Mcquay

IT sounds like to me you should call mcquay tech. support. There are things inside that compressor you dont want to see and on the outside either like the compressor running but not pumping. These compressors do have a discharge check valve but I doubt you are that lucky. Get all your info together and call.

 

Don't know what your compressor failure is but the reason the refrigerant is first piped through the compressor is to cool the motor windings.

 

Sounds like you broke the gate rotor in compressor it is trash now, no saving it. Hope you have a large wallet Mcquay will bend you over on compressor price and then you are going to have to hire them to help you or you will not get any warranty on new compressor. Went thru same problem couple of months ago. Also when you get new compressor and don't hire them there are things you need that they won't sell you only available to Mcquay techs.

 

Agree, gaterotors are probably shot. Time to pull the condensor apart and clean them out.

 

It Looks That The Motor Is Runing, But The Compressor Not Working.

Call The Manufacturer For Help

 

Abs your right . The gates are gone AND with that low of an amp draw it probobally broke off avery tooth on the " gate " . Your screwed , no pun intended ! You need a new compressor and much more than just that shinny new compressor !! I highly recommend that you get McQauay service to do the job . It is your choice but if the propper steps are not taken you will be replacing that shinny new compressor shortly after you install it ! I'd hate to say I told you so a few weeks from now !!

 

Check the oil sightglass on the seperator, if you see a bunch of white stuff laying in the bottom of the glass, here is where it came from.

It should look like this

As far as getting factory McQuay involved, good luck.

 

The gate material hasn't been white in a long time. As for how to check. pump out the compressor, pull the gate covers, and also pull the oil filter it Will be blown out. at that point. You need to replace the compressor and install / preform a condenser clean up..
this entails removing the subcooler headers and U bends blowing out each tube and replacing the headers and U bends. Next install a 3 core drier in the subcooler U bend
and finally you should remove or inspect the suction line/evap head to insure no gate material went in that direction. You need the right parts and the right person cause brazing U bends without screwing up the tube sheet or tubes is not easy. If you have never done this repair I don't recommend you try cause one mistake and your buying a second new compressor. As for the line placement. The EXV feeds into the motor housing where there is an economizer wheel and a pressure regulating valve to increase the subcooling.

 

I have been to McQuay centrifugal school and screw school when I did not work for them. They gave me the books and service bulletins. It was a better than average school. I had a hard time getting service bulletins for Carrier equipment when I worked for Carrier. Parts are available for McQuay screw compressors. McQuay educates outsiders probally better than anyone else as my personal experience has been.

 

that's good to hear. It'll be interesting how McQuay picks up the ball after the JC purchase of York.

 

mcquay chiller help

If you can get mcquay tech support involved thay will send you info but you must stay involved with them to warrenty the new compressor and there is still no garrenty that you want have another failure.Also ch32 gave good advice and when you clean the suction line dont think you can leave off the new suction filter. When the gates fail it slings bits and peices in all directions including a 2-5/8 suction line.

 

McQuay comp. help

Agree with the with the last few posts, gate rotors are probably broken up, BUT those are one of the few available parts. Actually not a bad replacement job. I got alot of support from Staunton,VA. (FYI, inner and outer checks are also available). As one of the techs said condenser and or SUBCOOLER may need cleaning. Core/drier assy installed prior to inlet of sc is A MUST whether you repair or replace comp. I would recommend doing this first before opening subcooler/condenser (big project) Pull cores after a day, that will tell you ALOT-debis,pressure drop-extent of damage(to a point). I've also got several pictures of these rotors broken up and bearing issues. Will post if any one wants to see. Also Mcquay had OIL ISSUES-not enough from factory and type of oil, caused me MANY problems. Suction filter install also VERY important.

 

Jake it's real simple all you need is a crane and 1 each RTAA or RTAC alittle piping and your customer will love you our procedure for annual startup was check cond. fan motors clean coils Replace Compressors on those old McQuay units. By the time you get someone from the factory to do the work to get this mess right you'll be down for a month
at least we were.

 

OEM info and support

A lot of local branches are the ones keeping info from you and not so much the manufacturer. That applies to all the OEMs. Sometimes the best way is to "talk" with someone at corporate and ask them if they want to sell any more chillers to your outfit.

The McQ training I have been to was more accurate and detailed than some other OEMs. Just don't go to Staunton in August.

Or Syracuse in February...

 

If I were you, in dealing w/ the vintage ALS machines, I'd retro-fit in the oil seperator & other components w/ the compressor replacement. This way if it happens again you don't have to worry about the subcooler clean-out. Also, I know in the Dallas/Fort Worth area companys have been retrofitting in Hannbel dual rotor screws in place of the McQuay single screw P.O.S., I personally have not done this or seen this. Heard of it though, & heard it works just fine. Anybody else heard this one? Any feed back? I'm not bashing the OEM so don't get offended.

 

If I were you, in dealing w/ the vintage ALS machines, I'd retro-fit in the oil seperator & other components w/ the compressor replacement. This way if it happens again you don't have to worry about the subcooler clean-out. Also, I know in the Dallas/Fort Worth area companys have been retrofitting in Hannbel dual rotor screws in place of the McQuay single screw P.O.S., I personally have done this or seen this. Heard of it though, & heard it works just fine. Anybody else heard this one? Any feed back? I'm not bashing the OEM so don't get offended.

I have seen and worked on a ALS that had a Hitahi screw compressor in place of the McQuay screw. My opinion is this was the stupidest thing I have ever seen. That said it did work. I would rather see him replace this chiller then install a non OEM compressor.
Once you hack a Chillier McQuay has every right to disown that chiller and now you completely own it. You better 100% know what your doing.

 

Do your customer a favour and retrofit the machine to a bullet proof RTAA compressor as Controldude mentioned, than you don't get McQuay involved at all and don't let them make any more money for a poorly designed POS.

 

There was nothing poorly designed about the ALS A, B vintage. The bigger problems was mis application of the units ( IE not following the install instructions ). And probably the biggest was the service Techs that never bothered to read the IOMs, where it clearly stated the oil charge was 4-6% of the total refrigerant charge. Be careful trying to argue this because I worked for McQuay and seen alots of contractors handy work.


Its funny you call the Trane RTAA compressor bullet proof. I worked for Trane and seen many an RTAA that was being taken care of by the school janitor, or a 15 dollar per hour maint person. or some Hack contractor. they absolutely beat these compressors to death. and your correct they still ran. Just because they can take a lot of abuse doesn't mean you should do it. I would call them retard proof instead.

 

another example, this year I took over a pfs that is 6 years old and went through 4 compressors. customer wanted to know what was going on with it. last summer it was reset daily. I pulled a refrigerant sample and sent it to a lab. the results was .04% oil. it also had 200lbs too much freon in it. I put in 8% oil in it, one new compressor, new filter driers and all new oil filters. there was no tower control, water would dip to low 50's when chiller was off. I took control of the tower, the chiller now controls condenser pump and tower fans. since Jan. not one alarm. the problem here was a tech had no idea what he was doing so he blamed the unit. I find this all the time, techs wont read the manual or dont understand the unit and calls the unit junk.
the reason it had so little oil in it the same tech broke a line and blew the charge out of it. he recharged it but added no oil with it.

 

I'll give you guys that, there are ALOT, of "techs" who don't have any business working on different machines. However, I too worked for McQuay, and I've seen 1st hand how most of the vintage ALS machines under factory supervision ,guys who read the iom's & had the S.B.'s, still had major problems w/ the older screws. If it wasn't a poor design, then why the retrofits? Why did they redesign the newer AGS machines? How about the S.W.A.T. group? Screw Warranty Attack Team. That was all around the U.S. It was my understanding the 1st machines were rushed to market, which hurt the company pretty bad. I've heard many times that the install was poor or they don't know what they're doing in some cases this maybe true, but if McQuay started the thing up.....McQuay is liable, which equals cop -out, for not catching the construction or install issues before hand. I'm glad that McQuay got things worked out & is able to put out a better product. I've understood Daiken is really trying to turn things around. Again, I am not intentionally trying to insult McQuay. The same can be said for Trane, York, or Carrier. If they had as many problems w/ their machines.

 

I guess all I can say to that is there are ALS a and b vintage which never lost a compressor or gates. Swat was about cleaning up the cond/subcooler coils when the gates went as for changing things It made sense, by installing an oil sep they where able to increase the efficiency and make the unit much quieter. And as for the AGS change that was due to using 134A. I personally think the ALS C vintage was a great unit. aside from the oil foaming at starup. ( which required the oil be removed and replaced with fresh oil.) Well I guess since you worked for McQuay I 'll stop given you such a hard time

 

???

Thanks for all of the replys but I didnt expect so much soapbox talk about how much Junk McQuay's are. I was hoping to share info with a mcqauy tech as I give alot of info for equipment that I work on to people as they need it. Thats how our trade and tech's stay educated and at least keep us all working until they teach illegals how to change compressors (sorry no political agenda here)

As by my user name I would love to take out that McQuay and install an RTAA or RTAC. And I get that secret information that every one says factory guys get. Yeah, thats funny. (we get treated like mushrooms also).

I somewhat recieved some answers that it was the rotor gears. I always call the factories before changing another manufacturer's equipment.

This machine is only two years old and the owner has had numerous issue's with it and I speculated that it was just mechanical failure that we could not see on our PM's. We are in the process of getting info on a new compressor, but I can't imagine McQuay being helpful to any one with the screen name JAKETRANE.

So, I hope I got this right, this probably a gear failure and is not repairable without compressor changeout. I need to add filters in the suction line and line from the subcooler circut (confused on this one I didnt think we added filters before the condenser) or did one of the previous guys just mean change the liquid line filters. AND Lord help me if I have to take the condensor Ubends off and clean those tubes.

God Bless and thanks

 

if the machine is only 2 years old it will have a oil seperator. so with that in place you wont have any gate material in the condenser. it will be in the oil seperator and thats if it came apart. you can look at it when you remove the side and also look where the suction line goes into. just make sure all the sensors are reading right and the expansion valve is working properly.

 

The chiller that you are describing is not only 2 years old . It has to be atleast 3 - 4 and even then should be an ALS-C vintage meaning that it has an oil seperator and a comdenser clean up in not needed . Although from what you are describing it does not sound like a C vintage . The C vintage compressors rarely have gate failures .

 

Ok

I will post the model number on Tuesday

 

mcquay

Guess what ? If you think anyones chillers are bullet proof you are out of a job. Some manufacturers will work with you and some want .Personaly I think its best if thay work with all technitions.If its mechanical built by man or engineered by man kind it can and will at some point in its life fail to work properly.Thats were you come in. its our job to repair or recomend replacement and use our best judgement for whats best for our customers. thay are going to listen to you if you make honest judgements about their equipment and judgements on repair or replace.We all have our opinion which manufacturer has the best equipment and I know a lot of this is fun and games. But if you were fired from your job today! and the company you were fired from was a brand A company.You might have to except a job with a company that was a brand x dealer.What then is the best brand? Did you know that no matter what brand you ask a customer has he herd of he probably does not know the differance other than what you tell them.All thay know for the most part is turn this and it gets cooler turn that and it gets warmer.Just remember it is their decision to make new or repair either way you probably win.Try to keep your customers for life thay might follow you were ever you go brand A or brand X or what ever brand you decide to sell when you go in to buisness for your self. On all the start up jobs i have worked on there have always been problems to work out during the installation process and some have been an engineered nightmare some never get fixed until most involved are at the end of their rope and some technition makes the right suggestion. Some times it comes during the job and some times it comes years after the fact.I do have my preferance and I know what is brand A to me but I also know if it was not for brand X i would have a lot less work to do= no income!Work with them if thay will work with you if thay want the hell with them OK.Mcquay may have had their problems but thay appear to be working through them to me.thay also have also not left me in the dark when i worked with them so I cant say anything bad about that, Just remember their is no such thing as perfict equipment or perfict installation of equipment It must all be maintained, repaired, replaced If not we wouldnt have a job

 

Guess what ? If you think anyones chillers are bullet proof you are out of a job. Some manufacturers will work with you and some want .Personaly I think its best if thay work with all technitions.If its mechanical built by man or engineered by man kind it can and will at some point in its life fail to work properly.Thats were you come in. its our job to repair or recomend replacement and use our best judgement for whats best for our customers. thay are going to listen to you if you make honest judgements about their equipment and judgements on repair or replace.We all have our opinion which manufacturer has the best equipment and I know a lot of this is fun and games. But if you were fired from your job today! and the company you were fired from was a brand A company.You might have to except a job with a company that was a brand x dealer.What then is the best brand? Did you know that no matter what brand you ask a customer has he herd of he probably does not know the differance other than what you tell them.All thay know for the most part is turn this and it gets cooler turn that and it gets warmer.Just remember it is their decision to make new or repair either way you probably win.Try to keep your customers for life thay might follow you were ever you go brand A or brand X or what ever brand you decide to sell when you go in to buisness for your self. On all the start up jobs i have worked on there have always been problems to work out during the installation process and some have been an engineered nightmare some never get fixed until most involved are at the end of their rope and some technition makes the right suggestion. Some times it comes during the job and some times it comes years after the fact.I do have my preferance and I know what is brand A to me but I also know if it was not for brand X i would have a lot less work to do= no income!Work with them if thay will work with you if thay want the hell with them OK.Mcquay may have had their problems but thay appear to be working through them to me.thay also have also not left me in the dark when i worked with them so I cant say anything bad about that, Just remember their is no such thing as perfict equipment or perfict installation of equipment It must all be maintained, repaired, replaced If not we wouldnt have a job The Filters that need to be installed go between the u bend and sight glass at the sub coolung circuit of the bad compressor,if this is needed you will be given pressure dropsthroughout the hi side at load conditions for your chiller. You need tech support. Where are you getting your compressor from. Dont be afraid to ask for help we all need it.

 

Looking for service bulletin on repairing chiller after a gaterotor failure. Does anyone have directions on retrofit of subcooler to oil seperator. Upgrade of oil supply to bearings ect...

 

Are you serious? This is "rocket science". Only McQ factory techs are capable of humping in a seperater, pulling the condensor apart and changing these "special" compressers properly. It takes some huge kahunas on McQ's part to charge for a retrofit on a POS design, they should be getting sued in a class action suit for this junk. They must have some great PR people working for them. JMHO

 

The oil sep is an upgrade to the unit which helps increase the energy savings by removing the oil from the system and containing it within the compressor/Oil Sep section.
It does not replace the subcooler.

If you are looking at upgrading your or a customers unit to include the Oil Sep and soft starters. You will need to contact McQuay Factory service. All the parts for the upgrade can be purchased from local suppliers with the exception of the optical sensor, oil filter, and Benshaw Soft Starter. The more Important reason for calling in McQuay is because there are certain prior updates the unit and compressor must meet to be a candidate for the CEK softstart upgraqde. Not to mention you also need the software and finally you need to know what your doing in terms of modifying the unit and controls or when you turn the power on it might go BOOOOOOOOOOOOM!

 

there is also a software upgrade that must be done to accept the changes made. Just finished one this week that still had the orginal compressors in them.

 

I love the arguement " They are just junk ! " . THEY ARE NOT JUNK !!! If the ALS A & B vintage's are PROPPERLY maintained by a QUALLIFIED technician who knows what he is doing the compressors have no issues . The problems come in when a technician is working on it and treats it like any other screw chiller out there . IT'S NOT !! They are extremely easy to tear up if they are not maintained propperly . I have many ALS A&B vintage chillers under contract from the early 1990's that still have the original compressors in them . I have also replaced probobally 100 of these compressors over the past 4 years and I always open up the gate cover and check for oil . I would say like 90% of the time they are bone dry . Then I start looking around the chiller and most of the time will find numerous oil spots from previous refrigerant leaks !! HMMM I wonder why the compressor died !! Or you hear " This compressor is almost brand new. " This is an automatic red flag because if it has been replaced then where is the gate material from the compressor that went bad ???

Once an ALS A or B vintage is converted to a " C " vintage by adding the oil seperator and soft starter upgrades then I can almost guarentee that you will NEVER have any more compressor issues , even if you have no clue on what you are doing with that chiller . I have replaced 2 ALS C vintage compressors over the past 4 years . I would put the same POS compressor up against any other screw out there as long as it has the oil seperator ! They are for the most part bullet proof !!!

 

Could not have said it better myself! You guys out there that want to argue this need to understand the real issues before popping off and showing your lack of knowledge on the subject. It never ceases to amaze me how much someone seems to think they know. Facts do not lie and knowing the facts will set you free, or in this case teach you guys something.

 

We just took care of the problems with ALS compressors sucessfully about two years ago. We pulled out the ALS compressors, replaced them with Hanbell screws and installed a MCS control panel. Three year warranty on the compressors and controls to boot! I agree the CEK kits made a difference on reliablity but to me, it is a patch.

 

Yep sounds like to me another misinformed decision that cost the owner as much or more than the McQuay factory backed, engineered, warranted, performance certified option. Yep, just another misinformed contractor ripping off his customer. Did all this retrofit work done this way have hard, up front performance and energy data prior to doing the work? I think not, hence you ripped the customer off!