How to Check Amperage on Compressor and Fan Motor
ฝัง
- เผยแพร่เมื่อ 12 ก.ย. 2024
- This will be great in allowing you to determine if the amp draw on your compressor is causing your breaker to trip. I also included the amp draw test for the condenser fan motor. Always refer to the specs on your compressor to determine the proper amp draw for your specific system which is usually located on the identification plate on the compressor itself. When checking specs for condenser fan motor you will find the specs on the fan motor itself.
Thanks for demonstrating this test! People, do yourselves a favor and buy a clamp multimeter. It only cost about $25 on Amazon and could save you thousands! I had two HVAC technicians come over and test our compressor and they both told us that it was drawing over 30 amps which means it's about to die and needs to be replaced asap! The quoted us $13,000 for a new system. What they failed to mention is that the reason the compressor was drawing so much power is because the capacitor was bad. I had it replaced myself for $20 and then used my own multimeter to test the amps. What do you know, it was drawing 18 amps! Be careful, there are a lot of HVAC scammers out there! They all want to make money on account of your ignorance! Don't let them do it. Get educated and fix things yourselves whenever possible!
Good video right here and good explaining just wish you would have shown what was the amp draw asking for in the diagram
You should be an instructor, Sam, awesome tutorials, very informative.
In case anyone is watching and wondering like I was, he's working on a 5 ton unit hence the higher than you would expect in-rush and running current. The spec is actually 165 and 28.9 amps respectively for that particular unit. For comparison, I have a 3 ton unit and my in-rush is supposed to be 82 and 16.1. His meter is not capable of reliably measuring in-rush amps btw.
One clarification. To check the start up draw or so called inrush you have to have a clamp with the inrush fuction. MinMax function is not fast enough.
I’m glad to see this was 5 years ago and if you stuck too it I know you have gained the experience necessary since this video.
Your amp drawl should be read if your testing the starting or running amps of compressor would always be at the in line that feeds cap and compressor as well as fan 👍🏼
Not the L2 which coming from said components
Now if the starting amps which I’m sure you know by now your meter has a feature that if set will record max amperage should never exceed more than 80 in any residential circumstance. In that case you would know that the windings of the compressor are are going bad and you need to add a hard start kit to the system to increase the life expectancy of said compressor. But great video though don’t know why algorithms showed me a five year old video but I’m confident you’ve progressed since 🙌🏼 great start
Sam great video but for education purpose the amp reading you always have to take it from the C wire from the compressor or CFM
All single phase motors we want to take amperage readings from the common right?
Negative!!!!!!!!! I’ve been in the industry for 13 years and take pride in my work and knowledge and no the amp draw is taken from the L1 or the line going into the components as that is where power is being drawn from before it is powering anything and cfm refers to cubic feet per minute and that’s referring to air speed nothing to do with electricity
@@brandonh2993
Thank you for the replay I really appreciate it but talking about motor if you know how to read schematics cfm refers to condenser fan motor , if you talking about airflow refers to cubic feet per minute , the common wire on any single face motor it’s the highest amperage reading and that’s what you have to take in consideration, I’m so glad you have 13 years in the trade and I’m glad you feel pride of your job , I have 25 years in the trade and I’m glad I’m still learning it’s a never learning trade . You have a great day college 🤟🏻
@@antoniovallejo337 the schematics refer to condenser fan motor as outdoor fan motor or OFM. CFM is airflow.
Good explain. Are u a general contractor ? U sound like u know stuff very well.
You said there is no other way to know when compressor is running. That is incorrect. There are many other ways to tell if compressor is running. 3 to mention below. First it is loud and your can hear it. Second you can touch the suction line and if it’s cold means compressor is running. Third you can disconnect the fan from capacitor and just hear for compressor if it’s hard to listen with fan on.
When training technicians simply doing the things you stated will not suffice. Here is a real life example. I had a technician call me. He said that a compressor needed to be replaced. I asked him the 3 questions. Did you put your guages on? He responded no. The next question... Do you hear the compressor starting/running? He stated no. The next question I asked was the low side line cold... he stated no. I arrived on site connected my guages and sure enough the compressor was running however it had little to no refrigerant. Just enough so that on start up I observed the needles on my guages move slightly The reason the line was not cold... the reason the compressor did not sound as if it was on... was because their was no refrigerant. The only way to truly determine if your compressor is running is to connect your guages... check incoming voltage and outgoing voltage to the compressor... as well as do a amp draw. I admit for years this was the technique I used... grabbing line and listening for the compressor however I realized implementing this for training purposes is not only inefficient but dangerous. Tools are needed to properly evaluate and troubleshoot the compressor... simply relying on your senses such as touch and hearing are not sufficient. With that being said I do agree if you have a service call... you can utilize this method... grab line is it cold? Do you hear compressor running? However if you run into an issue with low refrigerant... this method will not work. In this case the compressor was working and replacing shrader valves and charging the system solved the issue. I say this to say that I am constantly growing and learning every day... this was one lesson I realized was not ideal in regards to training purposes. Hope this helps friend 🙂
I had a compressor that was extremely low on refrigerant. Therefore the compressor was extremely quiet. That led to the next point... the lines were not cold...
Sam ok yeah that’s a good example and I see your point now. Checking the amps is definitely hands down the best way to determine if any electrical component is running agree but I still have to come across that situation you just explained. Interesting. Thanks for sharing bro.
good camera work, good information and explanation, keep it up.
Anthony Jeselnik does HVAC videos? Nice!
Thanks for the video, and in particular for mentioning not to measure both wires at once. Explains why my measurements were off =)
Superb info! Thank you very much for taking the time to share it with us!
I guess the Klein tool doesn’t record maximum draw? My 4 ton unit had a max of 80 amps on each leg at the circuit breaker at the panel and 17.5 amps on each leg steady state running. Fluke 87V. Thanks for the video.
O yes CL 900 Klein multi meter, in rush and running no problem.
how do you now how much amps should be? does it say in plate?
Yes you are correct! Thank you for watching!
Did you show what the compressor amp load max is? Is it on the compressor or the data sticker? You just showed the amperage but was it ok or too high etc?
Yeah! Good job explaining 👍
I assure you, if you don't have any refrigerant, your condenser will NOT sound like it's off. If you can't hear the difference, go back to school. I learned everything in the field - no schooling - best education of my life
Who cares. He did a good video of how to check amperage.
Hi Sam, thank you for the vid. How do you know what the running amps should be?
Good job man. I like your videos!
What are the three amperage readings that we are supposed to get on a good compressor from common start run as far as numbers?
Title says fan motor, did not see that tested.
Good vid, I have the same meter.
I'm guessing there's no way to check the microfarads with the same meter?
There is no function on the meter to check microfarads. Still you can check the cap with this meter (under load). As long as the compresor and/or fan will turn on. With that being said if the cap is dead the fan/compressor wont turn on and you wont be able to use this method.
check the amps on the wire connected to the fan terminal on the cap. Then check the amps on the wire connected to the herm terminal on the cap. Now, check the voltage from common to fan and then common to herm. Once you have that info just use this formula
2650 x amps/volts= uf
😉
How do you know youre getting the proper amps not just amps in general and what is the LRA on the unit
Thank you sir! Well described!
148.3 amps at start up?
so black and yellow wire had different amp, which one is real compressor amp
Whichever one goes into the compressor color of wire doesn't matter
The common wire is the reading you want to check. Typically the side of the contactor that has wires that are the same color (not the black wires)
When do you recommended to add a kick start to the compressor?
Hard start kit, or just a bigger capacitor
When your locked rotor amps are drawing above what it's rated for.
A hard start kit wont save your comressor and it will only reduce abot 25% of the initial start. You'd better invest in a soft starter like EasyStart from Micro Air or Hyper Engineering.
Thanks, I'm learning.....
I saw 148 amps on start up.
Just check it inside the disconnect box using each lead. A lot quicker.
Thank you!
Very clear, thanks
If I don't have th eClamp Meter, where do I connect the wires from the meter? JUst where they connect to the termicals on each end?
Sam I notice your meter is like mine. It isn't designed for hvac. Is there a way to.check the capacitor with the meter you are using?
If the multimeter can test capacitors, it will have a setting marked "capacitance" or "MFD" on the selector. Some may have a "uF" symbol. This meter does not have this setting.
Ok
Just curious as to what causes low amps on a condenser fan motor?
Good question. Unfortunately nobody ever gave a fk to answer . Have u ever found out ?
@@sagemaster3408 pretty sure because it’s not designed to do as much work as the compressor. Compressor has to move refrigerant, a fan motor has to spin a fan.
Not causes low amps it just is lower in amperage by nature of the motor. Fan motor amps 1-4 , compressor 8-18
and what is too much amp draw how to determine
So quick question what amps does it read when you have a bad compressor ?
The panel in the condenser , shows you the LRA. If the start up amps are higher , I would recommend a hard start kit. To check for bad compressor just test the compressor terminal.
what happend if the amp in the comp is 10.97 and the RLA is 20.3
What about on a RTU , do i check AMP for my CF on a capacitor or from the contractor , i’m not sure which place is the correct place to check the amperage, both read different amps as well
Did you ever get an answer
@@roboo8460 no but it is from the contactor that’s the best place
Testing fan motor amps right off the cap…?
As someone with no experience I still don't know if the Fan and Compressor were good because you didn't say what amperage you were looking for. You can't just assume everyone know what amps it should be or where to find that information. Would have been great to show the plate info first.
I agree. Showing the plate would of been great.
Im pretty sure its HERM... not erm!!! Great video though
hermetically sealed compressor/motor. hard H when pronouncing.