CSR-20 & CSR-40, September 1999
µP-D Controller Initiating a Manual Defrost 4-19
Initiating a Manual Defrost
With the unit On/Off switch ON:
1. Press the DEFROST key. The display flashes “ENTER
DFRST”.
2. Press the ENTER key.
• If the unit operating conditions allow a manual defrost
(e.g. evaporator coil temperature is less than 10 C [50
F]), the display briefly shows “LOAD DFRST”. The
unit enters defrost as the Defrost LED turn ON. The
defrost cycle automatically terminates.
NOTE: If the ENTER key is not pressed within
10 seconds, the controller will default (return) to
the Standard Display.
• If unit operating conditions do NOT allow defrost, the
display shows “DFRST INVAL” for 3 seconds.
3. The controller then returns to the Standard Display.
Initiating a Full Pretrip
To perform a Full Pretrip test, turn the unit On/Off switch ON:
NOTE: The controller will not perform an auto-
matic pretrip test until all alarms have been cor-
rected and cleared.
1. Press the PRETRIP key. The display flashes “ENTER
PTRIP”.
2. Press the ENTER key. The display briefly shows “LOAD
PTRIP”. The controller then conducts a Full Pretrip Test.
3. When the Pretrip test is complete, the display returns to
the Standard Display (e.g. setpoint and controlling sensor
temperatures). The unit returns to normal operation.