User manual SCOTSMAN NDE750

[. . . ] NDE750 INTRODUCTION To the owner or user: The service manual you are reading 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 maker-dispenser. The NDE750 is a combination nugget ice maker and countertop dispenser. The NDE750 ice making section is equipped with the following features: electronic controls for bin level and low water; thermostatic expansion valve; front service for most components; and R-404a (HP62) refrigerant. The ice dispensing section is a seamless plastic storage bin, with a stainless steel ice agitator at the bottom to sweep the ice into the dispensing chute. Table of Contents FOR THE INSTALLER: Specifications . [. . . ] Check the low side pressure, the low pressure cut out opens at pressure below 4 psig. Check if the auger is turning, if it is not, remove the gearbox and: Check for internal damage, repair and replace in the machine. Check for low charge, add some refrigerant, if the unit will operate, (normal low side pressure being about 38 psig) stop and look for a leak, repair, replace the drier, evacuate, and weigh in the nameplate charge. If, with added charge, the unit does not operate: Check for a restricted system, replace the drier, evacuate, and weigh in a nameplate charge. Check for a Thermostatic Expansion Valve that does not open, if defective, replace it. Replace the drier, evacuate, and weigh in the nameplate charge. E. Check the high pressure cut out, if closed, go to F; if open: 1. Check the high side pressure, reset the control, and observe: on water cooled, that water soon begins to flow from the condenser drain; or, on air cooled, that the fan is forcing air through the condenser. If the unit trips out on pressures below 450 psig, replace the control. If the pressures rise above the trip out point, and the unit shuts down: a. Check for adequate water flow on water cooled, if adequate, clean the interior of the condenser. If the pressures are still too high replace the water regulating valve. Check for adequate air flow on air cooled. Clean the condenser and (if used) the filter. If the air flow is poor because of the installation, advise the user that the unit should be moved, or the air around it kept cooler. Check the fan motor for tight bearings and proper rotation. Check that the fan blades are clean, and the fan secure to the fan motor shaft. The machine will not run if there is not enough water in the reservoir. See the next step. December 1993 Page 18 NDE750 SERVICE DIAGNOSIS: Condition - No Ice Being Produced STATUS: ICE MAKER DOES NOT OPERATE G. Check: The gear motor, if it will not run, the compressor will not run. If no power to it: Check: The indicator lights on the circuit board, the bin empty light should be ON, the no water light should be OFF . If the bin empty and no water lights are off, check the transformer. [. . . ] The valve must be closed and the caps must be on or the valve will leak. · If gauges must be used, don't always check the high side pressure. If the condenser is clean and seems to be operating correctly, it most likely is. The low side pressure is more important on an ice machine than the high side. · If gauges must be used, use very short hoses to minimize refrigerant discharged into the air. Allen Wrench · Refrigerant should not be added except as a way to determine the proper operation of the product. If the system was low on refrigerant, there is a leak, and it must be found and repaired. Torque Stem to 6-8 ft. [. . . ]