ReplyI'd put my money on your lines expanding/contracting and the foam insulation inside the paneling is making noise because of it. My frigerator at home makes pops out of defrost.
Former Site Administrator- Now Retired
Frigidaire Residential side by side FRS26HF7
It's back from 2002 but has worked perfectly until a few months ago. The fridge is in my garage and I use it to hold drinks to grab before hitting the field.
Here's the knogg'n scratcher...
Compressor died, open windings but no burn out, acid test was negative. So, I replaced the compressor as I just hated to get rid of my old buddy. Matched the compressor, pulled the spun filter and installed. Pulled a long vacuum, no leaks... got back to it the next day. Charged the system with 5.25 oz of 134a and off she went.
Two days later it went back out... compressor hot. Nothing of real value inside so I let it go a few days unplugged and got back to it on the weekend.
Pulled the spun drier off and blew out the system with a few good shots of nitrogen back flushing from the suction line with an open cap tube. Got a little oil out of the system but that's about all that was on the paper towel I used to catch any gunk that may be in there. Then I installed a CAPT-032S, pulled another good vacuum and adjusted the charge. This time I used the same factory charge but knew it needed more about 9 oz and let is settle to about 9 pounds suction side, 120 high. Before I added refrigerant, due to the new drier, it was -10 low and 80 high.
Well, it's been running fine for several months but....
It turned into a Popcorn machine !!!!
There is no rhyme or reason, no pattern to it at all. It sounds just like the last minute of a popcorn microwave bag... Most of the time when it cools it is silent as a ghost. Sometimes there is a slight knock in the upper right hand corner of the refrigerator side rear. Other times it makes this Popcorn maker sound for 5 or 6 minutes fairly loud then it goes away as quickly as it started.
OK... scratch yer knogg'n and tell me what the heck this is.
Nope... it's coming from the refrig side not the freezer side so it's not a gear on the ice maker.
This ought to be good....
Professional Member
I'd put my money on your lines expanding/contracting and the foam insulation inside the paneling is making noise because of it. My frigerator at home makes pops out of defrost.
Professional Member
its overcharged. Take a little gas out, let it run for 15 mins and see if the noise decreases. If its less, but not gone, take a little more gas out.
a resi freezer should run about 0-2 PSI on the suction side.
If liquid refrigerant makes it into the suction line, you get the poping noise. I don't know why, but this only happens on resi equipment.
Professional Member*
I'm gonna say a uninsulated wire is poppn' inside the cabinet!!!! But, i don't know. Usually after one loud pop the breaker trips!!!
Professional Member*
The compressor will always be hot on a resi unit, always when running anyway.
These units are a different animal, and therefore-The charge should have been weighed in on these units. you said you charged 5.25 ounces first time and 9 the next. 4 ounces is a lot of difference on these units, and just note, you can not go by the superheat on resi units because the cap tube is wound around the suction line to help ensure no liquid makes it back to the compressor and to cool the cap tube. I feel pretty confident that you checked superheat because I have done the same in the past and came up with numbers close to what you have described.
As said, the unit is overcharged. 9 pounds is too high on 134a (assuming). You should be able to verify this with the compressor amp draw (more easily taken at breaker panel minus the fan amp draws, which can be checked by turning unit on and off and then back on which will take the compressor out on limit for a couple minutes)
The poping sound is likely hot gas trying to force it's way into a condensor that is full of liquid refrigerant.
The main thing is to keep the main thing the main thing!
Health = Wealth! To wager otherwise is a Fools Bargain
Former Site Administrator- Now Retired
I added 4 oz due to the change in spun drier and the CAPT. I'll work on reducing the charge down to or near 2 lbs suction.
Amp draw is within specs now so no damage is being done. Didn't charge by superheat but did think about it. Just went +4 oz
Thanks for the replies guys... will get to it this weekend and give heads up.
Professional Member*
soooooo refrigerators like to run at RLA ?
Professional Member*
Your refrig has a heat exchanger so definately SH should not even be measured.
Frigidaire has this noise on lots of units. I even owned a similar refrig that also popped.
I tried several things to make it stop but no avail.
I have a bro-in-law that works for them I will see if he will email the bulletins addressing in.
If I remember correct they actually said to add nitrogen to system which I never tried.
Seemed to go against nature.
Former Site Administrator- Now Retired
OK... update
I had a few minutes so I pulled it out and grabbed my gauges.
Was at 0 suction and 110 high. Slight frost on the suction line right up to the compressor.
I blew the air out of my high side 4' hose until I got liquid then unhooked the high side connection... that's about an oz. Took the gauges off then unplugged the unit for a while. I depressurized both hoses.
Came back out and hooked up the gauges again. Plugged in the fridge and let it run. When I came back, about an hour later, I had -8 low and 100 high. No frost on the suction line. Yes, it still is a popcorn machine but not as loud and not as frequent... Box is still holding temp just fine.
Professional Member*
Frost on suction line is sure sign of overcharge.
Pressures don't mean much either as the evap temp fluctuates so frequent on these little boxes. They don't ever publish data that ive ever seen.
Professional Member*
That said my popcorn machine is at my grandmothers still poppin away.
Professional Member*
Some reading material -
Former Site Administrator- Now Retired
Dry Nitro... who'd thunk it.
Thanks...
Don't think it's important enough for me to pull the panels apart to access the evap but I may try the DN just for grins.
Will report back.
Former Site Administrator- Now Retired
The addition of Nitrogen raises the back pressure without adding refrigerant, causing frost to
form on suction line.
LOL
Professional Member*
The panel is super easy unless freezer is fully loaded. Just one lower cover.Originally Posted by Dad
Professional Member*
Doesnt the label have a charge amount ?
It should tell how much to put in it and the spun drier will have charge info as well.
As for adding nitrogen to the system, IImagine someone misunderstood when to add the nitrogen, as in while brazing. Nitrogen is a noncondensible, and is never used to charge a refrigeration system. It would likely gather in the top of the condenser and take up valueable space
Professional Member*
Hehe good catch. I will tell him about that.
It should read WHICH WOULD cause suction line to frost.
Professional Member
Did you read the bulletin that was just posted?
It specifically gives instructions on adding a nitrogen charge to an operating system.
Professional Member*
At the posted pressures and assuming r134a, the evap is at -27 and the condenser is 88 degrees.. that is a low temp on both coils. Perhaps a stupid question but is the evap fan operating? There isnt a bag blocking the evap airflow is there?
Professional Member*
If a evap fan on a sxs is bad you know it. Dads gatorade would be warm .
And to get that box to 0 you're goona need a -27 coil.
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