User manual SCOTSMAN NM1852R

[. . . ] NM1852R 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 NM1852R is a remote condenser modular ice system. It features: front service for the freezer, gearmotor, control box, water reservoir, and bin control; an electronic circuit for monitoring ice and water level; a thermostatic expansion valve; and R-22 as the refrigerant. TABLE OF CONTENTS For the Installer Specifications . 24 Removal and Replacement Water Reservoir & Bin Controls . [. . . ] Clean the auger and evaporator as required. Reverse to reassemble. ALLEN SCREWS BREAKER & BEARING & AUGER ASSEMBLY December 1992 Page 23 NM1852R SERVICE DIAGNOSIS: Condition - No Ice Being Produced STATUS: NOTHING OPERATES A. Check: Voltage to the unit, restore it if there is none. Check: The master switch, switch ON if off. Check: The 2 reset switches (spout switch, or on prior models, the circuit board; and high pressure): depress and release each switch. If the unit still does not start, check the spout switch, or high side pressure. Check the high pressure cut out switch, if closed, go to E; if open: 1. Check the high side pressure, reset the switch and observe that the fan is forcing air through the condenser. If the switch opens at pressures below 400 psig, replace the switch. If the pressures rise above the trip out point, and the unit shuts down: a. 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. Check the head pressure control valve, it should be maintaining a head pressure above 220 psig. If the unit has the correct charge, and the condenser is clean, and the refrigerant lines are not kinked or twisted, and the condenser is not overheated by external heat loads, the head pressure should be under the trip out point of the head pressure control switch. If all of the above are found to be good, and the machine trips out on high head pressure, replace the head pressure control valve. E. This switch will open if the bin control (ice level sensor) does not shut the machine off when the ice storage bin is full of ice: ice backs up in the ice chute, and internal pressure opens the switch, stopping the machine. The ice level sensors, they may need cleaning (see maintenance). If there is not enough water in the reservoir, the water level sensor will keep the machine from starting. a. Check the water level, restore/adjust if low. Check the water level sensor, clean if dirty, (see maintenance). If the machine does not start, see the next page. December 1992 Page 24 NM1852R SERVICE DIAGNOSIS: Condition - No Ice Being Produced STATUS: NOTHING OPERATES G. [. . . ] Close the valve and replace the caps when the job is finished. NM1852R 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. [. . . ]