Adjusting TXV superheat.

[Andy Schoen]

Originally posted by freezerfixer
i was talking to a friend of mine that works for another service company the other day about superheat and he said "I have never had to check superheat like you do."
i think he is more of a "beer can cold" kind of guy. [/B]

If he drinks enough beer and has good sensitivity to temperature, he may do ok

[freezerfixer]

Originally posted by Andy Schoen

Originally posted by freezerfixer
i was talking to a friend of mine that works for another service company the other day about superheat and he said "I have never had to check superheat like you do."
i think he is more of a "beer can cold" kind of guy.

If he drinks enough beer and has good sensitivity to temperature, he may do ok [/B]

hahaha you might be right! theres only one way to practice.....drink more cold beer!

[hvacmike33]

What about your charge? If your were low on gas, and the box had a big load on it, wouln't that cause the txv to hunt? I've worked on units that do fine until you put a load on them, just a thought.

[freezerfixer]

Originally posted by hvacmike33
What about your charge? If your were low on gas, and the box had a big load on it, wouln't that cause the txv to hunt? I've worked on units that do fine until you put a load on them, just a thought.

in a low charge situation,your valve would probably be wide open trying to keep up with the load. the liquid refrigerant would be boiling off to a vapor really quick and the sensing bulb wouldn't get cold....valve continues to stay open.
also, i wouldn't think that you would be able to flood the evap. with liquid if there wasn't a solid column of liquid coming to the TXV. depends on how low the charge was.

[Freezeking2000]

Originally posted by freezerfixer
sounds like the valve is oversized. I replaced one the other day and misread the model number of the coil and put in too big of a cartridge. (sporlan "Q" body valve kit)
the valve could never find its happy spot.
my superheat would be 20 degrees and then the valve would open up and drop to no superheat at all within seconds.

anytime i build a valve, if i am between two sizes of orfices, lets say a 1 1/2 or 2 ton, i always go with the smaller size.
i may have to open the valve a little, but at least I'll have a more consistant superheat.

Very good point, a to large of a valve will work bad. Also a dirty coil will cause the same!

[cphc]

I agree here with checking the size of that valve. I have only had to adjust the SH on several TXV mostly on the new refrigerants used now. The TXV is very reliable device.
I have a buddy that works for sporlan and he always tells me that adjusting the SH is a last thing to do.

[OntimeJ]

Hey everyone !! im new to the website . hope all is well with everyone . got a problem . my compressor has ice on the body .( 404A W/I Freezer) after reading some of your replies, i need to understand how to correctly adjust my supperheat . i made some adjustments to the txv. got the system down to -4 degrees everyone happy .except for me cause my sight glass was not full . i added more 404 made another adjustment now my compressor is iceing up! and they loaded the W/I for the weekend (40x60)big box! im worried im hurting the compressor.

[rayr]

Hey everyone !! im new to the website . hope all is well with everyone . got a problem . my compressor has ice on the body .( 404A W/I Freezer) after reading some of your replies, i need to understand how to correctly adjust my supperheat . i made some adjustments to the txv. got the system down to -4 degrees everyone happy .except for me cause my sight glass was not full . i added more 404 made another adjustment now my compressor is iceing up! and they loaded the W/I for the weekend (40x60)big box! im worried im hurting the compressor.

You should be very worried about hurting that compressor.
Open to much and you will be slugging the compressor with liquid and BAMMM. The comressor is built to compress Vapor Liquid. I surely would not attempt to perform brain surgery unless I knew what made it tick.
Here is a link that might be helpful. Are you a tech or and end user??

http://hvac-talk.com/vbb/showthread.php?t=80383

[gdl1968]

Hello I'm new to this site and have a quick question. I have a walkin ,cooler 404A with two evaps. One is working great the other can't seem to adjust for nothing.unit is down to 40 but My superheat is super high and no amount of adjustment seems to work.my question is this, would a restriction in the the line prior to the TEV cause such a reading? The line to the working one is warm as should be but the non working is cool.

[rayr]

Hey everyone !! im new to the website . hope all is well with everyone . got a problem . my compressor has ice on the body .( 404A W/I Freezer) after reading some of your replies, i need to understand how to correctly adjust my supperheat . i made some adjustments to the txv. got the system down to -4 degrees everyone happy .except for me cause my sight glass was not full . i added more 404 made another adjustment now my compressor is iceing up! and they loaded the W/I for the weekend (40x60)big box! im worried im hurting the compressor.

What is the superheat?????? That will tell you if there is a problem.

[pecmsg]

Hello I'm new to this site and have a quick question. I have a walkin ,cooler 404A with two evaps. One is working great the other can't seem to adjust for nothing.unit is down to 40 but My superheat is super high and no amount of adjustment seems to work.my question is this, would a restriction in the the line prior to the TEV cause such a reading? The line to the working one is warm as should be but the non working is cool.

Gdl1968
This thread is 3 + years old, you might want to ask your question in a new thread
http://hvac-talk.com/vbb/newthread.p...newthread&f=12

[anasmilbes]

I find that if you need to adjust superheat it's better to replace. I work in supermarkets and a store can have up to 100 txvs for different applications. Adjusting usual doesn't work

[davidadavis]

I find that if you need to adjust superheat it's better to replace. I work in supermarkets and a store can have up to 100 txvs for different applications. Adjusting usual doesn't work

This is bad advice.... The AC and Ice Machine equipment have pre-adjusted SH settings on their valves. But in supermarkets they normally don't, and adjusting is normally required and or at least advised.