Capacitor replacement

[DanSTL]

I’ve got a carrier AC model 68RV14103A which is original to my 2009 2720 and recently the AC won’t run more than a minute before tripping the 20amp breaker in my converter (WFCO) both at home on 20A and on 30 Amps. I use a 30 foot 10 gauge wire powering RV and a 12 guage pigtail converting from 30amp extension to 20A wall socket in my garage (no extension cord).

I’ve opened up the AC and all appears normal but looking to replace my dual capacitor (it's a dual 45/12 microfarad). Tried taking closeup pics of the capacitor which is testing good. AC still runs on fan and worked great before a power surge at a COE site (but I had a surge protector) in early May, so hoping it’s an easy fix of a capacitor, heat overload or something else.

Description of what happens

AC tested with killawatt device at home (20A) here’s what I found.
1. Amp draw goes up to about 14.23 Amp when I first turn on AC on low fan, high fan, low cool and
2. spiked up to 18.2 amp when I flip switch AC to “on”, then hovers there but after about about 1 minute
3. Shoots up to just over 22 Amp RIGHT before the WFCO 20amp breaker switches it off.

Tried on 30 amp and had similar issues. Next- I have a 60/12micorfarad capacitor on way to replace my 45/12, even though it still reads "good." I also tested resistance on my compressor and it appears normal (A= B + C)

[Wavery]

Hope these pics help.

I just installed a SPP6E Hard Start Capacitor in my A/C. I had to add about 12" of wire to the SPP6E and install it in the pan under the condenser fan.

[DanSTL]

Originally Posted by Wavery

Hope these pics help.

I just installed a SPP6E Hard Start Capacitor in my A/C. I had to add about 12" of wire to the SPP6E and install it in the pan under the condenser fan.

Wayne this is very helpful thanks. I’m hoping to find the replacement 2 in 1 capacitor but if not will try for the same fix based on your pics and steps!

Can you clarify- does the SPP6E get added to the failing 2 in 1 or does it just replace it? Given the way you had to install it, seems it’s an add on but not sure. If it’s an Add on to the 2 in 1 , does it just only substitute the failing start capacitor? Or does it completely replace the 2 in 1 capacitor with this single SPP6E? Thanks again

[Shane826]

Wayne- What’s the difference between a hard start and a soft start?

[Wavery]

Originally Posted by DanSTL

Wayne this is very helpful thanks. I’m hoping to find the replacement 3 in 1 capacitor but if not will try for the same fix based on your pics and steps!

Can you clarify- does the SPP6E get added to the failing 3 in one or does it just replace it? Given the way you had to install it, seems it’s an add on but not sure. If it’s an Add on to the 3 in 1 , does it just only substitute the failing start capacitor? Or does it completely replace the 3 in 1 capacitor with this single SPP6E? Thanks again

Sorry, I was in a hurry when I posted that. Be sure that your camper is unplugged from 110V power for several hours before attempting this repair or you could get a pretty good shock.

The SPP6E is an add-on "Hard Start" capacitor that adds a jolt of electricity through the original failing "Run capacitor". In this system, both capacitors are in one can but they have 3 separate terminals (1 ground for both). I'm not sure how that works but the 2-terminals that you want to add your connectors to (from the new SPP6E) are the one with blue wires on it and the one with red & white wires on it. Each of those terminals already has an extra connector for you to plug your wires on to. Leave the terminal with brown wires alone. It doesn't matter which wire from the SPP6E goes to which of those 2 terminals.

I mounted my SPP6E on the pan, under the big round condenser fan, as shown in the picture. I laid a couple of zip ties flat on the pan, then I took a flat piece of aluminum (about 1"x4") and drilled 2 small holes in it. I then screwed it into the pan with the zip ties trapped under that piece of metal. I then laid the SPP6E on top of that piece of metal and wrapped the zip ties around it.

The wires on the SPP6E are not long enough to reach the old capacitor terminals so I spliced in 12" piece of 16awg wire to each wire on the new SPP6E. Then I ran the wires as shown in the picture.

If you can find a replacement for the original capacitor, you may want to do that. I was not able to find one and this job was fairly simple. More importantly, it worked.

EDIT: 3-in-one was an error on my part. It's a 2 in 1 with 3 terminals. The 2 share a common ground (3rd terminal).

[Wavery]

Originally Posted by Shane826

Wayne- What’s the difference between a hard start and a soft start?

The "Hard start" capacitor does the same job (plus a little) as the original capacitor, which is a sudden jolt of power to get the motor in the compressor to overcome the initial surge that it needs to get started. The capacitor depletes it's entire charge in a fraction of a second, them slowly recharges itself for the next time that the compressor cycles.

The "Soft Start" module slowly increases the available amperage to the air conditioner making it easier (but a little longer) to start. It's more of a voltage stabilizer with excess amperage capacity for sudden demand.

The theory is that "the soft" will be easier on the air conditioner electronics than the jolt from a capacitor. For ME...... I can buy a lot of "Hard start" capacitors and for as little as I use MY air conditioner, I'm not too concerned about the effect that the "Hard Start" capacitor will have on longevity.

[DanSTL]

Originally Posted by Wavery

Sorry, I was in a hurry when I posted that. Be sure that your camper is unplugged from 110V power for several hours before attempting this repair or you could get a pretty good shock.

The SPP6E is an add-on "Hard Start" capacitor that adds a jolt of electricity through the original failing "Run capacitor". In this system, both capacitors are in one can but they have 3 separate terminals (1 ground for both). I'm not sure how that works but the 2-terminals that you want to add your connectors to (from the new SPP6E) are the one with blue wires on it and the one with red & white wires on it. Each of those terminals already has an extra connector for you to plug your wires on to. Leave the terminal with brown wires alone. It doesn't matter which wire from the SPP6E goes to which of those 2 terminals.

I mounted my SPP6E on the pan, under the big round condenser fan, as shown in the picture. I laid a couple of zip ties flat on the pan, then I took a flat piece of aluminum (about 1"x4") and drilled 2 small holes in it. I then screwed it into the pan with the zip ties trapped under that piece of metal. I then laid the SPP6E on top of that piece of metal and wrapped the zip ties around it.

The wires on the SPP6E are not long enough to reach the old capacitor terminals so I spliced in 12" piece of 16awg wire to each wire on the new SPP6E. Then I ran the wires as shown in the picture.

If you can find a replacement for the original capacitor, you may want to do that. I was not able to find one and this job was fairly simple. More importantly, it worked.

EDIT: 3-in-one was an error on my part. It's a 2 in 1 with 3 terminals. The 2 share a common ground (3rd terminal).

Thanks ! So I’m hoping I can find a replacement and also struggling, though my old capacitor is a little different than yours.

Does anyone know if it’s okay or how risky it is to use a 45/5 uF to replace the 45/12uF that’s failing ? This 45/5 fits but believe the 2nd number is for the fan and possibly too low at 5uF vs 12.

If I can’t find a 45/12 that fits (low profile AC has a tight sleeve it must slide into at under 2 inches diameter) can I use something with higher capacity like 45/15uF or even 50/15?

[Wavery]

Originally Posted by DanSTL

Thanks ! So I’m hoping I can find a replacement and also struggling, though my old capacitor is a little different than yours.

Does anyone know if it’s okay or how risky it is to use a 45/5 uF to replace the 45/12uF that’s failing ? This 45/5 fits but believe the 2nd number is for the fan and possibly too low at 5uF vs 12.

If I can’t find a 45/12 that fits (low profile AC has a tight sleeve it must slide into at under 2 inches diameter) can I use something with higher capacity like 45/15uF or even 50/15?

https://getrvparts.com/dometic-air-c...pacitor-45-10/

[Bill]

I'm a little unclear about why you would connect a new capacitor in parallel with one that is failed or failing. Isn't that asking for a future problem? Or have I missed something? When I did this several years ago, I simply removed the old capacitor and mounted the replacement in its place.

Bill

[Wavery]

Originally Posted by Bill

I'm a little unclear about why you would connect a new capacitor in parallel with one that is failed or failing. Isn't that asking for a future problem? Or have I missed something? When I did this several years ago, I simply removed the old capacitor and mounted the replacement in its place.

Bill

Fair question. The first time that I had a capacitor issue was in the central A/C system in my home about 20 years ago. The technician came out and diagnosed the issue and told me that the compressor was good but the run capacitor was bad and that is the problem about 90% of the time. He replaced the old capacitor with a new one and all was good (and still is).

Fast forward to 2011. The A/C on my 2004 TrailManor displayed similar symptoms. I purchased an identical replacement, installed it and the A/C started but made a terrible noise at start-up. I did a little research and found the SPP6 Hard Start capacitor and bought it. I installed it in parallel (as per instructions) with the new capacitor and the A/C started as new. After doing a little more research, I found that it really wasn't just the capacitor that failed, it was a combination of a weak capacitor and an aging compressor.

The SPP6 puts out about 5x the boost of the original capacitor and that was what my A/C (and several others that I've replaced) needed. I haven't heard of any negative effects from the stronger boost, although, I would suspect that a compressor that is experiencing hard start issues may suffer an early retirement anyway. Although, what does that mean in an RV A/C unit? I don't know about others but we only use our A/C a few times a year and if the Hard Start capacitor extends the life of the compressor for say 100 hours, that would me several years for me.