User manual SCOTSMAN NS650

[. . . ] NS650 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 system. The NS650 is a complete ice system that produces and stores nugget ice. It features: front service for the condenser, control box, and water reservoir; a slide out chassis; an electronic circuit for monitoring ice and water level; a thermostatic expansion valve; and R-502 as the refrigerant. TABLE OF CONTENTS Installation For the Installer Specifications . 6 Start Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Component Description . [. . . ] 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 30 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. Check the high pressure cut out, if closed go to F; if open check: 1. The pressure control opens at 450 psig. 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. It opens from excess pressure of ice inside the ice chute: this should only happen when the machine does not shut off when the ice storage bin is full. This switch will reset when the ice melts, but the machine will not resart until the reset switch on the circuit board is pressed. The machine will not run if there is not enough water in the reservoir. See the next step. December, 1988 Page 17 NS650 SERVICE DIAGNOSIS: Condition - No Ice Being Produced STATUS: NOTHING OPERATES H. Check: The gear motor, if it will not run, the compressor will not run. [. . . ] Bench test the gearmotor, check for oil leaks, noise, and amp draw. December, 1988 Page 29 NS650 Circuit Board Testing ///////////////////////////////////////////////////////////////////////WARNING////////////////////////////////////////////////////////////////// These procedures require the machine to be connected to the power supply. The voltages of the electronic circuit are very low, but HIGHER VOLTAGES ARE PRESENT IN THE UNIT. Do not touch anything but the tester while the unit is being checked out. Make all connections to the circuit board with the ELECTRICAL POWER OFF. [. . . ]