r-22 walk-in on rack giving me fits

[KB Cool]

Copeland semi model # KANB-007E-CAV-800 on coldzone rack.
Evap AA18-66B. Are they a match?

I noticed HPC5-1 headmaster is bypassing some hot gas into the receiver at 190 psi. Temp readings around valve = R-98f, C-88f, D158f.


Can't clear glass without flooding back. It's almost like "did somebody just turn off the evap fan motor". My glass is not even clear and I'm flooding back.



This is what pressures I left unit at tonight.
190 High
52 LOW
LLT 96
SLT 62
Outdoor Temp. 86F

Box is cold at 36 F. But again sight glass is not clear and customer will call back. Last week I found unit flooding back and suction was high. Recovered 3 lbs. of gas and obtained these same pressures and box temp dropped fine. Today I get call back. found suction at 35, suction warm, Add maybe a pound of gas and bingo suction goes up to 55 and box begins to pull down.
But sight glass is not clear.



With this limited info. (probally get more later) I can provide can anybody give me any ideas.

I am thinking TXV overfeed, Mismatch, or could it be Headmaster?

[ReferTroop]

I had a TXV that would adjust but wouldn't hunt, R-22. Bottom of evap would frost but not the other 90%, no superheat and was getting ready to slug the compressor, close the TXV and no cooling but superheat was at 12 degree's. Called the manufacturer, they were thinking the same as I and said oil logged evap., tried everything. Finally I changed the TXV and alls well that ends well.
Never saw a TXV that would adjust but not hunt before, Possibly similar...?

Suggestion: Close TXV, run high superheat, watch sight glass to clear, take TD across evap.

problem is the TXV needs to be able to change with the load conditions, and then again 86F ambient on the condensor your headmaster should not be passing any hot gas into the reciever.

Sorry I'm not much help, left you with the same diboggle...

[k-fridge]

Don't have my reference handy, but that "E" in the compressor number indicates ester oil and I have my doubts that it's supposed to be running R-22. Better check the TXV in that unit to see what refrigerant it's set up for, I'm betting 134 or 404. That would explain why it's flooding with 22.

[ReferTroop]

Don't have my reference handy, but that "E" in the compressor number indicates ester oil and I have my doubts that it's supposed to be running R-22. Better check the TXV in that unit to see what refrigerant it's set up for, I'm betting 134 or 404. That would explain why it's flooding with 22.

Just checked it, that compressor runs 404A.

[k-fridge]

Just checked it, that compressor runs 404A.
That's what I thought, thanks man. I bet the evap is set up with a 404 TXV and it's flooding like crazy with 22 in it.

[ReferTroop]

That's what I thought, thanks man. I bet the evap is set up with a 404 TXV and it's flooding like crazy with 22 in it.

If thats the case, how in the sam hell it got r-22 in it in the first place...!

JS

[Airmechanical]

If thats the case, how in the sam hell it got r-22 in it in the first place...!

JS

i guess we all learn, check that tx valve before adding any gas!

one day soon (hopefully) someone will design an affordable refrigerant identification tester!



.

[ReferTroop]

i guess we all learn, check that tx valve before adding any gas!

one day soon (hopefully) someone will design an affordable refrigerant identification tester!



.

And if someone comes up with an "affordable" handheld refrigerant ident. tester I will be first in line to purchase.

JS

[k-fridge]

And if someone comes up with an "affordable" handheld refrigerant ident. tester I will be first in line to purchase.

JS
Put me down for several of those too.

[KB Cool]

Hey thanks guys.
I will double check the model number on the compressor and the valve. Rack is clearly marked r-22, circuit D, on data plate. But I guess it could of been changed. I'm gonna head back there today and scope the valve first:)

[KB Cool]

Well guys,
I went back to Box and I was hoping to find a 404 valve but this is what I found instead. Alco HFESC 1HC. Supply house confirmed it was a 22 valve.
Also they said copeland semi is either or 404 or 22. Box holding at 35f. And sight glass again is half full.

[k-fridge]

Well guys,
I went back to Box and I was hoping to find a 404 valve but this is what I found instead. Alco HFESC 1HC. Supply house confirmed it was a 22 valve.
Also they said copeland semi is either or 404 or 22. Box holding at 35f. And sight glass again is half full.
Time to get out the superheat thermometer. You'll need to get a full charge in that thing or you'll have Headmaster problems in cold weather.

[KB Cool]

Kfridge,
What do you think about the headmaster modulating at 190. Should it not be in play? It is a 180 PSI valve. Or is 190 to close to 180 to even consider it?
I think I'm gonna have to install a suction tap at evap. to get an accurate reading. It would make life easier if the manufactures did it for us.:D

[k-fridge]

Kfridge,
What do you think about the headmaster modulating at 190. Should it not be in play? It is a 180 PSI valve. Or is 190 to close to 180 to even consider it?
I think I'm gonna have to install a suction tap at evap. to get an accurate reading. It would make life easier if the manufactures did it for us.:D

Close enough to be within margin or gage error. If you do have the correct refrigerant in that critter you need to get the superheat in line, finish charging, and make sure the superheat is still inline. Sounds to me like the TXV is way to far open. Gonna smoke a compressor if not careful.

I'm a bit surprised they are using 22 with ester oil. While it is approved, there are better oil choices for 22.

[gerryboy00]

I'm a bit surprised they are using 22 with ester oil. While it is approved, there are better oil choices for 22.

it is approved,...but each time we replaced a compressor on a r-22 rack, it come with POE in, but i do replaced the oil with mineral.....the E on the nameplate tell you that the compressor contain POE from manufacturer.....the E is there for ever (on the nameplate) but the oil inside is not ;)

[gerryboy00]

KBGHBG
did you verified the check valve (by-passing txv for hot gas defrost)??????
i bet it leak a lot :eek:

if it isnt HG Defrost...then concentrate on the TXV

[ReferTroop]

Not right. put a false heat load on it by covering the condensor, if it doesn't change chop off the weld tube at the top of the headmaster releasing the bulb charge, that will eliminate the head master from the equasion. If everything pops into line you know whats happening....

You may also have to bang on the body to get it unstuck...
Risky ? yes.....(no balls no glory)....
Remember rule one about TXV, TXV will never operate porperly until solid liquid line is acheived.
Rule # 2 the headmaster needed to be replaced anyhow....
JS

[k-fridge]

it is approved,...but each time we replaced a compressor on a r-22 rack, it come with POE in, but i do replaced the oil with mineral.....the E on the nameplate tell you that the compressor contain POE from manufacturer.....the E is there for ever (on the nameplate) but the oil inside is not ;)
I'm with you, I see no reason to use POE with 22. AB is my choice for HCFC refrigerants.

[KB Cool]

Hey guys,
I ended up talking to Dave at Coldzone.
He believes my Headmaster is stuck in bypass due to low charge. And the gas along with the liquid thats being sent down to evap is causing the TXV to be wide open and due to the increased velocity of the refrigerant flowing through the valve and evaporator is the reason why I have floodback when attempting to clear glass. So in other words the TXV is over feeding because I don't have a good liquid seal because of headmaster and the low charge.Or something like that:D
He wants me to shut down machine overnight and come in the morning and heat a fresh jug of 22 up and try to jam liquid into the receiver as best I can and try to make the headmaster come out of bypass. He said I need to get the head over 200 at least before it will come out. I am thinking about sticking sensing bulb of txv in a cup of ice water. (should help slow down the flow, I would think) when I get back to this box and do what Dave say's.

[ReferTroop]

Bad headmaster if its bypassing, what reason do we have headmaster, low ambients like 20F to -20F. If your not worried about those conditions for a few months chopping the weld tube off the top with a pair of side cutters and releasing the bulb charge isn't going to do you any damage but will tell you if your assumption was right. Been here, did that, it worked. Not saying it will every time but doesn't sound like TXV to me.

MHO

JS

[k-fridge]

Hey guys,
I ended up talking to Dave at Coldzone.
He believes my Headmaster is stuck in bypass due to low charge. And the gas along with the liquid thats being sent down to evap is causing the TXV to be wide open and due to the increased velocity of the refrigerant flowing through the valve and evaporator is the reason why I have floodback when attempting to clear glass. So in other words the TXV is over feeding because I don't have a good liquid seal because of headmaster and the low charge.Or something like that:D
He wants me to shut down machine overnight and come in the morning and heat a fresh jug of 22 up and try to jam liquid into the receiver as best I can and try to make the headmaster come out of bypass. He said I need to get the head over 200 at least before it will come out. I am thinking about sticking sensing bulb of txv in a cup of ice water. (should help slow down the flow, I would think) when I get back to this box and do what Dave say's.
As suggested above, block off part of the condenser to run the head up and tap on the Headmaster with a screwdriver handle or a plastic hammer. Something that will jar the valve but not dent it. I still think you're TXV may need some adjustment regardless.

[ReferTroop]

Hey guys,
I ended up talking to Dave at Coldzone.
He believes my Headmaster is stuck in bypass due to low charge. And the gas along with the liquid thats being sent down to evap is causing the TXV to be wide open and due to the increased velocity of the refrigerant flowing through the valve and evaporator is the reason why I have floodback when attempting to clear glass. So in other words the TXV is over feeding because I don't have a good liquid seal because of headmaster and the low charge.Or something like that:D
He wants me to shut down machine overnight and come in the morning and heat a fresh jug of 22 up and try to jam liquid into the receiver as best I can and try to make the headmaster come out of bypass. He said I need to get the head over 200 at least before it will come out. I am thinking about sticking sensing bulb of txv in a cup of ice water. (should help slow down the flow, I would think) when I get back to this box and do what Dave say's.
Hopefully its a refrigerant cooled and not air-cooled compressor, just watch the heck out of the superheat and slugging.

[k-fridge]

Hopefully its a liquid cooled and not air-cooled compressor, just watch the heck out of the superheat and slugging.

K-body is air cooled, should still have plenty of airflow in that unit though.

[ReferTroop]

Copeland semi model # KANB-007E-CAV-800 on coldzone rack.
Evap AA18-66B. Are they a match?

I noticed HPC5-1 headmaster is bypassing some hot gas into the receiver at 190 psi. Temp readings around valve = R-98f, C-88f, D158f.


Can't clear glass without flooding back. It's almost like "did somebody just turn off the evap fan motor". My glass is not even clear and I'm flooding back.



This is what pressures I left unit at tonight.
190 High
52 LOW
LLT 96
SLT 62
Outdoor Temp. 86F

Box is cold at 36 F. But again sight glass is not clear and customer will call back. Last week I found unit flooding back and suction was high. Recovered 3 lbs. of gas and obtained these same pressures and box temp dropped fine. Today I get call back. found suction at 35, suction warm, Add maybe a pound of gas and bingo suction goes up to 55 and box begins to pull down.
But sight glass is not clear.



With this limited info. (probally get more later) I can provide can anybody give me any ideas.

I am thinking TXV overfeed, Mismatch, or could it be Headmaster?

Or could it be headmaster...you were right from the get go bro....

[ReferTroop]

Air cooled the suction line enters the head directly of course, refrigerant cooled the suction line enters the back of the motor windings causing any liquid refrigerant to cross the motor windings subsiquently flashing off any liquid that could slugg the reed valves, or at least for the most part until constant liquid flow is acheived.
Air cooled the liquid is introduced directly to the head.:eek:

[KB Cool]

Bad headmaster if its bypassing, what reason do we have headmaster, low ambients like 20F to -20F. If your not worried about those conditions for a few months chopping the weld tube off the top with a pair of side cutters and releasing the bulb charge isn't going to do you any damage but will tell you if your assumption was right. Been here, did that, it worked. Not saying it will every time but doesn't sound like TXV to me.

MHO

JS

I asked Dave about headmaster failure. He said it doesn't ever happen. "They only fail to bypass",Not fail to come out of bypass. I shut every compressor off on the rack. And then turned both the condensor fan motors off head rose well over 250 and glass looked like it wanted to clear but did not. I was thinking WTF is my dip tube broke off inside the receiver. I don't know. I am gonna do what he say's and go from there.

[ReferTroop]

I asked Dave about headmaster failure. He said it doesn't ever happen. "They only fail to bypass",Not fail to come out of bypass. I shut every compressor off on the rack. And then turned both the condensor fan motors off head rose well over 250 and glass looked like it wanted to clear but did not. I was thinking WTF is my dip tube broke off inside the receiver. I don't know. I am gonna do what he say's and go from there.

Thats why I had this happen to me not 4 months ago...:D

absolutly

JS

[ReferTroop]

Give it a shot, if nothing else works don't be afraid to cut the weld tube on the top of the headmaster.

Would be glad to hear I'm wrong because changng a headmaster can be a beech when these manufacturers stick them in so tight...

Good luck


JS

[KB Cool]

Give it a shot, if nothing else works don't be afraid to cut the weld tube on the top of the headmaster.

Would be glad to hear I'm wrong because changng a headmaster can be a beech when these manufacturers stick them in so tight...

Good luck


JS


Dave's the tech support guy at COLDZONE.

[ReferTroop]

Dave's the tech support guy at COLDZONE.

Let us know, gotta get to bed man.

Long day ahead...

JS

[thegoodhumorman]

Dave is a support guy not out in the field.

Technical Assistance is a guy giving you his experience which most of is likely from his engineering book or the like.

He may be earnest but those guys aren't throwing out the Gospel is all I am saying whether they believe it or not.


It can happen. Sounds like it needs a fan cycler to me after some modifications with the stem....

I think you had it pegged- and IMHO you will be money ahead with a fan cycler- hwo much are those callbacks...?

(I just HATE nonadjustable control components period)

just my $.02

[the mojo]

Plan on replacing the Alco and put in a LAC-4 with a check valve. Verify the Russel evap as having the correct spider with the open venturi,for R-22.

[KB Cool]

The guy from Coldzone emailed me this info.
Note where it says. Headmaster's fail closed. With very few exceptions. I hope mine is not the exception:D
I am gonna call the guy again and see about just recovering what gas is in there and weighing in charge. The customer is not gonna let me shut their box down overnight and let their Kegs get warm. I wanna change the TXV while I'm at it.

BASIC UNIT CHARGING PROCEDURE FOR FLOODED UNITS ONLY

Warning: Not to be used in Lieu of IOM Manuals included with the unit.
Specials units or construction may or may not differ.

Caution: Please verify if the unit, you are charging, is a Flooded or a Floating Head System. The following is meant for Flooded System with an 180psi Headmaster or 3-way valve (with a 180 marking) piped around the condenser coil. This procedure will not work on a floating head System (Like Sierra or High Sierra Units) and could damage equipment.

Basic Info
Tech note: You can speed read (not skip) this paragraph, the good stuff to follow.
Once the system has been energized for 24 hours and a proper vacuum has been accomplished, be sure the compressor discharge valve is open and the suction valve is open 2 or 3 turns with a valve stem wrench attached for quick throttle adjustments if needed (Valves are usually at mid-seat to accommodate brazing. but not all).

Compressor Start-up
Tech Note: Some little “ old school meets new school” stuff in here.
With gauges attached charge the unit with 50 to 60% of the system charge into the receiver (mandatory R-404A and R507 must be charged as liquid) before the start up of the compressor. Once started it may be necessary to throttle the compressor suction valve to keep suction pressure reasonable to prevent trip outs during charging and pull down. If necessary to add liquid refrigerant to the suction side, a full control ball valve must be used in the charging line to slowly meter refrigerant into the system.
Tech Note: You know to keep the L.P. switch from tripping or prevent slugging and stuff.

Tech Note: Here’s the meat and potato and gravy.
Flooded Systems Require Extra Winter Charge
When charging the unit it will be necessary to bring the head pressure to a minimum of 200 PSIG before just clearing the sight glass (a bubble or two is ok). In low ambient conditions it may be necessary to block off part of the condenser (or shut off the fans) to achieve the 200 PSIG minimums.
Tech Note: This is to insure the headmaster is closed and simulate a summer charge. If you’re a touchy-feely kind of tech: You can verify this, by feeling the condenser coil outlet drain line and the line feeding down to the receiver. These should be the same temperature or within a few degrees F. If the pipe leading to the receiver is “much hotter” then the headmaster is open and allowing hot discharge gas through. When you’re over 200# this could be because the pressure drop across the valve is two high (+12psi). You may need to shut the system down and let the pressure equalize or tap it with a rubber mallet. Headmasters’ fail closed. Therefore, having the entire refrigerant charge feed to the condenser coil, with very few exceptions. (See the Tech Note for Headmasters for more info.)

Extra Winter Charge Info
Now that you have achieved the summer charge, addition of the “winter charge is required for the “Flooded” System. Prior to this and if you blocked the coil to maintain the 200psig minimum head pressure, you can remove the block on the coil (to prevent nuisance High pressure switch tripping while adding the winter charge).
Tech Note: The winter charge is necessary, when the outside ambient starts getting below approx. 70degF, the headmaster will start opening and send hot discharge gas into the drain line to the receiver. This “hot discharge gas” will hit the liquid present and expand to maintain 180+/-10% PSIG. You can feel by touch, as mentioned above. (the purpose for this type of control can be found in the Tech Notes –Headmaster page.)
For Russell units get the “extra” winter charge weight from the tag on the coil or the IOM Manual the came with the unit.
For Multi-Compressor units only: you will need to add the extra charge required for winter conditions as follows, on Medium (+10sst or above) Temperature systems, you will need to add 3 lbs of refrigerant per compressor horse power and 4 Ibs of refrigerant per horsepower for Low Temperature.
Wait, your not done!!
The Last thing to do is set the superheat on your system and you can go home.
SUPERHEAT SETTING
Superheat setting at the compressor should be between 25 and 35 degrees F. Measured on the suction line six (6) to eight (8) inches from the compressor and subtracted from the suction pressure when converted to degree F. Make sure you leave at least four (4) to six (6) degF superheat at the evaporator minimum measured around the TXV bulb.
Tech Note: Superheat at the compressor has a direct effect to the life of the compressor. Frost line is an indicator, but not an exact science and your compressor needs you. At the same time we need to make sure that the “change of state” from liquid to gas is being done inside the evaporator coil, (plus a little additional superheat) hence the “4-6degF minimum” superheat, as noted above. I know, you were taught and in a perfect world the evaporator is “supposed to be adjusted for 10degF superheat but the piping in a building is rarely perfect or other addition loss is encountered. Also the compressor performance may not be an exact one to one match up to the evaporator design. Superheat for Low temp systems usually is around 6-12degF and med temp systems are usually 8-14degF. Some systems may have been designed for even higher superheat and TD setting to remove moisture from the box. Bottom line is; the compressor must be protected. (See Tech Note for TXV for more)
Final: This should provide years of trouble free performance, as long the employees don’t use the box to cool themselves off. Thanks for putting up with the humor. See our website for even more info www.russellcoil.com under ”Products and Literature”.
Thank you for helping us, help, our Customer.

[ReferTroop]

it was headmaster wasn't it...


?
JS

[yotaman16]

dave at coldzone is a dip $hit.. Had to deal with him a few times on stuff.. Waste of breath talking to him

But i agree im thinking headmaster stuck.

[KB Cool]

dave at coldzone is a dip $hit.. Had to deal with him a few times on stuff.. Waste of breath talking to him

But i agree im thinking headmaster stuck.


You can say that again:D
I did exactly what he said today. Warmed bottle in bucket of hot water.
Jammed about 5lbs into receiver. Fired unit up and yes sight glass was clear. But I almost took out the valve plate. It was flooding back so bad that discharge temp. went luke warm. I shut unit down and went to txv and cranked it all the way closed and fired it back up and it still flooded and I could still hear flow going through the valve. I shut unit off and went and bought a new Txv valve. Installed it and fired unit back up and it's not flooding but still had to recover some of the over-charge that Dave had me put into it. And now it's working great and sight glass is clear. I told DAVE that I originally found the unit flooding and He gave me this "of course it is you have no liquid seal and due to the velocity of the refrigearant flowing through.........Whatever
But I am glad it's over with and repaired:)

[k-fridge]

You can say that again:D
I did exactly what he said today. Warmed bottle in bucket of hot water.
Jammed about 5lbs into receiver. Fired unit up and yes sight glass was clear. But I almost took out the valve plate. It was flooding back so bad that discharge temp. went luke warm. I shut unit down and went to txv and cranked it all the way closed and fired it back up and it still flooded and I could still hear flow going through the valve. I shut unit off and went and bought a new Txv valve. Installed it and fired unit back up and it's not flooding but still had to recover some of the over-charge that Dave had me put into it. And now it's working great and sight glass is clear. I told DAVE that I originally found the unit flooding and He gave me this "of course it is you have no liquid seal and due to the velocity of the refrigearant flowing through.........Whatever
But I am glad it's over with and repaired:)

I knew that......:D:D:D:D:D

[KB Cool]

I knew that......:D:D:D:D:D


I did too. But I still question myself. Maybe in a few more years, I'll get better.:)

[k-fridge]

I did too. But I still question myself. Maybe in a few more years, I'll get better.:)


Trust your instincts my brudder.

[aprophet]

so the txv was bad ?