Tweco 81 with SL100SV - Manual (Page 79)

Manual 0-4641 5-15 SERVICE
5
6. Improper input power cable connections inside Power Supply
a. Refer to System Schematic and correct if needed.
7. Defective input power cable
a. Replace input power cable. Refer to subsection 5.09-L.
8. Fuse blown inside Power Supply
a. Replace internal Fuse per Subsection 5.09-C.
9. Line voltage above 10% tolerance (over voltage protection)
a. Reduce line supply.
10. Faulty Auxiliary Transformer (refer to Appendix pages, 28 VAC Circuit Diagram)
Measure for 28 VAC on Main PC Board from J23-1 to J23-3.
a. If voltage is not present, replace the Main PC Board.
11. Faulty ON/OFF switch
Measure for 28 VAC on the Main PC Board between J18-5 to J18-6.
a. If voltage is not present replace the ON/OFF Switch.
12. Faulty Main PC Board
Measure for 12 vdc on Main PC Board from TP4 to TP1.
a. If voltage is not present, replace the Main PC Board.
D. AC and TEMP indicators ON, fans do not run
1. Air flow through unit is restricted
a. Provide adequate air flow
2. Exceeded Duty Cycle of Power Supply
a. Deactivate torch and wait for fan to cool unit. Refer to Specifications Section for proper duty Cycle for this unit.
3. Faulty Fan(s)
Measure for 230 VAC (±) on the Main PC Board from J15-1 to J15-2, and from J15-5 to J15-6.
• If voltage at J15-1 to J15-2 is correct, replace lower Fan (M1).
• If voltage at J15-5 to J15-6 is correct, replace upper Fan (M2).
4. Faulty Temperature Sensor / Switch
a. Check IGBT Heatsink Temp Sensor (TS1). Disconnect wire connector P29 from terminal J29 on Main PC
Board. Check connector pins 1 and 2 for 10K ohm (±25%) (at ambient temperature). If resistance is not 10K
ohm (±25%), replace TS1.
b. Check Inductor Temp Switch (TS2). Disconnect wire connector P32 from terminal J32 on Main PC Board.
Check connector pins 1 and 2 for at least 12K ohms. If resistance is less than 12K ohms, replace output
inductor (L1). If temp switch is open, replace Main PC Board.