Bulletin 100-50-9.1 –
Page 13
case controller supports a weekly schedule with one light
on time and one light off time for each day of the week.
4.8
ANTI-SWEAT HEATER CONTROL
Anti-Sweat Heat control is accomplished via two methods:
1. The heaters are pulsed based on a fixed duty cycle. The
duty cycle can be adjusted by the user to suit the needs
of the application.
2. The heaters are pulsed on and off based on humidity,
ambient air temperature and the surface temperature
of the case. The temperature and humidity values are
used to calculate the dew point. The heater will be
pulsed to maintain case surface temperature suffi-
ciently above the dew point as to avoid the formation
of condensation on the case surface. The Sporlan RHT
sensor along with a case surface temperature sensor
must be installed. The case surface temperature sensor
is wired into the “Auxiliary” location on the case con-
troller. See Section 11.17 for configuration.
4.9
LINE-UP CONTROL
A line-up is a group of cases that form a refrigeration circuit
and share the same liquid line, suction line, temperature set
point and defrost schedule. Cases in the line-up are con-
trolled in a synchronized manner such that they all defrost
and refrigerate at the same time. Each S3C Case Control in
the line-up will communicate to its peers to maintain effi-
cient control and synchronization. The S3C Case Control
with connection to the liquid line solenoid and/or EEPR
for the line-up will coordinate the control of the liquid line
solenoid and EEPR for the line-up for Defrost, Refrigera-
tion and Service purposes. The controllers within a line-up
may share a single pressure transducer on the suction line
or each controller can be equipped with its own pressure
transducer for EEPR control and/or superheat calculation
per case.
The S3C Case Control system additionally uses peer – peer
communication to maintain synchronization of operating
parameters and user configuration between controllers in a
line-up network. If this communication is lost the controller
will revert to stand alone operation with the risk that some
functions may become unsynchronized.
Note: Line-ups configured for hot gas defrost will not
defrost during periods of stand alone operation as
this may cause damage to the refrigeration system.
4.10 MODULAR/MULTI COILS
The S3C Case Control system supports control of case
designs that incorporate more than one evaporator. For
control of additional evaporator coils, an S3C Valve Module
expands the S3C Case Controller to add additional hard-
ware support for 1 Pulse valve and 2 stepper valves (2 EEVs
or 1 EEV and 1 EEPR), pressure transducer, and six temper-
ature sensors. The temperature sensors measure coil out-
let, discharge air, and defrost termination temperatures for
up to two additional evaporators. The standard 60W power
supply will support one case controller, one Display Mod-
ule and up to two valve modules.
4.11 MULTIPLE VALVE CONTROL
The S3C Case Controller system is capable of controlling
five electronic stepper valves; three EEVs and one EEPR.
Solenoid valves are powered externally, and power for step-
per valves is generated by the case controller.
4.12 DUAL-TEMPERATURE CASE CONTROL
The S3C Case Control supports control of Dual-Tempera-
ture cases using an EEPR for control of selected operational
temperature. The controller maintains two sets of alarm
threshold values and set points that can be selected by
mechanical switch input or via communication from the
BAS. If communication is lost to the BAS, the S3C Case Con-
trol will continue to operate based on the last temperature
set point received.
4.13 SELF-CONTAINED CASES
The S3C Case Control supports control of medium temper-
ature or low temperature self-contained cases that incorpo-
rate a compressor and condenser built into the case. The
S3C Case Control is capable of controlling the compressor
to turn refrigeration on and off. The case will operate with
a cut in/cut out temperature control scheme. The control
scheme minimizes the amount of time the compressor is
on while maintaining Discharge Air or Return Air tempera-
ture within set point using user programmable minimum
compressor run time selection. The relay output for refrig-
eration ON/OFF control can pilot the compressor control
contactor or alternatively control the liquid line solenoid.
4.14 S3C CASE CONTROL DATA INTERFACE
Data interface to the BAS and other enterprise control sub-
systems can be achieved using either Ethernet or RS-485 as
a hardware interface and the S3C Case Control system sup-
ports the following communication protocols:
1. BACnet/IP (Ethernet)
2. BACnet MSTP (RS-485)
3. MODBUS UDP/IP (Ethernet)
4. MODBUS RTU (RS-485)
4.15 LOCAL USER INTERFACE
The S3C Display Module (DM) provides visual indication of
alarms, operational status (defrost, refrigeration or system
off), fans, lights, network status and process values such as
temperature, pressure, superheat, valve position, etc. The
Display Module has six buttons to navigate the menus/text
on the display and can be used to initiate service functions
and configure the control for operation. The S3C Display
Module prominently displays system health in the form of a
color status indication visible from >100 ft.
