Kemppi MasterTig MLS 2300 ACDC User manual

1
Service manual
Mastertig MLS 2300 ACDC
Version 1.3.1

2
Technical data
The device may be repaired only by a person legally authorized
perform electric work!
Connection voltage, 1 50/60 Hz 230 V ± 15%
Loadability TIG
40% ED
230 A / 19,2 V (5,7 kVA)
60% ED 200 A / 18,0 V (4,8 kVA)
100% ED
170 A / 16,8 V (3,9 kVA)
Loadability MMA
40% ED
180 A / 27,2 V (6,0 kVA)
60% ED 150 A / 26,0 V (4,8 kVA)
100%
ED
120 A / 24,8 V (3,7 kVA)
Supply cable / fuse 2,5 mm² S - 3,3 m / 16 A slow
Adjustment range
TIG 3 A (AC 5 A) / 10,0 V…230 A / 19,2 V
MMA 10 A / 20,4 V…180 A / 27,2 V
Maximum welding voltage 32 V / 180 A
OCV 50 V
Efficiency 0,8
Power factor 0,99
Open circuit power
TIG 6 W
MMA 180 W
Degree of protection IP 23C
Measures
Length 500 mm
Width 180 mm
Height 260 mm
Weight 15 kg
8 kVA generator can provide maximum output power for the power source however
recommended generator size is 10 kVA

3
User interface
1
2
3
4
5
6
1Gas connector for TIG torch
2Welding current connection (negative)
3Operation panel
4Remote controller connection
5TIG -torch control connection
6Welding current connection (positive)
7Main switch
8Gas connector
7
8

4
Setup functions
Welding current upslope time * A1
ON The upslope time depends on the welding
current
OFF The upslope time is fixed
Welding current downslope time * A2
ON The downslope time depends on the welding
current
OFF The downslope time is fixed
TIG Antifreeze * A
ON TIG Antirfeeze is ON
OFF TIG Antifreeze is OFF
MMA Antifreeze * A4
ON MMA antifreeze is ON
OFF MMA antifreeze is OFF
VRD * (MMA open circuit voltage) A7
ON VRD-function: MMA open circuit voltage < 5
Vdc
OFF Normal open circuit voltage is 50 Vdc
2T-function´s downslope cutoff A8
ON On 2T-function the downslope is cut off by a
quick press on the start switch
OFF Quick press on the start switch has no function
Tacking automatics A9
ON Tacking automatics is ON; no downslope, if the
weld is shorter than s
OFF Tacking automatics is OFF
Current upslope speed A10
ON If upslope time is 0,0 s, it goes to 0,2 s from the
halfway of currents > 100 A.
OFF Maximum current upslope speed
Method selection by remote
controller * A12
ON Method selection; TIG: minimum end of the
range of the remote controller, MMA: the
maximum end of the remote controller range
OFF The remote controller works as a normal current
adjustment
Entering the advanced setup press and hold the setup and Return buttons at the same
time. Changing the level press Setup button shortly
* Setting is always on ** Adjustable also by the Quick Setup

5
Setup functions
Start current level A1
ON Start current level in use
OFF Start current level not in use
Current ”freezing” A14
ON During downslope the current can be ”frozen”
onto a certain level, using the start switch
OFF ”Freeze” function is OFF
TIG -torch auxiliary switches (RTC
20) * A15
ON Torch auxiliary switches are used to select
memory channels
OFF Torch auxiliary switches adjust welding current
TIG -torch auxiliary switches (RTC
20) activation * A16
ON Auxiliary switches are always active
OFF Auxiliary switches are active only when torch
control is selected
Cooling unit flow control * A17 ON Flow control is active
OFF Flow control is not active
Cooling unit control * A19
ON Controlled run
OFF Continous run
Coolant temperature watch * A20
ON Temperature watch is active
OFF Temperature watch is not active
Remote controller automatic
detection * A21
ON Automatic detection is ON
OFF Automatic detection is OFF
End current level A22
ON 4T-LOG: End current level is in use
OFF MINILOG: End current level is not in use
* Setting is always on ** Adjustable also by the Quick Setup

6
Setup functions
Contact ignition current * B1
20 Factory setting 20 A
…2
0
Adjustment range …2 0 A
Spark ignition duration * B2
1.0 Factory setting 1,0 s.
0.2
…2.
0
Adjustment range 0,2…2,0 s.
Downslope cutoff level * B
10 Factory setting 10 % of the welding current
5…4
0
Adjustment range 5…40 % of the welding
current
Factory settings recall * B5
OFF Factory setting
PAN Recalls factory settings to the panel, but keeps
memory channels
ALL Recalls factory settings and empties the memory
channels
Downslope interruption – upslope
angle * B6
1 Upslope speed maximum
2 According to the upslope setting
According to the downslope
Non-linear downslope
(Current drop in the beginning of
downslope)
B7
OFF Factory setting
0…5
0
Adjustment range 0…50 % of welding current
Torch switch long press * B8
0.4 Factory setting 0,4 s.
0.
…1.
0
Adjustment range 0, …1,0 s.
Cooling unit post running time * B9 OFF Factory setting 4 min.
ON Post-running time 0 s.
* Setting is always on ** Adjustable also by the Quick Setup

7
Setup functions
Spot welding spot-time * B10
OFF Factory setting 0,0…15,0 s.
ON 0…150 s.
MMA dynamics ** B11
0 Factory setting
-
9…0
…9
Adjustment range -9 = soft arc, 9 = rough arc
MMA ignition pulse ** B12
0 Factory setting
-
9…0
…9
Adjustment range -9 = minimum overrun, 9 =
maximum overrun
Start current level * B1
10 Factory setting 10 % of the welding current
OFF Minimum current
5…4
0
Adjustment range 5…40 % of the welding
current
Display recovery time B14
5.0 Factory setting 5,0 s.
1.0
…20
,0
Adjustment range 1,0…20,0 s.
2T Hot Start duration ** B15
1.0 Factory setting 1,0 s.
0.1
…5.
0
Adjustment range 0,1…5,0 s.
* Setting is always on ** Adjustable also by the Quick Setup

8
Setup functions
Pregas time minimum * C1
0.0 Factory setting 0,0 s.
0.0
…2.
0
Adjustment range 0,0…2,0 s.
Postgas time minimum * C7
1.0 Factory setting 1,0 s.
0…1
0
Adjustment range 0…10 s.
AC balance minimum * C16
-80 Factory setting -80 %
-
80…
-10
Adjustment range -80…-10 %
Pregas time maximum * D1
1 Factory setting 1 s.
0…1
0
Adjustment range 0…10 s.
Postgas time maximum * D7
0 Factory setting 0 s.
15…
150
Adjustment range 15…150 s.
AC balance maximum * D16
10 Factory setting 10 %
0…2
0
Adjustment range 0…120 %
* Setting is always on ** Adjustable also by the Quick Setup

9
Setup functions
AC frequency ** E1
60 Factory setting 60 Hz
50…250 Adjustment range 50…250 Hz
AC waveform ** E2
Sqr Square wave
Sin Sinus wave
Half cycle AC E
5 Factory setting 5 A
5…20 Adjustment range 5…20 A
AC balance ** E4 -25 Factory setting -25 %
-50…10 Adjustment range -50…10 %
Negative ignition current * E5
100 Factory setting 100 %
100…500 Adjustment range 100…500 % (Limited by
the max. of the power source)
Positive ignition current * E6
50 Factory setting 50 %
0…150 Adjustment range 0…150 % (Limited by
the max. of the power source)
Positive ignition sequence time * E7 10 Factory setting 10 = 0,01 s
0…20 Adjustment range 0…20 = 0,0…0,02 s
Ignition cycle total time * E8
0.20 Factory setting 0,2 s (up to 0A8) / 0,01 s
(since 0A9).
0.01…1,0 Adjustment range 0,01…1,0 s.
MIX TIG cycle time ** E9 0.6 Factory setting
0.1…1,0 Adjustment range 0,1…1,0 s.
*Setting is always on
**Adjustable also by the Quick Setup
***Note panel software version

10
Setup functions
MIX TIG AC pulse ratio ** E10
50 Factory setting 50 %
10…
90
Adjustment range 10…90 %
MIX TIG DC level ** E11
100 Factory setting 100 %
50…
150
Adjustment range 50…150 %
Spotwelding time * E12
10 Factory setting 10 ms.
1…2
00
Adjustment range 1…200 ms.
* Setting is always on ** Adjustable also by the Quick Setup

11
Construction
Z004
A004
A002
A001
Z002
Z001 (behind the isolator)
Z003
A003
T001
T002
L001

12
Main circuit diagram

13
Operation principle
Functions and components:
This is the block diagram of an AC TIG -power source with active power factor
correction. A power source based on this principle can be loaded in TIG -process with
230 A current by a duty cycle of 40 % (1 230 Vac / 16 A slow fuse).
Primary- and secondary inverter control
Error code Description
Err Over/Undervoltage
Err 4 Overheating
Err 6 Internal fault, secondary voltage over the limit.
Err 8 Maximum overheat time, machine doesn’t cool down fast enough. Only machine
shutdown and restart removes error.
Err 61 Water cooled gun connected but no water cooler in the system.
Cooler Cooler error:
- Cooling liquid over- / under pressure state
- Overheated alarm
BuS Err Communication between panel and power source isn’t possible
Err rSt System error, machine makes reset itself.

14
Main circuit card Z001
Functions and components:
Main circuit card Z001 includes following operational blocks:
- Energy reserve
- Power stage (full bridge)
- Damping circuits
- Gate buffers
- Electrolyte capacitors C2, C3, C4 and C5 (470µF/450V) provide the energy storage
- Power stage is a traditional full bridge, where the power switches are parallel connected discrete
IGBTs (30A/600V).
- The current transformer T1 measures the primary current
Note ! IGBTs V 2 – V 4 and V9 – V are insulated from the heat sink!
-Primary inverter's operating frequency is constant, being approx. 65 kHz (cycle time is about 15,3 µs)
throughout the whole power range. Power is controlled by changing the IGBT’s conductivity timings.
Energy reserve
Pulse transformer
Current transformer
Negative half cycle (-) IGBT s
insulated from heat sink !!!
Positive half cycle
(+) IGBT s
Positive half cycle (+) IGBT`s

15
Main circuit card Z001
Connectors:
X8
X2
X8 Z004
X1 X7
X6
X5
X4
X3
X4 A001

16
PFC card Z004
Functions and connectors:
The PFC -card Z004 includes these operational blocks:
- EMI -filter
- Net connecting transient damping
- Primary rectifier
- PFC -power stage
- PFC -power stage control
- Net overvoltage watch
- Auxiliary voltages developing
- EMI -filter reduces the electromagnetic disturbances conducting to the net (EN50199).
- The net connecting transient is damped by the PTC-resistor R23 and relay K1 together. The rectifier
unit V1 rectifies the net voltage to DC, which can fluctuate between + 260…380 V. Power
supply to the power supply card A002 via connectors X13 and X14.
- PFC’s power stage (boost converter) increases the full-wave rectified net voltage up to +400 V DC and
forces the net current into sinus form.
- Note. IGBT -transistors V4…V7 are insulated from the heat sink! Diodes V2 and V3 are not insulated, so
diode cathodes and heat sink share the same potential approx. + 400 V!
X5 X7
X15
X8
X6
X3
X2
X1
X14
X13
X10
X9
X12
X11

17
PFC card Z004
Components:
Main switch S001
EMI –choke L002
Varistor R002
EMI -filter
Primary rectifier V1
IGBT -transistor
insulated from the heat
sink!!!
Diodes V2 and V3
X2 and X4: control card A002
power supply, 230 Vac
Intermediate circuit
charging resistor and relay
X5 A001
X11 Z002

18
Secondary rectifier Z002
Functions and main components
Secondary diode card Z002 includes the following operational blocks:
- Full wave rectifying for secondary
- AC –welding auxiliary pulse rectifying
- Damping circuits
- Machine size code
- Voltages of the main transformer's secondary are rectified by a full wave rectifier, which consists
of parallel connected diodes (60A/600V). Note ! Diodes V – V 5 and V 6 – V20 are insulated
from the heat sink !!!
- Damping circuits (RC) reduce the voltage stress of secondary diodes. The machine size is coded
by resistor R1 s value.
- AC –welding auxiliary pulses are developed from the voltages of the auxiliary coils of the main
transformer T001. AC –welding auxiliary pulses stabilize the AC -arc by increasing secondary
voltage up to +/- 350 V (max. about 500 µs) at the beginning of the half cycle. Chokes L1 and L2
limit the current to a few amps.
Negative side diodes
insulated from heat sink !!!
Positive side
diodes
AC -welding
auxiliary pulse
diodes
AC -welding
auxiliary pulse chokes

19
Secondary rectifier Z002
Connectors
X6 X5
X2
X1
X4 X3
X10
X9
X8
X7
X11

20
Secondary inverter Z003
Functions and main components
The secondary inverter card Z003 includes these following operational blocks:
- Power supply for control circuits
- Gate control circuits
- Under voltage watches
- Secondary overvoltage protection
- Secondary inverter s power stage
Negative side IGBTs
insulated from heat sink !!!
Positive side IGBTs