally pull
about 30 amps, depending on the size. At any rate, when I look at my
electrical service box, there are two 20 amp breakers that are unused.
Is it easy to somehow combine these two to support the needs of the
central air? Should the contractor that installs the AC be able to
handle this as a standard part of the job, or am I looking at additional
expenses?

Thanks.


If the breakers are truly unused, they'll pull them out and install the
double 30 or 40 that your new compressor will need. What are you gonna
do for the air handler? Unless you have central heat already with an
air handler, tou'll need at least one more breaker. If your electrical
service is large enough but you are just out of spaces, use the 2
remaining slots for a 60A or 70A breaker to go to a subpanel. If you
have a 100A panel you may can ad a feed-thru lug kit to it and wire a
small 100A "main lug" subpanel right next to it without using those last
two spaces. (if you use feedthru lugs, the subpanel and the feeder
wires must be rated for as much amperage as the main panel)

Bob

Lots of interesting answers.
Assuming they are full size breakers, your contractor will pull them out and
replace them with what he needs. No problem.
Even if they are half size, he can still probably finagle something without
too much trouble.

But the person who said it depended on the size of your service was right.
If you have a 60a service you won't have the capacity. Maybe not even with
100a unless you make sure you don't use any heavy electrical devices at the
same time.

"Andrew Taylor" wrote in message
. com...
The heat has motivated me to have central air installed at my home. I am
trying to avoid getting ripped off on the electrical part of the job.

My understanding is that central air conditioning units generally pull
about 30 amps, depending on the size. At any rate, when I look at my
electrical service box, there are two 20 amp breakers that are unused. Is
it easy to somehow combine these two to support the needs of the central
air? Should the contractor that installs the AC be able to handle this as
a standard part of the job, or am I looking at additional expenses?

Thanks.

Thanks for your comments. I have a 100 amp service, with gas heat, gas
stove, gas clothes dryer, so hopefully there will be adequate capacity.


Andrew Taylor wrote:

The heat has motivated me to have central air installed at my home. I am
trying to avoid getting ripped off on the electrical part of the job.

My understanding is that central air conditioning units generally pull
about 30 amps, depending on the size. At any rate, when I look at my
electrical service box, there are two 20 amp breakers that are unused.
Is it easy to somehow combine these two to support the needs of the
central air? Should the contractor that installs the AC be able to
handle this as a standard part of the job, or am I looking at additional
expenses?

Thanks.

In article , "RBM" rbm2(remove wrote:
It's a little more complicated than that. You have two unused breakers in
the panel, but unless you have a forced hot air heat system, you'll need
four spaces in the panel. A double pole for the condenser, and a double pole
for an air handler.

Naaah. The air handler will be a 120V load.


--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

In the Northeast, the only ones I've ever seen that were 120 volt were part
of a furnace


"Doug Miller" wrote in message
. com...
In article , "RBM" rbm2(remove
wrote:
It's a little more complicated than that. You have two unused breakers in
the panel, but unless you have a forced hot air heat system, you'll need
four spaces in the panel. A double pole for the condenser, and a double
pole
for an air handler.

Naaah. The air handler will be a 120V load.


--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

In article , "RBM" rbm2(remove wrote:
In the Northeast, the only ones I've ever seen that were 120 volt were part
of a furnace

And what are the 240V blowers part of? Commercial installations?

Using a 240V blower in a residential application is just a bit of overkill,
dontcha think?


"Doug Miller" wrote in message
.com...
In article , "RBM" rbm2(remove
wrote:
It's a little more complicated than that. You have two unused breakers in
the panel, but unless you have a forced hot air heat system, you'll need
four spaces in the panel. A double pole for the condenser, and a double
pole
for an air handler.

Naaah. The air handler will be a 120V load.


--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.



--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

RBM wrote:
In the Northeast, the only ones I've ever seen that were 120 volt were part
of a furnace


Since this is alt.home.repair, isn't as "part of a furnace" where you'd
typically find an air handler? Typically a furnace fan will only draw
about 5 amps at 120 volts anyway, so there's not much motivation to move
to 240V.


"Doug Miller" wrote in message
. com...

In article , "RBM" rbm2(remove
wrote:

It's a little more complicated than that. You have two unused breakers in
the panel, but unless you have a forced hot air heat system, you'll need
four spaces in the panel. A double pole for the condenser, and a double
pole
for an air handler.

Naaah. The air handler will be a 120V load.


--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.





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

Just stand alone residential central AC air handlers. Virtually all of the
blowers attached to furnaces are 120 volt, but I don't believe I've ever
seen a 120 volt stand alone airhandler



"Doug Miller" wrote in message
.com...
In article , "RBM" rbm2(remove
wrote:
In the Northeast, the only ones I've ever seen that were 120 volt were
part
of a furnace

And what are the 240V blowers part of? Commercial installations?

Using a 240V blower in a residential application is just a bit of
overkill,
dontcha think?


"Doug Miller" wrote in message
y.com...
In article , "RBM" rbm2(remove
wrote:
It's a little more complicated than that. You have two unused breakers
in
the panel, but unless you have a forced hot air heat system, you'll need
four spaces in the panel. A double pole for the condenser, and a double
pole
for an air handler.

Naaah. The air handler will be a 120V load.


--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.



--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

Most of the furnace mounted blowers I've wired,(residential) draw 12 amps @
120 volt


"CJT" wrote in message
...
RBM wrote:
In the Northeast, the only ones I've ever seen that were 120 volt were
part of a furnace


Since this is alt.home.repair, isn't as "part of a furnace" where you'd
typically find an air handler? Typically a furnace fan will only draw
about 5 amps at 120 volts anyway, so there's not much motivation to move
to 240V.


"Doug Miller" wrote in message
. com...

In article , "RBM" rbm2(remove
wrote:

It's a little more complicated than that. You have two unused breakers
in
the panel, but unless you have a forced hot air heat system, you'll need
four spaces in the panel. A double pole for the condenser, and a double
pole
for an air handler.

Naaah. The air handler will be a 120V load.


--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.





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

On Sun, 23 Jul 2006 02:24:26 GMT, Andrew Taylor
wrote:

The heat has motivated me to have central air installed at my home. I am
trying to avoid getting ripped off on the electrical part of the job.

My understanding is that central air conditioning units generally pull
about 30 amps, depending on the size. At any rate, when I look at my
electrical service box, there are two 20 amp breakers that are unused.
Is it easy to somehow combine these two to support the needs of the
central air? Should the contractor that installs the AC be able to
handle this as a standard part of the job, or am I looking at additional
expenses?

Thanks.


I see people replying to this about yoru orginal question, but I have
one of my own. Why do you have two unused 20 amp breakers in the
panel?

later,

tom

In article , "RBM" rbm2(remove wrote:
Just stand alone residential central AC air handlers. Virtually all of the
blowers attached to furnaces are 120 volt, but I don't believe I've ever
seen a 120 volt stand alone airhandler

I have one in my basement... house has central air, and hot-water heat. 3700
sq ft, and the 120V air handler is more than enough to keep the house cool.



"Doug Miller" wrote in message
y.com...
In article , "RBM" rbm2(remove
wrote:
In the Northeast, the only ones I've ever seen that were 120 volt were
part
of a furnace

And what are the 240V blowers part of? Commercial installations?

Using a 240V blower in a residential application is just a bit of
overkill,
dontcha think?


"Doug Miller" wrote in message
gy.com...
In article , "RBM" rbm2(remove
wrote:
It's a little more complicated than that. You have two unused breakers
in
the panel, but unless you have a forced hot air heat system, you'll need
four spaces in the panel. A double pole for the condenser, and a double
pole
for an air handler.

Naaah. The air handler will be a 120V load.


--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.



--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.



--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

RBM wrote:

Most of the furnace mounted blowers I've wired,(residential) draw 12 amps @
120 volt


That surprises me. Mine draws about 5.2 amps, for a 2000 sq. ft.
house. I guess you must be dealing with some pretty big houses,
but I would have thought those would be zoned systems.


"CJT" wrote in message
...

RBM wrote:

In the Northeast, the only ones I've ever seen that were 120 volt were
part of a furnace


Since this is alt.home.repair, isn't as "part of a furnace" where you'd
typically find an air handler? Typically a furnace fan will only draw
about 5 amps at 120 volts anyway, so there's not much motivation to move
to 240V.


"Doug Miller" wrote in message
gy.com...


In article , "RBM" rbm2(remove
wrote:


It's a little more complicated than that. You have two unused breakers
in
the panel, but unless you have a forced hot air heat system, you'll need
four spaces in the panel. A double pole for the condenser, and a double
pole
for an air handler.

Naaah. The air handler will be a 120V load.


--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.




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





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

wrote:

On Sun, 23 Jul 2006 16:31:43 GMT, (Doug Miller)
wrote:


And what are the 240V blowers part of? Commercial installations?

Using a 240V blower in a residential application is just a bit of overkill,
dontcha think?


I know this is a foreign concept in places where a furnace is
installed but South Florida air handlers will have 10 or 15 KVA of
heat. We only use it about 10 days a year so the funace would be
overkill.

I probably wouldn't call that a mere "air handler," but a
combination unit or something similar. But you may be right
about people on this thread using terms to refer to different
sorts of things entirely.

BTW it is not unusual to have that on the same circuit as the
condenser since it is a non-coincident load. You use the breaker in
the outside disconnect to limit the "maximum O/C device" requirement
for the condenser. Having that 6 ga or 4 ga wire (satisfying the
heater requirement) in the attic satisfies derating issues you have in
the summer.


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

Most tend to be around four to five thousand square feet, but generally have
two units in them. I'm wasn't doubting 120 volt units exist, in fact I've
often wondered why they used 240 volts with a relatively small draw. I'll
have to ask an AC guy what the deal is


"CJT" wrote in message
...
RBM wrote:

Most of the furnace mounted blowers I've wired,(residential) draw 12 amps
@ 120 volt


That surprises me. Mine draws about 5.2 amps, for a 2000 sq. ft.
house. I guess you must be dealing with some pretty big houses,
but I would have thought those would be zoned systems.


"CJT" wrote in message
...

RBM wrote:

In the Northeast, the only ones I've ever seen that were 120 volt were
part of a furnace


Since this is alt.home.repair, isn't as "part of a furnace" where you'd
typically find an air handler? Typically a furnace fan will only draw
about 5 amps at 120 volts anyway, so there's not much motivation to move
to 240V.


"Doug Miller" wrote in message
igy.com...


In article , "RBM" rbm2(remove
wrote:


It's a little more complicated than that. You have two unused breakers
in
the panel, but unless you have a forced hot air heat system, you'll
need
four spaces in the panel. A double pole for the condenser, and a
double pole
for an air handler.

Naaah. The air handler will be a 120V load.


--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.




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





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

I have no idea why there are two unused 20 amp breakers there. I bought
the house 3 years ago, and that is the way I found it.

Tom The Great wrote:




I see people replying to this about yoru orginal question, but I have
one of my own. Why do you have two unused 20 amp breakers in the
panel?

later,

tom

On Mon, 24 Jul 2006 04:03:10 GMT, Andrew Taylor
wrote:

I have no idea why there are two unused 20 amp breakers there. I bought
the house 3 years ago, and that is the way I found it.

Atleast you won't have to hunt for breaker space when you get your AC
installed.

Please repost when you find a solution you like, so we can learn from
your experiences.

later,

tom @ www.Consolidated-Loans.info



Tom The Great wrote:




I see people replying to this about yoru orginal question, but I have
one of my own. Why do you have two unused 20 amp breakers in the
panel?

later,

tom

Tom The Great wrote:

On Mon, 24 Jul 2006 04:03:10 GMT, Andrew Taylor
wrote:


I have no idea why there are two unused 20 amp breakers there. I bought
the house 3 years ago, and that is the way I found it.


Atleast you won't have to hunt for breaker space when you get your AC
installed.


Not necessarily. You need two on opposite sides of neutral.


Please repost when you find a solution you like, so we can learn from
your experiences.

later,

tom @ www.Consolidated-Loans.info



Tom The Great wrote:




I see people replying to this about yoru orginal question, but I have
one of my own. Why do you have two unused 20 amp breakers in the
panel?

later,

tom


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