Page 30
Page 30
OPERATION - CONTROL SEQUENCE
At the start of freezing cycle the evaporator
temperature sensor controls the length of the first
part of the freezing cycle. As it reaches a
predetermined temperature it supplies a low
voltage current to the P.C. BOARD in order to
activate the electronic timer which takes over the
control of the freezing cycle for a pre-fixed time
according to the DIP SWITCH keys setting
(see Tab. B).
NOTE. The evaporator temperature sensor,
factory pre-set, is the same for all the models
and is not adjustable in the field.
Once completed the timed portion of the freezing
cycle the system goes automatically into the
defrost cycle which has also a pre-fixed length. At
completion of the defrost cycle the P.C. BOARD
command the unit to start again a new freezing
cycle.
OPERATION - ELECTRICAL SEQUENCE
The following charts illustrate which switches and
which components are ON or OFF during a
particular phase of the icemaking cycle.
Refer to the wiring diagram for a reference.
BEGINNING FREEZE
Electrical components (Loads)
ON
OFF
Compressor ...........................................
•
Fan Motor (Air cooled only) and TRIAC ........
•
Hot Gas Valve ........................................
•
Water Inlet Valve ....................................
•
Water Drain Valve ..................................
•
P.C.Board Relay 1 Coil ..........................
•
P.C.Board Relay 2 & 3 Coil ....................
•
Water Pump ...........................................
•
Contactor Coil (EC 125-175 only) ..........
•
P.C.B. Timer ...........................................
•
Elctronic Controls & Sensors
ON
OFF
Evaporator Sensor .................................
•
Condenser Sensor .................................
•
Ice Level Control ....................................
•
TIMED FREEZE
Electrical components (Loads)
ON
OFF
Compressor ............................................
•
Fan Motor (Air cooled only) and TRIAC ........
•
•
Hot Gas Valve ........................................
•
Water Inlet Valve ....................................
•
Water Drain Valve ..................................
•
P.C.Board Relay 1 Coil ..........................
•
P.C.Board Relay 2 & 3 Coil ....................
•
Water Pump ...........................................
•
Contactor Coil (EC 125-175 only) ..........
•
P.C.B. Timer ...........................................
•
Electronic Controls & Sensors
ON
OFF
Evaporator Sensor .................................
•
Condenser Sensor .................................
•
•
Ice Level Control ....................................
•
HARVEST (Drain portion - first 15 sec.)
Electrical components (Loads)
ON
OFF
Compressor ............................................
•
Fan Motor (Air cooled only)and TRIAC .........
•
Hot Gas Valve ........................................
•
Water Inlet Valve ....................................
•
Water Drain valve ...................................
•
P.C.Board Relay 1 & 2 Coil ....................
•
P.C.Board Relay 3 Coil ...............................
•
Water Pump ...........................................
•
Contactor Coil (EC 125-175 only) ..........
•
P.C.B. Timer ...........................................
•
Electronic Controls & Sensors
ON
OFF
Evaporator Sensor .................................
•
Condenser Sensor .................................
•
Ice Level Control ....................................
•
HARVEST (Water filling portion)
Electrical components (Loads)
ON
OFF
Compressor ............................................
•
Fan Motor (Air cooled only)and TRIAC .........
•
Hot Gas Valve ........................................
•
Water Inlet Valve ....................................
•
Water Drain valve ...................................
•
P.C.Board Relay 1 & 2 Coil ....................
•
P.C.Board Relay 3 Coil ...............................
•
Water Pump ...........................................
•
Contactor Coil (EC 125-175 only) ..........
•
P.C. Board Timer ...................................
•
Electronic Controls & Sensors
ON
OFF
Evaporator Sensor .................................
•
Condenser Sensor .................................
•
Ice Level Control ....................................
•