DIY Home Improvement Forum banner

1 - 20 of 26 Posts

·
Registered
Joined
·
131 Posts
Up until the compressor kicked in, it sounds like the evaporator fan has an issue or there are loose screws. Press around in those areas and see if the noise goes away. If so then there is the problem area.
 

·
Registered
Joined
·
5,868 Posts
Why is the compressor cycling off? Should be running when the condenser fan motor runs.
Lot of moisture around the base. Was that unit frozen up?
 

·
Registered
Joined
·
400 Posts
Discussion Starter #4
No, it doesn't freeze up, not sure if the moisture around the base was because or recent rain.
 

·
Hvac Pro
Joined
·
22,475 Posts
The compressor should not be cycling on/off with the condensor fan running.

It sounds like the compressor is groaning and dying. Put your gauges on and see what the freon pressures are doing. Check the compressor amps.

If it is seizing then it will be drawing LRA locked rotor or very high amps.
 

·
Registered
Joined
·
2,980 Posts
Could be building up pressure and opening the internal bypass. Overcharged or blocked high side somewhere would cause that.
 

·
Registered
Joined
·
400 Posts
Discussion Starter #7
thanks for your suggestion surferdude2.



about roughneck's comments, attached is a picture of the of the base with indeed, a lot moisture and yesterday did not rain.


also, the house does not appear to be cooling. we set it up for 72 and temp was between 78 and 79 the whole time.
 

Attachments

·
Registered
Joined
·
400 Posts
Discussion Starter #9 (Edited)
so apparently the system was overcharged. the guy that came recovered some refrigerant and the noise went away.

I do have some questions based on the pressures attached:

- how do one know what should be target super heat based only on the attached picture?

- I know you have to know what is the wet bulb temp at the return and the outside temp right close to the condenser.

- the guy that came over to look at it, he was only trying to get the target super heat based only on the attached picture.

- he did not get the wet bulb temp nor the outside temp. I asked I was told that with these gauges, this information was not needed.

- he kept on recovering refrigerant and then he said, that's close enough and called out.
 

Attachments

·
Registered
Joined
·
12,486 Posts
Those gauges just do the math - calculating sh and sc on the fly.

Still need the wetbulb return and outdoor temp to determine target.

Also, if the indoor airflow is way off, everything goes out the window - that must be checked and corrected if required first!

This is assuming the metering device is fixed and not a txv.
 

·
Registered
Joined
·
400 Posts
Discussion Starter #11
Thanks for confirming this user_12345a. That leads me to my next question that did not want to ask before all this was confirmed.


So I went ahead and did the super heat test myself with normal gauges. The inside coil has a piston.

I watched the following tutorials on how to get to get the wet bub temp and outside temp readings:

wet bulb temp demonstration shows at around the 2:17 min:

outside temp demonstration shows around the 2:49 min

attached are the reading I got. when I checked the target super heat chart, it gave me a current super heat of 0 and a target super heat of 9

So I need to keep on recovering more refrigerant right?

Also, can you clarify about the indoor airflow comment?
 

Attachments

·
Registered
Joined
·
12,486 Posts
Indoor airflow impacts pressures and superheat/subcooling - there are different ways to confirm proper airflow, depends on your setup.

Too high airflow produces high suction pressure & superheat + slightly elevated head, too little produces low suction pressure & superheat + slightly lower than normal head.

I think you may have read the low side gauge wrong, in the picture it looks more like 140 psi than 144.

What you have is not suggestive of low airflow, otherwise suction pressure would be low.

I suspect still a little over-charged but good to check subcooling too- tells you how much liquid is stacked in the outdoor coil.
 

·
Registered
Joined
·
400 Posts
Discussion Starter #13
sorry, the picture of the gauges were when I had already recovered some more refrigerant and the picture of the pressures are before doing it. I will check it again next week.

Do you think I should remove the air filter from the return to get a better air flow?

another question,

when you connect your pressure gauges, do you also open them up or leave them as they are (the wheel or knob, do not know how to call it)
 

·
Registered
Joined
·
12,486 Posts
Your readings don't suggest low airflow in itself since the suction pressure is high.

Low airflow produces a lower than normal supply air temp, suction pressure and superheat. Not high suction and high superheat unless you have more than one problem.

I'm pretty sure it's just slightly over-charged, provided the condenser coil is clean.

Superheat chart with target supply temp, get here: http://effcom.net/assets/documents/charging_and_td_chart.pdf
 

·
Registered
Joined
·
5,868 Posts
Just curious, since your a little unsure about your manifold gauges. How are you reclaiming? What reclaimer and scale are you using?
 

·
Registered
Joined
·
400 Posts
Discussion Starter #16
No scale, just used the recovery line in the middle. Did not do much as I was not sure if I was doing it right.

I'll be going to the house tomorrow and try it again but my other concern is that the technician that came with his digital gauges showed up to have about a 5 super heat reading. I did the testing myself right after he left and my super heat shows 0 or 1 super heat.

That's why I wasn't sure if I was doing it right.
 

·
Registered
Joined
·
5,868 Posts
What do you mean? Are you just releasing refrigerant into the atmosphere? Your just bleeding it out of the system with the yellow charging hose?
 

·
Registered
Joined
·
12,486 Posts
After refrigerant is removed, it may take a few minutes for the unit to stabilize and the tech needs to stick around.

I sure as hell hope you had a recover tank connected to the yellow hose and didn't vent - it's against the law to vent refrigerant and even if it wasn't, still wrong.
 
1 - 20 of 26 Posts
Top