• INTRODUCTION :1. The AK 400 and AK 600 welding power sources are constant voltage heavy duty

thyristorised power sources for high quality manual or mechanized MIG/MAG welding output.

2. Six phase rectification gives almost ripple free welding output free from spatter3. Stick out control eliminates demand for operator’s skill.4. Self hold circuitry with crater control module.5. Pre flow of shielding gas with burn back control for optimum utilizations6. An ideal choice for MIG/MAG welding application with enhanced productivity and

quality.

• DUTY CYCLE: Duty cycle is defined as the ratio of load time to the total time. Standard current ratings are based on a 10 minute cycle.

AK 400 AK 600

Characteristic Constant Potential Type

Supply Voltage, Phase & Freq. 415V ± 10%, 3 Phase, 50 Hz AC

Maximum Input Current 31 Amps 55 Amps

Maximum Rating 20.7 KVA 40 KVA

Output Current Range DC 60A – 400A DC 60A – 600A

Max O/P Current at 60% Duty Cycle 400A 600A

Max O/P Current at 100% Duty Cycle 310A 470A

Open circuit voltage(Max) 55V DC 68V DC

Welding Voltage & Current control Stepless

Cooling Forced Air Cooled

Weight (Approx.) 110 KG 155 KG

• GENERAL – Proper installation can contribute materially to the satisfactory and trouble free operation of the power source.

A. Unpacking and Placement1. Immediately upon receipt of the power source, it should be inspected for damage

which may have occurred in transist. Notify the carrier of any defects or damage at once.

2. After removing the power source from the wooden box, check for any loose parts. Remove all packing materials.

3. Check air passages at front, bottom, and rear of cabinet for any packing materials that may obstruct air flow through the power source.

4. If the machine is not installed immediately, store it in a clean, dry, well ventilated area.

5. The location of the power source should be carefully selected to ensure satisfactory and dependable service.

B. ASSEMBLING - The complete installation should consist the following instruments :

1. Welding Power Source2. Wire Feeder3. Remote Control Unit4. Welding Torch5. CO2 Regulator6. CO2 Heater with heater core7. Gas Hose8. CO2/Argon Gas 9. Input Cable10. Work Cable11. MIG Wire

Wire Feeder Wire Spool

Inter Connecting cable ( Power source to Wire Feeder)

• Connection between Wire Feeder and Power Source:

Remote control Control Cable

Gas Hose Work cable Power cable

• Connect Wire Feeder control cable

• Connect O/P Power cable

• Connect Gas Hose

• Connect Remote Cable

Complete connection between wire feeder and Power Source

• Wire Feeder

• Connect Torch

• Put Wire Spool

Connection for Heater

3 Phase I/P connection

Inlet Gas connection Ground ConnectionFrom Cylinder

REAR VIEW

• The power source is a 3 phase unit and must be connected to a 3 phase power supply.

• Capacity of equipment as follows:

AK 400 AK 600

Input Voltage AC 415 V ± 10%

No. of Phase & Frequency 3 Phase, 50 Hz

Max Rating of Equipment 20.7 KVA 40 KVA

Capacity of Fuse 32 Amps 63 Amps

Input Cable > 8 sqmm. > 14 sqmm.

Output Cable > 38 sqmm > 60 sqmm

• POWER ON/OFF SWITCH – Switch is located on the front panel. In the OFF position, the power source is electrically shut down. In the ON position, Power On light on front control panel will light and power is being provided to all circuits in the power source.• CHECK-WELD TOGGLE SWITCH – To ensure the gas supply before welding, set the SHIELD GAS switch to CHECK position. The shielding gas will start flowing. After confirmation release the switch and it will automatically return to weld position.• Set the switch at CO2 or Ar-CO2 depending on the Shielding used for GMA welding.

• SELF HOLD – When the Selfhold / Crater switch is ON, the arc is produced while the torch sw is ON and then selfhold is maintained even though the torch switch is turned OFF, and the crater control condition will start functioning if the torch switch is trigger on for

the second time. An Arc Crater normally formed at the end of the welding can be filled

without any defect by adjusting the crater current and crater voltage knobs at the front panel of the power source.

• Adjust welding Voltage and Current from Remote control unit.

Unpacking & Placement

Visual Inspection & checking of packing list

Connect the wire feeder

Connect the Work Cable

Connect the Torch

Connect wire

Connect Gas Regulator with heater

Connect Gas hose to the unit

Connect 3 phase Input Supply & Ground wire

Power ON MCB on DB

Switch ON the M/c

Apply Gas

Pass on the wire through Torch by pressing inching/torch switch

Apply correct pressure to the pressure device for smoothly passing of wire

Check wire feeding/gas

Start welding

• The maintenance and inspection should be carried out only after the switches in the switch box are certainly turned OFF.

• Regular Inspection ( Every 3 – 4 months ).

Inspection Portion Inspection Point Maintenance Method

Fuse Box Fastening & Looseness at the connection. Confirmation of proper fuse

Refer to the equipment capacity

Input & Output Terminals

Fastening & Looseness at the connection. Confirmation of Insulation

Fasten first & Tape

Interior of Power Source

Sedimentation of Dust. Trace of Overheat.

Blow off dust with compressed Air

• POWER ON/OFF SWITCH – Switch is located on the front panel. In the OFF position, the power source is electrically shut down. In the ON position, Power On light on front control panel will light and power is being provided to all circuits in the power source.

• MAIN TRANSFORMER – It is a step down transformer. Primary Voltage – 415 V AC, 3 Phase Secondary Voltage – 70 V (Between two winding)

• CONTROL TRANSFORMER (TR2)(165 1685 147 ) : Input Voltage : 0-415V AC Output Voltage: 0-11-22 V (Synchronizing Supply) 27-0-27 V (PCB Control Supply)

• CONTROL TRANSFORMER (TR3)( 165 1685 148 ) : Input Voltage : 0 – 415V AC Output Voltage: 0 – 11- 22 V ( Synchronizing Supply )

: 0 – 110 V AC for Heater : 0 – 200 V AC for Fan

: 0 – 220 V AC for Main Contactor• CONTROL TRANSFORMER(TR4)(165 1685 149) : Input Voltage : 0 – 415V AC Output Voltage : 0 – 11 – 22 V(Synchronizing Supply) • CONTROL PCB (165 1684 170) : Function as follows:1. Firing pulses to Thyristors2. Control voltage to wire feed motor3. Control voltage to solenoid valve4. Control voltage to main contactor5. Control self hold function6. Control Crater function• Gets input from remote• Power saving function

• CRATER PCB – It is responsible for self hold and crater fill. Remote control & Torch switch are connected to Main PCB through crater PCB.

• RECTIFIER - This is a full converter rectifier consist of six Thyristors. According to the firing pulse, rectifier gives the output. Open circuit voltages are 55V DC (AK 400) and 68V DC(AK 600).

• IPL/DCL – It is used for filtering to get smooth DC as well as di/dt protection of thyristors.

• SHUNT – Feedback gives to Ampere meter for display.• REMOTE UNIT - Remote control unit must be connected with the system.

Current and Voltage must be set through remote control potentiometer.• WIRE FEEDER UNIT - Wire feed unit bust be connected with the system. This is consist of wire feeder motor, wire feeding mechanism( roller, pressure roller etc), wire inch push button switch and connector for Torch.

• Assembled the m/c as per installation procedure.• Apply 3 phase input supply.• Switch on the three phase input supply.• Switch on the ON/OFF switch. Control supply voltage will be available at control

transformer as well as PCB. Fan will rotate.• Press the wire inch button. Wire feed motor will rotate and it will be varied by

rotating current control potentiometer. 0 to 16V DC will be available between pin 43 and 38.

• Keep the gas check switch to check position. 24V DC will be available between pin 91 and 17. Gas valve will operate and gas will start flowing.

• Keep the self hold switch in off position. Press the torch switch. Main contactor will be energized. Wire feed motor will rotate slowly and OCV will be available at output terminal. Also Gas will start flowing.

• Release the torch switch, wire feeding & gas flow will be stopped immidiately. Also there will be no OCV. But Main contactor will be remain on for 25 seconds.

• Now m/c is functionally OK. Start welding.

• CN1 – Thyristor Firing Pulse• CN2 – Thyristor Firing Pulse• CN3 – Snubber Circuit• CN4: Pin 91 – Solenoid valve (24V DC) Pin 104, 105, 106, 107 and 44 – Mig/Mag Selection Pin 17 – Ground of solenoid valve. Pin 38 – Ground Pin 97 – Supply voltage of power LED Pin 98 – Supply voltage of Warn LED• CN5: Pin 68 – Feedback from IPL Pin 38 – GND Pin 13 – Thermostate connection Pin 38 – GND

CN6: Pin 38 – GND

Pin 42 – Torch switch signal from Crater PCBPin 80 – Wire feed control voltage to crater PCB

Pin 85 – Negative terminal of W/F Motor through Auxiliary contactor(NC)Pin 38 – GNDPin 48 – Negative terminal of W/F Motor through Auxiliary Contactor(NO)Pin 43 – Supply voltage for W/F Motor

CN7:Pin 49 – 27V AC control supply from TR2Pin 39 – 27V AC control supply from TR2

Pin 83 & 84 – Arc sense relay(NO)

CN8:Pin 41 & 47 – Reference voltage for Wire Feed control from crater PCB

Pin 57 & 59 – Reference for welding voltage from crater PCB

CN9 :Pin 82 & 81 – Self holdPin 10 – connection of 50/60Hz selectionPin 96 – Supply voltage of main contactor coil

CN10:Pin 8 – 220V AC supply from Control Transformer

DTR1: Synchronising Supply ( 0 – 11- 22 V AC ) from TR2 Transfromer

DTR2: Synchronising Supply ( 0 – 11- 22 V AC ) from TR3 Transfromer

DTR3: Synchronising Supply ( 0 – 11- 22 V AC ) from TR4 Transfromer

• Pin 1, 2 and 3: Out put of synchronous Transformer ( 0–11- 22V AC)• Pin 4, 5 and 6: Output of synchronous Transformer ( 0- 1-22V AC )• Pin 7, 9 and 10: Output of Synchronous Transformer ( 0 -11-22V AC )• Input Voltage between pin 13 & 39: 27V AC• Input Voltage between pin 13 & 49: 27V AC• Output voltage between pin 38 & 43: 0 to 16V DC ( rotate current control pot

with load )• Output voltage between pin 38 & 43: 1.32 to 3.8V DC when Torch Switch is

pressed without load• Output voltage between pin 91 & 17 : 0V ( Torch Switch not pressed )• Output voltage between pin 91 & 17 : 24V DC ( Torch Switch is pressed )• Output voltage between pin 7 and 96: 220V AC ( Torch switch is pressed )• 11. Output voltage between pin 57 and 38: 2V to 4.5V DC ( rotate voltage

control pot)• 12. Output voltage between pin 47 and 38: 2.5V to 15V DC ( rotate current

control pot )• 13. Output Firing pulse: 21&22, 23&24, 25&26, 27&28, 29&30, 31&32 – 130 to

140 mv DC

Crater PCB:(a) Voltage between 55 & 38: 36V DC ( Torch switch not pressed )(b) Voltage between 55 & 38: 0V DC ( Torch switch pressed )© Voltage between 42 & 38: 36V DC ( Torch Switch not pressed)(d) Voltage between 42 & 38: 0V DC ( Torch Switch pressed )

YES OK

OK

OK

NO

SWITCH ON THE M/C

Fan Rotate?

Fan does not rotateI/P Fuse blows

Check ZNR AssyCheck ON/OFF Switch

& 3Φ Supply

Check Fuse FU1

Check Control TR TR2

Check Fan

Torch switch pressed, Is

OCV available ?

No wire feed on pressing wire inch

button

Is main contactor faulty?

Current Control Pot in Min position

YES

NO NO YES

NO OK YES

NO

Current control

pot in min position

Increase

Motor Fuse

blowsReplace

Wire feed control cable disconnected

or imperfect contact

Check & rectify

Replace Main PCB

Is main contactor faulty?

Check main transformer secondary voltage or disconnection

All thyristor Gate-Cathode not connected properly, thyristor faulty

YES

YES

YES NO

YES

Torch switch pressed, Is OCV

available ?

Welding automatically stopped, warn LED on

Current/Voltage adjustment not working

Is control cable connection OK?

Is Remote control Pot OK ?

Change crater PCB

Does fuse FU1 blow

Replace Fuse

Thermal overload, Keep m/c running, Cooling fan

ON until LED off.