Page 108
– Bulletin 100-50-9.1
11.16 MINIMUM SATURATION
TEMPERATURE
The S3C includes a minimum saturation temperature
setpoint, that can be used to limit the temperature in the
evaporator coil during operation. This is typically used
on high efficiency coils to minimize formation of frost on
the coil. In normal operation the EEPR will modulate to
maintain the control temperature or pressure based on user
defined settings. Once the temperature reaches the setpoint,
the EEPR will modulate to maintain the temperature at or
above the setpoint.
1. From the
default
display, press the
button. The
display will show
.
2. Use the
▲▼
buttons to enter the
administrator
password and press
SET.
3. The display will show
; press
SET.
4. Press the
▲
button to scroll to the
; press
SET.
5. Press the
▼
button to scroll to the
o
; press
SET.
6. Press
▲▼
buttons to change the low pressure setpoint;
press
SET
to commit the change.
7. Press the
ESC
button 3 times to revert to the
default
display.
11.17 ANTI-SWEAT CONFIGURATION
The S3C Case Control offers two methods of anti-sweat
heater control; Fixed Duty Cycle and Dew Point Control.
The fixed duty cycle selection offers simple pulsed heat
based on a user selectable duty cycle and pulse period. The
duty cycle is the amount of time the heaters stay on over the
period. The pulse period establishes the total time for the
on/off cycle.
The dew point control pulses the heaters to maintain case
surface temperatures above the local dewpoint around
the case. Additional case surface temperature sensor
and Sporlan RHT sensor must be used. A user defined
temperature offset is entered to maintain the heater
temperature above dewpoint.
11.17.1 FIXED DUTY CYCLE CONTROL
1. From the
default
display, press the
button. The
display will show
.
2. Use the
▲▼
buttons to enter the
administrator
password and press
SET.
3. The display will show
; press
SET.
4. Press the
▼
button repeatedly until
is displayed;
press
SET.
5. When display shows
(Anti-Sweat Control Type);
press
SET.
6. Use the
▲▼
buttons, scroll to
d
(Fixed Duty Cycle);
press
SET.
7. Scroll to
d
(Anti-Sweat Fixed Duty Cycle); press
SET.
8. Use the
▲▼
buttons to adjust duty cycle in %; press
SET.
For example,
1
means constant on,
8
means
that the heaters will be on for 80% of the period and off
the other 20%.
9. Scroll to
(Anti-Sweat Pulse Period); press
SET.
10. Use the
▲▼
buttons to adjust pulse period, in seconds;
press
SET.
11. Press the
ESC
button 3 times to revert to the
default
display.
Example: Setting Duty cycle,
d
to
6
% and Period,
,
to
2
seconds will provide a control scheme with heaters
on for 12 seconds (60% X 20 seconds) and heaters off for 8
seconds.
11.17.2 DEW POINT CONTROL
1. From the
default
display, press the
button. The
display will show
.
2. Use the
▲▼
buttons to enter the
administrator
password and press
SET.
3. The display will show
; press
SET.
4. Press the
▼
button repeatedly until
is displayed;
press
SET.
5. When display shows
(Anti-Sweat Control Type);
press
SET.
6. Use the
▲▼
buttons, scroll to
d
(Dew Point Control);
press
SET.
7. Scroll to
d
(Anti-Sweat Fixed Duty Cycle); press
SET.
8. Use the
▲▼
buttons to adjust control offset
temperature, in degrees; press
SET.
The offset
temperature is the maximum temperature above
dewpoint that the heaters will operate to.
Example: If anti-sweat control offset,
o
, is set to
8
degrees and the dewpoint is 60 degrees then the heaters
will start to pulse when the case surface temperature
drops to 60 degrees. Heaters will then stop pulsing
when the case surface temperature reaches 68 degrees.
9. Press the
ESC
button 3 times to revert to the
default
display.
