Condenser Fan Motor on the air-cooled versions. The high Pressure Control is manual reset with the reset button at the on the rear of the machine and a monitoring Red LED on the Front Console Panel.
7.9Water Regulating Valve (water-cooled models only).
The water Regulating Valve function is to maintain a constant Compressor head pressure by regulating the amount of water flowing through the condenser, on water-cooled models. The valve operates through the refrigeration system high-pressure side. Rotating the adjusting screw, located at the top of the valve, will Increase or Decrease the water flow through the water-cooled condenser, which in turn will Decrease or Increase the Compressor operating head pressure.
7.10Water Distribution System.
The Water Distribution System functions to evenly supply water to all of the cells of the evaporator plate. The water is pumped from the water reservoir to the distributor, above the evaporator, through the holes and flows over the ice moulds. Gravity returns the unfrozen water to the reservoir for recirculation.
7.11Water Drain Solenoid Valve.
The Water Drain Solenoid Valve functions in conjunction with the water pump to flush-out the reservoir assembly at the beginning (first 40 seconds) of every harvest cycle. This action cleans-up and rinses the reservoir during each harvest cycle preventing dangerous water mineral concentration.
7.12Thermostatic Expansion Valve.
The Thermostatic Expansion Valve regulates the flow of refrigerant to the evaporator and reduces the pressure of the liquid refrigerant from condensing pressure to evaporating pressure.
7.13Water Pump.
The water pump primes the water from the reservoir to the distributor tube and through the holes (in the distributor) it cascades over the evaporator moulds by gravity to be frozen into clear ice cubes. The water pump remains OFF during the first 30 seconds of the freezing cycle whilst it continues to run for the first 40 seconds of the defrost/ harvest cycle to drain the remaining water in the reservoir.
7.14Water Inlet Solenoid Valve (male fitting).
The P.C. Board energises the Water Inlet Solenoid Valve during the beginning of the freezing cycle until the water reaches the maximum level in the reservoir (controlled by the Water Level Sensor).
After 3 minutes, from the start of the freezing cycle, the Water Inlet Valve is energised again for a short period to re-fill the reservoir to the maximum level to minimise the possibility of slush ice forming.
A flow control is fitted in the feed pipe to reduce the pressure of the water.
7.15Water Level Sensor.
The Water Level Sensor, located in the upper right side of the reservoir, works in conjunction with the P.C. Board in order to control the water level at the beginning of the freeze cycle by receiving a low power current through the water. When the current reaches the P.C. Board the water inlet solenoid valve is de-energised.
If the P.C. Board doesn’t receive any signal from the Water Level Sensor within the first 3 minutes of the freeze cycle the P.C. Board trips OFF the operation of the machine with the switching ON of the two Red LED’s blinking slowly.
8.Wiring Diagram - F200 & F300
8.3Compressor Contactor
Located in the control box, the compressor contactor functions is to carry the compressor line current. The contactor is wired to receive power from the ICE/OFF/WASH switch through the P.C. Board.
8.4Ice Thickness Sensor
Located in the front upper right side off the evaporator, the sensor is made with two metal reeds in which passes power at low voltage. The two metal reeds, which are individually insulated, are set, through a setting screw, to maintain a minimum clearance from the evaporator (7mm) Once ice is formed into each mould and is thick enough to fill-up that minimum clearance existing between the two sensor reeds, and the evaporator, the water that cascades over the ice has gradually increased to make contact between the two sensor reeds.
Contact remains there for about 6 seconds the P.C. Board receives the signals to put the ice machine on defrost.
8.5N.C. Microswitch/Magnetic Switch
Signalling the ice cubes release. Located in the upper left side corner of the evaporator, this low voltage switch - single pole/single throw - mechanically operated by the evaporator deflector actuator, signals to the P.C. Board the end of the defrost cycle and to re-start a new freezing cycle. The swinging motion, to which the ice deflector is subject to when the ice cubes drop into the bin below, causes the deflector actuator to press (open the contact) and the release (close the contact) microswitch plunger. This OFF and ON situation of the N.C. contact is enough to signal to the P.C. Board that the timed defrost cycle is over. On later models the sequence is controlled by a magnetic switch attached to the bottom right hand side of the deflector.
If the bin is full of ice, the evaporator deflector will be left in the open position by the last batch of released cubes. This means that the deflector actuator will keep the N.C. microswitch plunger pressed,or the magnet and switch separated, as long as the deflector remains in open position.
If the N.C. contact are open for more that 30 seconds, the switch signals to the built-in time delay of the P.C. Board to turn the unit OFF
NOTE: In case the Interface P.C. Board does not receive the second pulse from the microswitch/magnetic switch, after 30 to 32 seconds from the first pulse, it will send a signal to the main Board, to switch the unit from defrost to freezing cycle.
It is possible to vary the maximum waiting time for starting a new freezing cycle after the pulse sent by the first switch, by adjusting a ‘trimmer’. The waiting time variation ranges from 22 to 45 seconds.
8.6Hot Gas Solenoid Valve
The Hot Gas Solenoid Valve functions only during the Harvest Cycle, to divert the hot discharge gas from the Compressor, bypassing the Condenser and thermostatic expansion valve, for direct flow to the Evaporator Platen Assembly to release ice cubes from the ice cube moulds.
The Hot Gas Solenoid Valve is comprised of two parts - the Body/Plunger and the Coil assemblies. Installed in the discharge line of the Compressor, the energised solenoid coil liffs the valve stem within the valve body to cause the hot discharge gas to be diverted when the ice Thickness sensor has signalled to the P.C. Board to start the Harvest Cycle.
8.7High Pressure Fan Control - Air Cooled Models
A reverse acting automatic reset, high pressure control is electrically connected to the two condenser fan motors and by a capillary tube to the liquid line.
Its function is to maintain the head pressure during the freezing cycle between the preset values and the head pressure during the harvest cycle ensuring sufficient heat to release the cubes from the cube moulds.
The control contacts are set to open at 13 bar cutting off the electrical power supply to the fan motors and to close at 15 bar.
8.8High Pressure Control - Water Cooled Models
