Page 12
– Bulletin 100-50-9.1
4. CONTROL SYSTEM OVERVIEW
4.1
TEMPERATURE CONTROL
The Control Temperature can be user selected as either Dis-
charge Air (DA) or Return Air (RA). Future references in this
manual to “Control Temperature” refers to the temperature
source selected. Temperature control for the case line-up
is based on the average Control Temperature of all cases in
the line-up. The S3C Case Control will maintain the control
temperature set point by managing the EEV in the case and/
or EEPR on the common suction for the case line-up.
Note: Only DA is used as Control Temperature in
Dual-Temperature case applications.
4.2
SUPERHEAT CONTROL
The S3C Case Control system will modulate attached EEVs
to maintain the superheat set point. Suction pressure and
temperature are used for superheat calculation. For mul-
tiple evaporator cases, individual coil outlet temperature
sensors are required; however, only one suction pressure
transducer is required on the common suction leaving all
the evaporators. For redundancy, a second transducer may
be added as a backup. Both stepper EEV and pulse width
EEV designs are supported.
4.3
EEPR CONTROL
When an EEPR is present, the S3C Case Control will modu-
late the EEPR to maintain temperature or suction pressure
based on the type of control selected by the user. The S3C
Case Control uses the average of either line-up Discharge
Air or Return Air as the temperature control input based on
user selection. The inherent redundancy of temperature
sensor inputs available in multiple case line-ups allows for
the S3C control to continue to control line-up temperature
in the event of sensor fault on one or more cases in the line-
up. The same is true for pressure control if more than one
pressure transducer is present in the line-up. The S3C sup-
ports an EEPR per line-up or an EEPR per case.
4.4
DEFROST CONTROL
The S3C Case Control supports multiple defrost schemes
and controls attached valves, fans and heaters as dictated
by the defrost scheme and user selected defrost param-
eters. The controller has been designed to pilot many third
party contactors to energize electric heaters. Termination
can be determined by temperature or time. Temperature
termination can be selected to be from a Defrost Termina-
tion Sensor or Discharge Air Sensor if Air (Off-Time) defrost
is selected. See Operating Mode Section for more details.
Sporlan offers an additional defrost CT that allows the S3C
to monitor defrost current if electric heaters are used. See
Service Section for information on this additional feature.
4.5
LIQUID LINE SOLENOID VALVE
CONTROL
The case refrigeration system includes a solenoid valve
placed in the liquid refrigerant supply line. A normally
closed solenoid is typically used to provide positive closure
of the liquid line in the event of power loss. The solenoid
may be used on the liquid line for each case or a single
solenoid can be used for a line-up of cases; depending on
the application. The case controller will open and close the
solenoid to maintain control temperature set point. A liquid
line solenoid is recommended; however, the S3C does not
require one for proper control. If a solenoid valve is used,
ensure that
(Liquid Line Solenoid Present) is set to
e
.
From the
default
display, press the
button. The display
will show
.
1. Use the
▲▼
buttons to enter the
Administrator
pass-
word and press the
SET
button.
2. The display will show
(will skip to Process Values
if system is self-contained).
3. Press the
SET
button an
d
(Process Values) will be
displayed.
4. Press the
▼
button until
(Valve Configuration) is
showing.
5. Press the
SET
button and scroll to
(Liquid Line
Solenoid Present).
6. Press the
SET
button, scroll to
(if solenoid is used),
then press
SET.
7. Press the
ESC
button two times to exit the menu and
return to the
default
display.
4.6
FAN CONTROL
The case controller will operate the evaporator fans in the
case based on the operating mode of the system. The case
controller supports single speed and variable speed fans.
See Service Section for additional fan features.
4.7
LIGHTING CONTROL
The S3C Case Control will control fluorescent and LED
lights. Fluorescent lights can be switched ON/OFF based
on an internal schedule or by data communication from
the BAS. LED lights can be on, off, or dimmed to a lower
light level. LED lighting is to be powered by an external
LED power supply. The dimming features of the LEDs are
determined by the type of power supply used. Power sup-
plies that support 0 – 10V input to control dimming of the
attached LED lighting are compatible with the S3C Case
Control system. Lights can be controlled in accordance with
a lighting schedule and/or input from a Passive Infrared
occupancy sensor provided by Sporlan. Occupancy Sensor
input state (Occupied/Unoccupied) is user configurable to
be shared across a line-up in the event the user desires to
have all case lights operated based on input for any sensor
on the line-up.
The case controller is capable of operating the lights based
on light on/light off commands from the BAS. The case con-
troller additionally supports an internal lighting schedule in
the event communication to the BAS is not available. The
controller supports a daily simple schedule with one light
on time and one light off time that is repeated each day. The
