I have a question for you. When you are testing the load on a condenser what are your parameters for checking. Do you go off the manufacturer’s data plate.
I guess since I have never used a clamp meter or tested a condenser with one I was just curious how you went about testing.
There is a rating on the nameplate for compressor and fan motor.
Note: The compressor will run at all different loads and the amp draw will change all over the place as well.
There are name plates on all motors and compressors themselves as well.
There are three wires (legs) going to a single phase compressor; common, start & run. The amperage in not going to be the same threw all three legs (so you must select your wires wisely).
Three phase (three wire) compressors should have a balanced load across all three.
None of the amp readings should exceed nameplate.
http://www.amprobe.com/cgi-bin/pdc/viewprod.cgi?pid=2171&tid=main_e&type=elec
I have the older version but works the same , I have all attachments also comes in handy if you need them
There are no “hard and fast” rules when checking condensers. But generally, you should expect the condenser to be drawing 60% to 75% of its maximum circuit rating. Higher draws may indicate that the unit is working to hard and may be near to failing.
Lower draws may indicate that the system is low on refrigerant, and the compressor is not working hard at all.
In any event, you should never rely solely on the readings of your meter. As with most meters/equipment, you should be looking and/or listening for other indicators that there are problems with the system.
Thanks for the info guys
That is fairly outside a generalist inspection wouldn’t you say? What would be your next step when discovering a high amp reading?
It’s just an indicator Joe. A unit with an excessive load could mean the compressor is failing or nearing the end of its useful life.
Often in these cases, I will stress the importance (in writing) of keeping a home-warranty plan in place, to cover the “likely” event that the unit may fail in the very near future.
It’s just an indicator. A unit with an excessive load could mean the compressor is failing or nearing the end of its useful life.
Excellent point. It can be very helpful in warding off that call ‘you inspected my AC unit and said it was workig. I moved in and the compressor died.’ That reading has helped me and probably saved me grief many times. If the fan is easily accessible, I will also take a reading on that too. It is listed on the labe.
I had that exact phrase used against me in a Lawsuit. I no longer mention Warranty companies in my report.
Can you elaborate on this Brian? What was their argument?
Its none of my business but I got this from another site and it might be worth considering:
RLA: Acronym for “rated load amps”. The maximum current a compressor should draw under any operating conditions. Often mistakenly called running load amps which leads people to believe, incorrectly, that the compressor should always pull these amps. You should never use the listed RLA to determine if the compressor is running properly or to condemn a compressor. The running amps of a compressor are determined by the evaporator temperature, condensing temperature and the line voltage.
FLA - Full Load Amps: Changed in 1976 to “RLA - Rated Load Amps”.
Here’s a link to more definitions.
The whole lengthy ordeal is in the legal thread, but in a nutshell: 20 year old package I reported past it’s useful life, it worked at the time of the inspection (I now report that it should be serviced). Also I reported client should keep a home warranty in place,
Unit dies, warranty company sends out guys, they say unit was not repaired properly previously and deny claim. Turns out seller tuned up unit before inspection. Client calls Realtor, Realtor tells her to keep quiet so you do not ruin things. :(:shock:
Long story short by the time I was notified of this fustercluck the client had an Attorney. I was dragged into a Lawsuit with 10 or 11 others. The group as a whole settled for a LARGE sum, mine not so large.
What I learned is as a HI is it turns out I do not have many friends in the business world, including my insurance company and attorney, it is business, period. I am better served if I control my own destiny and will not ever mention a warranty company again.
Amprobe RS-3, RS-3A, and RS-1000
Huh?..I thought FLA stood for the Fan load amps. Look at an AC data plate and you will still see FLA and RLA…I was always taught with the system running you would take the RLA and the FLA and add them together for the max rated load amps and I agree with Mr. Pope and it should be running about 75% or less of that. IE the Fla is about 1.9 and the RLA is about 14.7 which means max amps is 16.6…Hopefully this is correct
Standard Amprobe
Looks like there is an old FLA and a new FLA. Agreed that FLA can be found on most plates and refers to fan amps.
Whether inspectors should be checking amps is another matter. Too much info for too little money IMHO.
Personally…my view is I dont see a real reason for any HI’s to take on the increased liability. Even at the neglect of the installer who did it, it is beyond the scope to venture into this level of detail. However, this is only my opinion and does not in any way mean I am right or wrong…only that I am opininionated.
I agree - I almost never check the actual load on any appliance during a home inspection unless I run across something really unusual - then I normally do it only to satisfy my own curiousity. On the other hand, if the client would like me to perform an engineering evaluation of the electrical system, I can do that, but at substantailly higher cost. 