iRV2 Forums

iRV2 Forums (https://www.irv2.com/forums/)
-   RV Systems & Appliances (https://www.irv2.com/forums/f54/)
-   -   Replacing all 3 capacitors on A/C units (https://www.irv2.com/forums/f54/replacing-all-3-capacitors-on-a-c-units-347129.html)

marjoa 06-28-2017 09:20 PM

Replacing all 3 capacitors on A/C units
 
2 Attachment(s)
Final stages of going FT and since our A/C units and capacitors are 5 going on 6 years old, I bought all 3 new capacitors for each unit and plan on replacing them this weekend.

My question is:
To avoid any shock from the existing old capacitors while I'm installing the new ones that are installed now on the A/C units, should I just discharge the existing capacitors by touching the posts with a screwdriver BEFORE I remove the wires one at a time, OR remove the wires one at a time first, place wires on the new capacitors and then discharge the old ones and set them aside?

Dutch Star Don 06-28-2017 10:07 PM

"marjoa"......They could last another ten years. Why not keep them as spares until one of the units quit. If you decide to replace them, transfer the wires first and then discharge the old ones. Shorting them with wires attached could be problematic.

windsorbill 06-28-2017 10:17 PM

Quote:

Originally Posted by marjoa (Post 3672778)
Final stages of going FT and since our A/C units and capacitors are 5 going on 6 years old, I bought all 3 new capacitors for each unit and plan on replacing them this weekend.

My question is:
To avoid any shock from the existing old capacitors while I'm installing the new ones that are installed now on the A/C units, should I just discharge the existing capacitors by touching the posts with a screwdriver BEFORE I remove the wires one at a time, OR remove the wires one at a time first, place wires on the new capacitors and then discharge the old ones and set them aside?

Mine are still going strong and they are the originals. Why not just keep spares for now?

CJ7365 06-28-2017 10:26 PM

Quote:

Originally Posted by Dutch Star Don (Post 3672867)
"marjoa"......They could last another ten years. Why not keep them as spares until one of the units quit. If you decide to replace them, transfer the wires first and then discharge the old ones. Shorting them with wires attached could be problematic.

I am no expert at electricity, but I was under the impression you should discharge the capacitors before touching/disconnecting the wires, that would prevent you from being shocked, I understand about the possible problem with discharging them when attached.


Agree with everyone else as leaving them in place, until you need one. Just my opinion, replacing capacitors are not preventive maintenance, but having them on hand is a smart thing.

spyderRV 06-29-2017 03:24 AM

If you are worried about them failing, get a set to replace them as a backup and go by the theory, "If it's working, don't fart with it".

https://c1.staticflickr.com/5/4164/3...dbc1078d_b.jpg

marjoa 06-29-2017 05:35 AM

Ok, ok I leave them as spares for now. But hey, I still need to know how to change them out when they do go bad.

So my original question still stands.

Bilgerat 06-29-2017 05:46 AM

I was told the same thing, if it's not broke... Good advice.
Here is a video that was shared on here a few months ago, long but gives a lot of information.


https://www.youtube.com/watch?v=soP0uZFd0nQ

ransil 06-29-2017 05:53 AM

Yes short them with a screwdriver before touching them, obviously disconnected from shore power and do not run the generator

marjoa 06-29-2017 06:33 AM

Great video to understand how the A/C works and draws power to different sources and how to run A/C with a under sized generator. Not helpful though in my situation. Thanks for the link.

Bigd9 06-29-2017 07:28 AM

Quote:

Originally Posted by spyderRV (Post 3673074)
If you are worried about them failing, get a set to replace them as a backup and go by the theory, "If it's working, don't fart with it".

https://c1.staticflickr.com/5/4164/3...dbc1078d_b.jpg

I love it! Wish I had that when I was in the working world!

Waiter21 06-29-2017 07:33 AM

Make sure there is no AC power in the coach.

Use your screwdriver or a short jumper wire and short across the terminals and short to the can. You may or may not get a spark. This will discharge the capacitors and you should be able to handle them safely.

When I do a time change on any components, i.e. capacitors, starter, alternator, water pumps, hoses, plugs, etc. I always keep the old part in my spare parts box. This guarantees I will never need it. :thumb: :thumb:

Mudfrog 06-29-2017 08:16 AM

Quote:

Originally Posted by marjoa (Post 3673105)
Ok, ok I leave them as spares for now. But hey, I still need to know how to change them out when they do go bad.

So my original question still stands.

I've always discharged capacitors before removing any wiring. Never had a problem doing it this way. One thing's for sure, doing it first certainly reduces the risk of me inadvertently getting the discharge. :thumb:

Playtime III 06-29-2017 09:10 AM

Flashback to autoshop class. Working car engines mounted on stands. Adjusting the timing by twisting the distributor cap while your partner pointed the timing gun at the flywheel. Twisting was fine until I put my other hand on the engine mount stand. I swear I can still taste the metal fillings in my teeth.

Deep Water D 06-29-2017 09:15 AM

For future reference, discharging a capacitor with a screwdriver is not the correct way to do it. Using a screwdriver can destroy the capacitor and/or cause personal injury. The correct today is with a bleeder resistor. I have a 10K ohm resistor with alligator clip leads for discharging capacitors.

Bigd9 06-29-2017 09:42 AM

Quote:

Originally Posted by Playtime III (Post 3673365)
Flashback to autoshop class. Working car engines mounted on stands. Adjusting the timing by twisting the distributor cap while your partner pointed the timing gun at the flywheel. Twisting was fine until I put my other hand on the engine mount stand. I swear I can still taste the metal fillings in my teeth.

Oh those were the days! The wire coming from the coil to the distributer seemed to always be "porous" causing the capacitor charge to leak out into whatever unsuspecting human was leaning over and getting too close to it. I still have a dent in the top of my head when I got zapped by that coil wire and my head shot up and impacted the stupid hood hold down latch pin that looked like a bullet pointing down! Till this day I have a healthy respect for any capacitor.

cruzbill 06-29-2017 10:38 AM

Dometic says to use a VOM set to 500v or higher range. Black to one wire, then touch red lead to other wires one at a time. Don't need a fall from 13' up on an RV roof!

Matfam1 06-29-2017 11:16 AM

As a professional HVAC tech for 25 years... I verify no power to the unit, phase to phase and phase to ground. Then short the caps using pliers or a screwdriver. Replace them one wire at a time. Do not save them as spares, buy a new set of spares if you are worried about it. Capacitors are cheap, compressors and fan motors are not.


All times are GMT -6. The time now is 04:10 AM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.