Part B, Section 1 This section covers the following unit configurations. Model 3100 3400 3500 Voltage 1, 2 Pump Piston (E, F, or G) Manifold 4-Port (A) 6-Port (B or C) Control UniScan (1)
B 1-0
B 1-1 Section B 1 WARNING: Allow only qualified personnel to perform the following tasks. Follow the safety instructions in this document and all other related documentation. 1. Introduction This section includes UniScan control system troubleshooting procedures and repair procedures. Obvious causes of problems, such as broken wires, are generally not included in the troubleshooting procedures. Refer to the Parts section for the part number of any component that needs to be replaced. If you try all the suggestions in this section and still cannot solve the problem, call your Nordson representative for assistance. Refer to the Pump section for adhesive application troubleshooting procedures and for troubleshooting procedures and repair procedures for the melter s pump, motor (if present), and manifold assemblies. For hose or gun troubleshooting, refer to your hose or gun manual. The following sections of this manual contain additional information on the control system: Overview includes an overview of the control system. Installation includes procedures for making the parent machine interlock (PMI) and fault output contact connections, connecting electrical service, and setting up the control system for your operation. Operation includes procedures for operating and monitoring the control panel. Schematics includes a set of schematics for your system. Refer to the Options section for troubleshooting, repair, and parts information for the following options: Electric line filter
B 1-2 2. Overview of the Control System The UniScan control system determines how your melter functions and the temperatures at which the tank, hoses, and guns operate. The control system includes several printed circuit boards (hereafter referred to as boards) and other components that you should be familiar with to safely troubleshoot and repair your melter. See Figure B 1-1. 3 4 1 2 4131047A Fig. B 1-1 Standard UniScan Components 1. Main control panel and board 3. Hose/gun power modules 4. Tank power module 2. Control-end frame
B 1-3 3. Troubleshooting Tables These troubleshooting tables describe the kinds of control system problems you may encounter and provide corrective actions for handling those problems. When necessary, the tables refer to more detailed troubleshooting procedures. Refer to the appropriate troubleshooting table for the type of problem you are experiencing: Melter Not Powering On Circuit Breaker Trips or Will Not Stay On Zone Not Heating Indicating a Fault Opening and Closing the Electrical Enclosure The electrical enclosure must be opened before you can proceed with many of the procedures in this section. Follow this procedure whenever you are instructed to open or close the electrical enclosure. 1. Place the melter circuit breaker in the OFF position. 2. See Figure B 1-2. To open the the electrical enclosure: a. Remove the electrical enclosure lid (1) and disconnect the ground wire. b. Loosen the two captive screws (2) near the top of melter (on either side of the control-end frame) and carefully lower the frame (3). 1 3 Fig. B 1-2 Opening the Electrical Enclosure 1. Electrical enclosure lid 3. Control-end frame 2. Captive screw 2 4131051A
B 1-4 Opening and Closing the Electrical Enclosure (contd.) 3. To close the electrical enclosure: a. Carefully raise the control-end frame and secure it with the captive screws. b. Reconnect any ground wires that were disconnected. c. Reinstall and secure the electrical enclosure lid. Melter Not Powering On If your melter will not power on, use this troubleshooting table. WARNING: Risk of electrical shock. Failure to observe electrical safety procedures may result in equipment damage, personal injury, or death. Allow only qualified personnel to perform electrical troubleshooting. Observe all high voltage indicators. Problem Possible Cause Corrective Action Circuit breaker in ON position but melter will not turn on No input power Blown fuse on main control board Failed circuit breaker Make sure the power is turned on at your branch circuit disconnect switch and that you are supplying the proper voltage to the melter. If necessary, refer to Making the Electrical Service Connections in the Installation section. Check the two 1 amp fuses on the lower part of the main control board for continuity. Replace if necessary. Check the voltage at TB1 (located on the center frame) and at TB2 (located under the tank power module). If there is sufficient voltage between each leg of service at TB1 and little or no voltage between wires 4 and 5 or wires 5 and 6 at TB2, replace the circuit breaker. Refer to Replacing the Circuit Breaker in Repair Procedures.
B 1-5 Circuit Breaker Trips or Will Not Stay On If the circuit breaker trips off or will not stay on, use this troubleshooting table. WARNING: Risk of electrical shock. Failure to observe electrical safety procedures may result in equipment damage, personal injury, or death. Allow only qualified personnel to perform electrical troubleshooting. Observe all high voltage indicators. Problem Possible Cause Corrective Action 1. Circuit breaker trips repeatedly (no fault condition indicated) 2. Circuit breaker trips intermittently (no fault condition indicated) Tank overtemperature thermostat tripped circuit breaker Failed circuit breaker or failed shutdown relay on main control board Overcurrent or short circuit Electrical noise from other equipment in area Disconnect the overtemperature thermostat (close-on-rise). If the circuit breaker holds when the thermostat is disconnected, replace the thermostat. Do not operate the melter unless the thermostat is connected. Refer to Replacing a Tank Thermostat or RTD. Disconnect and lock out power to melter. Disconnect wire 7 on the back of the circuit breaker and wrap the terminal on the end of the wire with electrical tape. Restore power to the melter. Turn the circuit breaker on. If the circuit breaker does not hold, replace the circuit breaker. If the circuit breaker holds, replace the main control board. Refer to Replacing the Circuit Breaker or Replacing a Component in Repair Procedures. Visually check the wiring inside the electrical enclosure. Look for incorrect connections or loose or crossed wires. Check all circuits for a line-to-line or line-to-ground short. Check for electrical noise generated by other equipment in the area. Other motor drives are often the source of the electrical noise. Make sure the melter and the parent machine are on the same ground plane. Check the continuity between the frame of the melter and the frame of the parent machine. If there is no continuity or if there is high resistance, electrically ground the melter to the parent machine using as short a length of braided cable as possible.
B 1-6 Zone Not Heating If a tank, hose, or gun does not heat, use this troubleshooting table. WARNING: Risk of electrical shock. Failure to observe electrical safety procedures may result in equipment damage, personal injury, or death. Allow only qualified personnel to perform electrical troubleshooting. Observe all high voltage indicators. Problem Possible Cause Corrective Action Tank, hose, or gun does not heat or underheats Zone temperature setpoint too low Insufficient input voltage Blown fuse on power module High resistance on heater circuit caused by loose or oxidized heater connection or failed component Make sure the temperature setpoint is high enough. Make sure you are supplying the proper voltage to the melter. Refer to Making the Electrical Service Connections in the Installation Section. Remove the electrical enclosure lid and examine the red control LED and the heater power neon on the power module for the nonheating component. If the red control LED is on and the neon is off, check the continuity of the fuses on the power module. If a fuse is open, replace the fuse. If a fuse is okay, replace the power module. Refer to Replacing a Component in Repair Procedures. Remove the electrical enclosure lid and examine the red control LED and the heater power neon on the power module for the nonheating component. If both lights are on, check all connections to the heater circuit, including hose and gun plugs. Tighten loose connections. If the connections are okay, replace the heater or defective component. To verify that a heater has the correct resistance, refer to Note A and use the wiring diagram in the Schematics section. Refer to the gun manual for instructions on replacing a gun heater. You cannot replace a hose heater or a tank heater you must replace the hose or tank. Refer to the Tank section for procedures on tank replacement.
B 1-7 Problem Possible Cause Corrective Action Tank, hose, or gun does not heat or underheats (contd.) RTD circuit resistance high Failed ribbon cable in the circuit of the problem zone Remove the electrical enclosure lid and examine the red control LED and the heater power neon on the power module for the non-heating component. If the red control LED is off and the neon is off, check the resistance on the RTD circuit for that zone. Refer to Checking an RTD or RTD Circuit in Troubleshooting Procedures. Remove the electrical enclosure lid and examine the red control LED and the heater power neon on the power module for the nonheating component. If the red control LED is off, check the ribbon cable. Refer to Checking a Ribbon Cable in Troubleshooting Procedures. Replace the ribbon cable if it is defective. If the ribbon cable is okay, replace the main control board and the display board. NOTE A: To determine what the resistance of a tank heater should be, refer to Table B 1-1. To determine what the resistance of a hose or gun heater should be, use the following formula: V 2 W= R (where V=voltage, W=wattage, and R=resistance). To determine the voltage of a gun heater, look at the gun identification plate or the heater cartridge. To determine the voltage of a hose heater, look at the hose tag. Table B 1-1 Tank Heater Resistance Data Melter Component Resistance 3100 Tank 28.15 32.85 3400 Tank 23.93 27.92 3500 Tank 17.09 19.94
B 1-8 Indicating a Fault When a tank, hose, or gun fault occurs, the red FAULT light next to the circuit breaker turns on the melter shuts down after a two-minute time delay After the two-minute time delay elapses, the melter will turn off. You can reset the circuit breaker immediately to obtain an additional two minutes of troubleshooting time. This may be repeated any number of times unless the temperature of the tank wall reaches 260 C (500 F). When the tank wall temperature exceeds 260 C (500 F), the tank overtemperature thermostat closes, causing the circuit breaker to trip. The circuit breaker cannot be reset until the tank wall temperature falls below 260 C (500 F). NOTE: Each heated component (each hose, each gun, and the tank) is referred to as a heated zone or zone. Zones may also be referred to as channels. WARNING: Risk of electrical shock. Failure to observe electrical safety procedures may result in equipment damage, personal injury, or death. Allow only qualified personnel to perform electrical troubleshooting. Observe all high voltage indicators. Problem Possible Cause Corrective Action FAULT light turns on Shorted RTD, RTD circuit, or ribbon cable in the problem zone Shorted power module Check the RTD for a shorted condition. If the RTD is defective, replace it. If the RTD is okay, check the wiring and ribbon cable for a shorted condition. Check for a shorted power module. Observe the red control LED and the power neon on the power module. If the red control LED is off and the power neon is on, replace the power module (the switching component on the power module board is not turning off). Refer to Checking the Power Module Lights in Troubleshooting Procedures.
B 1-9 4. Troubleshooting Procedures Use these procedures as directed in the troubleshooting tables to further troubleshoot control system problems. Checking an RTD or RTD Circuit NOTE: If the faulted zone is a hose or a gun, you can disconnect the hose or gun at that zone and connect a hose or gun that is known to be good, or you can move the faulted hose or gun to another connection. If the fault disappears or follows the hose or gun, then you will know that the problem is in the hose or gun, not inside the melter. As an alternative to using this procedure, refer to your hose or gun manual for instructions on checking the hose or gun RTD and replacing the RTD. 1. Turn off the melter, disconnect and lock out electrical power to the melter at the branch circuit disconnect switch, and disconnect and lock out electrical power supplied through any I/O wiring. 2. Open the electrical enclosure. Refer to Opening and Closing the Electrical Enclosure. 3. Check the RTD resistance. To check the tank RTD, use a surface-temperature sensing device, such as a pyrometer, to measure the temperature of the heated zone at or near the RTD. Then measure the RTD s resistance. NOTE: If the faulted zone is a hose or gun, measure the RTD resistance at the hose or gun electrical plug. Refer to your hose or gun manual for a diagram of the electrical plug and for procedures for checking RTD resistance. Because the core elements of a hose are not accessible, the easiest method to check the actual temperature of a hose is to secure the end of the hose over a waste container. Then use a pyrometer with an immersion probe and measure the temperature of the adhesive as it is being discarded into the waste container. 4. Compare the RTD s temperature and resistance reading to the normal resistance range shown in Figure B 1-3. If the RTD resistance is significantly outside the normal range, replace the RTD. If a hose RTD is defective, you must replace the hose. To replace a gun RTD, refer to your gun manual. To replace a tank RTD, refer to Replacing an RTD or a Thermostat in Repair Procedures. If the RTD resistance is within the normal range, go to the next step. NOTE: For hose resistance data, refer to your hose manual.
B 1-10 Checking an RTD or RTD Circuit (contd.) 5. Check the continuity of the RTD circuit by measuring the RTD resistance at other points in the circuit. Refer to the Schematics section. Note that intermittent connections are the most difficult to troubleshoot since they are not always evident during continuity testing. 6. If you find a continuity problem in the RTD circuit, replace or repair the defective component as appropriate. If you do not find a continuity problem, replace the main control board. Refer to Replacing the Main Control Board in Repair Procedures. 360 340 320 300 280 RTD RESISTANCE IN OHMS 260 240 220 200 180 160 140 120 10 C 32 C 54 C 77 C 99 C 121 C 143 C 166 C 188 C 210 C 232 C (50 F ) (90 F ) (130 F ) (170 F ) (210 F ) (250 F ) (290 F ) (330 F ) (370 F ) (410 F ) (450 F ) RTD TEMPERATURE 5940833 Fig. B 1-3 RTD Resistance vs. RTD Temperature
B 1-11 Checking a Ribbon Cable Follow this procedure to check the continuity of a ribbon cable. 1. Turn off the melter, disconnect and lock out electrical power to the melter at the branch circuit disconnect switch, and disconnect and lock out electrical power supplied through any I/O wiring. 2. Open the electrical enclosure. Refer to Opening and Closing the Electrical Enclosure. 3. Disconnect both ends of the suspect ribbon cable. 4. Place a small-gauge solid wire into corresponding positions on the connectors at each end of the ribbon cable. Pin 1 is usually indicated by an arrow or some other distinguishing mark on the connector housing. 5. Check the resistance. The resistance should be less than 1 ohm at each position. Flex the cable to check for a possible intermittent open circuit. For a complete test, check for continuity between each position and its adjacent positions at each end of the ribbon cable. If continuity is detected between any two adjacent positions, then the ribbon cable is defective. NOTE: A ribbon cable may pass a continuity test but still be defective due to an undetected intermittent open circuit. You may need a fast-responding meter to detect an intermittent open circuit.
B 1-12 Checking the Power Module Lights The power modules supply power to a hose, gun, or tank heater when a low-voltage signal is received from the main control board. There can be up to two four-channel power modules for the hose and gun heaters. There is a one-channel power module for the tank heater. Each power module has diagnostic lights to assist you in troubleshooting temperature problems. Follow this procedure to check the power module lights. WARNING: Risk of electrical shock. Failure to observe electrical safety procedures may result in equipment damage, personal injury, or death. Allow only qualified personnel to perform electrical troubleshooting. Observe all high voltage indicators. 1. Open the electrical enclosure. Refer to Opening and Closing the Electrical Enclosure. 2. Observe the power module for the problem zone. See Figure B 1-4 and refer to Table B 1-2 to interpret the power module lights. FAULT Light on Control Panel Red Control LED on Power Module Table B 1-2 Checking the Power Module Lights Heater Power Neon on Power Module Condition Off Off Off The zone is above the temperature setpoint and is cooling. Off On On The zone is below the temperature setpoint and is heating, or, if the temperature does not increase, the heater circuit is open. Off Flashing Flashing The zone is at the temperature setpoint. Off On Off The power circuit to the heater is open. Check the fuses. Off Off On The power circuit to the heater is not turning off. Replace the power module. NOTE: This is a normal indication for a disconnected hose or gun zone. On On On The RTD is shorted. On Off On There is an overtemperature condition because the power module is shorted on. A four-channel power module will also display this sequence of lights if the zone is turned on but the hose or gun is disconnected electrically.
B 1-13 TANK LED TANK NEON GUN 1 LED AND NEON HOSE 1 LED AND NEON GUN 2 LED AND NEON HOSE 2 LED AND NEON GUN 3 LED AND NEON HOSE 3 LED AND NEON GUN 4 LED AND NEON HOSE 4 LED AND NEON 4131109A Fig. B 1-4 Location of Indicator Lights on Power Modules 5. Repair Procedures Troubleshooting procedures may identify failed components. Use these repair procedures to replace failed components. Refer to the Parts section to locate and order replacement parts and service kits. You can also use the parts drawings as a guide as you perform the following repair procedures. WARNING: Risk of electrical shock. Failure to observe electrical safety procedures may result in equipment damage, personal injury, or death. Allow only qualified personnel to perform electrical repairs. Observe all high voltage indicators. Replacing the Tank RTD or Thermostat 1. Turn off the melter, disconnect and lock out electrical power to the melter at the branch circuit disconnect switch, and disconnect and lock out electrical power supplied through any I/O wiring. 2. Remove the electrical enclosure lid and disconnect the ground wire. 3. Remove the front cover and disconnect the ground wire. 4. Locate the tank RTD and overtemperature thermostat behind the cutaway in the tank insulation (above the manifold filter).
B 1-14 RTD Replacement 1. Disconnect the RTD plug. 2. See Figure B 1-5. Follow these steps to replace the RTD: a. Remove the RTD retainer plate (2) and then remove the RTD (1). b. Coat the new RTD with thermal compound and insert it into the tank. c. Reinstall the RTD retainer plate in the orientation shown in Figure B 1-5. 3. Reposition the insulation over the tank RTD and thermostat. It is not necessary to tape the insulation, but if you do be sure to use high-temperature tape. 4. Connect the RTD plug. Î ÎÎ ÎÎ ÏÏÏ ÎÎÎÎ ÎÎ ÏÏ ÎÎ 2 1 4103516A Fig. B 1-5 Replacing the Tank RTD 1. RTD 2. Retainer plate
B 1-15 Thermostat Replacement 1. Disconnect the thermostat plug. 2. See Figure B 1-6. Follow these steps to replace the thermostat: a. Push back the rubber insulator and remove the screws that secure the thermostat to the tank. b. Remove the old thermostat and install a new one. c. Push the rubber insulator back over the thermostat. Î ÎÎ Î ÏÏÏÎÎ ÎÎÏÏÏÏ ÎÎ Î ÏÏÎÎ 4103515A Fig. B 1-6 Replacing the Tank Thermostat 3. Reposition the insulation over the tank RTD and thermostat. It is not necessary to tape the insulation, but if you do be sure to use high-temperature tape. 4. Connect the thermostat plug. System Restoration 1. Reinstall the front cover and attach the ground wire. 2. Reinstall the electrical enclosure lid and attach the ground wire. 3. Restore power to the melter and resume normal operation.
B 1-16 Replacing a Component Follow this procedure to replace any control system component. The control system components include control panels, and power modules. 1. Turn off the melter, disconnect and lock out electrical power to the melter at the branch circuit disconnect switch, and disconnect and lock out electrical power supplied through any I/O wiring. 2. Open the electrical enclosure. Refer to Opening and Closing the Electrical Enclosure. 3. Attach a static wrist strap from your wrist to the ground stud on the base of the melter. 4. Refer to the illustrations in Control Assembly Parts in the Parts section. Disconnect all ribbon cables and other connections from the component you are replacing. Mark or label the connections for later reference. 5. Remove the hardware that secures the component; then carefully remove the component. 6. Install the new component using the hardware you removed earlier. 7. Connect all ribbon cables and other connections to the new component. 8. If you are installing a main control board, make sure the time delay switches are set properly. Refer to Changing the Time Delay Setting in the Installation section. 9. Close the electrical enclosure. Refer to Opening and Closing the Electrical Enclosure. 10. Restore power to the melter and resume normal operation. Replacing the Circuit Breaker Follow this procedure to replace the circuit breaker. 1. Turn off the melter, disconnect and lock out electrical power to the melter at the branch circuit disconnect switch, and disconnect and lock out electrical power supplied through any I/O wiring. 2. Open the electrical enclosure. Refer to Opening and Closing the Electrical Enclosure. 3. Remove the front cover and disconnect the ground wire.
B 1-17 4. See Figure B 1-7. Remove the screws (4) that attach the circuit breaker to the base. 5. Remove the wire ties to the cable clamp (1) and push the boot (2) from the circuit breaker. 6. Label the wires connected to the circuit breaker (3) and disconnect them from the terminals. 1 2 3 5 4 4130899A Fig. B 1-7 Circuit Breaker Components 1. Cable clamp 2. Boot 3. Circuit breaker 4. Screws 5. Lights 7. Connect all wires to the new circuit breaker and push the boot over the circuit breaker. Attach a new wire tie around the wires at the back of the boot to prevent the boot from sliding off the circuit breaker and exposing the terminals. If necessary, refer to the Schematics section. 8. Attach the circuit breaker assembly to the base with the screws you removed earlier. 9. Install the front cover and connect the ground wires. 10. Close the electrical enclosure. Refer to Opening and Closing the Electrical Enclosure. 11. Restore power to the melter and resume normal operation.
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