User manual SCOTSMAN NM952

[. . . ] NM952 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 NM952 is a modular ice system that fits a variety of Scotsman ice storage bins. 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 Installation For the Installer Specifications . 15 Service Diagnosis Removal and Replacement Reservoir and Bin Controls . [. . . ] ////////////////////////////////////////////////////////////////////////// 6. To remove the auger, remove the front and top the evaporator drain hose. Remove 3 hex studs holding ice chute cover to After the auger has been removed, allow the auger ice chute, and remove cover. Loosen band clamp under ice chute, and Clean the auger and evaporator as required. Reverse to reassemble. August 1993 Page 18 NM952 SERVICE DIAGNOSIS: Condition - No Ice Being Produced STATUS: NOTHING OPERATES A. Check: The 3 reset switches, (spout switch, high and low pressure): depress and release each switch. If the still does not start, check: the spout switch; the high and the low side pressures. Check the low pressure cut out, if closed, go to E; if it is open, it could be due to: · Low refrigerant charge · The auger not turning · Restricted system · TXV not opening 1. 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 25 psig) stop and look for a leak, repair, replace the drier, recover, evacuate, and weigh in the nameplate charge. If, with added charge, the unit does not operate: Check for a restricted system, replace the drier, recover, evacuate, and weigh in a nameplate charge. Check for a Thermostatic Expansion Valve that does not open, if defective, replace it. Replace the drier, recover, evacuate, and weigh in the nameplate charge. E. 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 400 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. 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 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. [. . . ] If the condenser is clean and seems to be operating correctly, it most likely is. The low side pressure is much more important on an ice machine than is the high side. Minimal refrigerant discharged into the hoses equals minimal refrigerant discharged into the air. · If using recycled refrigerant, it must meet ARI spec 700-88 or have been cleaned by a machine capable of attaining ARI spec 700-88. ALLEN WRENCH Torque Stem to 6-8 ft. [. . . ]