Snap-On TIG 250 AC-DC, Service Manual

Page 1: ...CEBORA S p A 1 TIG 250 AC DC POWER SOURCE art 236 76 SERVICE MANUAL 3 302 221 15 01 07 ...

Page 2: ...han 48 Vac 25 3 4 2 Led F on Temperature of the transformer 46 or inductor 50 too high or low pressure of the coolant fluid 25 4 COMPONENTS LIST 26 4 1 Power source art 236 76 see file ESP236 76 pdf enclosed at the end of the manual 26 4 2 Components table see file ESP236 76 pdf enclosed at the end of the manual 26 4 3 Spare parts list 26 5 ELECTRICAL DIAGRAMS 27 5 1 Power source art 236 76 see fi...

Page 3: ... replace them with original Cebora spare parts 1 3 Safety information The safety notes provided in this manual are an integral part of those given in the Instruction Manual Therefore before working on the machine please read the paragraph on safety instructions in the aforementioned manual Always disconnect the power cord from the mains before accessing the interior of the equipment Some internal ...

Page 4: ...services connected to it are always powered at 230 Vac The mains filter board 51 connected to the terminal board 52 contains the filter to reduce conducted interference reflected in the mains The transformer 46 has a second power winding with voltage and current values suitable for welding and two secondary service circuits all windings are made up of two half windings arranged on the two columns ...

Page 5: ...and the HF start command on the connector J9 terminals 7 and 8 of control board 40 HF relay start command The connection before the AC output terminal of the power source hosts the Hall effect current transducer 5 which sends to the control board 40 the output current feedback signal used to regulate the welding current Near the output terminals of the power source is the HF filter board 41 which ...

Page 6: ...e on connector 13 between terminals 1 and 3 to prevent the power source from remaining blocked The fan 45 to cool the power elements of the power source is powered directly by terminal board 52 and therefore always at 230 Vac On the front panel is the connector board 49 which acts as an interface for the power source input and output signals It dialogues directly with the control board 40 and cont...

Page 7: ...the power source cool Check the conditions of the output terminals the output and power cables of the power source replace if damaged Check the conditions of the internal power connections on the electronic boards if you find loose connections tighten them or replace the connectors 3 2 Operating sequences The following sequences reflect proper machine operation They may be used as guidelines for t...

Page 8: ...1 3 3 2 3 3 3 YES Press the button E several times the Mode selection is repeated in sequence Press the button P several times the Cicle selection is repeated in sequence Each time the button E is pressed the leds G H M and N light in sequence together with one of leds F or L that lit alternatively one each other Correct Each time the start button P is pressed the leds Q S T R V U W and X light in...

Page 9: ...ut voltage and high frequency are no longer generated TIG operation stops if there is no current at the power source output after start and the post gas stage begins NO see 3 3 6 3 3 7 YES Use the knob AA to set the current based on the welding you intend to perform Move the torch near the workpiece and press the torch trigger Begin welding Turn the knob AA or the torch potentiometer to obtain the...

Page 10: ...e switch 15 and transformer 46 primary winding with particular care to the connections that perform mains voltage adjustment and between transformer 46 secondary winding and terminals A of scr group 47 and C8 of switch AC DC 30 If you find damage connections restore them or devices in short circuit replace them Mains not suitable to power the power source ex insufficient installed power MAINS CONN...

Page 11: ...ignal winding of the transformer 46 With power source off temporarily disconnect connectors J2 J3 J5 J6 and J8 on control board 40 and check the resistance on the following points of control board 40 Conn J2 terminals 1 2 approximately 900 ohm Conn J3 terminals 4 1 4 2 Mohm Conn J3 terminals 4 5 4 6 Mohm Conn J5 terminals 1 2 Mohm Conn J6 terminals 5 4 5 6 Mohm Conn J6 terminals 1 2 Mohm Conn J8 t...

Page 12: ...iments blocking the fan 45 With the power source off temporarily disconnect the fan 45 terminals from terminal board 52 and check resistance between terminals of fan 45 Correct value 50 ohm approximately If incorrect replace the fan 45 Replace the fan 45 Check the wiring between switch 15 terminal board 52 the wired bridges on terminal board 52 and fan 45 terminals Check connections between transf...

Page 13: ...control board 40 ERROR CODE TEST Correct At start up after lamp test leds J or Y remain lit to indicate an alarm condition NO YES See Signaling alarm par 3 4 COMMAND AND SIGNALING TEST Correct With control panel buttons are possible all the Mode and Programs selections as described in the par 3 2 Operative Sequence and in the Instructions Manual NO YES Regular operation CURRENT EXTERNAL ADJUSTMENT...

Page 14: ...dc If not correct replace control board 40 Make sure with torch inserted on connector AE of Power Source voltage on terminals 7 and 8 of J5 on control board 40 Corrected value from 0 to 5 Vdc by turning torch potentiometer If not correct check wiring between J5 control board 40 connector board 49 and torch potentiometer and if necessary replace connector board 49 If correct replace control board 4...

Page 15: ...minals 3 and 4 of J5 control board 40 Correct values junction of a diode in both directions for this measurement the voltage at the diode junction can be between 0 5 and 1 Vdc approximately If incorrect replace control board 40 Check the power supply to the control board 40 performing the CONTROL BOARD 40 POWER SUPPLY TEST in par 3 3 1 if necessary Make sure the tracks of the printed circuit on co...

Page 16: ...valve 43 approximately 26 ohm If 0 ohm short circuit replace solenoid valve 43 and control board 40 See CONTROL BOARD 40 POWER SUPPLY TEST par 3 3 1 e START SIGNAL TEST par 3 3 4 Replace control board 40 With power source off make sure the resistance between the terminals of solenoid valve 43 approximately 26 ohm If Mohm winding broken replace solenoid valve 43 Check the presence of the gas at the...

Page 17: ... TP2 of HF filter board 41 with the shared point between inductor 50 and HF transformer 28 If you find damaged components or connections replace HF filter board 41 Make sure that the output terminals AC and AB of the power source gifas are not in isolation leak thus that there are no high voltage surface discharges Replace with new ones if necessary Check the torch and torch cable if worn or damag...

Page 18: ...ctor J3 terminals 1 2 30 Vac with HF operation set Led L on YES NO Check the wiring between J3 HF board 42 and J9 control board 40 With power source off temporarily disconnect connector J3 from HF board 42 and check the resistance between terminals 1 2 of J3 on HF board 42 Correct values Mohm in both directions If incorrect replace HF board 42 If in short circuit also replace control board 40 Chec...

Page 19: ...tor disconnected from J4 Correct values approximately 30 40 Kohm If incorrect replace current transducer 5 With AC DC selector switch 30 in the 0 position power the power source with J4 on control board 40 disconnected and check the voltage on J4 of control board 40 terminals 3 and 2 15 Vdc terminals 1 and 2 15 Vdc If incorrect replace control board 40 Replace current transducer 5 and or control b...

Page 20: ...lace SCR2 47 or the complete thyristor group Check for the presence and phase of the 16 Vac synchronization signal on J2 of control board 40 This signal must have the proper phase ratio with the secondary voltage of the power transformer 46 If incorrect reverse the wires of the primary circuit of the service transformer 4 on terminal board 52 or those on J3 or J4 of fuse board 4 or those on J2 of ...

Page 21: ... incorrect check the connections of the primary and secondary windings of the transformer 46 power circuit considering that each one is made up of two semi windings arranged on the two columns of the magnetic core Perform the tests in par 3 3 1 if necessary Check for voltage at the secondary circuit of the power transformer 46 measuring between terminal A of the thyristor group 47 and terminal C8 ...

Page 22: ...g 5 2 4b 20 Vac fig 5 2 5b Start button pressed OUTPUT VOLTAGE TEST ON RESISTIVE LOAD Output terminals AB and AC of the power source values as shown in the table NO YES Regular operation SCR3 ENABLE TEST FOR AC OPERATION NOTE This signal is present only when the welding current is greater than approximately 50 Aac With lower currents this signal is absent and the SCR3 function is performed by just...

Page 23: ... AC of the power source If you find loose connections tighten them and replace any components with damaged terminals Check operation of the AC DC selector switch 30 making sure the closing sequence of the contacts matches the table in the electrical diagram in par 5 1 With the power source off temporarily disconnect the thyristor group 47 and check the integrity of the thyristor group 47 measuring...

Page 24: ...h voltage pulse depends on the type of oxidation that the material presents a special circuit of the control board 40 makes sure that this voltage does not reach levels hazardous for operation of the converter causing SCR2 47 to engage prematurely if necessary The premature engagement of SCR2 47 interrupts a semi period of the welding current which produces poor quality welding Therefore if the we...

Page 25: ...thin the allowed limits If the alarm is due to the pressure of the coolant fluid check operation of the cooling unit see Cooling Unit Service Manual To identify the origin of the blockage it is possible to cut out the cooling unit by connecting together terminals 1 and 3 of the connector 13 on the rear panel of the power source or insert the special connector provided with the power source In case...

Page 26: ...closed at the end of the manual 4 3 Spare parts list Essential spare parts Ref Code Description Qty 4 5610097 service transformer 1 40 5602293 control circuit 1 42 5602290 HF circuit 1 47 5605539 thyristor group 1 48 5602289 shut off circuit 1 Recommended spare parts Ref Code Description Qty 5 5710307 current transducer 1 19 3200030 diode group 1 3 302 221 15 01 07 ...

Page 27: ...at the end of the manual 5 2 Waveforms 5 2 1a 5 2 1b 5 2 1 Output voltage with open circuit power source par 3 3 7 5 2 2a 5 2 2b 5 2 2 Firing pulses for SCR1 with open circuit power source par 3 3 7 5 2 3a 5 2 3b 5 2 3 Firing pulses for SCR2 with open circuit power source par 3 3 7 3 302 221 15 01 07 ...

Page 28: ...nt with power source loaded in table conditions par 3 3 8 5 2 5a 5 2 5b 5 2 5 Output voltage with power source loaded in table conditions par 3 3 8 5 2 6 Firing pulses for SCR3 with power source loaded in table conditions par 3 3 8 3 302 221 15 01 07 ...

Page 29: ... 5 Vdc J2 1 2 6 5 Vac output to pulse generators for SCR1 power supply on control board 40 J2 4 5 0v 6 dual 6 5 Vac output to pulse generators for SCR2 and SCR3 power supply on control board 40 J3 1 2 230 Vac mains input to power service transformer 4 J4 1 2 16 Vac output synchronization signal for control board 40 Fuse Value Function F1 2 A 230 Vac power supply for service transformer 4 F2 0 5 A ...

Page 30: ...nce current signal input from external potentiometer cursor J6 1 2 6 5 Vac input to pulse generator for SCR1 power supply on control board 40 J6 4 5 0v 6 dual 6 5 Vac input to pulse generators for SCR2 and SCR3 power supply on control board 40 J7 1 3 gnd oxide destruction high voltage pulse signal input J7 2 NU J7 4 G 3 K gate command output for SCR2 47 J7 5 NU J7 6 G 3 K gate command output for S...

Page 31: ... G gate command output for SCR1 47 J2 1 2 2nd shut off circuit enable relay command input on shut off board 48 J3 1 G 2 K gate command input for SCR3 SC1 and SC2 on shut off board 48 J3 5 G 2 K gate command input for SCR2 47 J3 6 G 4 K gate command output for SCR2 47 J4 oxide destruction high voltage pulse signal output referring to J3 2 on shut off board 48 3 302 221 15 01 07 ...

Page 32: ...l J1 2 converter output voltage input potential J2 1 2 converter output voltage signal output 5 8 HF board 42 code 5 602 290 5 8 1 Topographical drawing 5 8 2 Connector table Conn Terminals Function J1 J2 output for HF transformer 28 J3 1 2 AC power supply input to HF board 42 power circuit power supply J4 1 2 27 Vac command input for HF enable relay 3 302 221 15 01 07 ...

Page 33: ... Conn Terminals Function CN1 1 2 start signal input CN1 3 5 5 Vdc output to external current potentiometer power supply CN1 4 reference current signal input from external potentiometer cursor CN1 6 7 NU CN1 8 earth connection CN1 9 10 11 12 13 14 NU TP1 TP7 earth connection TP2 TP3 start signal output TP4 TP6 5 Vdc input to external current potentiometer power supply TP5 reference current signal o...

Page 34: ...CEBORA S p A 34 5 11 Diode group 19 code 3 200 090 A 5 11 1 Assembly drawing 3 302 221 15 01 07 ...

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Page 36: ...51094 CAP 22 CKS251098 FIXED WHEEL 23 3080052 AXLE 24 5803804 SUPPORT 25 5803805 SUPPORT 26 5801773 BOTTOM 27 5800527 SUPPORT 28 5610055 HF TRANSFORMER 29 3130079 WHEEL 30 3190517 SWITCH 31 5802183 FRONT PANEL 32 3175354 CONNECTOR 33 5802184 FRONT PANEL 34 3070015 PROTECTION 35 3070336 FRAME 36 5803956 HANDLE 37 3060247 SUPPORT 38 CKS250920 KNOB 39 CKS251089 KNOB 40 5602293 MICRO CIRCUIT 41 560229...

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