CVHE rear bearing changeout

[ChillerWisperer]

Anybody ever change a centravac rear bearing by bringing the pressure up to zero and doing it on the fly? At Trane we always pulled the charge.
If I could, that would give me justification to buy a good pressurizer. Sorta kill two birds with one stone.

[txhvac]

No tail bearings too involved, I've zeroed a machine & pulled oil pump assembly before, pump failing had to have the machine later that day! I've done quite a few 1st stage tang operators.

[Healey Nut]

You gotta be F&%#@ing kiddin ??????? and what happens when you pass out from the fumes and fall off the chiller and break your neck !!!!!!!
It takes a good four hours to swap the bearings using the proper procedures and tools , ie the bearing press. Your not doing a quick switch of a vane operator or oil reg here your talking an extensive repair which takes time and concentration. If you dont use the bearing press I guarantee you will be doing them again 6 months from now because you cannot do the preload properly without it . JMHO

[klove]

... Sorta kill two birds with one stone.

You can sorta kill you and the guy workin' with you, while you're at it....... :lilhelp:

I go back to what I said before in that other thread about the boiler - your boss needs to decide whether he wants to fish or play with the worms. Having a job that calls for a certain tool is justification for buying that tool in this instance. You shouldn't have to consider such a thing as this thread was predicated on just to try and get what you need to work with.

[Healey Nut]

Also what happens if something goes wrong and you need to use some heat with torches ?????? Go ahead gas yourself ????? Hope you have lots of insurance .
I know it may sound harsh but I cant believe you would even consider it ???? Totally dumb idea if you ask me

[drivewizard]

Not only is it a bad idea, I am pretty sure it is against EPA Reg.s also.
If my memory serves me, I think anytime you expose a hole over 2-3 inches, it requires recovering refringerant on low pressure machines.

Even though enforcement is pretty much non-existent, it is just a bad idea from a safety stand point alone.

[triggerhappy]

I don't want to pile on here but depending on the vintage of the machine you will most likely need to solder a line back together.

I prefer not to solder with gas in the machine.(I am not saying that I have never soldered with gas in the machine but really don't like to)

[triggerhappy]

ChillerWisperer,
I know that it is none of my business but after reading a few post about your current state of employment.

I have to ask why don't you just come back to work for Trane and quit messing around with these contractors?

[jimbob73]

Not only is it a bad idea, I am pretty sure it is against EPA Reg.s also.
If my memory serves me, I think anytime you expose a hole over 2-3 inches, it requires recovering refringerant on low pressure machines.

Even though enforcement is pretty much non-existent, it is just a bad idea from a safety stand point alone.

This is a true statement.

[absrbrtek]

ROFLMAO, not all contractors are as screwed up as CW's employer. There are plenty of non factory contractors that are better than the factory. JMHO
ChillerWisperer,
I know that it is none of my business but after reading a few post about your current state of employment.

I have to ask why don't you just come back to work for Trane and quit messing around with these contractors?

[Healey Nut]

I have to agree with the other guys if the contractor you work for isnt prepared to come up with the bucks for the proper tools for the job then he sould get the F&%# out of the way and let someone else in there ????

[ChillerWisperer]

OK OK...geeze guys, I was just asking. I wouldn't have tried it unless someone had done it sucessfully. I've done a few, so I know what's involved. Pulling the gas isn't any big deal, after all.

[klove]

OK OK...geeze guys, I was just asking. I wouldn't have tried it unless someone had done it sucessfully. I've done a few, so I know what's involved. Pulling the gas isn't any big deal, after all.

It is if your boss won't get you a decent low pressure recovery unit......... :D:p:eek:

[Healey Nut]

Come on CW you knew the answer before you asked the question . If your not prepared for the answers then why did you ask ??????????????

[ChillerWisperer]

It is if your boss won't get you a decent low pressure recovery unit......... :D:p:eek:

I was going to sub that part out to a friend anyway. I always used this guy at Trane and he does good work at a reasonable price. For about the last 6 years or so, we didn't do our own recovery in the office I worked out of which was a sub office. We always got the cast off tools from the main office and our recovery equipment was a POS that we were always repairing anyway. Finally, for the number of times a year we needed to pull the charge on a big machine (maybe 8 or 10), the main office decreed that it was cheaper to sub it out than time lost on repairs or purchasing new equipment. We often referred to ourselves as the red headed step children of the main office, but the good thing about that is they never bothered us as long as the customers were kept happy and the money continued rolling in.
I think making us do more with less made us more self reliant mechanics. When they would send someone down from the main office to help out when things got busy and we in the middle of a teardown, they would invariably complain about how we worked. To us it was just business as usual. A lot of jobs that would be two man jobs up in the main office were done by one guy down here. We were spread out pretty thin at times.

[heavymetaldad]

you work at my shop? :D

[ChillerWisperer]

Come on CW you knew the answer before you asked the question . If your not prepared for the answers then why did you ask ??????????????

Well, I knew what my answer would have been, but when I present the job to my boss I want some opinions I trust that can back me up when he asks me if it can be done that way. I'm still trying to figure him out. I don't know if he is just real old school or if he doesn't know WTF he is talking about. He used to work for JCI/York before he came to this company. One of the things he wanted me to do was pressurize a chiller with nitrogen on top of R-11. That was one of my WTF moments. I didn't realize what he was asking at first and I asked him if the charge had been pulled or do I need to schedule it. He said no, add nitrogen to leak check it, then use the purge to pull it back out.:eek2:
The bearing job is one of my old accounts that I took care of for almost ten years and the customer is questioning Tranes diagnosis since the machine was rebuilt three years ago and the motor rewound and with new bearings installed then. He wanted to go with my new company when I left, but the bean counters in his corporate office wouldn't let him since Trane services all of their locations and you know how bean counters love consistancy. He sees this as justification to get me back in there.

[Healey Nut]

Well I guessing that if you dont have a good low pressure recovery unit you probably dont have the bearing press either ??? So how do you propose to do the job correctly ??

[ChillerWisperer]

Being a mechanical company, they do have a bearing press and an oven. I would just need to get the proper attachment if they don't have it and a shaft nut socket.

When I was talking about not having a good low pressure recovery machine, that was at Trane.

[absrbrtek]

LOL, but the manufacturers have everything. :pop:
Being a mechanical company, they do have a bearing press and an oven. I would just need to get the proper attachment if they don't have it and a shaft nut socket.

When I was talking about not having a good low pressure recovery machine, that was at Trane.

[triggerhappy]

LOL, but the manufacturers have everything. :pop:

If his office did not have everything that they needed it was no ones fault but their own.

There are probably contractors that get along just fine out there.

But there is no substitute for working for the manufacturers. You have unlimited access to information, electornic data base, tech. assistance, confidential information and parts.

For instance we had a big CVHE that was shaking and was out of warranty.
At that point I was just following instructions from LaCross and probably took the machind down at least 5 times as they sent bearings, rotors, seals, gkt. kits and finally the part that made the fix. The Ball Bearing Bracket itself.

Not to mention the rental chiller that sat there for a month.

And all this with no down time to the pharm. plant.

And at no COST to the customer.

I don't beleive that the job could have been resolved the same way by any contractor.

[jayguy]

...The Ball Bearing Bracket itself...

i would be very interested in that story.

[triggerhappy]

In short the ball bearing bracket (end bell of the motor).

The casting was not machined parallel for the outer race of the bearing.
Someone in LaCross had seen it before and sent a new end bell and that cured the problem.

I had seen that on a vertical split case pump from B&G before.

[jayguy]

thanks!

[ChillerWisperer]

Anyone have the service bulletin that covers the bearing replacement? It's CTV-SB-33, I think.

[heavymetaldad]

Anyone have the service bulletin that covers the bearing replacement? It's CTV-SB-33, I think.

your email address correct? won't go thru

[heavymetaldad]

think i figgered it out

[Healey Nut]

The bulletin comes with the bearings .

[ChillerWisperer]

think i figgered it out

Gracias amigo

[ChillerWisperer]

The bulletin comes with the bearings .

I needed the part numbers of the press parts and socket I need to get and have on hand when I do it.

[txhvac]

I needed the part numbers of the press parts and socket I need to get and have on hand when I do it.

So what do think...you gonna try it on the fly? Like your first post?:D

[ChillerWisperer]

So what do think...you gonna try it on the fly? Like your first post?:D

Heck no! I was just wondering if anyone had done it that way back in the day. Worst thing I ever did on the fly was a motor terminal plate gasket on a CVHE at a hospital that only had the one chiller. Took it down at 1:00 AM and had it running by 4:30 AM including bringing the pressure up to zero. I used a full face scuba mask with regulator and breathing 50/50.

[chillrdude]

CW you need to be there in person when you tell your boss how much Trane wants for the press and hydraulic nuts, you are going to love the expression his face makes then.

The press is not a necessity, I spent about 14 years with a factory Trane office, there were hundreds of overhauls done on CVHEs long before the press idea ever came out and they all ran just fine. Make sure you check the clearance between the bearing and the shaft with a feeler gauge, there should be none, do that and you wont have any problems.

There are a lot of guys on here who have done them both ways and never had a problem.

Let us know whether he lets you buy it or not, my money says he sh*ts his pants at the cost.

[triggerhappy]

I needed the part numbers of the press parts and socket I need to get and have on hand when I do it.

I didn't check to see how old the SB is that you were looking, but there has been a lock nut change in recent years and you need a new style lock nut socket along with special torx sockets.

As for not using the press. All I will say is you should follow the instructions included with the bearings.

Or I guess you could go on the assumption that you have more insite into the process than the Trane eng. dept.

[chillertech257]

All the tools needed are in the cvhesb33 everything except the part#'s for the new style sockets.

[Healey Nut]

Ditto triggerhappy's post they wouldnt ask you to do it if it wasnt nessacary??? Also you dont have to buy the tools from you know who . You can get them at any bearing supply house or hydraulic place . They even put the manufacturers #'s in the bulletin .

[CaptJackSparrow]

[

For instance we had a big CVHE that was shaking and was out of warranty.
At that point I was just following instructions from LaCross and probably took the machind down at least 5 times as they sent bearings, rotors, seals, gkt. kits and finally the part that made the fix. The Ball Bearing Bracket itself.

Not to mention the rental chiller that sat there for a month.

I don't beleive that the job could have been resolved the same way by any contractor.[/QUOTE]


Sorry trigger but I could not stop myself.

What about a job we "Big bad FACTORY" did where we installed a cooling tower of a different design and didnt think about a check valve in the discharge of the pump so we left the customer with running the pump 24/7/365 so that it would not air lock on start up as a final solution.

What about the courthouse we installed condensating boilers on a building with a steel stack and and would not do anything about it until the county got the lawyers involved?

What about the time I had to rebuild a CVHE by myself around the clock because the hospital was down and there was nbody out of 40+ techs that could work that weekend?

What about the guys with 20+ yrs, poses sells the company and the retirement is gone?

What about Carrier not allowing techs to cary a pocket knife? Is that saftey or BS?

What about GPS on their trucks?

The factory does have "some advantages" for sure like the tech info and factory support. But there are advantages of working for indipendents as well. We are real people who can make our own decisions without checking in with corporate! I never could accept the answer that "it's CORPORATE POLICY". Who is corporate anyway? God almighty? Do we throw away common since because CORPORATE SAYS SO? I could not stand to hear someone say that! Do we have to slay a fattened calf and put it on the alter to get into the holyest of holys at the corporate office? If they say the C word then you can forget it because that means we cant even propose it as we are lowly and unworthey!

:rules: Rules
You have to live by them! We get to make em or break em! Being a pirate has some disadvantages but life is allot more fun! He He He

[klove]

[

For instance we had a big CVHE that was shaking and was out of warranty.
At that point I was just following instructions from LaCross and probably took the machind down at least 5 times as they sent bearings, rotors, seals, gkt. kits and finally the part that made the fix. The Ball Bearing Bracket itself.

Not to mention the rental chiller that sat there for a month.

I don't beleive that the job could have been resolved the same way by any contractor.


Sorry trigger but I could not stop myself.

What about a job we "Big bad FACTORY" did where we installed a cooling tower of a different design and didnt think about a check valve in the discharge of the pump so we left the customer with running the pump 24/7/365 so that it would not air lock on start up as a final solution.

What about the courthouse we installed condensating boilers on a building with a steel stack and and would not do anything about it until the county got the lawyers involved?

What about the time I had to rebuild a CVHE by myself around the clock because the hospital was down and there was nbody out of 40+ techs that could work that weekend?

What about the guys with 20+ yrs, poses sells the company and the retirement is gone?

What about Carrier not allowing techs to cary a pocket knife? Is that saftey or BS?

What about GPS on their trucks?

The factory does have "some advantages" for sure like the tech info and factory support. But there are advantages of working for indipendents as well. We are real people who can make our own decisions without checking in with corporate! I never could accept the answer that "it's CORPORATE POLICY". Who is corporate anyway? God almighty? Do we throw away common since because CORPORATE SAYS SO? I could not stand to hear someone say that! Do we have to slay a fattened calf and put it on the alter to get into the holyest of holys at the corporate office? If they say the C word then you can forget it because that means we cant even propose it as we are lowly and unworthey!

:rules: Rules
You have to live by them! We get to make em or break em! Being a pirate has some disadvantages but life is allot more fun! He He He[/QUOTE]

AMEN!!!!!!!!!!!

[CaptJackSparrow]

YOU CAN TAKE ME LAAND!!!

BUT YOU CAN NEVER TAKE ME FDEEDOM!!!!!

[MKnyc]

Interesting thread. Incidently, the repair in question cannot be done that way. The rule is anything over 15 square inches for 15 minutes, is considered a "Major" repair, therefore requires discharging a machine. Raising pressure with nitrogen will work as well for doing minor repairs but is ILLEGAL. This due to the refrigerant that will be lost during purging. As for not preloading the bearings, nice try. They absolutely will fail if not preloaded. As for working Factory or Non-Factory, There are pluses and minuses just like everything else. The GPS thingy is coming whether we like it or not. Whats more important is whether the continued micromanaging will drive experienced industrial HVAC technicians out of this trade because of the disparity of pay versus what some other field would pay for the technical knowledge we possess.

[chillrdude]

. As for not preloading the bearings, nice try. They absolutely will fail if not preloaded.

Let me see here, CVHEs came out in like 1979, the hydraulic nut and press gig came out in the mid to late 90s I think. So you are saying that ALL the machines that were ever overhauled without using the press have failed, Incredible.

[Healey Nut]

Yes they did come out in 79 but there have been numerous design changes and in particular bearing design changes and thats the reason for the bearing press etc . Go ahead be my guest. Change them without the press and I guarantee you will be back in 6 months, the customer if you still have them will be pissed ,and you or someone else will be changing them again and doing it the right way .

[always looking]

Lately I have heard of more failures using the press than not using it. We have one at our shop but the previous office I was in still doesn't have the thing' They never have had to do any over again.