Your Opinion Please....

imchud

Well-known member
I pulled my Rig off site for the season:( we had a small amount of work to be done before we store it for the winter. One of the issues was my A/C unit, the compressor kept cycling on and off to much. The dealer called today and told me that it was a bad "capacitor", which they are in the process of replacing. Now for the question... He told me one of the main reasons a capacitor would go bad is because of "air flow restriction" - He thought because I did the Air Flow Modification (that was a big hit on this site) with the air dirverter, caused to much air restriction and burned out the capacitor, please let me know what your opinion is, thanks.

Tommy
 

jimtoo

Moderator
I'm not an A/C expert, but the capacitor is used only for starting the compressor. It stores extra juice to kick the compressor off when it starts and needs a little help to get things going. I do not think the mods that have been made would have anything to do with it. Too many have been made with no bad reports.

Jim M
 

nscaler2

Well-known member
Tommy,
We have had the tent in the vent mod since the summer of 2006. We have suffered NO ill affects from it. Maybe I am wrong, but since it creates better airflow down each of the main ducts, instead of the air just rumbling around in the plenum, I would think that it would actually be good for the air conditioner. Anyway we sure like it, and it hasn't hurt ours.
 

Bob&Patty

Founders of SoCal Chapter
Sounds like a good fish story to me. I did the "tent-in-a-vent" and it hasn't hurt mine. JMHO..............Bob:D
 

2010augusta

Well-known member
I can't say much as we just use the rapid cool (chill grill) vent most of the time, but the "goods are being cooled by the intake air, I would say that a dirty filter or a dirty evaporator would have more ill effects than the tent in the vent.
 

Ray LeTourneau

Senior Member - Past Moderator
I also have the (should be patented) tent in the vent mod on our main a/c along with mods to the vents themselved to direct flow into the room instead of past the vent to a dead end duct. We have had no ill effects from the modification. In fact, it was 95 here in So. Cal. today and we maintained 75 inside with one a/c. We have the bedroom a/c but rarely use it.
 

mrcomer

Past Ohio Chapter Leaders (Founding)
Absolutely not! Just like jimtoo said, it is only to start the compressor, this has nothing to do with air restriction. They are feeding you poopoo.
 

jmaguire

Well-known member
I am a Licensed Master HVAC Mechanic, and I teach HVAC in Maryland. Since I am not there and looking at the unit it is hard to tell if someone is lying or just doesn't really know the truth. The capacitor you have in your A.C. is used to change the capacitance of the motor making it more efficient to run. It has nothing to do with the airflow. If that capacitor was bad the compressor would most likely not run at all. I have never seen a bad cap. causing the compressor to short cycle. Capacitors can act similar to fuses in that they can go bad with electrical issues like brown outs and electrical spikes. You most likely do not have a start capacitor, but rather a run capacitor which is in the circuit the entire time the unit is running. If you have a short cycling situation and the fan and the compressor are going on and off together than it almost has to be the thermostat bringing the unit off and on. Again, without being there and seeing for myself it is hard to question what anyone is telling you. Let me know exactly what was going on and I will be glad to offer any advice. John
 

westxsrt10

Perfict Senior Member
Jimtoo.....is correct! It's not the capacitor. You might try aiming the vents so air flow dosnt hit the thermostat or install a clear vented cover over the thermostat controls to stop the short cycling.
 

timdebs

Well-known member
My a/c was doing the same thing, compressor was cycling on and off even when the thermostat was cut off. Took it to a Dometic Tech and the control was bad, he replaced and have not had the problem since.
 

imchud

Well-known member
I am a Licensed Master HVAC Mechanic, and I teach HVAC in Maryland. Since I am not there and looking at the unit it is hard to tell if someone is lying or just doesn't really know the truth. The capacitor you have in your A.C. is used to change the capacitance of the motor making it more efficient to run. It has nothing to do with the airflow. If that capacitor was bad the compressor would most likely not run at all. I have never seen a bad cap. causing the compressor to short cycle. Capacitors can act similar to fuses in that they can go bad with electrical issues like brown outs and electrical spikes. You most likely do not have a start capacitor, but rather a run capacitor which is in the circuit the entire time the unit is running. If you have a short cycling situation and the fan and the compressor are going on and off together than it almost has to be the thermostat bringing the unit off and on. Again, without being there and seeing for myself it is hard to question what anyone is telling you. Let me know exactly what was going on and I will be glad to offer any advice. John

Thanks all for the information.... John, what started to happen when the unit was new (the 1st time out) the A/C unit was working fine for a few hours, then when it reached temp the blower would shut down but the compressor kept running?? In order to get it to shut down I tried the breaker and no luck, it didn't kill the power. I finally had to open the grate up and up plug it, I guess it wasn't even hooked to the breaker? I took it in and the dealer and they said they fixed it. This season we have only had to use it a few times because of the cool summer and it seems to cool things down pretty good, but now when it reaches temp the compressor and blower will shut down, which I think it's supposed to do. But then when it calls for cool air again and kicks back on the compressor will only stay on for about 10 to 15 seconds while the blower keeps running. Then after about 60 seconds the compressor will kick on again for enother 10 to 15 seconds then shuts down, all the while the blower keeps running. I't seems to get much worst when the air outside starts to cool... This time the dealer said i had a dead capacitor and when they replaced it the problem went away??? Do you think it would help if I change out the
Thermostat to a digital one??? Thanks


Tommy
 

jmaguire

Well-known member
Yes, that can happen with a bad capacitor. The compressor never actually gets started. It is humming and trying to start, and after a few seconds the internal overload cuts it out. When the ovrload cools down the compressor will try to start again. It will continue to try and start while the fan continues to run. Short cycling is when the entire unit works properly, but comes on and off very frequently. That is very hard on the equipment and kills any efficiency you might need. It also does not remove much humidity that way. It may be airflow hitting the thermostat as mentioned making the unit run and shut off. Try covering the thermostat with a towel or rag and see if that makes any difference.
 

imchud

Well-known member
Yes, that can happen with a bad capacitor. The compressor never actually gets started. It is humming and trying to start, and after a few seconds the internal overload cuts it out. When the ovrload cools down the compressor will try to start again. It will continue to try and start while the fan continues to run. Short cycling is when the entire unit works properly, but comes on and off very frequently. That is very hard on the equipment and kills any efficiency you might need. It also does not remove much humidity that way. It may be airflow hitting the thermostat as mentioned making the unit run and shut off. Try covering the thermostat with a towel or rag and see if that makes any difference.


Thanks John, I will give it a try.... Also, what do you think about replacing the thermostat.
 

jmaguire

Well-known member
I am going to replace our thermostat with a good quality digital. The thermostat that came with the unit is O.K., but a good digital should be able to help the system work a little better. There were some posts on the site that had good instructions for changing the t-stat. It can be a little tricky because of the way the heating and cooling systems are both connected to the t-stat. Search for thermostat replacements and you can find detailed information about what stat to use and how to hook it up.
 

imchud

Well-known member
I am going to replace our thermostat with a good quality digital. The thermostat that came with the unit is O.K., but a good digital should be able to help the system work a little better. There were some posts on the site that had good instructions for changing the t-stat. It can be a little tricky because of the way the heating and cooling systems are both connected to the t-stat. Search for thermostat replacements and you can find detailed information about what stat to use and how to hook it up.


Thanks everybody for your help...
 
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