stumped !! need pro advice please

[freemandela]

i'm doing maintenance at a gymnastics club where my kids go to. they have 4 systems about 14 years old. the 2 5tons in the gym are the most under stress dues to big volume and lots of chalk in the air. i have to clean those thing 3-4 times a year even with good filters.
today, while cleaning the filters a saw that one a/h in the gym had a solid block of ice on the coil, suction line up to the compressor.
i stop it, let it thaw, 2h later i'm back (i'm in florida, it melts fast) to inspect the unit:
coil ok
blower ok
blower cap ok
amps ok
cond runs ok

now the numbers:
low 60psi / 33°
high 270psi / 123°
superheat 18°
subcool 35°
outdoor ambient 88°

i added 5oz of r22 just to see what would happen
low side stays the same
high side goes up a bit 278psi and SC 38°

i could not see any filter drier.
i think it "might" be (and i put quotes because often badly diagnosed) the TXV.
but it could also be air or non-condensables because the head would be higher, more SC due to less space for refri. therefore less R to go through MD and flahes faster and freezes giving a low suction....

did i just answer my own question or am i wrong ??

any thoughtfull input would be welcome; i'd like to fix that unit tomorrow.

thanks guys !


update:
i went back this morning briefly and had my daughter stand underneath while i shined a light through different parts of the coil and yes it needs cleaning but it's not clogged to the point of no return.
although i can understand that in the heat of the day it makes a lot of water and that water would start to freeze up creating a chain reaction i still don't understand the high head AND subcool...
they are most likely several problems
it's like having a dirty coil, air in the system and bad txv !

[HeyBob]

Clean everything first!

Other than that, too technical for the open forums. Get your 15 posts, apply for pro membership then we can do this in the pro forums.

There is a link in my signature line.

[Mr Bill]

now the numbers:
low 60psi / 33°
high 270psi / 123°
superheat 18°
subcool 35°
outdoor ambient 88°


If your a service tech or in the business you should apply for a Pro membership, we really can't help you, no diy "per rules" If you look at what I have in red real close, and think about it for a minute or two, I think you will figure it out.

How to apply for Pro membership:
http://hvac-talk.com/vbb/showthread.php?threadid=116113

[freemandela]

Clean everything first!

Other than that, too technical for the open forums. Get your 15 posts, apply for pro membership then we can do this in the pro forums.
.

i guess i'm not familiar enough with the forum and the 15 posts....
i'm trying to get enough good info to get me going on monday morning.
for the cleaning yes but since i have to pull the coil anyway i'm trying to see if the txv has to be changed as well so i don't have do it over again...

[freemandela]

If your a service tech or in the business you should apply for a Pro membership, we really can't help you, no diy "per rules" If you look at what I have in red real close, and think about it for a minute or two, I think you will figure it out.
[/U]

i'm a service tech in the starting blocks; been doing a lot of hvac but only recently came out of school... still learning obviously !

the only thing i can think of is overcharge but why the low suction??

[HeyBob]

12 posts to go, tell us about yourself, training, school etc!

[freemandela]

12 posts to go

..... thanks for the encouragement !:rolleyes:

can you tell me at least if i was right or wrong about the overcharge ? :)

[beenthere]

Probably is now that you added gas.

Your standing in right field. Waiting to catch a line drive down third base.

[jdblack]

How long did you go to school?

[freemandela]

Probably is now that you added gas.

Your standing in right field. Waiting to catch a line drive down third base.

i come from soccer and tennis country so baseball metaphores are like chinese to me my friend.....

[freemandela]

How long did you go to school?

meaning that i should know better if it's been about 9 month ?

[jdblack]

but why the low suction??

What is the suction pressure the measure of and what can control it?

You must think about it?

You are off to a very good start as a service tech. It's nice to have all that info for us to help.

[jdblack]

meaning that i should know better if it's been about 9 month ?

No, not saying anything negative. I was just asking. I didn't get any formal training in a school program, and you seem to be doing good and I was just wondering.

[beenthere]

You charged a player from behind.

Your doing cut offs, at the other teams goal.

[freemandela]

"How many times must one fix something before it is fixed? "

this is EXACTLY why i spend time on this forum to try to find an answer that actually MEANS something to me instead of poking a stick in the water hoping to catch a fish... makes sense ?!

[Mr Bill]

"How many times must one fix something before it is fixed? "

this is EXACTLY why i spend time on this forum to try to find an answer that actually MEANS something to me instead of poking a stick in the water hoping to catch a fish... makes sense ?!


Get your Pro membership here, you will probably learn more here than you ever will in "ANY" of today's classrooms, we discuss real world problems, not stuff you "might" need to know every 30 years. :munching:

[freemandela]

You charged a player from behind.

Your doing cut offs, at the other teams goal.

still not sure but i think you're saying i'm wrong...
ok

so let me tell you a bit about myself:
i'm 40, went around the world a couple times, been there, done that, several times and liked it !
did a lot of different jobs, the last ones being in the hvac sector since i moved in florida 6 years ago.
when i started i knew NOTHING about a/c, i just thought it made cold air... little did i know !
i spent 4 years doing residential new installs, trims, punch-out than i went to work more commercial RTUs, sheet metal, DB, foreman, "make it work" kinda of guy and happy customers.
wasn't satisfied with the learning rate, so i decided to go backto school thinking it would be more service/engineering but was only service . since i was in and on worker's comp i decided to stay and learn as much as i could (probably did not as much as i should but tried my best)
just graduated with a 4.0 gpa from core & a/c and might go back for refrigeration.
the teacher knows his stuff like crazy, he's been in the industry for over 30 years and he's always here to help us except just know because we're on break and he's off somewhere.
so back to present days:
i always try to get as much info as possible, think about, then think about it again and before i call someone i think about it again.
just right now the numbers don't make much sense and i'm probably missing something too; there you go my friend

[freemandela]

time for more school

sure !
so what's your opinion on the subject ? you seem to have one

[artisancorp]

I agree I would totally make sure it was clean and had proper airflow before going any further

[freemandela]

I agree I would totally make sure it was clean and had proper airflow before going any further

yes but if the txv is bad i would have to pull the coil again and do same the job
twice....
see, if i can determine a bad txv now,i recover the 22, pull the coil, clean it unsweat the txv , sweat the new one, put the coil in place leak check, vacuum and charge with nominal charge.
if i do all that withut changing the txv and it's bad i got to do all over again !

[freemandela]

I agree I would totally make sure it was clean and had proper airflow before going any further

well yes but think about it, an air flow restriction won't give a high SH & head, it will give a low suction and high SC though.
that's why i'm thinking to have at least 2 issues

[small change]

Before working or going out on the town one usually
gets into the shower and cleans thoroughly his entire body

One usually doesn't wash the inside of his body but
concentrates on washing the outside of his body thoroughly

[freemandela]

Before working or going out on the town one usually
gets into the shower and cleans thoroughly his entire body

One usually doesn't wash the inside of his body but
concentrates on washing the outside of his body thoroughly

yes master yoda.....

what ??!
speak pidgin to me please

[jdblack]

Okay lets stop with the analogies.

This is getting weird.

[freemandela]

Okay lets stop with the analogies.

This is getting weird.

thank you !

[freemandela]

Okay lets stop with the analogies.

This is getting weird.

yes, how about we stay focussed and try to help little fredy here ....:angel:

[small change]

yes, how about we stay focussed and try to help little fredy here ....:angel:

think about it

[small change]

yes master yoda.....

what ??!
speak pidgin to me please

Do or do not... there is no try

Apply you may, with one more post

[beenthere]

yes, how about we stay focussed and try to help little fredy here ....:angel:


Well. You need one more post. Then you can apply for pro membership.

And after your accepted. You can get clear answers in the pro tech forum.

We realize that this is a pressing issue for you and your customer. Surely you have a tech at your work place that can help you in the mean time. Until your application is approved.

[freemandela]

think about it

that's all i've been doing, i'm dedicated !
it's possible that the coil is clogged just enough to freeze up under the right load (it's new, just happened this week, i go there once a week) wich would cause low suction (still don't know why slightly high SH) and an overcharge that was there before i "took over" wich would cause the head to go up as well as the SC.

[freemandela]

Well. You need one more post. Then you can apply for pro membership.

And after your accepted. You can get clear answers in the pro tech forum.

We realize that this is a pressing issue for you and your customer. Surely you have a tech at your work place that can help you in the mean time. Until your application is approved.

well actually i' alone , nobody to help me besides my instructor who's on vacation... but that's ok, i never give up and always find an answer that leads me to another question.
that's the point: learning is questioning not just answering

[freemandela]

Well. You need one more post. Then you can apply for pro membership.
And after your accepted. You can get clear answers in the pro tech forum..

done !
sent an email with all info and scan of cards...
told you i don't let go !