User manual SCOTSMAN CMS1202

[. . . ] CMS1202 INTRODUCTION To the owner or user: This service manual is intended to provide you and the maintenance or service technician with the information needed to install, start up, clean, maintain and service this ice system. Table of Contents Specifications . 2 3 4 5 6 7 8 10 11 12 15 17 19 20 23 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . For the Electrician For the Plumber Final Check List Initial Start Up . Service Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Removal and Replacement . [. . . ] A change in either ambient air or incoming water temperature will affect the efficiency of the refrigeration system, and this will vary the length of time it takes the evaporator to reach the temperature at which the cube size control is preset to close. Relay The multi-function, three pole, double throw, plug-in relay is inserted into a receptacle on the printed circuit board in the control box. The relay functions in part to by-pass the bin thermostat control to prevent the icemaker from shutting OFF, when the bin thermostat opens during the freezing cycle. The bypass action serves to ensure full-sized ice cubes with each harvest cycle and, to prevent short cycling on the bin thermostat control. CONTROL BOX Timer - Timer & Switch Assembly The timer cam is controlled by the cube size control. The outer surface, or large diameter lobe of the timer cam, determines the timer cycle for finish freezing of the ice cubes, while the inner surface, or small diameter lobe, determines the time cycle for the harvest cycle. When the microswitch button is pushed in there is power connected to the coil of the relay, and the unit is in the freeze cycle. When the microswitch button is released, the power to the relay is stopped, and the unit goes into harvest. The microswitch is actuated by a cam assembly directly connected to the timer motor. High Pressure Safety Control This is a manual reset control that shuts down the icemaker, should the discharge pressure ever reach 450 PSIG on air cooled and 350 PSIG on water cooled. Found below the control box. CUBE SIZE CONTROL RELAY TIMER AND MICROSWITCH ICE/OFF/WASH SWITCH BIN ICE LEVEL SELECTOR SWITCH September 1993 Page 12 CMS1202 COMPONENT DESCRIPTION Bin Level Control This electronic control uses sound waves to measure the distance between the bottom of the ice machine and the top of the ice in the bin. It is designed to control the machine's ice production to maintain that distance. The control is adjustable so that the ice machine will maintain a certain height of ice. When set at FULL it will not allow the machine to fill the bin any closer to the ice machine than about 8", and it will not work if the distance to the bottom of the bin is greater than 8 feet. ICE/OFF/WASH SWITCH Because it uses sound waves, a slight "ticking" sound can be heard coming from the bottom of the machine. There are two parts to the control, the circuit board, and the level control switch. BIN ICE LEVEL SELECTOR SWITCH THE USER CAN SELECT THE AMOUNT OF ICE TO BE MAINTAINED IN THE BIN. SOUND WAVES FULL PARTIAL September 1993 Page 13 CMS1202 COMPONENT DESCRIPTION Water Inlet Solenoid Valve The water inlet solenoid valve fills the sump assembly with water. Water Regulator Valve - Water Cooled Model The water regulator valve maintains a constant compressor head pressure, by regulating the amount of inlet water flow through the condenser on water cooled models. Rotating the adjusting screw, located on top of the valve, can INCREASE or DECREASE the water flow through the water cooled condenser, which in turn, will DECREASE or INCREASE the compressor operating head pressure. When installing a replacement water regulator valve, be sure the replacement valve is installed with the arrow positioned in the direction of the water flow. Water Distribution System The water distribution system functions to evenly supply water to all cells of the evaporator plates. The water pump pumps water from the sump up the vertical tygon tube to the tee. From there water is channeled through the water manifold to the water distributors, above each evaporator plate, and from six holes within each distributor, water flows to the cells of each side of the evaporator plates. Gravity flow returns the unfrozen excess portion of water to the sump reservoir for recirculation. Hot Gas Solenoid Valve The hot gas solenoid valve opens only during the harvest cycle, to divert the hot discharge gas from the compressor, by passing the condenser and capillary tube, for direct flow to the evaporator plates to release ice cubes from the ice cube molds. [. . . ] Disconnect electrical power and test ice machine circuit by attaching a jumper wire between bin thermostat posts on circuit board part no. If machine starts, disconnect electrical power, remove jumper wire and reconnect electrical power. If this does not repair unit, replace the board. Machine runs, makes ice, switches on and off, but ice level cannot be controlled. Machine runs, but will not shut off. Ice level switch may be defective. [. . . ]