hussman display case

[james264]

Got a hussmann display case med temp. r22 for storing sandwiches to go on in afternoon on sun.What type of evaporator temp. should I be looking at don't have the model # yet it's a small case about 4 ft wide with it's own compressor in the bottom it's not not tied to a rack system standalone only .The customer said it's running about 50 degrees and normally runs in the 30's . Isn't that a little low for an air curtain open display ??Thanks

[yotaman16]

from what ive seen in those hussman displays anything in the 50s seems to be pluged condenser.. Just check all your basics then check your super heat and subcooling

[james264]

Does 30 degrees sound too low ?? Are these designed for these temps.??

[hvaccop]

In the thirtys maybe 34 or 35 otherwise an air defrost may not do it

[yotaman16]

Ive for some reason been getting a lot of calls on these hussmann units like this. The one i worked on thursday the stat would kick the compressor off at 36 however the case would still drop down to 31 -32 degrees.

[engineerdave]

In my travels, I've mostly seen these cases in high-traffic spots. C-stores. The condenser coils get dirty quick.

[icemeister]

These open display cases generally are controlling to discharge air temperature in the 26ºF-28ºF range to maintain 36ºF-38ºF shelf temperatures. They typically have about a 10ºF differential to help keep the coil clear of frost but have a defrost clock for several off-cycle defrosts per day.

Here's a link for Hussmann's SHF I&O manual:

http://www.hussmann.com/docs/inst_manuals/sc/SHM_06_im.pdf

[james264]

Thanks Ice aka mister "Link"

[absrbrtek]

The defrost clock is an option on some models.


These open display cases generally are controlling to discharge air temperature in the 26ºF-28ºF range to maintain 36ºF-38ºF shelf temperatures. They typically have about a 10ºF differential to help keep the coil clear of frost but have a defrost clock for several off-cycle defrosts per day.

Here's a link for Hussmann's SHF I&O manual:

http://www.hussmann.com/docs/inst_manuals/sc/SHM_06_im.pdf