Appendix D. - Recommendations To User - Hussmann RDI-27 Installation & Operation Manual

1.1 The following recommendations are made for the
purpose of arriving at easily taken and understood
data which, coupled with other observations,
may be used to determined whether a display
refrigerator is working as intended:
a) INSTRUMENT - A stainless steel stem-type
thermometer is recommended and it should
have a dial a minimum of 1 inch internal
diameter. A test thermometer scaled only
in Celsius or dually scaled in Celsius and
Fahrenheit shall be accurate to 1°C (1.8°F).
Temperature measuring devices that are
scaled only in Fahrenheit shall be accurate to
2°F. The thermometer should be checked for
proper calibration. (It should read 32°F when
the stem is immersed in an ice water bath).
b) LOCATION - The probe or sensing element
of the thermometer should be located in the
airstream where the air fi rst enters the display
or storage area, and not more than 1 inch
away from the surface and in the center of the
discharge opening.
c) READING - It should fi rst be determined
that the refrigerator is refrigerating and has
operated at least one hour since the end of the
last defrost period. The thermometer reading
should be made only after it has been allowed
to stabilize, i.e., maintain a constant reading.
d) OTHER OBSERVATIONS - Other observations
should be made which may indicate operating
problems, such as unsatisfactory product, feel/
appearance.
e) CONCLUSIONS - In the absence of any
apparent undesirable conditions, the
refrigerator should be judged to be operating
properly. If it is determined that such condition
is undesirable, i.e., the product is above proper
temperature, checks should be made for the
following:
1. Has the refrigerator been loaded with warm
product?
2. Is the product loaded beyond the "Safe
Load Line" markers?
3. Are the return air ducts blocked?
4. Are the entering air ducts blocked?
5. Is a dumped display causing turbulent air
fl ow and mixing with room air?
6. Are spotlights or other high intensity
lighting directed onto the product?
7. Are there unusual draft conditions (from
heating /air-conditioning ducts, open doors,
etc.)?
Appendices (Cont'd)
8. Is there exposure to direct sunlight?
8. Are display signs blocking or diverting
9. Are the coils of the refrigerator iced up?
11. Is the store ambient over 75°F, 55% RH
12. Are the shelf positions, number, and
13. Is there an improper application or control
14. Is the evaporator fan motor/blade
15. Is the defrost time excessive?
16. Is the defrost termination, thermostat (if
17. Are the refrigerant controls incorrectly
18. Is the air entering the condenser above
19. Is there a shortage of refrigerant?
20. Has the equipment been modifi ed

Appendix D. - Recommendations to user

1.0 Hussmann Corporation provides instructions and
recommendations for proper periodic cleaning.
The user will be responsible for such cleaning,
including the cleaning of low temperature
equipment within the compartment and the cooling
coil area(s). Cleaning practices, particularly with
respect to proper refrigerator unloading and
warm-up, must be in accordance with applicable
recommendations.
26
airfl ow?
as set forth in ASHRAE Standard 72 and
ASHRAE Standard 117?
size other than recommended by the
manufacturer?
system?
inoperative?
used) set too high?
adjusted?
design conditions? Are the condenser fi ns
clear of dirt, dust, etc.?
to use replacements for CFC-12,
CFC-502 or other refrigerant? If so,
have the modifi cations been made in
accordance with the recommendations
of the equipment manufacturer? Is the
refrigerator charged with the proper
refrigerant and lubricant? Does the system
use the recommended compressor?