Table of Contents
Advertisement
Troubleshooting Cont'd
Problem
Product too warm
Possible Cause
Improper Superheat
Setting
Improper EPR Set Point
Improper Thermostat Bulb
Location
Improper TXV Bulb
Location
Improper Deck Plates
(and Pans) Sitting
Gravity Coil Air Flow
Obstruction
Defrost Failure To Clear
All SDC Ice Buildup
Improperly sized
refrigerant lines
Solid Column Of Liquid
Refrigerant NOT reaching
the TXV
Liquid Refrigerant case
inlet Temperature is
excessive
Product Introduction
Temperature Too High
Product Is Stacked Too
High
Product is displayed in
containers that impede
the conduction cooling
from the SDC
Incorrect replacement
lighting is adding too
much heat
Possible Solution
Verify superheat. Adjust TX valves accordingly. Deck/Spiral
coil may be set as low as 1-2° SH. Gravity coil may be set
as low as 3° SH. (NOTE, when adjusting TXV superheat,
first adjust the corresponding T-Stat below equivalent suction
temperature. This will ensure that the T-Stat does not close
during the adjustment period. Be sure to return T-Stat to SP.
If SDC inlet temperature is above 28°F reduce the EPR set
point
Ensure that the thermostat bulb for the gravity coil (A) is not
contacting any coil parts and is located in the discharge air
stream
Ensure that the TX valve bulbs are located as per the piping
diagram. Refer to Pipe Diagram
Ensure that the deck plates (and pans) are seated and
making good contact with the SDC and each other
Ensure that gravity coil is fully cleared all the time
The SDC will eventually pack with ice and refrigeration
performance will be severely degraded. Confirm Evaporator
Temperature is 28°F, SDC T-Stat SP to specification,
and SDC termination temperature reaching at least 42°F.
Increase the defrost time in 5 minute increments if this
condition is observed, and termination temperature not
achieved.
Ensure that refrigerant lines are properly sized per the
installation manual. Inspect liquid line for kinks, pinched or
excessive u-bends
Inspect liquid line for kinks, pinched or excessive u- bends.
Ensure that the liquid refrigerant entering temperature is not
excessive. Liquid greater than 110°F at 6" ahead of the TXV
may be an indication of equipment problems
Correct product introduction temperature should be
34°F.-36°F.
Reduce display height of product. Less than 6" is
recommended
Use containers with full length, flat bottoms. Refer to
MERCHANDIZING RECOMMENDATIONS (page 29) section
for further information.
Use only Hussmann genuine replacement parts or equivalent.
42
Advertisement
Table of Contents
