Hussmann RL2W Installation & Operation Manual page 27

2-4
CASE ELECTRONIC CONTROLLER
Reach-In self-contained R-290 cases are controlled by
a CoreLink Electronic Controller, for refrigeration and
defrost control and control of lights and fans. The
controller is factory programmed with the required
parameters to safely operate the merchandiser and
maintain required product temperature. There is no
need to make adjustments to the controller, however,
it is recommended that the program be checked
at startup. Refer to the display case data sheet for
discharge air temperature, setpoint, defrost cycle and
other information.
Control Operation
The case temperature is controlled by cycling the
compressor ON and OFF based on the discharge air
temperature. The case is divided into 2-door control
sections: 2-door and 3-door cases have only one
control section. 4-door cases have two 2-door control
sections, and 5-door cases have one 2-door and one
3-door control sections. The discharge air temperature
sensor is located above the honeycomb at the center of
each control section. Compressors are cycled based on
the average of the sensors in the two control sections.
The second compressor has a 5-second delay at each
startup to prevent excessive startup current.
The discharge air temperature is factory set for -3°F
for low temperature cases, and 37°F for medium
temperature cases.
P/N 3053328_C
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lEctrIcal ontrollEr
U.S. & Canada 1-800-922-1919 • Mexico 1-800-890-2900 • WWW.HUSSMANN.COM
/ W / r
atEr EfrIgEratIon
There are two methods for accessing CoreLink: The
wireless connection kit directly at the CoreLink
hosted by Web UI on a connected smart device, or
users can use Building Automated System (BAS) to
change parameters from a single, central location. For
explanation of wireless connection at the case, consult
the CoreLink user manual under Web User Interface
Section.
NOTE: Individual cases may be designed to run at a
specific temperature setting and may not perform well
at lower or higher settings, depending on such things
as condenser water temperature, ambient conditions,
etc.
Defrost is time-initiated, and is programmed with the
correct number of defrosts per day and the correct
termination. Low temperature cases are temperature
terminated at 48°F based on a sensor mounted on
the left end of the evaporator coil. The start time for
defrost must be programmed using BAS.
Additional Safeties
CoreLink incorporates additional safeties to protect
the case from critical failures in an MDS installation.
These safeties may, or may not be installed, depending
on case model. Following safeties protects the
compressors in the event of water system failure or any
other blockages in the heat exchanger. Some or all of
the safeties are enabled depending on the case model.
Compressor Discharge Temperature Safety
The controller will alarm and disable the compressor
output until the temperature falls below threshold.
Compressor Pressure Safety Switch
The controller will disable compressor output when
the pressure safety switch is activated. Compressor will
resume operation when the safety switch is deactivated.
Compressor Run-time Safeties
Additional run-time safeties are incorporated to
protect the compressor and MDS products.