Digital pack

[friging hell]

My boss has come up with the idea of placing a digital pack r404a (single scroll compressor) on a small system comprising of a 4 door and 3 door undercounter fridges, chiller coldroom 3m x 1.8m x 2.3m all running around +2/+5 degrees c which is fine. The only problem is he wants a 3m saladette table top also to run on this system.
I think that as its a static coil the evap pressure will be a lot lower but not sure around -15 as opposed to -5 on other units. Firstly does this sound right and secondly would there be any problems caused by this??

Cheers for any help with this

[al]

You'll need the EPR for the salad bar to stop it icing up.

Is the duty of the smallest load enough to run the compressor at minimum load? Otherwise temps will be erratic and condensing unit will shortcycle. Also for what it is worth i'd leave the cold room on a condensing unit but that is only personal preference.

alec

[RONB]

[QUOTE=al;274751]You'll need the EPR for the salad bar to stop it icing up.

Is the duty of the smallest load enough to run the compressor at minimum load? Otherwise temps will be erratic and condensing unit will shortcycle. Also for what it is worth i'd leave the cold room on a condensing unit but that is only personal preference.


al forgive me if I've misunderstood the post but the EPR's would be the other way round if the othe cases are evaping at -5 and the saladette is evaping at -15. It would seem to be a waste of energy to run the pack so low to satisfy one case when all the others should be at their control temp long before the system gets to -15. You could also get short cycling of the plant as well if you are running it to satisfy the saladett.

[al]

The saladette shouldn't need to be at -15, any static coolers i've used i set to about -5 as well, but in saying that it is many years since i've seen static coolers in use.

The point i make about the duty holds true though, short cycling will kill a digital as quickly as any other compressor.

alec