CSR-20 & CSR-40, September 1999
µ
P-D Controller
Menu Program Functions
4-39
Dehumidify Mode (Option)
The Dehumidify Mode reduces the humidity level in the con-
tainer by condensing more moisture from the container air.
More moisture is condensed from the air by lowering the evap-
orator coil temperature. The use of the Dehumidify Mode
should be established by the shipper. The Dehumidify Mode
option is turned on from the Program menu of the controller.
NOTE: If the Dehumidify Mode is set to ON, the con-
troller display will show “DEHUM” in the left display
and the container humidity level (e.g. “74.5”) in the
right display for 1 second every 10 seconds.
When the Dehumidify Mode is ON:
•
The supply air temperature must be In-range before the
controller will operate the dehumidify function.
•
When the dehumidify function is operating (dehumidify
valve energized), the supply air LED will flash ON and
OFF.
•
The controller energizes (closes) the dehumidify valve
when the humidity level in the container is between 1%
and 5% above the humidity setpoint. This reduces the
size of the evaporator providing cooling by 50%, causing
the coil to become colder and condense more moisture
from the container air.
•
The controller energizes (closes) the dehumidify valve
and pulses the electric heaters ON and OFF when the
humidity level in the container is 5% or more above the
humidity setpoint. This increases the cooling load and
causes the evaporator coil to become even colder, con-
densing more moisture from the container air.
Setting the Dehumidify Mode
1.
Press the SELECT key to enter menu (display shows
“MENU <--->”.
2.
Press UP key until display shows “MENU PRGRM”.
3.
Press the SELECT key to show “PRGRM <--->”.
4.
Press the UP or DOWN key until the display shows the
current “HUMID” setting:
• “HUMID OFF”.
• “HUMID DEHUM” — Dehumidify option is ON.
• “HUMID HUM” — Humidify option is ON.
NOTE: The Dehumidify and Humidify option
screens do not appear unless the unit is
equipped with the option and the controller is set
to the correct unit configuration. Also, the
Dehumidify and Humidify options can NOT be
turned ON at the same time.
5.
To change the current setting, press the SELECT key.
“HUMID” will begin to flash in the left display.
6.
Press the UP or DOWN key to scroll the right display to
the desired setting: “DEHUM”, “HUM” or “OFF”.
7.
To load the new setting, press the ENTER key. The dis-
play briefly shows “HUMID LOAD”.
8.
When the Dehumidify mode is turned ON, the left display
shows “HUMSP” and the right display shows the current
humidity setpoint in percent (e.g. “85.0”). To change the
humidity setpoint:
a.
Press the SELECT key. “HUMSP” will flash in the left
display.
b.
Press the UP or DOWN key to adjust the humidity
setpoint to the desired setting (see shipping manifest).
The right display scrolls up or down to the new
humidity setpoint in percent (e.g. “70.0”).
c.
To load the new setpoint, press the ENTER key. The
display briefly shows “HUMSP LOAD”. The new
humidity setpoint then shows in the right display (e.g.
“70.0”).
NOTE: Press and hold the SELECT key for 3 sec-
onds to return to the Standard Display.
Humidify Mode (Option)
The Humidify Mode increases the humidity level in the con-
tainer by injecting atomized water directly into the evaporator
supply air stream. The use of the Humidify Mode should be
established by the shipper. The Humidify Mode option is
turned on from the Program menu of the controller.
NOTE: If the Humidify Mode is set to ON, the con-
troller display will show “HUM” in the left display
and the container humidity level (e.g. “74.5”) in the
right display for 1 second every 10 seconds.
When the Humidify Mode is ON:
•
The evaporator fans must be ON before the controller will
operate the humidify function.
•
When the humidify function is operating (air compressor
energized), the supply air LED will flash ON and OFF.
•
The controller energizes (operates) the air compressor
when the humidity level in the container is more than 2%
below the humidity setpoint. The air compressor atomizes
and injects water into the evaporator supply air stream to
add moisture to the container air.
