Check out some similar questions!

Paul V · Apr 14, 2008, 07:52 PM

I've read several of the questions similar to this, but would like a further explanation. My (Bryant) outside condenser/compressor unit looks rather old, and we've been in the house for 16 years. The only problem we have is when the outside air temp gets up into the 90 degrees+ range (when we need the A/C the most), the condenser fan shuts down. I hear what sounds like the compressor still running, and we get only warm air from the ducts when the fan quits. When this happens, I turn off the A/C at the thermostat and give it a rest for about an hour or two. When I turn it back on, it runs just fine for about 30-60 minutes and then when the fan dies again, we do the shutdown procedure.

Per the label on the motor, there is thermal protection in the Westinghouse 1/4 horse 1050 rpm 230 volt 4.2 amp motor. The metal data plate that came with the Bryant unit indicates the fan motor should be 3.6 amps, so I assume the Westinghouse is a replacement. There are only 3 wires connected to the large capacitor: a black wire running from what appears to be the outside of the capacitor to a grounding point on the structure of the condenser unit/box; a yellow wire leading back to one side of the contactor; and a red wire leading to the compressor motor. The condenser fan leads are hooked to the same points in the contactor as the compressor motor/capacitor, so it appears that the compressor and the condenser fan are connected in parallel to the same capacitor connectors for startup.

My question is: if the capacitor were bad, wouldn't that cause a startup problem for BOTH the fan and the compressor? If it were bad, wouldn't it fail altogether rather than operating as designed and then crapping out when it gets hot? And if the problem is the motor, why won't it operate when it is most needed (when things heat up)? I've already thoroughly cleaned the unit inside and out with jet-stream from the garden hose and wet/dry-vac, so air circulation should not be the culprit.

Also need to know where I can find parts for homeowners (retail) in Orange County CA. I've tried several local parts houses and they only want to sell to A/C businesses.

hvac1000 · Apr 14, 2008, 09:51 PM

Sounds like the motor overload built in to the condenser fan motor is doing its job. The only way to know for sure is to take a voltage reading when the motor shuts off. If voltage is still present and going to the motor the motor is bad.

Capacitor probably not bad but if you get a new motor get a NEW capacitor rated for the new motor.

Most units use a dual capacitor. One side for the fan motor the other for the compressor. The new motor will have a wiring diagram on the label. Just follow it for correct hookup.

Paul V · Apr 15, 2008, 10:05 AM

That's what I was afraid of. Only point available for checking incoming voltage for the fan motor is where the 2 fan motor leads tie into the contactor, which, if the condenser is running, will still have voltage.

I've only found one source so far on the internet for the motor (expertappliance.com), and their price is about $300. Does this sound about right? Most other motors I've seen on the internet are much less expensive, but don't appear to have the appropriate mounting lugs on the motor case in the product photos. Any ideas for other sources?

Paul V · Apr 15, 2008, 10:06 AM

I forgot to mention that the $300 price includes a capacitor.

hvac1000 · Apr 15, 2008, 01:08 PM

Souns a bit expensive. Try Graniger.

Paul V · Apr 16, 2008, 07:49 PM

Okay, Grainger wasn't much help, but I found americanhvacparts.com, and their motor description seems to pretty well match what I've got, both dimensionally and electrically. They also indicate it is a direct OEM upgrade replacement for Bryant, and it's a step up from the 1/4 hp I have now to a 1/3 hp, but lower amperage draw (4.2 old vs. 2.3 new), so I assume it will blow at least as much air without getting as hot as the old motor. Their price is about $200 plus shipping. Does this sound reasonable?

Now I am wondering which capacitor to order. They recommend a 4 ufd 370 volt (which they stock) for this motor. The current capacitor for the compressor is a 35 ufd 440 volt oval. I've read elsewhere that substituting a 440 in place of a 370 volt is no problem. I'm thinking I should buy a dual capacitor so I can just slip it into the bracket that's currently holding the single. The closest match I've found to what I need and what I've got is a 35/5 ufd 440 volt dually. Seems to me I was reading somewhere else during my search that a 1 ufd difference is acceptable. Think this setup should work? It's either that or drill holes into the condenser cabinet for a separate mounting bracket.

hvac1000 · Apr 16, 2008, 09:34 PM

It will be cheaper to just get a single small capacitor for the fan motor only and wire according to the label on the motor. You have to watch going to too much horse power on a replacement motor since the air flow is designed around the hp of the motor and associated drag on the air flow from the coil.
You need to get to the basics. What is the model number of your unit?
You need to find out exactly what was the RPM and HP of the original motor to start with. Then figure out what you can use from there. BTW exact motor replacements are available for your unit. If all else fails you can call the distributer to find out exactly what motor was in the unit originally.

The reason I am saying this is because your original motor might have been a 825 RPM unit and someone just stuck a 1050 in there as a replacement. Higher HP in that case will cause a problem.

Paul V · Apr 17, 2008, 09:43 AM

The data plate that was laying loose on the floor of the compressor cabinet when I opened it up says I've got a Bryant model # 36-567S Series A, Serial # 15B-841829. I've made e-mail inquiries to several online parts houses for motors & capacitors (including Bryant.com) and they have all indicated that model number is not valid. I assume this unit is ancient, from the rust on it. The data plate doesn't list the fan rpm, just says 3.6 amps full load, 6.1 amps locked rotor, 1/4 horse, 230 volts, 60 hz, single phase. The website I noted above (americanhvacparts.com) says their motor is a "Direct OEM replacement" and that it is "upgraded", and all the vital physical measurements match, so it should bolt right in.

When you say "contact the distributor", are you saying ANY local distributor? I have no idea who installed the thing, since it was here when we bought the house, and there's no local dealer sticker on the thing. And like I said, nobody online seems to be able to verify the model number is valid.

hvac1000 · Apr 17, 2008, 12:12 PM

I also cannot find the model listed. Look up a Bryant distributer in the area you live. They sell the equipment to the dealers and have a record of all model numbers. Other than that I have no idea

Paul V · Apr 17, 2008, 01:59 PM

OK. Thanks for the assistance. I'll see what I can find out.

T-Top · Apr 17, 2008, 07:07 PM

On the older bryant units that was 825 rpm the condenser fan blades would have very little pitch to them and was big(square surface inch). The 1075 motor blades would be small, around 14 inch diameter with a steep pitch and 4 blades.

Paul V · Apr 18, 2008, 01:29 AM

The fan that's on there now is a 3-bladed 20" diameter with fairly steep pitch. Any suggestions for what to do in terms of ordering a motor? Do I need to order a replacement fan as well in order to get the thing to operate properly?

hvac1000 · Apr 18, 2008, 03:42 AM

The fan size is determined by the hole size so to speak. That is due to the air catch surround built into the top of the fan area. If that blade is that big I feel you have a 825 RPM stock motor. The fan blade could have also been replaced with one of a different pitch but not different size unless the hole is way to big for the blade.

Is there a way you can post a picture of the unit from the top and then front of unit. I hate to see you spend $$ for something new and not get the correct one. I always use the model number when ording parts but in this case that will not work.

T-Top · Apr 18, 2008, 04:27 PM

Its hard to say with out seeing the pitch of the blade but it sounds like you may have a 825 motor. A 1075 rpm motor will not last with a 825 blade it will over heat. If you can't find out I would go to a parts house (any hvac supply house) and get a 1075 motor with a 1075 3 blade prop fan and let it run. I would not run a 1/4 hp with that size of blade(20 inch) That's a lot of prop fan for a small 1075 motor.

Paul V · Apr 18, 2008, 09:45 PM

I'm attaching a few pics so you can see what I've got: the dataplate, the outside view of the unit (I laid a yardstick on top to give an idea of the size of the unit), a couple of the inside view (from above) and I tried to get one from directly above to show the pitch of the fan blades relative to the plane of rotation (the wire fan guard is parallel to that plane).

hvac1000 · Apr 19, 2008, 05:55 AM

How clean is that coil? Take a light and see if you can see it from the other side through te fins. That unit is from back in the 60's and if not real clean it will cause high pressure readings on the high side and since the air over the motor is restricted it could also be effecting the fan motor.

I see the mod # on the tag.

I am checking

hvac1000 · Apr 19, 2008, 06:17 AM

Info direct from Bryant.

Just got off the phone

Motor1/4 HP 1050 RPM 230 volt New Bryant part number HC680028.

Fan blade 20 inch diameter 1/2 bore 30 degree pitch 3 blade.

Fan blade NLA BUT one can be made to work using a fan blade replacement comparison chart usually available at electric motor rebuild companies or guess your best.

This info is all that is available.
Best advice from here is to replace the entire A/C system since putting money into something that old is not a smart thing to do. Also you utility bills will be 1/2 the price with a new unit. The old units like this were lucky to have a 4/6 seer rating.

T-Top · Apr 19, 2008, 07:04 AM

You can buy a universal motor 1/4 hp 230 volt 1050 or 1075 rpm. Rotation counter clock wise shaft end. It will need to be a ear mount type motor or you will need to buy a kit with it so it can mount back the same way. Good luck.

Paul V · Apr 19, 2008, 11:40 AM

Ya, I knew this thing was ancient and figured the best thing for the long term would be to buy a new system, but the upfront cost for replacement is a problem for us right now (I'm assuming a new system will run in the neighborhood of $5,000 installed), so I'm hoping I can squeak by until we can afford one. Besides, we use ceiling fans as much as possible to avoid the electric bill this thing runs up, and only turn the thing on when it gets REALLY uncomfortable. In the meantime, I'm hoping to spend less than $300 on parts and have a system that will be able to run when we REALLY need it, until we can afford a new system. I'll take a close look at the coil. Might have to bite the bullet and get financing for a new system.

Thanks for all the advice, guys. Much appreciated.

Paul V · Apr 19, 2008, 11:54 AM

One last thought. If I do buy a new system, I'm thinking it would be a good idea to relocate the condenser unit from its current location (on the patio, east side of the building, near the living room and master bedroom) to the south side of the building (full sun exposure) next to the master bedroom and 2 other bedrooms. Having that hot air from the condenser blowing across the patio (along with the noise) makes for less than hospitable outdoor leisure conditions. As far as I can tell, the only reason it was located on the patio was to minimize the cost of running 230 volt and coolant lines.

Would there be any reason NOT to place a new unit on the south side of the building (it would only add about 20 feet of wire and coolant line through the attic)? We've got about 9 feet of space to the property line/wall on the south side, if that's an issue.