here are my notes. cant figure it out

[timjimbob]

3 ton split system complaint was insufficient cooling. Noticed the LL sweating in the attic to piston evaporator.

Put gauges on R22 system and noticed low suction. (evap not iced and good airflow)

Added about 1 lb and cooling was giving me 16 degree split.

Low 60 psi @ 51 (12 SH)
High 160 psi @89 (0 SC) (this isn't same as measurement i took at LLF (maybe I misread thermometer)
Ambient= 81, inside 78
measure 57 degrees at evap LL and 76 LL, in and out of LLF.

Don't understand LL temp sweating and zero SC. Conflicting, LL restricted or not.

[lkapigian]

Drier inside condensing unit plugged, you are reading pressure downstream from that drier

[pecmsg]

3 ton split system complaint was insufficient cooling. Noticed the LL sweating in the attic to piston evaporator.

Put gauges on R22 system and noticed low suction. (evap not iced and good airflow)

Added about 1 lb and cooling was giving me 16 degree split.

Low 60 psi @ 51 (12 SH)
High 160 psi @89 (0 SC) (this isn't same as measurement i took at LLF (maybe I misread thermometer)
Ambient= 81, inside 78
measure 57 degrees at evap LL and 76 LL, in and out of LLF.

Don't understand LL temp sweating and zero SC. Conflicting, LL restricted or not.

Didn't some units have a screen in the piping before the piston?

[pageyjim]

3 ton split system complaint was insufficient cooling. Noticed the LL sweating in the attic to piston evaporator.

Put gauges on R22 system and noticed low suction. (evap not iced and good airflow)

Added about 1 lb and cooling was giving me 16 degree split.

Low 60 psi @ 51 (12 SH)
High 160 psi @89 (0 SC) (this isn't same as measurement i took at LLF (maybe I misread thermometer)
Ambient= 81, inside 78
measure 57 degrees at evap LL and 76 LL, in and out of LLF.

Don't understand LL temp sweating and zero SC. Conflicting, LL restricted or not.

Looks like 17SH to me. Did suction raise with added coolant?

[timjimbob]

SH did rise when added freon. might have screen

[pageyjim]

SH did rise when added freon. might have screen

Would have been useful to have numbers before and after adding ref. along with wetbulb. I would have expected SH to lower with added ref and suction to hopefully rise. At this point I think it may still be low on ref.

[timjimbob]

Suggested by an oltimer who experienced this to him.. No piston installed

[Makeitcold]

So your reading 160 psi and 89 degrees at the liquid line service valve, then its 76 degrees going thru the filter/drier and finally 57 degrees right at the coil? Just making sure I read that correctly as i have the flu and my brain only half works. Sounds like a plugged filter driver in the condenser or liquid service valve not fully open.

[timjimbob]

LLD has no temp. drop. 89 and 76 degrees. I measured something wrong so I'll go back.

[BNME8EZ]

160 PSI Is 87°

With an 81 ambient you should have around a 225 head assuming less than 12 SEER.

76° LLT at the filter is lower than ambient so there has be be a restriction before the point you took the reading.

Put a probe on the LL right at the cond coil outlet, see haw that compares to ambient.

You may have a restricted service valve or you may have restricted pass(s) in the cond coil.

[oldguy1949]

Didn't some units have a screen in the piping before the piston?

90's Carrier/BDP had a screen in liquid line before service valve & some evaporator just ahead of the piston body on the flares outside cabinet.

[gravity]

Liquid line can’t be colder than the ambient air entering the condenser.

Upstream restriction. Cant always use temp to find the restriction. Especially since you added more gas.


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[timjimbob]

[QUOTE=BNME8EZ;25725327]160 PSI Is 87°

"With an 81 ambient you should have around a 225
76° LLT at the filter is lower than ambient"

This is an obvious observation that I failed to see. How could liquid be colder then the air cooling it? Has to be a changing of state property.
My second mistake is I look at my Iphone to see the ambient. Need to take a actual measurement.

[DOGBOY]

3 ton split system complaint was insufficient cooling. Noticed the LL sweating in the attic to piston evaporator.

Put gauges on R22 system and noticed low suction. (evap not iced and good airflow)

Added about 1 lb and cooling was giving me 16 degree split.

Low 60 psi @ 51 (12 SH)
High 160 psi @89 (0 SC) (this isn't same as measurement i took at LLF (maybe I misread thermometer)
Ambient= 81, inside 78
measure 57 degrees at evap LL and 76 LL, in and out of LLF.

Don't understand LL temp sweating and zero SC. Conflicting, LL restricted or not.

So I am VERY confused. You say low is 60# @ 51*. I thought 60# = 34*. So I must be screwed up if no one else thinks this.

My actual thoughts are dude you don't have a clue what you are doing. You may want to do as you suggested go back and get better/correct information.

[beenthere]

Look for a LLFD inside the condenser cabinet. Probably restricted if there is one there.

[martyinlincoln]

With a zero subcool you're changing state in the liquid line before it gets to the metering device. At 80 ambient I'd expect to see around 12 sc with a fixed orifice before the sh came in line where it should be. That's why it's important to check sh and sc no matter what type of metering device. If nothing else you'll have a memory of what they should look like at various conditions.

[Mr Bill]

90's Carrier/BDP had a screen in liquid line before service valve & some evaporator just ahead of the piston body on the flares outside cabinet.

You are telling your age, the first one of those I ever encountered about had me checking into the mental hospital. But I finally figured it out. :-)


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[oldguy1949]

You are telling your age, the first one of those I ever encountered about had me checking into the mental hospital. But I finally figured it out. :-)


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I worked hard for these grey hairs and retirement is great. I'm Trout fishing today on the White River and it beats the hell out fixin ac's. I am one of the older codgers , 70, but a few here are older, but I'm not laid out on display at the funeral home so it's a good day no matter

[BNME8EZ]

I worked hard for these grey hairs and retirement is great. I'm Trout fishing today on the White River and it beats the hell out fixin ac's. I am one of the older codgers , 70, but a few here are older, but I'm not laid out on display at the funeral home so it's a good day no matter

Wow, what will I don when I retire in a few years? I was always of the opinion that the worst day of work was better than the best day of fishin'. I guess it's a good thing I have my truck to work on. Nothin like the song comin from a well tuned engine.

[timebuilder]

Working everyday is what's going to keep me from laying there with people looking at me saying, "he looks like he's sleeping...."