Danfoss/Maneurop recips

[SteinarN]

I have a few systems with Maneurop recips. Those compressors has been notorious unreliable. I have replaced two MT80 and two MT125 due to leak in the internal HP pipe from the compressor to the shell. After the last replacement i installed a new controller enabling me to configure it to have fewer starts each hour. Guessed the number of starts each hour is what determines the service life of that pipe.

Another coustomer has a chiller with two MT144. It is not instatalled by me. After one year the windings in one comp got shorted. Replaced the comp. Installed burn out filter and changed oil. After three years the internal "klixon" got faulty. One of the 3-phase terminals lost its conection. Replaced the comp for a second time. Now the oil seems to have disapeared from the comp. Its of course seized. There is no leak. Only short pipes, low wolume PHE evaporator. I cant understand that the oil shouldnt come back to the comp. However these comps have internal suction gas accumulators. I suppose the oil is there.I havent disconected the comp yet. The TEV is function properly and the system is running well as long as the comp is ok.

Besides this comps have the most poorly COP of any comps i have calculation program for. Even lower COP than old Dorins.

What is your experiences with these comps?

[Springbok]

Hey SteinarN.I personally dohave experience with thme Danfoss Maneurop.When we used them back in South Africa,they were pretty much the cheapest compressor on our market,price wise that is.

Seeing we do experience somewhat 28degreesC - 40degreesC ambient,those compressors don't react well to excessive heat exposure.The supplier and manufacturer constantly reminds us that we should check our superheat settings as a protection for the compressor.Seemingly,they also handling a bit of liquid better than other compressors.

As for the oil problem,I have had that one before.The majority of the systems with the manuerops don't have oil seperators.As for the internal klixos,they do seem to cut the motor out if the motor overheats,and just doesn't come back on again.

Although every compressor breakdown does have its reasons.System faults,service engineer not doing the proper checks or even just a bad on in the box.Personally,Maneurop not my favourite....sorry Danfoss...thanks for sharing mate....

[expat]

This is a coincidence. I was just about to pump a little oil into a maneurop for a customer of mine. He told me it's only a couple of years old. It had had a leak which I found but apparently had had others before I came along, but the techs just re gassed.

The oil is right at the bottom of the glass. Do you guys think it came out during the leaks or is there some other mystery here?

[The Viking]

Maneurop,

If you can see a level, then I would leave it at that.

[SteinarN]

The recips dont like to much oil. Above half full the oil tend to "boil" heavily.

[expat]

Viking, I can't see a level it's just bearly touching the bottom of the glass. I was just going to try and bring it a little below half. Sound reasonable?

[The Viking]

Viking, I can't see a level it's just bearly touching the bottom of the glass. I was just going to try and bring it a little below half. Sound reasonable?

Yes.
(as long as all the gas is in before you start fiddling with the oil)

[Springbok]

Hey expat,having the oil level just below half is fine,thats the way the compressors are sent out brand new anyway.Maybe it lost some of the oil during the past gas leaks?You did say the engineers just kept topping up.Hope it solves the"Manuerop nightmare" buddy....

[old gas bottle]

love or hate em,the truth is there fitted to a lot of systems, nicest thing i can say is "there easy to change" and a fair bit lighter under your arm than a semi.

[Chunk]

Hi Guys.

I like these compressors alot.easy to change when they do have a fault.

The main reason for most of the failures is when people forget about the crankcase heater as the majority of these comps are used on outdoor units.
the other thing is these comps have an internal pressure relief valve that sometimes doesnt re-seat properly once comp has cooled down giving engineers reason to suspect comp is not pumping.A good whack with a spanner usually sorts this.

[expat]

To update (and explain). This Maneurop recip had lost a good part of it's gas charge and the oil level was bearly discernible at he bottom of the sight glass. I found the leak, fixed it and recharged. I waited three days, returned and found there was still hardly any oil. Another five days went by before I turned up there at 7am to recharge the oil only to find it had come back it's correct level.

Conclusion: be patient!

[Gary]

The system is trapping oil somewhere. The usual culprit would be a perfectly level horizontal suction line... especially one that is oversized.

Suction lines should never be level. This allows oil to build up along the bottom with the vapor passing over it... then when the level gets high enough, the vapor pushes it through all at once and the compressor gets a large and difficult to digest oil slug.

[PaulZ]

Maneurop are ok but I found that you need to adjust you TX valve to flood slightly back to the compressor. This keeps the compressor cool and helps improve the life of the windings. You might find it also helps get the oil back to the compressor. Some of Maneurop's advertising showed their compressors running with most of the compressor case iced up. The biggest problem is the internal motor protection which can take up to 3 hours to reset. Paul

[tsangep]

Hi Guys
Maneurop comprssors dont have a internal suction accumulator or metal liquid deflector walls. The compressor is built with a generously oversized shell and the oil sump which is heated by the discharge line which coils under the oil to keep the oil very hot.

This simple design makes the Maneurop Recip very robust and tough to liquid abuse. As liquid enters the shell it hits the motor and shell and starts to fill on top of the hot oil which makes the refigerant liquid boil off violently.

All of the discharge gas is channeled 100% through the motor so its "100% gas cooled" as stated by Danfoss.The motor is wound with F class insulation which is the best in industry. Any higher class have problemws with brittleness.Paulz is corect in saying the maneurops like slight floodback as it keeps the motor perfectly cooled without risking dilution and valve damage.

I would suggest filling the oil to the top of the sight glass and use the genuine 160P maneurop oil

Systems with dodgy oil return need to have their run times increased with using Hotgas valve on the liquid to purge the oil out of the eveporator and to ballance the capacity so the comprssor can match its duty to the load. The motor will still draw a high current but its power factor will be low so the real power consumed will reduce as the hot gas bypass increases. No pont saving power if you keep ceasing compressors.

Theres is an absolute massive number of maneurops used in mining in australia used to chill electrical rooms etc which can hit maximum temperatures of 65 degC at startup and the machine is forced to condese in 50 degree C ambients with very little failure rate. Condensing pressures are stratopheric but failures are always due to very poor maintenece where the machine is forced run with massive continuous superheat and no oil.

To keep a maneurop alive it needs plenty of gas and oil and it will keep working hard for you, Yes they are very noisy but who cares when its industrial refrigeration

[taz24]

I have a power point presentation from Danfoss / Maneurop, that explains about faults and causes.

I will email to you if you PM me.

Cheers taz.

[dear.mr.davidov]

I have a power point presentation from Danfoss / Maneurop, that explains about faults and causes.

I will email to you if you PM me.

Cheers taz.

dear taz if you can to email me this presentation i will very thankful for you
my email: DELETED

[taz24]

I have tried to up load the powerpoint pressentation here.

http://www.mediafire.com/?dmjuxj9g1im

http://www.mediafire.com/?yjztzizoz1t

Try it to see if it works.

If it works thanks Nike for the help and advice

If it does not work blame Nike

Cheers taz.

[nike123]

If it works thanks Nike for the help and advice

If it does not work blame Nike

Cheers taz.

I think, that I am going to rest on laurels!