Air Conditioning - dumb capacitor question

My outside AC fan has quit running. I bought two new capacitors for it. I got them pretty cheap and I figure it couldn't hurt to replace both. My old capacitors had 2 terminals with a single connector on each and a ground connector soldered to the capacitor chassis. These new caps have just 2 terminals with four connectors on each. What do I do with the ground wire? Do I connect it to one of the terminals? If so, which one? Or do I just not connect it at all?

It won't be necessary to hook up the ground wire. You definitely do not want to hook it up to one of the terminals.

thanks for the fast reply. I hooked it up but my outside fan still won't start.
The compressor is warm. Any idea what might be wrong? Is my fan motor bad? It was working off and on for about a week before it stopped running altogether.

Considering that I'm here and you're there. What is the brand and model number of the unit you are working on? That could give us a reference point to start with and being handy with a voltmeter is the next step to figure this problem out.

Sorry, I know I didn't give near enough info. The unit is a Lennox HS13-261V-4P. It's over 20 years old so I guess it's just time to replace it. Any advice on the best model to replace it with?

It's probably time to consider having it replaced.

Back on the old unit. Is the motor hot too? If so, the motor and the compressor could be out on a thermal overload, if the fan capacitor was the problem. Let the unit sit for awhile and try it again. The next step would be to confirm that you have proper voltage to the motor and check to see that the motor is free spinning with the power off, of course. It may very well be a bad fan motor and it being replaced would get more life out of the unit.

Back to talking on a new unit.Brand is not as important to me than WHO installs the new unit. I'd recommend changing the outside unit and the air handler (inside unit) at the same time.

One thing I find odd is that the compressor is always warm. Even if the AC has been turned off for a long time. Is that normal? I will inspect the fan motor tomorrow.

You might look and see that your compressor has a crankcase heater on it is why its warm. When it dont run.
20 years most of the time we look at life of a unit as 15 years tops/ Although I know of one 39 years old and runs like a top.


ED ;)

Buy the most efficient unit you can afford. You will save money each time you use it.

Many different brands use common core parts, so why pay extra for the name?

To echo an earlier comment, be certain that the unit is installed properly. Brazing is better than soft soldering, but make sure a nitrogen sweep is used. Is the installation checked for leaks with a micron gauge? Is the lineset properly sized? Is the evaporator coil sized properly? Is the condenser sized properly?

There are too many fly by night outfits.

New standards (13 SEER) coming on line in 2006, so it is best to replace now, and save some money.

@danski

It sounds like you have some great tips. Would you please e-mail me with detailed requirements for the installation of a new unit? Most of your advice is gibberish to me so I need something that I can give to the potential installer.
My e-mail is webmaster@plucky.com

Thanks,
Brad

Brad,

Micron gauge: A device to measure vacuum, much, much more accurate than the vacuum gauge on the typical HVAC gauge set.

Most techs will simply pull a vacuum for twenty minutes, and see if it holds for ten, then call it good. It is impossible to verify leaks with the manifold gauge set vacuum gauge because it will not show small changes.

A micron gauge will show a small leak during the initial system vacuum, and it will also show a leak if the vacuum pump is turned off, and the system is isolated. There are 19,000 microns in the 29 to 30 IN Hg (absolute vacuum) range. Most new AC condensers spec a vacuum at 450 microns. If the system has a leak, it will be impossible to attain 450 microns.

I know for a fact that if an AC unit is changed on a humid day, it can take hours to attain a satisfactory micron reading due to the moisture that enters the open lineset.

Brazing vs soldering: Brazing is at a much higer temperature (around 1200 degrees F), and it will not fatigue from vibration like soft soldering (around 450 degrees F). A silver bearing brazing alloy, 15% silver, is recommended. It may be possible to braze small residential refrigeration tubing with a MAPP torch, but an air-acetylene torch works every time. Soldering is much faster, can be done with a propane torch and a nitrogen sweep is not required. Most techs will use the soldering method on a residential appliction because it saves company time, but the consumer gets a compromised prouct. That is what happens when consumers shop based on price.

Be warned, the new 410-A (Puron is a brand name) units REQUIRE brazed joints, and must be tested at 400 PSI. The special dryer and TXV valve that comes with the unit MUST also be installed.

Nitrogen sweep: Nitrogen (an inert gas) is flowed through refrigeration lines during brazing to prevent the formation of scale. Scale will form inside a brazed joint from impurities in the air. This scale comes off when the unit is charged, and gets caught in the filter. The nitrogen also helps the brazing alloy flow better.

Nitrogen purge: Pressurization of the refrigerant lines when brazing is completed. This does two things: allows for gross leak checking before the vacuum pump is used, and the dry nitrogen absorbs moisture saving some time during the vacuum pump stage.

Lineset size: Determined by the size of the new unit in combination with the total length. Tables are provided with the new unit.

Evaporator coil: The part inside that feels cold. It must be matched in size to the outdoor unit (condenser).

Condenser size: Determined by a load calculation (aka "Manual J"). MOST residential units (furnaces and air conditioners) are seriously oversized. Simpy replacing same size for same size will cost you more up front now for the larger equipment and later in operating costs.

2006 standards: The new minimum SEER will be 13, compared to 10 now. Refrigerant R-22 is also being phased out of new equipment at that time. There is so much R-22 equipment out there, that refrigerant will continue to be available for a long time, just like R-12. You will have a problem if the system leaks and needs an annual "topping off", that is why proper installation is paramount. Prices will drop for the new 13 SEER equipment with economies of scale (just like the jump from 8 to 10 SEER), but there is a significant price difference now

It will take a long time to justify the cost difference with energy savings alone, but due to the longevity of modern equipment, consumers must buy the most efficient equipment they can afford. Energy costs will not go down.

Top of the line, "name brand" equipment will not perform properly if it is installed poorly.

If your installer does not understand this, then find another one.

Dan

Poll People. Friends, neighbors, family, employees of local hardware stores, building department officials, the local chamber of commerce, better business bureau. I know it sounds like work, but spend some time getting a consensus of who does the best work in the area. Not who the cheapest is, but who is concerned with quality work and service AFTER the installation.
Insist that a complete room by room load calculation be done. This involves measuring out the house, noting which direction your exterior walls face, size and construction of the windows, insulation in the walls and attic, lots of factors. Don't forget to mention your favorite room temperature. Load calculations are a good sign of a reputable and knowledgeable contractor. This should all be free and included with the estimate.
Check with www.acca.org and see if you have any members around your area. When the estimates are all in and you've made your choice on company, trust their reccomendations of what to go with. Things to ask for in the quote, my opinion, a variable speed blower, an expansion valve on the indoor coil . Both of these options will probably yield a system rating at 13 SEER or better. Most of my systems installed rate between 13 and 14 SEER. I also do not reccomend any new refrigerants at this time. R-22 still looks like the way to go.

Trane AC units go up to a seer of 19.50. Best buy now is XL16i seer of 17.15. The freon R 22 will be made till 2030. The cost of the R 410a is high and if you have a leak in the unit of over 50% they have to recover the freon left in it and put all new freon R410a in it as it is a mix. make sure and get 3 bids for the job.


ED ;)

What's a ballpark total cost for a 2-ton 14 seer unit and installation? Can I replace just the condensor unit and the coils or do I need to replace the air handler too?

Thanks for all the great advice from everyone.

The fan motor is cold. The compressor does not make any indication of trying to come on. If the fan motor is bad, would that prevent the compressor from even trying to start? I've decided to go ahead and get a new system later during the winter but now I'm fixated on trying to figure out what's wrong with my old unit. Unfortunately I do not have a volt meter.

on trying to figure out what's wrong without a meter. It's time to head to Wal-mart or Radio Shack and start learning to read one. Without the meter, your only guessing, and guessing can be expensive and dangerous.

I've needed a meter for a long time so I went ahead and ordered one.

What's a ballpark total cost for a 2-ton 14 seer unit and installation? Can I replace just the condensor unit and the coils or do I need to replace the air handler too?

How can you expect a "ballpark" figure?

What brand equipment? How professional will the installation be? What kind of additional work is involved? There is always someone out there willing to do it for cheaper, even if that means compromising the installation.

No way I would want a 14 SEER 410A unit without a new indoor coil and lineset... the refrigerant oils are not compatible. If the lineset is inacessible as far as replacement is concerned, then it needs to be flushed out.

Sorry. 2 ton, 14 seer unit with R-22. Let's assume the equipment is Lennox since that's what I have now and it worked well for 21 years. New indoor coils and lineset. The air handler and coils are in the attic but the run for the line is very accessible. There is a 12"x12" chase that runs straight up to the attic from the garage where the current line comes in from the condensor. The installation would be done per the guidelines you specified before.

For sure you want to replace the coil and the condenser unit at the same time.As for cost get 3 bid for the job there. No one can say what the cost will be for where your at. Its as different as night and day from one place to another.

ED ;)

If the lineset is serviceable, and you are staying with R-22, then there is no need to change it.

Changing the indoor coil is a good idea because of all the caked on dirt and the possibility that an old metal drain pan has the potential to develop a leak.

If it is a horizontal unit in an attic, then there will likely be sheet metal work required to adapt the new coil (assuming it is metal and not something like duct board).

Just because the old Brand X equipment has done well in the past is no guarantee that the same performance will continue.

In my area, this changeout would be between $3k and $5k, depending on the amount of work involved and the equipment brand.

Please get at least 3 estimates, and check references.