Emerson CCUs compressor rotation

[dannycool]

Hi Guys

We have taken over a site with 3 brand new Emerson/Liebert CCUs.

While scrolling though the controller run times, I noticed that 1 compressor has over 350 hours, while the other has 0 hours, this is the same on all 3 units.

I have spoken to the installer and he insists this is normal and they are not designed to rotate the compressor starts.

This would potentially mean that one compressor could have thousands more start ups than the other.

I find it hard to believe, but im not familiar with this make of equipment.

Can anyone advise if it is normal, or if its a setting that needs to be made

Regards

Danny

[Brian_UK]

All depends on how you look at these things.

One one motor at all times, if if breaks then the standby is 'unused'.

Or

Alternate the run hours and wear out both at the same time.

Would like to see the odd start of the second motor just to keep it lubricated.

[dannycool]

Hi Brian

Yeah I do understand what your saying, and i tend to agree in principal.

But i was thinking more in of the amount of startups.

At the moment the server room is running at reduced capacity so if it is running on a duty/assist basis, the starts are never going to be equal or lifespans predictable.

Also on the commissioning sheet Comp number 2 running conditions have not been noted, so nobody has seen them run at all.

Regards

Danny