Danfoss SZ125 & SZ185 failures

[tvl]

Hi all,

We have had 2 SZ185s and a SZ125 fail 3 months outside warranty. The failure manifested itself by blowing a fuse in the isolator at the supply end approx 20m away. None of the fuses or trips in the cabinet had failed. These compressors had been fitted as replacements for 20 year old SM series compressors when we replaced R122 with MO99. The failure mechanism as I see it is a winding going s/c, the overcurrent protection not being set correctly, leading to the supply fuse blowing. We've been in dispute with the suppliers for nearly a year at this point and they are adamant the fault lies with us, not the compressors!

I had a conversation with and engineer who said it was a known problem with an earlier series of compressor when the manufacture was moved to a different factory, the overcurrent protection provided wasn't correct and the failure mode was exactly as described above. The company he was working for then replaced the individual fuses supplied with 3 phase MCBs.

Does anyone have any experience of this happening with SZ series compressors?

Thanks,

Tim.

[chemi-cool]

If they are Chinese Compressors? I had some similar problem and eventually changed to Copeland.

[Glenn Moore]

Hi
Interesting problem, I was the Danfoss Field Service manager for the UK looking after all Danfoss and Maneurop field problems and warranty issues until I semi retired . What reasons are the suppliers blaming you for the failures, and what proof do they have. Or are they just rejecting them due to out of warranty.
It is worth getting the failed compressors cut open and stripped and inspected by a competent engineer to ascertain the reason for failure.

in 99% of cases a mechanical failure has then caused the electrical failure. I used a company in the Birmingham area to strip the machine before I did the final inspection. The reason for failure is always inside the compressor.
If you go on Google and search for Glenn Moore Why Compressors Fail or on the Danfoss website you can download some articles I wrote on why compressors fail which Danfoss published , these are on Recips I retired from Danfoss before I finished the Scroll compressor version but they are similar in types of failures .I wrote these Notes to help explain to customers the reasons why their compressors had been rejected under warranty and how to stop further failures.
If you have any further relevant info on these machines failures I would be interested to see it

[tvl]

The ratings plate says made in France.
The SZ185s were commissioned in 2013.
The SZ125s were commissioned in 2015.
In both cases the contractor have just said they're out of warranty and blamed the age and condition of our installation (commissioned 1991) but didn't raise this as a concern when quoting for the upgrades which I find unsatisfactory to borderline suspicious!
WRT the SZ185s, when I first found a blown fuse in our isolator and no problems in the cabinet I replaced the fuse believing it to be a problem with our supply installation. When it blew again I called our AC contractors, who sent over their chiller subcontractor who subsequently claimed that replacing the fuse caused the damage.
Oil samples were taken which were clear of contaminants.
I was also told that there was no point getting the compressors cut open because the very act would contaminate the compressor.
Could you recommend a competent engineer in the north London area?
I have read both of your articles, very informative.
What other info would be useful for you?

[Glenn Moore]

Hi there
Have you any pictures of the installation and any service reports prior to the failures.Please send me a private message with your contact details so that I can discus this problem with you. The answer to the failure is always inside the compressor . Ps there are 9 articles in the series Br Glenn

[cadwaladr]

I use that company in Birmingham,very competent knowledgeable all round good eggs and have visited the factory many times.
Hi
Interesting problem, I was the Danfoss Field Service manager for the UK looking after all Danfoss and Maneurop field problems and warranty issues until I semi retired . What reasons are the suppliers blaming you for the failures, and what proof do they have. Or are they just rejecting them due to out of warranty.
It is worth getting the failed compressors cut open and stripped and inspected by a competent engineer to ascertain the reason for failure.

in 99% of cases a mechanical failure has then caused the electrical failure. I used a company in the Birmingham area to strip the machine before I did the final inspection. The reason for failure is always inside the compressor.
If you go on Google and search for Glenn Moore Why Compressors Fail or on the Danfoss website you can download some articles I wrote on why compressors fail which Danfoss published , these are on Recips I retired from Danfoss before I finished the Scroll compressor version but they are similar in types of failures .I wrote these Notes to help explain to customers the reasons why their compressors had been rejected under warranty and how to stop further failures.
If you have any further relevant info on these machines failures I would be interested to see it

[tvl]

Can you name the company in Birmingham without compromising the rules of the forum? Our owners have finally conceded that an independent 3rd party inspection & review would be a good idea...

[Glenn Moore]

Hi tvl
Please mail me with your contact details at glennmoore1948@gmail.com
I can't work out how to send you a private message via RE
Br Glenn

[nike123]

I can't work out how to send you a private message via RE
Br Glenn

Probably he did not allowed private messaging to himself in his profile settings!

[tvl]

Ditto, I can't work out how to PM Glenn! I can't find anything in my profile called 'private messaging', is it disguised as something else???

[chemi-cool]

http://www.refrigeration-engineer.com/forums/private.php?do=newpm&u=74885&code=AQCXfiHw4JynAJlcrlh2t3TbM5VmQSL41CWIpCmSzI-B6nigYTUL40WH99XIg8K9T81UZnjHCQY5GUvWvgIOzDUMQwJQNB4TLmFt3b45hNW4-I7n_Eq6VswD690hFSCVCWQ3eg87w1A4KnSvqArmr93WyHKAGMthFNOAh6x88YYj3PsZnfhytdYJjhk3Jc9kosxcQzECVY3J032e-9QKWfMhGqjlARJOAW--cKmB9RQsHRYTblFYCCGXSBdsCiINCcR3ahiNVBLvCb4gzPAvNIu1MrfdlC_Zm3GE0xWtmRWLMUe9AmCLBVvxpx64cDzdAAo&state=78805e22c5a15dc0ef2ce6100e51a9bd#_=_

[tvl]

So when I clicked on the link I got:

"tvl, you do not have permission to access this page. This could be due to one of several reasons:

Your user account may not have sufficient privileges to access this page. Are you trying to edit someone else's post, access administrative features or some other privileged system?
If you are trying to post, the administrator may have disabled your account, or it may be awaiting activation."

????