R series chillers

[ed-man]

Yes we have a chiller 12 yrs old txv Valve is not working. Would kick out low evaporator. Temp pressure so anyway .well most of you know that trane has discontinued that txv the 4248 I think. And go to the 6080 and connector. And cable. And from what I read their is a lot of problem with that as far as up dating software and such. What I'm. Asking. Is their. Any of you techs that has a old txv. I have the part # pretty sure its Val 4248 that you have taken out I know you have to replace them all when you do the change so I know there are some good ones out their but this is an old church building and they have already spent close to 20000 on this thing this summer

[Healey Nut]

Are you 110% certain that the EXV is bad . I would guesstimate that 95% of the EXVs that get changed have absolutely nothing wrong with them .
Usually its a sensor or refrigerant or compressor problem causing the nuisance lockout and the tech replaces them on the off chance it will fix the issue .
Ive been working on the R series chillers for 15yrs and only ever changed maybe 2 valves .

[ed-man]

train service tech took txv. Apart well the head off that is and peace were loose in it and fell out he stuck them back in and stuck it back together it ran for 2 days without an issue kicked out and now kicked out pretty quickly like in 20 or 30 seconds before it would run for 3 or 4 minutes but had really I really low pressure on low side lot 25 pounds in high pressure on my side like almost 400 pounds before it kicked out. train said censors on both sides of the txv was causing that so we had them replaced we had the system completely evacuated oil and freon our back at factory levels when service tech was there I would watch the gauges for him and he would tap on txv and pressures wood stabilize some

[ed-man]

also line on high pressure side of txv would frost over before lockout

[Six]

I just replaced 2 EXVs on a R series chiller because circuit A on the off cycle was bleeding a significant amount of liquid refrigerant back through the barrel and then to the compressor.

Unfortunately both have to be replaced along with the cables and the 1U3 module.

I was a little surprised that the module and EXV cost were relatively low compared to a comparable Carrier valve and board.

If I were you and you've vetted this issue thoroughly and decided the EXV needed to be changed I would buy new components and do the repair correctly.

[zw17]

also line on high pressure side of txv would frost over before lockout

You need to pay close attention to this right here. What does that tell you?

[Six]

You need to pay close attention to this right here. What does that tell you?

I read that and thought he made a typo.

It seemed to obvious for a technician on sight to overlook.

[ed-man]

Ps the tech used the term txv. He main works on residential units I'm sure he knows it's an electronic expansion valve

[alcomech]

Ps the tech used the term txv. He main works on residential units I'm sure he knows it's an electronic expansion valve

I wonder if the tech understands what the saturation temperature sensor is used for. He must if he knows how an EXV works.

_____________
Understand the symptoms and you will find a solution.

[ed-man]

I'm sure he knows how to expansion valve works he took the head off of it as I said previously and we put it back together thought we may have had it I have worked with him on this chiller for 3 months. Off And. On I think very highly of him. He is just so busy. And. He don't work on chillers every day. I'm just. Thing to help. Him. Cause we will be trying again. Next week

[Tech Rob]

You need to pay close attention to this right here. What does that tell you?

I. agree. This. Is. A big clue.

[R123]

also line on high pressure side of txv would frost over before lockout

Like several other people have said, this ought to tell you what the problem is and it is pretty obvious.
Hint: It's not the EXV.

A model and serial number would help, we don't know exactly what you have.

When you say "A Trane service tech worked on it", do you mean a Trane service tech from the Trane sales office? Or possibly do you mean an independant Trane dealer who who sells and services residental Trane equiptment like a Trane Comfort Specialist? The reason I ask, you stated the Trane tech works mostly on residential equiptment. I don't know how it works in your part of the world, but in the States, Trane service techs who work for Trane or a Trane sales office generally only work on commercial units. Im a little concerned that he is referring to this as a "TXV" as anyone who has any experiance with chillers at all would call it an "EXV" as these have been around for over 20 years.

I also agree with Healey Nut that most of the time the problem is not the EXV and is something else. Thats why its so important you post the Model and Serial number.

[supertek65]

EEV

electronic expansion valve.

TEV

thermal expansion valve

TXV

slang for thermal expansion valve

[alcomech]

I'm sure he knows how to expansion valve works he took the head off of it as I said previously and we put it back together thought we may have had it I have worked with him on this chiller for 3 months. Off And. On I think very highly of him. He is just so busy. And. He don't work on chillers every day. I'm just. Thing to help. Him. Cause we will be trying again. Next week

As you have found out there is not much to look at when you take apart this type of EXV. It is very unlikely that the push rod is hanging up. As for the power head you will need to leave that to your imagination. The actuator either works or it does not. It only takes at most 30 minute to trouble shoot, that's it. This is where ohms law applies.

An EXV has to be told what to do, If I were you I would not look at it for more than 30 minute in your last effort and final test. Its very clear that your problem lies elsewhere.

This is so basic that on average it should take no more than two hours for a true diagnosis. A decade box would help for sure.
_________________________
Understand the symptoms and you will and you will find a solution.

[ed-man]

sorry on response times computer difficulties

[jayguy]

EEV

electronic expansion valve.

TEV

thermal expansion valve

TXV

slang for thermal expansion valve

AEV

Automatic Expansion Valve

[Six]

As you have found out there is not much to look at when you take apart this type of EXV. It is very unlikely that the push rod is hanging up. As for the power head you will need to leave that to your imagination. The actuator either works or it does not. It only takes at most 30 minute to trouble shoot, that's it. This is where ohms law applies.

An EXV has to be told what to do, If I were you I would not look at it for more than 30 minute in your last effort and final test. Its very clear that your problem lies elsewhere.

This is so basic that on average it should take no more than two hours for a true diagnosis. A decade box would help for sure.
_________________________
Understand the symptoms and you will and you will find a solution.

The trouble shooting methods Trane spells out in their Addendum are pretty straight forward. Keep a stop watch or a stop watch app handy and go into the test submenu.

That and ohming out the windings and checking the integrity of the cable.

[always looking]

I have three EXVs that I changed out 2 months ago if you still need one.

[ed-man]

Sure do how much do you want and do you have the part numbers

[supertek65]

show off!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

AEV

Automatic Expansion Valve