Like I said, I've never seen a cap in an AC contactor, which is just a relay, nor can I see any electrical design issue where one would be useful. An MOV surge protector, that might be there. And if you don't understand what you're working on, you shouldn't be screwing around there to begin with.
On Fri, 27 Aug 2021 07:28:31 -0700 (PDT), trader_4 posted for all of us to digest...
arc, no matter how small, occurring while dealing with a capacitor that is deemed ?deadly? in many forums and comments sections is enough to strike fear. The whole point was to describe a safe situation for the diy?ers. Its weird to see a statement such as ?So What? from a professional such as you.
This person is talking about the start cap for the fan & compressor, I presume.
Tremendous advice! For crying out loud, I don’t think any of the DIY’ers are professional who know exactly what they’re doing like a professional. I’ve seen situations where even MOVs have failed due to sustained over voltage. I don’t even know why you’d mention that. What a downer. Most of us are just trying to be helpful and yield cautionary measures for those that are bound to try to do some things on their own.
Anyway, yes Tekkie it is the start cap for the fan.
But the poster said it's a 24V cap, that it's humming without the unit running. Aside from the fact that caps don't hum, the fan and compressor are not 24V.
I mentioned it because you posted this:
"I too experienced a similar situation where the AC breaker was switched off and the disconnect pulled out yet a buzzing sound wad heard around the capacitor area. Turned out to be that the THERMOSTAT was still left on AUTO and was sending a signal to the switch next to the capacitor hence the buzzing!! Granted, it is low voltage in it being a 24v signal, but still when you?re dealing with capacitors that could potentially arc up and cause serious damage, the last thing you want is mistakes."
You dragged an alleged 24V cap into a two year old thread. I simply pointed out that it was likely the contactor coil making the humming sound, that a cap on the contactor circuit doesn't make sense and if there was some component at the contactor that looked like a cap, maybe it was an MOV surge protector. And it's called a contactor or relay, not a switch.
And yet you call an AC contactor, which is a relay, a switch and talk about discharging
24V caps that don't exist. I raised the issue that a 24V cap doesn't make any sense and you continued on the path of the mythical 24V cap. Now you say it's actually the fan motor cap, which isn't a 24V cap.Man you’re intent on being that guy, and succeeding well at it too. First of all I actually re-read my initial post trying to figure out whether you were misreading things or that I was erroneous. Low n behold, not once did I ever write anything about a 24V cap, NOR did I miswrite about an AC Contactor (or relay) being a switch. I WROTE THAT THERE WAS A BUZZ (at the contactor which happens to be right next to the capacitor) and that THE SWITCH (as in the switch at the thermostat) WAS STILL ON and hence the signal causing the buzz at the contractor. You read that wrong bud. Make an appointment at LensCrafters and again, stop being a genitalia. Best of luck to you. Oh one last thing, its not a 2 year old post either, it actually spans back 14 years. You must misread a lot of things. ✌️
By becoming one, yourself? Five or six years of training.
gincali, thank you! Your response is a big help. I diagnosed that my AC unit needs a capacitor. I watched quite a few videos and was pretty confident I could do this job myself, however not confident enough I took my neighbor’s for help. My husband was robbed & murdered abroad and I feel I need to learn to do the things he used to do (I don’t have the luxury to call the pros for every little job & I feel good about learning to do some of these jobs). I went out to my AC unit, removed the fuses from the disconnect box as (video said do this or switch off circuit breaker). As my neighbor watched (he is not an electrician & I could see he was not comfortable at assisting in my project). I removed the screws from the cover with my 5/16 socket. The next step the video said to do was: to insure the run capacitor is discharged, place a screw driver with with an insulated handle along both sets of terminals. That’s when everything came to a halt. Because we could hear the buzzing, which meant there was still electricity running to it. I took a photo of the capacitor I needed to order, & I put everything back together again. Since then I’ve been searching for the answer to my question - if the fuse box is off, what is powering the buzzing sound. That was not addressed in any of the videos I watched. So thank you. I will turn the fan off from the thermostat, a d that should tell AC unit outside not to attempt to turn on, right? I am not holding anyone responsible.
On Sat, 04 Jun 2022 00:31:42 +0000, Peppermint Patti posted for all of us to digest...
used to do (I don�t have the luxury to call the pros for every little job & I feel good about learning to do some of these jobs). I went out to my AC unit, removed the fuses from the disconnect box as (video said do this or switch off circuit breaker). As my neighbor watched (he is not an electrician & I could see he was not comfortable at assisting in my project). I removed the screws from the cover with my 5/16 socket. The next step the video said to do was: to insure the run capacitor is discharged, place a screw driver with with an insulated handle along both sets of terminals. That�s when everything came to a halt. Because we could hear the buzzing, which meant there was still electricity running to it. I took a photo of the capacitor I needed to order, & I put everything back together again. Since then I�ve been searching for the answer to my question - if the fuse box is off, what is powering the buzzing sound. That was not addressed in any of the videos I watched. So thank you. I will turn the fan off from the thermostat, a d that should tell AC unit outside not to attempt to turn on, right? I am not holding anyone responsible.
The buzzing is most likely from the contactor. That is energized by the transformer in the evaporater (inside) section. The power for that is not disconnected by the outside box. The inside unit should have it's own disconnect-which may be a simple switch-depending on it's electrical load. Just flip the breaker and you should be able to proceed.
Thank you! I’m still at it. I had hoped I wouldn’t have to call the pros. As I mentioned my husband was killed not too long ago and not only do I have to be self sufficient, I also like to learn & challenge myself. I’m in the process of replacing my capacitor on my AC. I ordered exact part for the unit; however the capacitor that’s in my unit now has 3 connectors: C-has 4 tines- 1 tine connected to yellow wire, 1 tine connected to black wire leading to Hard Start. Therm - has 3 tines -1 tine connected to blue wire & 1 tine connected to black wire also leading to Hard Start. Fan - has 1 tine and no wires are connected to it. Also found that my AC unit has 2 extra pieces: An “A -1 component Hard Start multiplier WSX -8 A”= 2 black wires - 1 connected to C other connected to Therm on existing capacitor. After more research I found that the other piece (squarish small box starting to rust at the bottom) is a small run capacitor. My challenge is starting to overwhelm me! You guys are all awesome and I’ve learned a lot from your videos. Any suggestions would be greatly appreciated. Btw - I purchased a tester to test capacitor. I just watched learned video that if one has a dual capacitor you can do away with the small start capacitor - but wiring is different. I’m not sure if I should just connect exactly as is, replace small run capacitor too or should I try to eliminate the run capacitor and how? I purchased a tester. Is it possible to I check the small rusting run capacitor while it’s on the AC unit outside, all power is off, top of capacitor is all wrapped up in black tape? Thanks again!
Some excellent HVAC training videos
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And the power to the coil of the contactor is 24V, so it's low voltage. If she wants to turn it off, switch off the furnace or air handler inside.
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