Trane CVHE with Earthwise purge - leaks and pumpout minutes?

[kaon]

Hi all,

I have three CVHG565 in one building and two in another. Each one is 500 RT. Abt 5 years old. They all have "Earthwise" purge units.

(As far as I can tell, CVHE are Trane's lineup of centrifugal R123, low-pressure, water-cooled chillers... Not sure about the difference between CVHE, CVHF, CVHG etc)

My question is about leaks and pumpout.
Am I right that to a first approximation, pumpout minutes per week is proportional to the speed of leaks?

What range of pumpout minutes per day or per week is considered

normal
should-fix-but-harmless
could be harmful
definitely harmful
?

[mustardman]

Are you a technician?

[acjourneyman]

With 5 chillers, there should be at least 1 IOM on site, we always leave them when we do startup, all the information is in there. All you have to do is read.

[kaon]

With 5 chillers, there should be at least 1 IOM on site, we always leave them when we do startup, all the information is in there. All you have to do is read.

Does anyone remember ball park figures off hand?

I could not find mention within the 112-page Operation Maintenance: CVHE-SVU01-EN (http://www.trane.com/Commercial/Uploads/Pdf/1050/cvhesvu01een_405.pdf)
(Is this the IOM you speak of?)
I am reading the Operation Maintenance for the EarthWise Purge, PRGD-SVU01C-EN (http://www.trane.com/webcache/rf/centrifugal%20chiller%20upgrade%20products%20(ctvu )/service/prgd-svu01c-en_04012006.pdf), on page 26, it un-helpfully informs that the "Daily Pumpout Last 24 Hrs" readout "allows a check against factory recommended values". (Which no one seems to know?)
My local Trane technician just told me that he considers up to 15 minutes per week to be OK. hmmm...

TIA

mustardman, no.

[jemawalton]

Do you have any reason not to trust your local guy?

[absrbrtek]

What is your 30 day average pumpout time? Most of the chillers I have are between 0 and 5 minutes a day, they are almost all over 1000 tons.

Trane has literature on acceptable daily pumpout limits in their Refrigerant Handling Guidelines, CTV-SVX05A-EN. Looks like around 5 minutes per day of pump out on a 500 ton machine is typical operation according to the literature. Between 5 and 30 minutes is a considered a small leak. Between 30 and 65 minutes is considered a large leak.

PG. 6 has the chart. http://www.trane.com/webcache/rf/centrifugal%20liquid%20chillers%20(ctv)/service/ctv-svx05a-en_10012006.pdf

[acjourneyman]

I would consider a chiller as leaking when it goes from no minutes a day to 5 or more.I would want to fix a leak of 5 minutes a day or more.

[mustardman]

I agree with what your Trane tech said basically translates to two minutes a day. Thats what the purge is for. If that number suddenly jumps then I would look into matters further. But for now you seem a ok

[txhvac]

Your purge pumping out is not normal operation, unless maybe you had some repairs done. The idea is to have a leak free "tight" chiller. Small leaks will generate small pump out times. It's all a matter if the purge can keep up w/ the amount of air in the condenser. In the CH530 controls you can set-up your max pump out min. per day, if it exceeds this point it can shut the machine down. At least w/ the Earthwise purge has the carbon tank, to help strip out as much 123, as possible. I don't know the ratio of refrigerant to non-condensibles on pump out. If you don't trust your service company, look in to getting a second opinion. Good luck.

[kcwong]

CVHE/F/G are the multi stage R123 chillers of Trane.

CVHE - 3 stages from 150 to 500 ton

CVHF - 2 stages

CVHG - 3 stages from 500 to 1400 ton

The tonnage may be varied with difference working condition.

[mustardman]

tx I agree in the sense that you should have a tight machine. But reality is they all leak a little otherwise you wouldn't need a purge. As for the mix of refrigerant to air I am not sure but the carbon tank should be changed after 5000 purge minutes. If the tank is full your purge minutes will go up. Also a
3/16 drill bit will open that orifice up and drop minutes too. kidding

[txhvac]

Correct, that's why they have purges... & that's also why we have service mechanics. Leaks don't fix themselves, & they have a tendency to get worse. :)

[kaon]

Do you have any reason not to trust your local guy?
In this case, 15 minutes per week agrees well with mustardman, acjourneyman and absrbrtek. Great.
But yeah, I have reason to check on forums.
E.g. When I asked him filter-dryer changing procedure, (before I found the purge manual), he gave me instructions that did not agree with page 32.
When I had a leak, their proposed leak testing method was to recover refrigerant, and charge with N2. This is expensive and contradicts the IOM, which specifically says not to use N2, but to simply warm up the refrigerant to positive pressure by circulating warm water.
When I had a phase loss trip message on startup, their recommendation was to change the Cuttler-Hammer soft starter. We held off, and did our own swap tests, and found the problem was something other than the softstarter. He recommended to buy replacement for at least 2 other parts, which we found were good too by swap tests. ...

[absrbrtek]

Sounds like its time to change service providers. Last thing I want to do is pull the charge.
In this case, 15 minutes per week agrees well with mustardman, acjourneyman and absrbrtek. Great.
But yeah, I have reason to check on forums.
E.g. When I asked him filter-dryer changing procedure, (before I found the purge manual), he gave me instructions that did not agree with page 32.
When I had a leak, their proposed leak testing method was to recover refrigerant, and charge with N2. This is expensive and contradicts the IOM, which specifically says not to use N2, but to simply warm up the refrigerant to positive pressure by circulating warm water.
When I had a phase loss trip message on startup, their recommendation was to change the Cuttler-Hammer soft starter. We held off, and did our own swap tests, and found the problem was something other than the softstarter. He recommended to buy replacement for at least 2 other parts, which we found were good too by swap tests. ...

[acjourneyman]

I have to disagree with you on this one Absrbtek.I will not leak check a large tonnage 123 chiller ever again with hot water.It is impossible to boil it up if the room is cold.I could pull the charge, charge it with nitrogen and find the leak quicker than trying to boil 123.And anyways, chances are you will have to pull the charge to fix the leak.

[mustardman]

And I hate to say it ac because I disagree with you on pulling gas to leak check. I usually agree with your posts. We rigged up a portable boiler on a hand truck and If I drain the condenser and some water in the evap I can have any 1200 ton Trane at 5 to 10 pounds which is high I know in four hours or less. There is no way you can pull the charge on that machine in under four hours. Geez takes that long to get the tanks on site if tere is stairs.

[kaon]

I have to disagree with you on this one Absrbtek.I will not leak check a large tonnage 123 chiller ever again with hot water.It is impossible to boil it up if the room is cold.I could pull the charge, charge it with nitrogen and find the leak quicker than trying to boil 123.And anyways, chances are you will have to pull the charge to fix the leak.
How cold is your climate? and yet you need air-conditioning?
Fortunately for me, temperatures are around 26-32 Celsius year-round.
We (owner) eventually did the warm water test on our own, and found the leak at the large flange joint under the economizer. I think it is the line from condenser to economizer.

[jayguy]

i know that we used to use N2 for some leak tests before i started here...but talk about your non-condensibles! we do not seem to use it much now.

we are starting to have problems with heating up the larger machines in a reasonable amount of time in some locations (lower ambients) so we rely on the purge minutes tracking method. i try to leak check all of my low pressure chillers in the run season (high side anyway) just to make sure that a "leak out" has not developed.

with regards to pulling the charge...the nice part is that you verify the charge...bad part is that it may not be practical under most "non-leaker/not-leaking-enough" chillers due to time/cost constraints. but if the chiller is short on charge...hot water is usually not enough since there is a lot less refrigerant to boil.

as far as purge minutes...trending/tracking is probably more important. 5 minutes per day...15 minutes per day...so what? is it getting worse and how fast. i have a chiller that puts on less than 15 minutes per year. i would start to get worried if it started putting on 30 minutes per year. it is not always the instantaneous value that is important (although sometimes it is!). yes, all leaks should be fixed, but at what cost? there are some chiller plants that have to have every leak fixed because they are already maxed out on tonnage and need every single ton that they can get...air does not help. and yet there are plants that have so much back up, if the chiller filled up with air, they would just turn on another one and have the leaker fixed some time this winter.

you need to decide what is right for your machine and your plant. keep in mind that some manufacturers literature is written with "help" from the marketing department.

good luck.

[acjourneyman]

I have seen all of the refrigerant boiled out of the evap and condensor and still had the machine in a vacuum.If you have a 55 deg chiller room it will all migrate into the volutes, economizer etc.And see, Kaon will have to pull the charge anyways to fix the leak. The other day I went against my better judgement and tried to boil a chiller up from 14", 4 hours later it was at 10", I had my boiler circulating through both bundles.

[chiller rob]

usually the young bucks have that problem when they are cycling the water thru the 1/4 gage ports...

i know you better than that...
some times 123 can be tough!

if i think i am going to have a problem, I will set up some heat lamps the night before...

cheers!

[Healey Nut]

The main thing to look for is a sudden increase in the number of pumpout mins, if it has been 15 mins a week for the past 6 months then why worry.If it suddenly increases then that indicates a worse leak that should be looked for. As for pulling the charge for 15 mins a week , how much refrigerant are you going to loose in the removal\leak test and repair. Probably a lot more than 15 mins a week . Change the carbon tank after 5000 mins. Why is'nt that what the regeneration cycle is for on the earthwise purge. Leak testing with hot water is fine I did a 2500 ton duplex only 2 weeks ago 65f mech room had it up to 5psi in about 5 hrs with water flowing in series through evap into cond and down the drain no problem. you just have to make sure the bundles are full and the flow is in the bottom and out the top for maximum heat transfer and flow.

[drivewizard]

I used to leak test with hot water, it was a PITA. I now pull refrig if a leak test is needed.
I am usually very successful stopping leaks with out testing, just from experience and knowing where the leaks usually show up.
If purge time doesn't slow down, its time to pull the charge.

I think the Factory is changing their opinion on using hot water, due to the repeated stressing of tubes. Also, a lot of customers don't want you draining treated water down the drain into the river.
Or don't want tower water mixed with chilled.

As far as how much refrig is lost during 1 minute of pumpout. This is the data I have:

For a purifier without a Charcoal canister:
@ 90 deg cond temp---- .0015#/ min
@ 70 deg cond temp---- .0011#/min

IF you have a charcoal tank or an earth wise purge the emissions will be zero, unless tank is full, then emissions will match above #'s
If tank is about half full then the emission rates start to climb, but not as bad as without a tank.

It's not a good idea to drill out orifice, but you can put a bypass on for short periods to get a large amount of air out quicker. I usually use a short 1/4" hose with an inline ball valve throttled down as a restrictor. Open valve just enuff to get pumpout to cycle. But try to keep the suction temp close to 30-35deg.

[Randy S.]

I've chased leaks before only to find that the real culprit was a faulty check valve on the gas line into the purge. This was on a "Carolina Purge", very similar to the Trane. High purge counts and not a leak in the darn thing after I pumped out 1400 pounds of 11 and spent a half day with the sniffer and ol' Blu.

Then the next time it was suction L gaskets, so don't just assume anything.

Log your machines and look for an increase in purging.

[mikeg3066]

When using hot water to leak check I have found that draining the barrels half way or even lower will help speed up the process.

[always looking]

The first place to look for a leak on a chiller with an Earthwise Purge is the float in the bottom of the tank. Leaks can be found while the machine is running, or you can isolate the purge and pressurize it to near thirty pounds. Just about every machine out there leaks there.

[ga1279]

ga1279, I agree on the trending daily logs for accumalated runtime (pump out) time. I find it easy just to leave the purge in the Adaptive mode and that will signal problems ahead of time. As far as the leak checking procedure I would say whatever works for you. Here in Houston you wouldn't think it would be a problem and it isn't during the warm weather. For the other month I find it best to run the chiller as cold as posible to get all the refrigerant in the chiller barrell, then valve it out and begin heating up the vessel. Most equipment rooms are air cond. but not heated. As I mostly work on older machines gradual heating and cool down will work without stressing the tubes. Some of the newer Tranes have ultra thin tubes that will flex in the supports and shrink in the tube sheets. I have also crossed over and heated the condenser along with the chiller barrell. Valve out the condenser and DRAIN the treated water, pump it back to the tower and flush the condenser and carry on. One last note if the purge was added to an older machine be sure and note exactly how it was installed. I've seen many purges with pump-out time but no leak, only a piss poor instalation of a good purge, especially when used on Carriers or Yorks. Thanks guys.

[absrbrtek]

In an answer to your disagreement. I am talking about the troubleshooting and bad diagnosis the contractor is giving the end user. If this guy is truely repairing the machine like he says, I think he should be suspicious.

As far as heating the chillers, I have 20,000 tons at the site I am at the most. I can just plug the heater in and go about my business while it heats up. I can check it every once in awhile until it comes up to pressure. When the leaks are found the customer gets a quote to repair the machine properly. It's not like there is nothing else to do while it heats up. :)


I have to disagree with you on this one Absrbtek.I will not leak check a large tonnage 123 chiller ever again with hot water.It is impossible to boil it up if the room is cold.I could pull the charge, charge it with nitrogen and find the leak quicker than trying to boil 123.And anyways, chances are you will have to pull the charge to fix the leak.

[rboston]

we have a 1500 ton CVHB double ender which is pumping out over 6 minutes a day and my trane rep is concerned . we also have 2 other units 1480 ton CVHF and a 1250 ton CVHE. we need all three during the summer months,now what ?

[klove]

we have a 1500 ton CVHB double ender which is pumping out over 6 minutes a day and my trane rep is concerned . we also have 2 other units 1480 ton CVHF and a 1250 ton CVHE. we need all three during the summer months,now what ?

Sounds like it's time to belly up and make a decision.

[jayguy]

we have a 1500 ton CVHB double ender which is pumping out over 6 minutes a day and my trane rep is concerned . we also have 2 other units 1480 ton CVHF and a 1250 ton CVHE. we need all three during the summer months,now what ?

like i posted earlier...6 minutes per DAY is not much unless is has only been 6 minutes per YEAR in the past. hurry up and leak check it...maybe you can find the worst leaks and have that chiller repaired before you need all 3 and try to ride out the rest of the season. what refrigerant? what is the purge history like?

[ga1279]

I don't remember responding to this thread, I guess I must have I just don't remember. And they say R-123 doesn't affect your mind ! One other point-Adaptive Mode of purge operation. 2-minutes of purge is considered acceptable.
Geo.