NME454, 654 & FME504, 804 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. This is a modular ice system that fits a variety of Scotsman ice storage bins.
NME454, 654 & FME504, 804 FOR THE INSTALLER These machines fit the following Scotsman products, check sales literature for other possible combinations: · SB480 and extensions (with bin top KBT18) · B530 using bin top KBT14 or KBT20 · B842 using bin top KBT28 · B948 using bin top KBT24 NME654 Dispenser Applications The NME654 can be placed on and used with certain ice and ice-beverage dispensers.
NME454, 654 & FME504, 804 SAMPLE BIN AND MACHINE COMBINATIONS FME804 ON BH550* The Nameplate is located on the back of the machine. A Serial Number Plate is located inside the cabinet, behind the front panel.
NME454, 654 & FME504, 804 FOR THE INSTALLER Location: Install the machine be installed in a location where it has enough space around it to be accessible for service. A minimum of 6" must be allowed at the back and sides for air circulation on air cooled models. Try to avoid hot, dirty and crowded locations. Be sure that the location for the machine is within the environmental limitations. Storage Bin: Tip the storage bin on its back, using parts of the carton to protect the exterior finish.
NME454, 654 & FME504, 804 FOR THE INSTALLER: Location ALLOW AIR SPACE ON BOTH SIDES TWO UNITS ON ONE BIN ALLOW ROOM FOR AIR CIRCULATION AND SERVICE ACCESS Airflow Notice: Airflow changed in 2006. Prior model's air flow was in the front and out the back. Current model's (shown) air flow is in the sides and out the back.
NME454, 654 & FME504, 804 FOR THE PLUMBER CONFORM TO ALL APPLICABLE CODES Water Inlet Drains Air Cooled Models: Use 3 8" O.D. copper tubing to connect cold potable water to the 3 8" male flare fitting at the back of the cabinet. Install a hand valve near the machine to control the water supply. Water Treatment: In most areas, a water filter of some type will be useful.
NME454, 654 & FME504, 804 FOR THE ELECTRICIAN CONFORM TO ALL APPLICABLE CODES Connect the electrical power to the machine to the wires in the junction box at the rear of the machine. Check the nameplate (located on the back panel) for the voltage requirements, and for the minimum circuit ampacity. The machine requires a solid chassis to earth ground wire. The ice machine should be connected to its own electrical circuit so it would be individually fused.
NME454, 654 & FME504, 804 FOR THE INSTALLER Final Check List 1. Is the ice system installed indoors in a location where the air and water temperatures are controlled, and where they do not exceed the design limitations? 2. Is there an electrical service disconnect within sight of the installed machine? Has the voltage been checked, and compared to nameplate requirements? 3. Have all the plumbing connections been made and checked for leaks? 4. Has the machine and bin been leveled? 5.
NME454, 654 & FME504, 804 INITIAL START UP Pre-Start Inspection 1. Remove the front and side service panels. are rubbing each other. Check that the fan blade turns freely (air cooled). 2. Check that any shipping blocks have been removed. 4. Check that the unit is installed correctly according to the final check list (page 8). 3. Inspect the interior of the machine for loose screws or wires. Check that no refrigerant lines Start Up · The air cooled discharge pressure will depend 1.
NME454, 654 & FME504, 804 COMPONENT DESCRIPTION Control Box: Contains the electrical controls that operate the machine. High Pressure Cut Out Switch: An automatic reset switch sensing the high side refrigeration pressure. It is set to shut the machine off if the discharge pressure should ever exceed 450 PSIG. Low Pressure Cut Out Switch An automatic reset control that shuts off the ice machine when the low side pressure drops below a preset point, 15 PSIG. Compressor: The refrigerant vapor pump.
NME454, 654 & FME504, 804 COMPONENT DESCRIPTION Evaporator: A refrigerated vertical tube filled with water and containing a water seal and auger. Auger: A solid stainless steel double spiral auger, it pushes the ice crystals up to the top of the evaporator. Water Seal: A two part “face” seal, the top half rotating with the auger, the bottom half stationary, the sealing action being where the two seal “faces” meet. Ice Sweep: A plastic cap with “fingers”.
NME454, 654 & FME504, 804 CONTROL BOX COMPONENTS Contactor: A definite purpose contactor connecting the compressor to the power supply. AutoSentryÔ Control Board The control board receives input signals from several sensors and translates them to control the electrical power supply to the various loads. The sensors include: · Electric eyes to check the ice level in the bin.
NME454, 654 & FME504, 804 ELECTRICAL SEQUENCE: There are 7 indicator lights on the control board: · WTR-OK (Water OK). Green. Normal = Glowing. Glows when there is water in the reservoir. · PWR-OK (Power OK). Green. Normal = Glowing. Glows when the control board has power and is functional. · Service. Red. Normally Off. · Freeze. Red. Normally glowing when making ice. · Bin Full. Red. Normally Off when making ice. · LED1. White. Located next to the board’s Compressor Relay.
NME454, 654 & FME504, 804 OPERATION: Water Water enters the machine through the 3/8" male flare at the rear of the cabinet, goes to the water reservoir which it enters through the float valve. The water then goes out the bottom of the reservoir tank to the bottom of the evaporator. Reservoir overflow or evaporator condensation is routed to the drain.
NME454, 654 & FME504, 804 OPERATION: Refrigeration Beginning at the compressor, the refrigerant is compressed into a high temperature gas. The discharge line directs this gas to the condenser. At the condenser (air or water cooled) the gas is cooled by either air or water and it then condenses into a liquid. This high pressure liquid then goes through the liquid line to the expansion valve.
NME454, 654 & FME504, 804 OPERATION: Performance Typical Low Side Pressure · Air Cooled: 34 - 38 PSIG · Water Cooled: 32 PSIG Typical Discharge Pressure · Air Cooled: 220 - 300 PSIG · Water Cooled: 245 PSIG Typical Compressor Amp Draw ·8-9 Typical Auger Drive Motor Amp Draw (115 volt) · 3.1 to 3.5 - Emerson · 4 to 4.
NME454, 654 & FME504, 804 CLEANING & SANITIZING A Scotsman Ice System represents a sizable investment of time and money in any company’s business. In order to receive the best return for that investment, it MUST receive periodic maintenance. It is the USER’S RESPONSIBILITY to see that the unit is properly maintained. It is always preferable, and less costly in the long run, to avoid possible down time by keeping it clean; adjusting it as needed; and by replacing worn parts before they can cause failure.
NME454, 654 & FME504, 804 SENSOR MAINTENANCE 1. The bin control is a device that senses light, therefore it must be kept clean so it can “see”. At least twice a year, remove the bin control sensors from the base of the ice chute, and wipe the inside clean, as illustrated. 2. The ice machine senses water level by a probe located in the water reservoir. At least twice a year, the probe should be removed from the reservoir, and the tip wiped clean of mineral build-up.
NME454, 654 & FME504, 804 AIR COOLED MAINTENANCE Hazardous Moving Parts. Moving fan blade can cause personal injury. Disconnect electrical power before beginning. Clean the air cooled condenser. The air flow on this model is from front to back, so the inside of the machine will have to be available to clean the air cooled condenser. Use a vacuum cleaner or coil cleaner if needed. Do NOT use a wire brush. A. Disconnect electrical power, and remove the filter. The filter may be cleaned or replaced. B.
NME454, 654 & FME504, 804 BEARING MAINTENANCE The bearing in the breaker should also be checked at least two times per year. A. Check the bearing by: · unscrewing the auger stud Auger Stud · removing the ice chute cover Chute Cover Cap Screw · unscrewing the ice sweep Ice Sweep Inspect the bearing. There should be plenty of grease in sight. If grease is needed the bearing and breaker should be removed to check the action of the bearing. It should rotate smoothly.
NME454, 654 & FME504, 804 AUGER MAINTENANCE 4. Remove 4 allen screws holding breaker to In some areas, the water supply to the ice maker evaporator. will contain a high concentration of minerals, and that will result in an evaporator and auger 5. Pull up to remove auger. becoming coated with these minerals, requiring a After the auger has been removed, allow the auger more frequent removal than twice per year.
NME454, 654 & FME504, 804 SERVICE DIAGNOSIS Symptom Possible Cause Probable Correction No ice is made, nothing operates Unit off due to no power Restore Power Unit off due to master switch in OFF position. Switch master switch to ON. Unit off due to low water level. Check water supply, filter, strainer, float valve. Correct water supply. Unit off due to ice level sensors (photo-electric eyes) blocked. Check/clean ice level sensors. Unit off due to scale on water level sensor.
NME454, 654 & FME504, 804 SERVICE DIAGNOSIS Symptom Possible Cause Probable Correction Water Leak Drain plugged up Clean out drain Tubing cracked Replace tubing Condensation on drain tubing Insulate tubing Hose off Reattach hose Reservoir cover off Return cover to reservoir Reservoir cracked Replace reservoir Evaporator water seal leaks Check base of evaporator & drip pan. If the seal leaks, shut off the water, remove the auger, replace the water seal.
NME454, 654 & FME504, 804 CONTROL SYSTEM DIAGNOSTICS The control system consists of: · Control Board · Water Sensor · Ice Sensors · High Pressure Cut Out · Low Pressure Cut Out If the unit is OFF, check the control board: 1. Is the Power OK light on? If not check power to the unit. If it has power, and the Power OK light is NOT on, check the high pressure and low pressure cut outs. If they are both closed, replace the board. If the Power OK light is ON, go to the next step. 2.
NME454, 654 & FME504, 804 REMOVAL AND REPLACEMENT: Bin Controls BIN CONTROLS (Ice Level Sensors) 1. Disconnect electrical power. 2. Remove front panel. 3. Remove control box cover. 4. Locate ice chute, at the base of the chute, in front of and behind it are two plastic bin control mounts. 5. Slide each bin control to the left, and in the control box, disconnect the electrical leads connecting the bin control to the circuit board. 6.
NME454, 654 & FME504, 804 REMOVAL AND REPLACEMENT: Bearing And Breaker Hazardous Moving Parts. Moving auger can cause personal injury. Disconnect electrical power before beginning. 6. Service the bearing. Check for rust, rough spots and damage. a. The bearing is pressed into the breaker, to remove the bearing and replace it an arbor press is needed. b. Replace lower seals before installing new bearing in breaker.
NME454, 654 & FME504, 804 REMOVAL AND REPLACEMENT: Auger Hazardous Moving Parts. Moving auger can cause personal injury. Disconnect electrical power before beginning. e. If the auger is stuck use a slide hammer type puller to pull on the auger at the threaded hole. The size of that hole is 5/8"-18. Inspect the auger, the critical areas of the auger are: 1. The auger body. It should be clean and shining. Sometimes an auger will appear clean when wet, but after it is dry it will be seen to be stained.
NME454, 654 & FME504, 804 REMOVAL AND REPLACEMENT: Water Seal To Remove the Water Seal: (Assuming all steps to remove the auger have been performed.) 1. The gearmotor/evaporator assembly will have to be exposed. 2. Remove the 4 hex head cap screws holding the evaporator to the gearmotor assembly. Lift the evaporator up and off of the gearmotor. 3. Remove the snap ring or wire retainer from the grove under the water seal. 4. Pull or drive out the lower half of the water seal.
NME454, 654 & FME504, 804 REMOVAL AND REPLACEMENT: Evaporator To Replace the Evaporator: (Assuming all the steps for removal of the thrust bearing, breaker, auger, and water seal have been performed.) 1. Recover the refrigerant from the ice maker. 2. Unsweat the refrigerant connections: a) At the thermostatic expansion valve outlet. Heat sink the TXV body when unsweating or resweating the adjacent tubing. b) At the suction line at the joint about 3" from the evaporator. 3. Remove the evaporator. 4.
NME454, 654 & FME504, 804 REMOVAL AND REPLACEMENT: Gear Reducer and Motor Electrical Shock Hazard. Electrical shock can cause personal injury. Disconnect electrical power before beginning. To Check the Motor: 1. Remove wires from terminals 1 and 2. 2. Use an ohmmeter to check for continuity. If there is none, replace the motor only. If there is continuity, but the motor will not start, check the motor's start switch. 3. Remove motor end bell or motor stator.
NME454, 654 & FME504, 804 REFRIGERATION SYSTEM SERVICE General: This ice machine uses R-404A refrigerant and polyolester oil. Do NOT use mineral oil in this refrigeration system. Instructions for Liquid Charging R-404A In preparation for charging, the low side hose should have a sight glass, and/or a restricting device (such as a “Charge Faster”) installed in it · When the system is serviced, a special liquid for metering liquid into the low side of the system. line drier is required.
NME454, 654 & FME504, 804 WHAT TO DO BEFORE CALLING FOR SERVICE If the machine is off, not making ice: 1. Check the water supply to the ice machine. The machine is designed to shut off if there is no water to it. Check the filters if there are any. 2. Check the power supply to the machine. Reset the breaker if it is tripped. 3. If both water and power have been checked and are available, try switching the power Off and then On. After 2 minutes the machine should restart.
