Scotsman Ice AFE325 specifications Mechanical Operation

AFE325

Mechanical Operation

ELECTRICAL SEQUENCE

There are two circuits in the AFE325: one is a series circuit with several switches connected in series to the compressor. The other is a parallel branch of the series circuit, controlling the gear drive motor.

∙The series circuit begins at the terminal strip in the control box. From there, the line side power is connected to the Master Switch.

∙When the master switch is closed, the power is then connected to the Spout Switch. This switch, located on the top of the ice chute, is closed unless the ice chute has overfilled with ice, it is a manual reset.

∙The line side power is also connected, in a parallel circuit, to terminal 1 of the Auger Delay pressure control. This pressure control, connected to the low side of the refrigeration system, is designed as a by-pass circuit to the auger drive motor whenever the low side refrigerant pressure is at it’s normal ice making range. At start up, the contacts between terminals 1 and 2 are open. The line side power does not pass any further through the auger delay pressure control, until the compressor starts, and the low side pressure drops.

∙The next control the power is connected to is the Low Water Pressure Control. This switch is designed to open should the water pressure to the machine drop too low.

∙The next control is the Bin Thermostat. It is closed when there is no ice on the portion of the control inside the ice bin. It is open when there is ice on the portion of the control inside the ice bin. Closing of the bin thermostat begins the process of making ice, because the line side power now goes to the compressor, gearmotor, and if air cooled, the fan motor.

∙Power is initially connected to the gearmotor through contacts 3 and 2 of the auger delay pressure control. This causes the auger motor to start and run. At the same time, if the centrifugal switch on top of the gearmotor closes (meaning the motor is at full speed) the compressor is connected to the neutral side of the power supply, and the compressor begins to run.

∙As the compressor runs, the low side or suction pressure begins to fall, when it reaches a preset point, the contacts within it move, opening 3 and 2, then closing 1 and 2. The power for the gearmotor is then connected to a point in the series circuit ahead of the low pressure control, the low water pressure control and the bin thermostat, so that if any of these open, the gearmotor will continue to run, pushing ice out of the evaporator.

The refrigeration system uses a hermetic compressor (specifically designed for R-134a), forced draft air cooled condenser, capillary tube and vertical flaked ice evaporator. Inside the evaporator is a slowly rotating auger. The auger is supported by bearings at each end, and there is a face-type water seal above the bottom bearing. The auger is driven by a 1/10 HP direct drive gear reducer. The auger drive motor has a speed operated switch on it that will keep the compressor from operating if the auger motor is not turning at full speed.

Water flows from the building supply to the reservoir . Water from the reservoir is used to make ice.

The bin and reservoir overflow have separate drains.

August 1994

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