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.