SRC Service Manual
Revision 02
Aug 2007
7. Operation & Control (SRC-250 to 1000)
7.1 Turning the Dryer On or Off
Once the dryer has been switched on by turning the main switch to position “I/ON”, the
controller does an internal check, during which for a couple of seconds the display
shows “d.t.1”, indicating the installed software version.
At the end of this procedure the dryer can be in one of these three operating modes:
•
OFF
: The display is off & all the lights are off except the yellow “Power” light.
•
ON:
The display shows the reading of dew point sensor (B1) and the “power” light is
green, while the other lights are normally off and they lit up if an alarm is occurring, or if
the drain valve is activated or if the fridge compressor turns off.
•
Remote OFF:
If the dryer is turned off remotely, the display shows “r.OF” &
all the lights are off except the yellow “Power” light.
The Remote OFF function can be activated by replacing the bridge between terminals X4.0 and X4.17
in the electrical cabinet with a switch. With the contact open, the remote OFF is activated (dryer is
turned off), with the contact closed, it is not activated (dryer is turned on).
To turn the dryer ON, press the ON/OFF button or provide the command via an external control
system. The display will show the B1 (dewpoint temperature) sensor reading and the refrigerant
compressor will turn on*.
To turn the dryer OFF, press the ON/OFF button or provide the command via an external control
system. The display goes off, and the refrigerant compressor stops.
The dryer can also be turned OFF remotely by opening the Remote OFF Contacts as described
previously. In this case the compressor stops and “r.OF” is displayed. Note that the On/OFF switch
must be in the On position in order to activate the Remote Off Mode.
When in remote OFF, closing the Remote Off Contacts turns the dryer on. The
compressor comes on** and the display blinks “on” for 5 seconds and then displays the
B1 dewpoint temperature reading.
The dryer status is recorded in the flash memory of the controller, so disconnecting power to the unit
while it is on will cause the dryer to automatically come back on 5 seconds after the power is restored.
If during these 5 seconds the ON/OFF button is pressed or an off command is coming through the
external control system, the controller stays off.
* If the coolant temperature is below the cycling set point, the refrigerant compressor will remain off and the
“Energy Saving” light will come on.
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