valutazioni - 4, GPA: 3.8
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Facilità d'uso
Disconnect the main AC input power to the 3. Remove the red insulating paint from the machine. heat sink test points. See Figure F.17. DO NOT DISASSEMBLE THE HEAT SINKS. 2. Locate and disconnect plug J9 from the thermal fan/snubber board and plug J5 from the firing board. See Figure F.16. IDEALARC DC-655 Return to Section TOC Return to Section TOC Return to Section TOC Return to Section TOCReturn to Master TOC Return to Master TOC Return to Master TOC Return to Master TOC F-40 F-40 TROUBLESHOOTING & REPAIR ACTIVE SCR TEST (continued) FIGURE F.17 – HEAT SINK TEST POINTS ANODE CATHODE SW1 R2 + R1 SW2V A R1 = 4 ohms/10 watts 6 VOLT G R2 = 3 ohms/10 watts LANTERN SCR BATTERY UNDER C TEST To test SCRs construct the circuit outlined above. Resistor values are plus or minus ten precent. The voltmeter scale should be low, approximately 0-5 or 0-10 volts DC. 4. Construct the circuit shown in Figure F.17. b. If the voltage is 3-6 volts only when the One 6-volt lantern battery can be used. Set switch is closed or there is no voltage the voltmeter scale low, at approximately 0-when the switch is closed, the SCR is 5 volts or 0-10 volts. defective. a. Test the voltage level of the battery. NOTE: Be sure the battery is functioning Short leads (A) and (C). Close switch properly. A low battery can affect the SW-1. Battery voltage should be 4.5 results of the test. Repeat the battery volts or higher. If lower, replace the bat-test procedure in Step 4 if needed. tery. 10. Open switch SW-1. 5. Connect the Tester to SCR 1 as shown in 11. Reconnect the Tester leads. See Figure Figure F.17. F.17. a. Connect Tester lead (A) to the anode. a. Connect Tester lead (A) to the cathode. b. Connect Tester lead (C) to the cathode. b. Connect Tester lead (C) to the anode. c. Connect Tester lead (G) to the gate. c. Disconnect Test lead (G) from the gate. 6. Close switch SW-1. 12. Close switch SW-1. NOTE: Switch SW-2 should be open. 13. Read the meter for zero voltage. 7. Read the meter for zero voltage. a. If the voltage is zero, the SCR is funca. If the voltage reading is higher than zero, tioning. the SCR is shorted. b. If the voltage is higher than zero, the 8. Close or keep closed switch SW-1. SCR is shorted. 9. Close switch SW-2 for 2 seconds and 14. Perform the Active Test Procedure outlined release and read the meter. in Steps 5-13 for SCRs 2-6. a. If the voltage is 3-6 volts while the 15. Replace all SCR assemblies that do not switch is closed and after the switch is pass the above tests. open, the SCR is functioning. 16. Plug J9 onto the thermal fan/snubber board and plug J5 into the firing board. IDEALARC DC-655 Return to Section TOC Return to Section TOC Return to Section TOC Return to Section TOCReturn to Master TOC Return to Master TOC Return to Master TOC Return to Master TOC F-41 F-41 TROUBLESHOOTING & REPAIR THERMAL FAN/SNUBBER BOARD LED CHART LED # LED FUNCTIONS AND INDICATIONS (Machine is ON) 1 Indicates fan should be running. 2 Indicates welding current is greater than 200 amps. 3 Indicates fan should be running due to heating of main SCRs. 4 Indicates an open thermal fan thermistor or an open connection between the thermistor and the thermal fan/snubber board. See the Wiring Diagram (leads #319 and #316). 5 Indicates a thermostat (choke or secondary) has opened. The thermal protection light should also be illuminated. 6 Indicates the fan motor should be running. LED 6 should be illuminated and the fan running when any of the following LEDs are lit: LED 2, LED 3, LED 4, or LED 5. IDEALARC DC-655 Return to Section TOC Return to Section TOC Return to Section TOC Return to Section TOCReturn to Master TOC Return to Master TOC Return to Master TOC Return to Master TOC F-42 F-42 TROUBLESHOOTING & REPAIR CONTROL BOARD LED CHART LED # LED FUNCTIONS AND INDICATIONS (Machine is ON) 1 Indicates that the mode switch (SW2) is in the CC mode. When LED 1 is on, LED 6 should also be illuminated. 2 Indicates that feedback voltage is present. This information is used when the machine is in a CV mode. This LED should get brighter as the output voltage is increased. 3 Indicates an input shutdown. The normally closed relay CR2 will activate causing input contactor CR1 to open. See Remote Control Leads Fault Protection Shutdown, Shorted Rectifier Fault Protection and Idle Shutdown Timer in the Operation Section. 4 Indicates an over current shutdown. See Over Current Protection Shutdown in the Operation Section. 5 Indicates output current is present. 6 Indicates that the machine is in the CC mode. LED 6 should be on whenever LED 1 is lit. 7 Indicates that the +16 VDC power supply is functioning. This circuitry is located on the control board. 8 Indicates the control signal is being generated to control the firing of the output SCRs. This signal is sent to the firing board. This LED should get dimmer as the output voltage is increased. This LED will normally be off when the machine is in the constant current mode at open circuit. 9 Indicates tha...