150

150 VRD

151

Service ManualVer. 1.1

Contents

Technical data………………………….……………...

Operation principle…………………………………….

Main circuit…………………………………….……...

Troubleshooting diagram………………………...……

Main ciruit diagrams………………………………….

Block diagram………………………………….……..

Operational tests / measurings…………...........……...

Measurings...……………………...…..

Main transformer T001 prim. voltage...

Main transformer T001 sec. voltage.....

Voltage after sec. rectifier..............…...

Auxiliary coil voltage..………………..

Fan M001 voltage..........………………

Pole voltage in OCV........…………….

Measuring points in the flat cable..…...

Gate control, upper IGBTs.…………...

Gate control, lower IGBTs.…………...

Aux. voltage in DC-link..………….….

Signal lamp H2 control / VRD ON..….

Main circuit card Z001 connectors.…………………...

Main circuit card Z001 layout…..……………………..

Control card A001 layout.……………………………..

Structure………………………………………………..

IGBT-transistor testing..............……………………….

Sec. diode testing.............……………………………..

Notes............…………………………………………..

3

4

4 - 6

7

8

9

10

10, 11

12

13

14

15

16

16

17

18

19

20

20

21

22

23

24, 25

26

26

27

Technical data

Supply voltage, 1~ 50/60 Hz 230 V ± 15% 230 V ± 15% 110 V ± 15%Loadability

35% ED (MMA) 140 A (7,5 kVA) 140 A (7,5 kVA) 140 A (7,5 kVA)100% ED (MMA) 100 A (5,1 kVA) 100 A (5,1 kVA) 100 A (5,1 kVA)

35% ED (TIG) 150 A (5,0 kVA) 150 A (5,0 kVA) 150 A (5,0 kVA)100% ED (TIG) 110 A (3,3 kVA) 110 A (3,3 kVA) 110 A (3,3 kVA)

Supply cable / fuses 2,5 mm² S / 3,3 m 16 A 2,5 mm² S / 3,3 m 16 A 6 mm² S / 2,0 m 32 AWelding current range (MMA) 10 A / 20,5 V…140 A / 25,6 V 10 A / 20,5 V…140 A / 25,6 V 10 A / 20,5 V…140 A / 25,6 VSuitable stick sizes ø 1,5…3,25 mm ø 1,5…3,25 mm ø 1,5…3,25 mmWelding power adj. Stepless Stepless SteplessOCV ~ + 85 V ~ + 30 V ~ + 85 VIdling power < 10W < 10W < 10WEfficiency 0,8 0,8 0,8Power factor 0,60 (140 A / 25.5 V) 0,60 (140 A / 25.5 V) 0,60 (140 A / 25.5 V)Temperature class B (130°C) / H (180°C) B (130°C) / H (180°C) B (130°C) / H (180°C)Operation temperature range -20…+40°C -20…+40°C -20…+40°CStock temperature range -40…+60°C -40…+60°C -40…+60°CCasing class IP 23C IP 23C IP 23CNorms IEC 60974-1, -10 IEC 60974-1, -10 IEC 60974-1

EN 50199 EN 50199 EN 50199Dimensions

Length 320 mm 320 mm 320 mmWidth 123 mm 123 mm 123 mm

Height 265 mm 265 mm 265 mmWeight 4,0 (4,6) kg 4,0 (4,6) kg 4,4 (5,2) kg

Minarc 150 Minarc 150 VRD Minarc 151

3

Operation principle

VDC

t

105

13µs

Max

. 0,5

~ + 320 V

1/3

V1

V2

When IGBTs V1 and V2 are non-conductive no power is transferred. Power is altered by changing the transistor´s timing (PWM).

Main circuit

Minarc power sources are”dual-Forward” inverters, controlled by PWM technology. Switching components are IGBT transistors. The operation frequency is ~ 80 kHz.Below is a picture of the ”dual-forward” inverter operation principle.

+ t + t

X5

X1

X3

R31

R32

L2

C9

C5

C10

L1

R30 R23

C15

V21

V20

V11

C2,

C3,

C4 V

7, V

3

V1,

V2

V4,

V5,

V6

V8,

V9,

V10

T001

T2

K1

X11/12

V16

C13

R9

X13

X12

Primary circuit connection, Minarc 150/150 VRD.4

Main circuit

Secondary circuit connection, Minarc 150/151.

T001

U

R35

U

V28, V29

C21R34

R37

C20

V26

, V27

R33

X7

X9

L001X003

X004

X6

X8

R20

V25

V26

V24

R21

V19

R11

X11/11

X11/14

X11/15

V18

V23

V22

C18

R29

R24

R25

C16

V30V28

V22

C14

C17

X5

C19

R27

R36

X10

X21

X22

5

X5

X2

X3

R24

L1

C9

C10

L2

C16 V10

C2,

C3

V6,

V2

V1,

V11

V3,

V4,

V5

V7,

V8,

V9

T001

T2

X11/12

V16

C11

R9

X13

X12

X1

X4

R8R13R17R14

C4,

C5

X11/7

Primary circuit connection, Minarc 151.

T001

U

R35

U

V28, V29

C21R34

R37

C20

V26

, V27

R33

X7

X9

L001X003

X004

X6

X8

R20

V25

V26

V24R

21

V19

R11

X11/11

X11/14

X11/15

V18

V23

V22

C18R

29

R24

R25

C16

V30V28

V22

C14

C17

X5

C19

R27

R36

X10

X21

X22

Main circuit

Secondary circuit connection, Minarc 150 VRD.

6

General

This machine may be repaired only by authorized repair shops and persons!

The visual check must be done first, to find possible damages; loose wires, breaks and signs of overheating.

DISTURBANCE POSSIBLE CAUSE REMEDYPower source doesn´t start; OCV~ 0 V;

Cooling fan M001 Disconnect the fan connector X20and start the power source again. Ifthe power source starts and theOCV is ok, change the fan.

The rectifier diodes are in shortcircuit.

Check the secondary diodescondition and change if needed. Seethe changing of secondary diodes,page 26.

Faulty primary circuit powersemiconductor.

Check the primary side powersemiconductors. If the voltage overthe PTC R30 is more than ~ 230Vac then there is a short circuit inthe primary circuit. Change thefaulty power semiconductor. Seethe IGBT transistor testing on page26.

Faulty control card A001. Change the control card A001.The power source starts and theOCV rises up to ~85 V, afterwhich the power source shutsdown. Th epower source can notbe loaded. The automatic fusesare blown during start up.

Relay K1 Check the relay operation.

Welding current can´t be adjustedby potentiometer R001.

Faulty power adjustmentpotentiometer R001.

Check the potentiometer condition(R001 = 10 kΩ)

Faulty control card A001. Change control card A001.

Troubleshooting diagram

7

Main circuit diagrams

8

Minarc 150/150 VRD

Minarc 151

Block diagram

A001

Controller (PWM)Gate buffer

Set value circuitVoltage watchMMA ignition

MMA dynamicsTemperature controlSupply voltage watch

Auxiliary voltage watchTIG-lockingTIG-scaling

Z001

Power stageEMI-filter

DC-link chargingAux. voltages

Voltage reserve circuitOCV controller

Overvoltage protection

16

9

Z002

Relaycard

4

Minarc 151

Operational tests / measurings

A

B

C

Measuring point A. Main transformer T001 primary voltageMeasuring point B. Main transformer T001 secondary voltageMeasuring point C. Voltage after seconday rectifierMeasuring point D. Aux. coil voltageMeasuring point E. Fan M001 voltageMeasuring point F. Pole voltage

E

D

F

10

A Main transformer T001 primaryB Main transformer T001 secondaryC After the rectifierD Main transformer auxiliary coilE Fan M001

AB

C

D E

Measuring points on main circuit card Z001 (Minarc 150)

11

Measuring point A. Main transformer T001 primary voltage

Main transformer T001 primary voltage, min. (MMA)

Main transformer T001 primary voltage, max. (MMA) 12

Measuring point B. Main transformer T001 secondary voltage

Main transformer T001 secondary voltage, min. (MMA)

Main transformer T001 secondary voltage, max. (MMA) 13

Measuring point C. Voltage after secondary rectifier

Voltage after secondary rectifier, min. (MMA)

Voltage after secondary rectifier, max. (puikko) 14

Measuring point D. Auxiliary coil voltage

Auxiliary coil voltage, min. (MMA)

Auxiliary coil voltage, max. (MMA) 15

Measuring point E. Fan voltage

Idling Min. load Max. load

Measuring point F. Pole voltage on idling

Power adj. Potentiometer, min. Power adj. Potentiometer, max.

16

X1/1 GNDX1/2 Current info from primaryX1/3 GNDX1/4 Gate control, upper IGBTsX1/5 Gate control, lower IGBTsX1/6 GNDX1/7 Supply voltage watchX1/8 Temperature watch (PTC:t)X1/9 GNDX1/10 Auxiliary voltage (+20…30 V)X1/11 Signal lamp H2 control / VRDX1/12 Auxiliary voltage from DC-linkX1/13 GNDX1/14 Auxiliary voltage +20 VX1/15 OCV control (~ +85 V)X1/16 GND

G

H

I

J

Measuring point on the flat cable

17

Measuring point G. Gate control, upper IGBTs

Gate pulse, min. (MMA)

Gate pulse, max. (MMA) 18

Measuring point H. Gate control, lower IGBTs

Gate pulse, min. (MMA)

Gate pulse, max. (MMA) 19

Measuring point I. Auxiliary voltage from DC-link

Measuring point J. Signal lamp H2 control / VRD ON

20

Main circuit card Z001 connectors (Minarc 150)

X3

X1

X6

X8

X9

X7

X14X15 X16 X17 X18

X19X20

X13

X12X10X11

X5

X21X22

X1, X3 Supply voltageX5 Protective earthX6, X8 Main transformer T001 sec.X7 Sec. Choke L001 (+)X9 X004 (-)X10 X003 (+)X11 Connection, A001X12, X13 Main transformer T001 primaryX14, X15 Main transformer T001 auxiliary

coilX16, X17 PTC RT101X18, X19 PTC RZ101X20/1, 2 Fan M001X21 X003 (+)X22 X004 (-)

21

Main circuit card Z001 layout (Minarc 150)

Smoo

thin

g ca

paci

tors

EMI

Primary rectifier

EMI, DC-link charging

X5LZ101

X1, X3

X11

Secondary rectifierX10

Main transformer

22

R26Max. currentadjustment

R35Min. currentadjustment

Control card A001 layout

R49Current adjustment

X1

S1MMA/TIG

H2ON / VRD ONH1Overheat protection

N1Voltage regulator(+ 20 V)

N2PWM-circuit

N3Comparator

N4Comparator

23

Structure

Z001A001

T10 T15 T25

3 mm

24

Structure

Extracting the control card A001

25

IGBT-transistor testing

G C E

IGBT-T

ESTE

R

TR 1

TR 2

CO

NTRO

L

OFF O

N

B2/6

C2E1/1

E2/2

C1/3

B1/4

Discrete-IGBTs (50 A, 600 V) can be tested with an IGBT tester.

When changing damaged IGBTs, the whole series must be changed,plus the gate resistors (10Ω)!!

Discrete-IGBT´s tightening torque to the heatsink is 0,6…1,2 Nm!

Secondary diode testing

When testing secondary diodes the other coil end of the main transformer (T001) must be disconnected. Main transformercable connector´s may break if bent!

If secondary diodes are in short circuit, then the power source will not start.

The tightening torque for the secondary diodes is 0,6…1,2 Nm!

The soldering must be done carefully, because they are stressed with high current, approximately 30 A/ leg!

26

Notes

27