ESAB | DTE 200 | Service manual | ESAB DTE 200 User manual

ESAB DTE 200 User manual
DTE 200
DTE 255
Service manual
0740 800 128
040621
Valid for serial no. 810--xxx--xxxx to 246--xxx--xxxx
LIST OF CONTENTS
Page
READ THIS FIRST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TECHNICAL DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
LOAD CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
COMPONENT DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTE 255 WIRING DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTE 200 WIRING DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DESCRIPTION OF OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP01 DC Control circuit board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP01:1 Power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP01:2 Temperature and fan monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP01:3a Lift Arc Test voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP01:3b HF Start voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP01:4 HF Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP01:5 Gas valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP01:6 Gate pulses from AP01 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP01:7 Primary overcurrent protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP01:8 Arc voltage sensing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP01:9 Current monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP01 Component positions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP02 Primary IGBT circuit board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP02 Component positions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP03 Mains rectifier circuit board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP04 Processor circuit board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP04 Component positions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP05 Front panel circuit board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP05:1 Power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP05:2 Operation mode selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP05:3 Analogue settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP05:4a Digital display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP05:4b Analogue settings and digital display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP05:5 Error monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP05 Version 1, Component positions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP05 Version 2, Component positions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP05 Version 3, Component positions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP06 Start and remote control circuit board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP07 AC control circuit board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP07:1 Power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP07:2 Gate pulses from AP07 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP07:3 Temperature and voltage monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP07 Component positions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP08 Interference suppression board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP09 DTE 255 AC snubber ’A’ circuit board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP10 DTE 255 AC snubber ’B’ circuit board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP11, AP12 DC protection boards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP09 DTE 200 AC snubber circuit board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Soft starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gate pulses to the AC IGBTs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DC IGBT, test and fitting instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AC IGBT DTE 255, test and fitting instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AC IGBT DTE 200, test and fitting instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Test circuit board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Conversion to DC machine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TOCe
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4
5
6
7
8
12
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16
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18
19
19
20
22
23
24
25
27
28
29
30
31
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40
41
42
44
44
45
47
50
52
53
54
55
56
58
58
60
61
62
63
64
66
INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SAFETY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Location and connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Controls and connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Remote control unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Protection against overheating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Control panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MMA welding (Hand welding electrodes) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TIG welding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
68
68
69
69
69
70
70
70
71
71
74
75
78
SPARE PARTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
78
NOTES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
79
Rights reserved to alter specifications without notice.
TOCe
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READ THIS FIRST
Maintenance and repair work should be performed by an experienced person, and
electrical work only by a trained electrician. Use only recommended replacement parts.
This service manual is intended for use by technicians with electrical/electronic training for
help in connection with fault--tracing and repair.
The circuit boards are divided into numbered blocks, which are described individually in
more detail in the description of operation. All component names in the wiring diagram are
listed in the component description.
This manual contains details of all design changes that have been made up to and
including June 2004.
The manual is valid for: DTE 200 with serial no. 914--xxx--xxxx, 246--xxx--xxxx and DTE 255
with serial no. 810--xxx--xxxx, 844--xxx--xxxx, 934--xxx--xxxx, 948--xxx--xxxx, 246--xxx--xxxx.
The DTE 200 and DTE 255 are designed and tested in accordance with international
and European standard IEC/EN 60974--1 and EN 50199.
On completion of service or repair work, it is the responsibility of the person(s) etc.
performing the work to ensure that the product does not depart from the requirements
of the above standard.
WARNING
Many parts of the power source are at mains voltage.
WARNING
ARC WELDING AND CUTTING CAN BE INJURIOUS TO YOURSELF AND OTHERS. TAKE PRECAUTIONS WHEN WELDING. ASK FOR YOUR EMPLOYER’S SAFETY PRACTICES WHICH SHOULD BE
BASED ON MANUFACTURERS’ HAZARD DATA.
ELECTRIC SHOCK -- Can kill
S
Install and earth the welding unit in accordance with applicable standards.
S
Do not touch live electrical parts or electrodes with bare skin, wet gloves or wet clothing.
S
Insulate yourself from earth and the workpiece.
S
Ensure your working stance is safe.
FUMES AND GASES -- Can be dangerous to health
S
Keep your head out of the fumes.
S
Use ventilation, extraction at the arc, or both, to keep fumes and gases from your breathing zone and
the general area.
ARC RAYS -- Can injure eyes and burn skin.
S
Protect your eyes and body. Use the correct welding screen and filter lens and wear protective
clothing.
S
Protect bystanders with suitable screens or curtains.
FIRE HAZARD
S
Sparks (spatter) can cause fire. Make sure therefore that there are no inflammable materials nearby.
NOISE -- Excessive noise can damage hearing
S
Protect your ears. Use ear defenders or other hearing protection.
S
Warn bystanders of the risk.
MALFUNCTION -- Call for expert assistance in the event of malfunction.
READ AND UNDERSTAND THE INSTRUCTION MANUAL BEFORE INSTALLING OR OPERATING.
PROTECT YOURSELF AND OTHERS!
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INTRODUCTION
On the DC side, this generation of ESAB inverters for AC/DC welding is based on
fast--switching IGBTs (Insulated Gate Bipolar Transistors). IGBT module Q05 is a half--wave
bridge with integral freewheel diodes.
Low saturation voltage IGBTs are fitted in the AC converter. Q01 - Q04 are single switch
modules with integral freewheel diodes.
Schematic circuit diagram for the DTE 255
The principle for the DC part is a “Half bridge push pull flow converter”. The nominal 400V
three phase mains supply is rectified and filtered and then centre--tapped.
The AC current through the primary winding of transformer TM01 is controlled by IGBT
module Q05. The output current is controlled by the duration of the On state of the IGBTs.
(Pulse Width Modulation, PWM)
The frequency is 20 kHz. Only one IGBT is on at the time. The minimum time gap between
On and Off state is 4ms.
The centre tap of the secondary side of transformer TM01 is the negative pole. Inductor L02
smooths the current and stores switching energy. Each end of the secondary winding is
connected to a fast recovery diode module V07. The following shunt RS01 provides the
actual current signal for control purpose.
The AC converter has four single--module IGBTs. If no control signal is applied, all IGBTs
are turned off. No output current is possible.
During normal operation there are control signals in either forward polarity (two IGBTs are
on and two are off) or in reverse polarity.
Just before changing the polarity the set value of the output current is decreased (or
increased), by the process board AP04, to a certain value from which the polarity is changed.
The change of polarity is so fast that the arc does not extinguish, even without using HF
ignition.
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TECHNICAL DATA
DTE 200
Permissible load at
25% duty cycle, MMA
35% duty cycle, MMA
60% duty cycle, MMA
100% duty cycle, MMA
35% duty cycle, TIG
50% duty cycle, TIG
60% duty cycle, TIG
100% duty cycle, TIG
170 A / 27 V
130 A / 25 V
100 A / 24 V
200A / 18V
DTE 255
250 A / 30 V
200 A / 28 V
165 A / 26 V
150 A / 16 V
120 A / 15 V
250A / 20V
225 A / 19 V
170 A / 17 V
Setting range TIG
5 -- 200 A DC
5* -- 200 A AC
5 -- 250 A DC
5* -- 200 A AC
Setting range MMA
5 -- 200 A
5 -- 250 A
Slope up
0 -- 10 seconds
0 -- 10 seconds
Slope down
0 -- 10 seconds
0 -- 10 seconds
Gas preflow, adjustable on the circuit board
0 -- 5 seconds
0 -- 5 seconds
Gas postflow
3 -- 30 seconds
3 -- 30 seconds
Open circuit voltage
70 -- 90 V DC
70 -- 90 V DC
No--load power, MMA
No--load power, TIG
115 W
60 W
120 W
60 W
Useful power, P (at max. current MMA)
6.2 kW
10 kW
Apparent power, S (at max. current MMA)
6.4 kVA
10.6 kVA
Power factor at max. current, MMA
0.95
0.93
Efficiency at max. current, MMA
73%
73%
Mains voltage
400V +/-- 10% 3 ~
400V +/-- 10% 3 ~
Mains frequency
50 -- 60 Hz
50 -- 60 Hz
mm2
Welding cable, cross--sectional area
35
Fuse, slow--acting
10 A
35 mm2
16 A
mm2
4 x 2.5 mm2
Mains cable, cross--sectional area
4 x 2.5
Dimensions l x w x h
510 x 310 x 555 mm
510 x 310 x 555 mm
Weight
45 kg
45 kg
IP23
IP 23
Application class
Enclosure class
These welding power sources fulfil the requirements of IEC 60974--1
*) The minimum current during AC welding depends on the alloy used for the aluminium plates and
their surface cleanliness.
Duty cycle
The duty cycle refers to the time in per cent of a ten--minute period that you can weld at a certain load
without overloading the welding power source.
Enclosure class
The IP code indicates the enclosure class, i. e. the degree of protection against penetration by solid
objects or water. Equipment marked IP 23 is designed for indoor and outdoor use.
Application class
The symbol
hazard.
cdte1de1
indicates that the power source is designed for use in areas with increased electrical
-- 6 --
LOAD CHARACTERISTICS
DTE 200
DTE 255
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-- 7 --
COMPONENT DESCRIPTION
WARNING !
STATIC ELECTRICITY can damage circuit
boards and electronic components.
ESD
S
Observe precautions for handling electrostatic
sensitive devices.
S
Use proper static--proof bags and boxes.
This component description refers to the diagram for the DTE 255 on page 12 and for the
DTE 200 on page 14. Data for components not mentioned here may be found in the spare
parts list.
AP01
DC control circuit board. See the description on page 16.
AP02
IGBT board. See the description on page 27.
AP03
Mains rectifier circuit board. Only for DTE 255. See the diagram on
page 29.
AP04
Circuit board. (Processor board). See the description on page 30.
AP05
Front panel circuit board. See the description on page 33.
AP06
Remote control connection circuit board. See the description on page 42.
AP07
AC control circuit board. See the function description on page 44.
AP08
Circuit board, suppression (EMC). See circuit diagram on page 52.
AP09
AP09
Circuit board (Snubber A). Only for DTE 255, see diagram on page 53.
Snubber circuit board for DTE 200, see diagram on page 56.
AP10
Circuit board (Snubber B). Only for DTE 255, see diagram on page 54.
AP11, AP12
Safety circuit boards. See circuit diagram on page 55.
AP13
HF unit, output voltage: 550V peak.
C01
Capacitor 0.1mF 1000V, transient voltage protection.
C04, C05
Filter capacitors, 10mF. Together with L01, they form a low--pass filter.
C06, C07
Filter capacitors.
C09
Capacitor, see V05.
C10, C11
Filter capacitors.
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EV01
Cooling fan, DC unit (230V AC).
EV02, EV03
DTE 255: Cooling fans, AC unit (230V AC).
To check if the fans are electrically sound: disconnect the supply to the fans
and measure their resistance with an ohmmeter across terminal XT23. The
resistance must be 315Ω ±15Ω for the two fans in parallel.
DTE 200: Supplied with only one fan (EV02) for the AC unit.
L01
Primary inductor.
L02
Secondary inductor.
L03
4 ferrite ring cores, included in TM01. Reduces transients to/from
transformer TM01.
L04
2 ferrite ring cores. Reduces transients to/from the mains.
L05
1 ferrite ring core. Reduces transients from the shunt.
Q01 - Q02
DTE 200: IGBT modules, AC unit.
See Test and Fitting Instructions on page 63.
Q01 - Q04
DTE 255: IGBT modules, AC unit.
See Test and Fitting Instructions on page 62.
Q05
IGBT module, DC unit. See Test and Fitting Instructions on page 61.
QF01
Main power supply switch.
R03
Current limiting resistor for C09.
R05
Resistor. With capacitor on AP09, forms a snubber circuit from positive to
negative.
RS01
Shunt. 250A/60mV
ST01, ST03
Thermal sensors (PTC). Sensing the temperature at Q5 (ST01) and in
TM01 (ST03). When the temperature exceeds 50_C the fans run at high
speed. When it exceeds 75--80_C, welding is stopped until the temperature
drops.
When the temperature is below 30_C, the. resistance of the PTC resistor is
between 50 and 150Ω..
ST02
Thermal switch (PTC). Sensing the temperature of the AC heat sink. When
it exceeds 75--80_C, welding is stopped until the temperature drops.
When the temperature is below 30_C, the resistance of the PTC resistor is
between 50 and 150Ω..
TC01
Control transformer. Fuses included, see the circuit diagram.
TM01
Main transformer. Supplies the main current circuit. Has an additional
winding for HF start voltage.
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TV01
HF coil. When replacing the coil it is important that the winding is
correctly connected. The connection is polarity sensitive.
Input voltage: about 550V; Output voltage: about 9kV.
V01, V02
Mains rectifiers for DTE 200.
Warning: Do not mix up wires 007 and 090, when connecting them to the
rectifiers. Wire 007 must be connected to the positive (+) pole of V02.
V05
Diode, used with C09 and R3 to limit the voltage between plus and minus
on the IGBTs (Q01 -- Q04). Only for DTE 255.
V07
Diode module. When measured with a diode tester the forward voltage
drop is about 0.2 -- 0.3V.
When replacing the diode module, follow the fitting instructions for the
IGBTs on page 62.
X
The pin connectors on the circuit boards are marked with XA, XB and so
on. This is repeated on each circuit board. The connectors on circuit board
AP04 are marked X1, X2 and so on.
XP
Pin connectors.
XS
Sleeve connectors.
XS12
Central connector for TIG. OKC connector for TIG on machines without
central connector.
XS13
OKC connector for MMA
XS14
OKC connector for return welding current cable.
XS15
Connection for TIG start. Only machines with OKC connector for TIG.
XT
Terminal block.
YV01
Solenoid valve.
Introduction to the wiring diagram
Some of the circuit boards are divided into function blocks which are described in the
descriptions of operation. The blocks are listed in the list of contents.
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DTE 255 WIRING DIAGRAM
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DTE 200 WIRING DIAGRAM
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DESCRIPTION OF OPERATION
AP01 DC Control circuit board
Circuit board AP01 controls the DC part of the machine. It also acts as an interface between
processor board AP04 and circuit boards AP02, AP05 and AP06. Some of the functions of
those circuit boards are also described here.
From serial no. 246--xxx--xxxx a new version of the board is fitted to the machines. This
description applies to all versions of the board. All versions can be used in all machines.
NOTE: All potentiometer settings are made at the factory. Only potentiometers R301, R333
and R335 may need to be readjusted when replacing the circuit board, see page 24.
AP01:1
Power supply
Power supply circuits on the DC circuit board, AP01
Power is supplied by a switched voltage regulator with a switching frequency of
about 40 kHz. The HF transformer, TR201, has a dielectric test voltage of 5kV.
The regulator is syncronised with the PWM controller via optocoupler IC1.
To check the output voltage: measure between connector XD pin 1 (DC+) and
XD pin 3 (0V). It must be 19V ±0.5V. If it is not, adjust with potentiometer R7.
See the componet positions diagram for location of R7 and connector XD.
The +5V and ±15V supplies are regulated by normal voltage regulators. The
tolerances are ±4%. When the machine is switched on the - 15V suppy powers
the Mains On LED on the front panel of the machine.
±UT1, ±UT2, E1 and E2 are used for the IGBT drives, see page 20.
+5V is used internally on AP01.
±15V, DC+ (19 ±0.5V) and DC-- (about - 18 to - 20V) are used internally and
also supply other circuit boards. See the overwiev below.
0V is connected to 0V on AP04, AP05 and to shunt RS01 via wire 015. See the
wiring diagram and the diagram below.
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Overwiev of the power supplies from circuit board AP01
AP01:2
Temperature and fan monitoring
Overwiev of the temperature monitoring on circuit board AP01
Temperature sensor ST01 is fitted at one of the screws securing the IGBT
module Q05. Sensor ST03 is fitted on the main transformer TM01. The sensors
are PTC resistors which are monitored by circuit board AP01.
When the temperature is below approximately 50_C the signal FAN_SLIN is 0V.
At higher temperatures the signal level changes to +5V and the fans (EV01,
EV02 and EV03) run at full speed. When the temperature drops below 50_C the
signal level of FAN_SLIN changes to 0V, but there is a 4--10 minute delay before
the fan speed changes to slow speed.
If the higher fan speed cannot remove the heat, so that the temperature continues
to rise, the signal *TEMP changes at about 75--80_C from +10V to 0V. This
generates a stop signal to the PWM circuit and the processor board. This also
causes the error LED on the front of the machine to light. See the signal path for
error monitoring on page 38.
The machine cannot be restarted until it has cooled down.
When ST01 and ST03 are cold (20_C), the voltage between terminal XT11:1
and XT11:2 is about 0.3V. The resistance is about 60Ω for each of the sensors.
When the mains is switched on, the fans run at high speed for about five
seconds, and then switch to low speed.
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AP01:3a
Lift Arc Test voltage
Lift Arc test voltage
In Lift Arc mode a test voltage is used to detect when the electrode is in contact
with the workpiece.
Normally the signal test from AP04 is +15V. When the torch trigger is
depressed it changes to 0V, activating transistors Q228 and Q226. DC--, which is
about --19V, is then connected in parallel with the welding voltage. The emitter
resistor of Q226 limits the current produced by DC-- to about 11mA.
The procedure for the Lift Arc start is as follows:
1. The torch switch is depressed, activating the test voltage and the gas valve.
2. The electrode contacts the workpiece. AP04 senses the change in voltage
via the arc voltage input (see the diagram on page 23). No action is
activated by the machine yet.
3. The electrode is lifted from the workpiece. AP04 senses the voltage change
and activates the modulation, i.e. the machine starts and strikes an arc.
This was a technical description of the Lift Arc start. The welder’s instructions
can be found on page 73.
AP01:3b
HF Start voltage
Auxiliary HF start voltage
To achieve a good HF start, it is neccessary also to increase the voltage at the
electrode during the start. The voltage from an auxiliary winding on the main
transformer is used to produce the increased voltage, which is about 90--100V.
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An output from AP04 activates the start voltage, which is connected in parallel
with the welding voltage by transistor Q14. The start voltage is activated as long
as the HF genarator is active: see AP01:4.
AP01:4
HF Generator
Control circuits for the HF start unit
The HF generator, AP13, is controlled from processor board AP04. It is on only
until an arc is established. If no arc is established, the generator is stopped after
about two seconds.
To check if the HF generator works: Make a short circuit between X9:1 and 2.
Note: Don’t leave the generator on for more than a couple of seconds, otherwise
it might be overheated. Some HF generators have an inbuilt overtemperature
protection feature which switches off the generator when it is too hot. When the
generator has cooled down, it can be operated again.
The output voltage from AP13 is about 550V. The voltage at the secondary side
of TV01 is about 7 to 9kV.
AP01:5
Gas valve
Control circuits for the gas valve
The gas valve is controlled from processor board AP04.
Easy test of the gas valve: Make a short circuit between X9:5 and 6.
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AP01:6
Gate pulses from AP01
IGBT drivers, symmetry monitoring and symmetry control
The IGBT drivers, symmetry monitoring and symmetry control employ opto
couplers with an isolation voltage of 5kV.
When there is no signal from the symmetry circuits on AP02, IC81:3 and IC83:3
are connected to 0 V.
When signal OUT1 is low, gate B2 of IGBT Q05 is negative, i.e. Q05 is off.
When signal OUT1 is high, gate B2 of IGBT Q05 is positive, i.e. Q05 is
conducting.
OUT2 and gate B1 of IGBT Q05 operate in the same way as the circuits above.
If there is a signal from the symmetry monitoring on circuit board AP02, either
gate B1 or gate B2 is locked, depending on the polarity, until the symmetry fault
is gone. This action does not stop the welding.
For more information about symmetry monitoring, see page 27.
Circuit boards AP11 and AP12 protect AP01 if there is a short circuit in the
IGBT module Q05. If the IGBT module is faulty, check the fuses on AP11 and
AP12: see instructions on page 55. Check the gate pulses too, using the
instructions on the next page.
Test instruction for the IGBT module is on page 61.
NEVER check the gatepulses when the machine is connected to the mains
in the normal way.
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CHECKING THE GATE PULSES
a.
Before attempting to measure the gate pulses to the IGBTs, it is essential to
disconnect the power supply from rectifier unit AP03.
DTE 255: Switch off the machine and remove wires 090 and 007 from
rectifier unit AP03. See the wiring diagram on page 12.
DTE 200: Switch off the machine and remove wires 090 and 007 from
rectifier V02. Mark the heat sink with a + where wire 007 is connected to
V02, before disconnecting. See the wiring diagram on page 14.
b. Disconnect AP11 and AP12 from AP01 and connect a gate load (4.7Ω
33nF) to each gate output (circuit board AP01 connector XI:1--2 and
XI:4--5).
See the diagram on page 20 and the component positions on page NO TAG.
c.
Connect the oscilliscope with its screen to XI:4 and the probe to XI:5,
alternatively with the screen to XI:1 and the probe to XI:2.
Set the machine to MMA mode and switch it on.
The pulse shapes must be as shown below.
Gate load
Gate pulses measured with gate load at AP01
d. Measure the following pulse parameters on both gate outputs:
e.
S
Frequency: 20kHz ±0.5kHz.
S
Pulse time: 19--21ms measured at the 0V level.
S
The voltage of the positive pulse must be 18 to 20V
The voltage of the negative pulse must be --9 to --15V
If the pulses are within the tolerances, the pulse driver circuits are OK.
NOTE: When reconnecting wires 007 and 090, make sure that wire 007 is
connected to the positive of the rectifier.
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AP01:7
Primary overcurrent protection
Primary current monitoring circuits
Current transformer TR1 is mounted on circuit board AP02, see the diagram on
page 27. The signal from TR1 is rectified on AP01. Potentiometer R401 (which
is factory--adjusted) adjusts the level of the signal to that needed to shut down
the PWM controller.
R401 has been adjusted to switch off the power source at a current
corresponding to 320A welding current under normal conditions. The shut down
input at IC31:8 is at +5V when the circuit is enabled for operation. If the input is
pulled down to 0V, the output signals are blocked.
When the PWM circuit is blocked there is no current, i.e. no overcurrent. The
PWM circuit is then automatically soft--started, which means that it slowly
increases the current. If the cause of the overcurrent, for example a short-circuited secondary rectifier diode, is still present. The shut down input will be
pulled down again, and this action will continue.
In case of primary overcurrent: There are no indications on the front panel, but
the machine cannot be used for welding.
NOTE: TR1 must never be operated with an open--circuit secondary
(= output). This could destroy it by flashover between the windings.
Signal measured at the cathode of D417
The signal above is measured at a welding current of 200A and 18V under
normal conditions. The higher the primary current, the more the signal is pulled
towards 0V.
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AP01:8
Arc voltage sensing
Signal path for arc voltage sensing in the DTE 255
IC32 has a gain of 0.1, which means that a welding voltage of 10V produces 1V
at the output (UNORM). The signal is connected to AP05 and AP04, and used
for process control on AP04. R631 is a zero offset trimmer.
Signal path for arc voltage sensing in the DTE 200
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AP01:9
Current monitoring
Welding current control circuits
The shunt voltage is 60mV at 250A welding current. The signal INORM from
IC32:8 is 1V at a welding current of 100A. Potentiometer R610 is a zero offset
trimmer for the shunt signal.
The current set point value ISET comes from the processor board: it is 1V for
100A welding current.
The minimum current can be adjusted with R301, and must be 5--7A.
The maximum current can be adjusted with R335, and must be 250 ±5A for the
DTE 255 and 200 ±5A for the DTE 200.
R333 is used to adjust the feedback of the controller (e.g. adjust R333 when the
arc is too noisy).
The welding current is controlled with the PWM circuit. The voltage at the
shutdown input (IC31:8) is +5V when the circuit is enabled for operation. If the
input is pulled down close to 0V, the output signals are blocked.
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AP01 Component positions
Component positions for version 1 of circuit board AP01, with part no. 0486 657 880
WARNING: high voltage in the shaded areas
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Component positions for version 2 of circuit board AP01, with part no. 0486 810 880
WARNING: high voltage in the shaded areas
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AP02 Primary IGBT circuit board
Circuit diagram for AP02
Comments to the diagram above: Capacitor C05 is fitted only in the DTE 255.
In the DTE 200, main transformer TM01 has only one primary winding.
Capacitors C1, C2, C13 and C14 are fitted to circuit board AP02 only in the DTE 255.
Test instructions for the IGBT module are on page 61.
IGBT circuit board AP02 performs the following duties:
S
Connecting the main transformer TM01 with the IGBT half--bridge Q05.
Q05 drives an alternating current through the primary side of transformer TM01 by
charging and discharging C1--C7 and C8--C14 at a frequency of 20kHz.
S
Creating a signal to maintain the symmetry (avoid saturation) of the main transformer.
The voltage difference between a fixed middle point at the anode of diode D2 and a
variable point at connector XF:2 is used as the reference for the symmetry. Unbalanced
operation of the transformer is avoided by blocking the firing cycle of whichever side
which is causing the unbalance. This is carried out by the gate circuits: see page 20.
A window of 62V without any interaction is provided by the zener diodes D2 and D8.
This means that only if the unbalance is more than 62V will the outputs of XF:1 and 2
start to act. This action does not stop the welding.
Note: The polarity of the signal from connector XF is important.
S
Generating a primary current signal to protect the machine.
Current transformer TR1 must never be operated with an open--circuit secondary
(= output). This could destroy it by flashover between the windings.
See page 22 for more information on the primary overcurrent protection .
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AP02 Component positions
Component positions, circuit board AP02
When connectors XC and XD have been disconnected, make sure that both sleeves of the two
connectors are properly reconnected. See the diagram on previous page.
The machine will also work with one of the primary windings connected, but the main
transformer, TM01, will be overheated.
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AP03 Mains rectifier circuit board
This circuit board is used only in the DTE 255.
Circuit diagram for circuit board AP03
Component positions for circuit board AP03
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AP04 Processor circuit board
There are two versions of the board, the in-- and output signals are the same, both versions fits
in any machine having version 1 or 2 of the front panel circuit board, AP05. Machines having
version 3 of circuit board AP05 must have version 2 of AP04.
Version 2 of AP04 has part no. 0486 770 880, it is fitted to the machines from May 2002.
Version 1 of AP04 has part no. 0486 665 880, this board is not more available.
The denominations of the in-- and output connections are different on version 1 and 2 of the
board:
Version 1 / Version 2 = X1 / XA, X3 / XC, X4 / XD, X9 / XB
Processor board AP04 performs the following duties:
S
Control of all logical functions, e.g. mode of operation.
S
Control of time functions:, e.g. slope time
S
Creating the current set value.
S
Setting the hotstart current level for MMA to two times the set current.
S
Creating the frequency and balance for the AC operation.
S
Controlling the AC unit, AP07.
S
Controlling the HF generator and the gas valve.
S
Matching the control signal according to the actual welding mode.
S
Realisation of the Arc Force for MMA welding.
An arrangement of analogue circuits that characterise the control function of certain welding
modes, such as TIG and MMA welding, is included on the board. All functions are monitored
and controlled by a microprocessor on the board.
The power supply to AP04 comes from AP01: see AP01:1 on page 16--17.
Functions on AP04 which are connected to other circuit boards are described in conjunction
with those boards.
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AP04 Component positions
Component positions for version 1 of circuit board AP04, part no. 0486 665 880
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Component positions for version 2 of circuit board AP04, part no. 0486 770 880
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AP05 Front panel circuit board
There are three versions of circuit board AP05. Version 1 is used in the DTE 255 up to serial
no. 844--950--xxxx. Version 2 is used in all other machines up to and including serial no.
948--xxx--xxxx. Version 3 is used in all machines from serial no. 246--xxx--xxxx.
The difference between the versions is described on pages 40 and 41.
AP05:1
Power supply
Valid for all versions of circuit board AP05
Power supply, front panel circuit board AP05
AP05 is supplied with ±15V from AP01. +5V from regulator VR1 is used
internally on AP05.
AP05:2
Operation mode selection
Valid for all versions of circuit board AP05
Selector switches SW1, SW2, SW3 and SW4 (of which SW1 and SW3 are
connected to diode networks) generate an 8 bit word. This is used by AP04 to
select the mode in which the machine is to work.
The location of the switches on the front panel is shown on page 71.
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AP05:3
Analogue settings
Valid for version 1 and 2 of circuit board AP05
Analogue settings, version 1 of circuit board AP05.
All analogue signals from AP05 to the processor board AP04 are related to a
regulated 5V supply from AP04 (UREF_POT +5V). This voltage has an accuracy
of ±1%. All boards, including spare parts, are adjusted at the factory.
The potentiometers on the front panel are described in the instructions on page
72, which also shows their locations.
TRIM POTENTIOMETERS
R10
TIG hotstart current, adjustable between 50 and 200A.
On delivery, the hot start current has been set to 100A.
The hotstart for MMA is set by the processor board, see page 30.
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R11
End current after slope down, adjustable between 5 and 55A.
On delivery, the end current has been set to 5A.
R12
Gas preflow time, adjustable between 0 and 5 seconds.
On delivery, the preflow time has been set to 10ms.
R29
Adjustment for the minimum reading of the display, 5A.
R43
Adjustment for the maximum reading of the display (250A for the
DTE 255 and 200A for the DTE 200).
R36
Is used in the DTE 200 to provide correct reading of the 200A range.
XA6 and 8 are bridged in the DTE 255.
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Trim potentiometers on version 1 and 2 of circuit board AP05
Analogue settings, version 2 of circuit board AP05.
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AP05:4a
Digital display
Valid for version 1 and 2 of circuit board AP05
Drive circuit for the digital display, version 1 and 2 of AP05
When a remote control is used version 1 displays always the welding current
which is set by potentiometer R1 on the front panel.
Version 2 displays the value set by the remote control.
On circuit board version 1, a is connected to b as in the diagram above. The
connection between a and b for version 2 is shown on page 35.
The minimum reading can be adjusted by potentiometer R29, while the
maximum reading can be adjusted by potentiometer R43.
The function of potentiometer R1 is described on page 72 and R36 is described
on page 34.
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AP05:4b
Analogue settings and digital display
Valid for version 3 of circuit board AP05
Analogue settings and digital display, version 3 of circuit board AP05
All analogue signals from AP05 to the processor board AP04 are related to a
regulated 5V supply from AP04 (UREF_POT +5V). This voltage has an accuracy
of ±1%. All boards, including spare parts, are adjusted at the factory.
The potentiometers on the front panel are described in the instructions on page
72, which also shows their locations.
TRIM POTENTIOMETERS
R10
TIG hotstart current, adjustable between 50 and 200A.
On delivery, the hot start current has been set to 100A.
The hotstart for MMA is set by the processor board, see page 30.
R12
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Gas preflow time, adjustable between 0 and 5 seconds.
On delivery, the preflow time has been set to 10ms.
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AP05:5
R26
Adjustment for the minimum current reference.
R27
Adjustment for the maximum current reference (250A for the DTE
255 and 200A for the DTE 200).
R36
Is used in the DTE 200 to provide correct reading of the 200A range.
XA6 and 8 are bridged in the DTE 255.
Error monitoring
Valid for all versions of circuit board AP05
Signal path for the error monitoring
All error messages are monitored by processor board AP04, which stops the
machine if neccessary.
The voltage at connector XC:12 is about 0V when an error is present. During
normal operation, the voltage is 14--15V.
Diode LD9 is on when the PWM circuit on AP01 is generating pulses, e.g. when
the machine is producing an output voltage.
Diode LD10 is on when the mains switch is on: see AP01:1 on page 16.
Diode LD11 is on when the machine is stopped by an error:
S Overheating in the DC part of the machine. One or both of temperature
sensors ST01 and ST03 is/are activated. See description on page 17.
S Overheating in the AC part of the machine. Temperature sensor ST02 is
activated. See description on page 47.
S Overtemperature at AP07 discharge circuit: see description on page 48.
S Overvoltage at AP07 discharge circuit: see description on page 48.
S Lack of water flow: see LD13 below.
Diode LD13 is on when the connection between XA:11 and 12 is open. When
LD13 is on, LD11 is also on.
The LEDs LD9, LD10, LD11 and LD13 are visible on the front panel.
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AP05 Version 1, Component positions
Version 1 of circuit board AP05 is used in the
DTE 255 before serial no. 844--950--xxxx. This
version has not been used in the DTE 200.
NOTE: when this version of AP05 is replaced by
version 3 of AP05, the machine must be equipped
with the latest version of circuit board AP04, part
no. 0486 770 880
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AP05 Version 2, Component positions
Version 2 of circuit board AP05 is used in all
DTE 200 and in DTE 255 from serial no.
844--950--xxxx up to and including ser. no.
948--xxx--xxxx.
The following improvements have been made to
version 2 of the front panel circuit board:
S In MMA mode the modulation is switched off for
a short moment when the welding polarity is
changed by the polarity selection switch (SW1).
S When the machine is in the MMA mode and not
used for 25 minutes, the open circuit voltage is
switched off. Restart it by turning the methode
selection switch to TIG and then back to MMA.
S Full balance range at DC pulsing, 20 -- 80%. AC
balance is limited to 40 - 80%.
S When a remote control is connected, the remote
set value is displayed.
NOTE: when this version of AP05 is replaced by
version 3 of AP05, the machine must be equipped
with the latest version of circuit board AP04, part
no. 0486 770 880
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AP05 Version 3, Component positions
Version 3 of circuit board AP05 is used from
serial no. 246--xxx--xxxx
The following changes have been made to
version 3 of the circuit board:
S SMD components are used for most of the
functions.
S New controller device (IC1) with display
driver.
S End current after slope down is set to 5 A by
the software (R11 is removed).
S Potentiometers for calibration of max and
min current added. See page 37.
NOTE: when this version of AP05 is used as
spare part, the machine must be equipped with
the newest version of circuit board AP04,
part no. 0486 770 880
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AP06 Start and remote control circuit board
Circuit diagram for circuit board AP06
START SIGNAL
Relay RE1 galvanically isolates the start switch from the machine. When the relay is
activated, the voltage at the cathode of V601/D24 is low (0 to --0.5V). When it is deactivated
the voltage is between 4 and 5V.
REMOTE REFERENCE
A potentiometer connected as in the diagram above can be used to set the remote reference. It
is also possible to use an external voltage to set the reference. When using an external
voltage, connect XB:G to 0V and XB:H to a voltage source.
For version 1 of AP05 the voltage source must be variable between 0 and +10V.
For version 2 of AP05 the voltage source must be variable between 0 and +5V.
When version 1 of circuit board AP05 is used the reference signal can be measured at
U600:8. When no remote control is connected the voltage is more than +5V. When the remote
control is in the min. position the voltage is 0V and when in the max. position it is +5V or
less.
With version 2 of circuit board AP05, the remote reference is connected as in the diagram on
page 35.
Note:
The internal current setting limits the current set by the remote control. See page 71 for
instructions.
DTE 255 before serial number 844--950--xxxx, with version 1 of circuit board AP05:
When using a remote control, the display will show the possible maximum current and not
the current set by the remote control.
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DTE 255 from serial number 844--950--xxxx and all DTE 200:
When using a remote control, the display will show the current set by the remote control.
Component positions for circuit board AP06
It is important that the connection shown above is properly connected to the front plate of the
machine and to the chassis connection cable marked 509. If the connection is poor, the
machine will be sensitive to external noise.
The connection point is marked with XE in the diagram on the previous page.
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AP07 AC control circuit board
All functions on this circuit board are galvanically isolated from the rest of the machine,
except GND3, which is connected to negative. See the the diagram on page 45.
From serial no. 246--xxx--xxxx a new version of the board is fitted to the machines. This
description applies to all versions of the board. All versions can be used in all machines.
AP07:1
Power supply
Power supply for AP07
A switched power supply, operating at 40kHz, is used in order to provide
galvanic separation of the IGBT drive voltages.
To check the adjustment of the power supply measure between pins 1 and 3 at
the test connector XD. The voltage must be 28V ±1V. If it is out of tolerance
adjust with potentiometer R1.
The voltages +17V/1--4, - 11V/1--4 and GND1--4 are connected to the IGBT
drives, see page 45.
+5V and +15V is used for internal power supply on the board. The tolerances
are ±4%.
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AP07:2
Gate pulses from AP07
Gate control circuits for the AC IGBT’s in the DTE 255
The IGBTs are contolled by AP04. When connection XC:4 is low (=0V) the
polarity of the electrode is negative. NOTE: when measuring at XC:3, measure
relative to XC:1, which is 0V from AP04.
The IGBTs can have four different states:
1. All off (= open).
Error state. IC1, which also monitors the fault control on circuit board
AP07, has deactivated the IGBTs. IC1 outputs T1 - T4 are high (+5V).
2. All on (= closed).
Is used during polarity change. The time for polarity change is controlled by
IC1, which holds its outputs T1 - T4 at 0.5V for about 200ms.
3. DTE 255: Q01 and Q03 are on, Q02 and Q04 are off.
DTE 200: Q01:1 and Q02:2 are on, Q02:1 and Q01:2 are off.
The electrode is positive.
4. DTE 255: Q02 and Q04 are on, Q01 and Q03 are off.
DTE 200: Q02:1 and Q01:2 are on, Q01:1 and Q02:2 are off.
The electrode is negative.
When an IGBT is on, the voltage at the gate is +17V: when it is off the
voltage is --11V.
DTE 255 has two snubber boards, AP09 and AP10, which are described on
pages 53 and 54. DTE 200 has one snubber board, AP09, described on page 56.
The snubber boards carry fuses to protect the gate pulse driver circuits against a
short circuit in the IGBTs.
The test instructions for the IGBTs are given on pages 62 and 63. To check the
gate pulses see: SOFT STARTING, items 9 and 10 on pages 58--59.
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Gate control circuits for the AC IGBTs in the DTE 200
The picture below shows the voltage peak that makes the polarity change so fast
that no additional HF ignition is needed when the polarity is changed.
Voltage between the welding terminals XS14 and XS13 at 200A AC welding
Compare the actual waveform with the above waveform only during AC
welding with a standard torch. The waveform above is not valid for a resistive
load.
Looking at the picture above from left to the right: First the welding voltage is
negative. Then all IGBTs are conducting for 130ms: the voltage is zero. Then
two IGBTs are turned on, producing a positve voltage peak of about 400V for
20ms, after which welding continues at normal welding voltage.
To ensure the correct voltage peak, the welding current must not be too high or
too low during the polarity change. This is controlled by the processor board
AP04.
If the current is lower than 50A, it will be increased to 50A shortly before all the
IGBTs are turned off. After the polarity is changed, the current is the same as it
was originally.
If the current is higher than 100A, it will be decreased to 100A shortly before all
the IGBTs are turned off. After the polarity is changed, the current is the same as
it was originally.
If the current is between 50 and 100A, there is no change in its value before the
polarity is changed.
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AP07:3
Temperature and voltage monitoring
This description applies to both the DTE 200 and the DTE 255. The IGBTs and
circuit board AP09 in the diagram below apply only to the DTE 255. The
corresponding diagram for the DTE 200 is on page 56.
Schematic diagram for the temperature and voltage monitoring of the DTE 255
R35, TA1 and TA2 are only fitted to version 2 of the board.
FAULT MONITORING
If the temperature monitoring or the voltage control detect an error, IC1 will
send an error signal to the processor board. This stops the machine and shuts off
all IGBTs in the AC unit. See page 33 for the signal path of the error
monitoring.
TEMPERATURE MONITORING
The temperature monitor has a four--channel external input. Unused channels
must be short--circuited to disable them. The voltage divider at IC3:5 is set to
10.8V. If the input voltage at IC3:4 exceeds 10.8V, the output of IC3 is switched
to 0V. PTC resistor ST02, activates the output of IC3 when the temperature
exceeds about 75--80 _C. This results in an error signal to AP04.
ST02 is mounted on the cooling fins. When the temperature is below 30_C, the
resistance of ST02 is between 50 and 150Ω, (about 60Ω at 20_C).
cdte1de1
-- 47 --
VOLTAGE CONTROL
To protect the IGBTs of the AC unit, the voltage across them must not exceed
600V. Filter Capacitor C09 is charged from the positive and negative rails via
diode V05. Measure the voltage between XA:5 (+) and XA:8 (--), V--LIMIT+.
The voltage over C09 is controlled by the monitoring circuit, which uses
transistor Q301 and resistor R03 for discharging. Adjust discharge with trim
potentiometer R302 so that the mean voltage level does not exceed 400V.
Voltage at discharge capacitor C09 at 200A (AC welding)
Version 1 of AP07
To protect Q301 and R03 from overload, a PTC resistor
(R317), of the same type as ST02 on previous page, is
fitted on the transistor. When the voltage across R317
rises due to high temperature, IC6 is activated and the
input to the error monitor IC1 goes low (0V). The
threshold level for the voltage across R317 is 5.1V.
R317 fitted on Q301
Version 2 of AP07
To protect Q301 and R03 from overload, a temperature detector (R317) is
fitted on the transistor. When the voltage across R317, testpoint TA1, rises due
to high temperature, IC6 is activated and the input to the error monitor IC1
goes low (0V). The threshold level for the voltage across R317 is 5.6V, it can
be measured at testpoint TA2. Trimpotentiometer R35 is adjusted at the factory
to set the voltage at TA1 to 4.77V 0.5V when the machine is cold.
As a last protection, in case the voltage control does not work, the maximum
allowed voltage is adjusted to about 580V with R301. If the voltage is too high,
IC6 supplies an error signal to IC1, which stops the machine.
Note: The voltage supply to the voltage control comes from the IGBT drive
supply +17V/3 and GND3. GND3, is connected to the machine negative rail.
0V for the supply voltages (+5V and +15V) on this board is not connected either
to GND3 or to the machine electronic zero (0V), which is connected to the
positive rail.
ADJUSTMENT PROCEDURE
All machines and circuit boards are adjusted when delivered from the factory.
The threshold levels may be checked and readjusted as follows:
WARNING: Take great care: if you do something wrong here, you may
destroy the IGBTs.
1. Disconnect the supply to the HF unit AP13, by disconnecting wires 021 and
041 from terminal XT11. See the wiring diagram.
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-- 48 --
Terminal XT11 is mounted on the side of the ferrite core of the main
transformer TM01.
2. Connect an oscilloscope or a multimeter across capacitor C09.
3. Disconnect wire 110 from the discharge resistor R03.
4. Load the machine with a resistive load and start it in AC mode. Set the
current to 50A. Slowly increase the current until the voltage is 570 - 580V.
The machine should then stop and the yellow Error LED on the front panel
should light. If the machine does not stop, adjust with R301 until it does.
5. Switch off the machine, connect wire 110 to R03.
6. Load the machine with a resistive load and start it in AC mode. Set the
current to 50A. Slowly increase the current until the voltage is about 400V.
If you continue to increase the current, the voltage must not exceed an
average of 400V, if it does, adjust with R302.
7. After the adjustment, secure the potentiometers with varnish and reconnect
the HF unit.
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-- 49 --
AP07 Component positions
Component positions for version 1 of circuit board AP07
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-- 50 --
Component positions for version 2 of circuit board AP07
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-- 51 --
AP08 Interference suppression board
Circuit diagram for circuit board AP08 (EMC board)
Component positions for circuit board AP08
It is important that connection points GND1 and GND2 are properly connected to the chassis
of the machine.
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-- 52 --
AP09 DTE 255 AC snubber ’A’ circuit board
This circuit board is used only in the the DTE 255. The snubber board for the DTE 200 is
described on page 56.
Circuit board AP09 protects the IGBTs Q02 and Q03 from voltage peaks generated by the
switching of the IGBTs. High--speed fuses F01 and F02 protect the IGBT drive circuits on
circiut board AP07 in the event of IGBT failure.
Circuit diagram for circuit board AP09, DTE 255
To protect the IGBTs in the AC unit, the voltage must not exceed 600V. Capacitor C09 is
charged up from the positive and negative rails via diode V05. This voltage is connected to
XA:5 and 6 on AP07.
AP07 monitors the voltage between connections XA:5 (+) and XA:8 (--). If it exceeds 400V,
the capacitor is discharged via a transistor on AP07.
If capacitor C04 is not properly discharged, the machine will be switched off if the voltage
exceeds 570V. There is a more detailed description of this function on pages 47 and 48.
Do not mix up connectors XA and XB.
<------ 4 wires are connected to connector XA
<------ 5 wires are connected to connector XB
Component positions for circuit board AP09, DTE 255
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-- 53 --
AP10 DTE 255 AC snubber ’B’ circuit board
This circuit board is used only in the DTE 255. The snubber board for the DTE 200 is
described on page 56.
Circuit board AP09 protects the IGBTs Q01 and Q04 from voltage peaks generated by the
switching of the IGBTs. High--speed fuses F01 and F02 protect the IGBT drive circuits on
circiut board AP07 in the event of IGBT failure.
Circuit diagram for circuit board AP10
Do not mix up connectors XA and XB.
4 wires are connected to connector XA ---->
5 wires are connected to connector XB ---->
Component positions for circuit board AP10
cdte1de1
-- 54 --
AP11, AP12 DC protection boards
The high--speed fuses on the boards protects the IGBT drive circuits on circuit board AP01 in
the event of IGBT failure.
To detect whether a fuse is healthy or blown, measure the resistance at connector XI. With a
healthy fuse, this resistance will be 10kΩ (resistor R1). If the fuse has blown, IGBT module
Q5 has probably also burnt out. Test instructions for the IGBT module are on page 61.
Circuit diagram for circuit boards AP11 and AP12
Component positions for circuit boards AP11 and AP12
cdte1de1
-- 55 --
AP09 DTE 200 AC snubber circuit board
This circuit board is used only in the DTE 200. The snubber boards for the DTE 255 are
described on page 53 and 54.
Circuit diagram for snubber and discharge circuits of circuit board AP09, DTE 200
Circuit board AP09 protects IGBT modules Q01 and Q02 from voltage peaks generated by
the switching of the IGBTs. High--speed fuses F1 -- F4 protects the IGBT drive circuits on
circiut board AP07 in the event of IGBT failure. The test instructions for the IGBTs are on
page 63.
To protect the IGBTs of the AC unit, the voltage must not exceed 600V. Capacitor C09 is
charged up from the positive and negative rails via diode D1. This voltage is connected to
XA:5 and 6 on AP07.
AP07 monitors the voltage between connections XA:5 (+) and XA:8 (--). If it exceeds 400V,
the capacitor is discharged via a transistor on AP07.
If C04 is not properly discharged, the machine will be switched off if the voltage exceeds
570V. There is a more detailed description of this function on pages 47 and 48.
Gate driver protection circuits on circuit board AP09, DTE 200
The following connections in connectors XC and XE are not used: 3, 6, 7 and 10.
cdte1de1
-- 56 --
Component positions for circuit board AP09, DTE 200
cdte1de1
-- 57 --
SERVICE INSTRUCTIONS
Soft starting
Note: NEVER use a mains fuse with higher rating than 16A.
We recommend that you perform the soft start when any components have been replaced. The
soft start procedure is also useful to use when fault tracing.
A special test circuit board (order no. 0486 640 880) is required for soft starting.
It is described on page 64.
1.
DTE 255: Remove wires 090 and 007 from rectifier unit AP03. Diagram on page 12.
DTE 200: Remove wires 090 and 007 from rectifier V02. Before disconnecting, mark
the heat sink with a + where wire 007 is connected to V02. See the diagram on page 14.
2.
Remove the top cover with the front panel and circuit
board AP05. (Unscrew four screws at the handle and
two screws below the front panel).
Disconnect all cables from AP05.
NOTE: The cable lug on the yellow/green ground cable
has a lock function.
Top cover with panel and circuit board
3.
Remove the screening box which is fitted over the circuit boards.
Remove connector XD (the ribbon cable to AP04) from circuit board AP01. See the
component positions on page NO TAG.
4.
Remove connector X4 from circuit board AP04 and connect it to XC on the test circuit
board. See the component positions for AP04 on page 31.
5.
Connect the two ribbon cables from the test circuit board to AP01.
Test XA to AP01 XD, test XB to AP01 XC.
6.
Connect a regulated external 30V DC power supply to wire 090 and 007, with the
positive connected to 007.
The power supply must have a current limit set to a maximum of 1A.
7.
Set the selector switch on the test board to position 1: OFF. Set the potentiometer on the
test board to about 20% from minimum position. (Min. pos. = max. anti clockwise)
Connect a multimeter to the welding outlets. Connect the positive terminal to XS13
(MMA) and the negative to XS14 (workpiece). Select DC voltage on the multimeter.
Leave the meter connected throughout the whole softstarting procedure.
8.
Switch on the machine. LEDs MAINS, TEMP and DC FAIL will briefly light up, and
then all except MAINS will go out.
Switch on the external DC power supply.
9.
Set the selector switch to position 2: TEST ON.
The meter must show 17 to 20V. This voltage comes from connections AP01:XB5 and 6.
It is a test voltage used to detect when the electrode is in contact with the workpiece
when Lift Arc is selected. See description on page 18.
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-- 58 --
The control voltages to the AC IGBTs can be checked in this and next test position: see
page 60. The polarity command comes from AP04: see page 45.
This tests AP07, AP09, AP10, Q1--Q4 and parts of AP01.
10. Set the selector switch to position 3: CHANGED POL.
The voltage must be - 17 to - 20V.
This tests AP07, Q01--Q04 and cabling for the reversed polarity.
11. Set the selector switch to position 4: MOD ON.
The primary IGBT Q5 is activated. The voltage must be 3 to 5V.
This tests AP01, AP02, AP11, AP12, Q05 and cabling.
12. Set the selector switch to position 5: MOD AND AUX.
The meter now displays a voltage which is about 25% higher than in the previous test.
The additional voltage is a rectified voltage from a separate secondary winding on the
main transformer TM01. See description on page 18.
This tests TM01, AP01 and cabling.
13. Set the selector switch to position 6: MOD CHA. POL.
The meter displays the same voltage as in item 11 above, but with reversed polarity.
Differences up to ±0.3V may occur.
14. If all the test values are correct, disconnect the machine from the mains and disconnect
the external DC supply. Reconnect wires 090 and 007. Note: 090 must be connected to
the negative of the rectifier and 007 to the positive.
Do not disconnect the test board. Set up the test board and the multimeter as described in
item 7 above. To improve the accuracy of the measurements, connect a 5.6kΩ 5W
resistor in parllel with the multimeter. Those measurements are shown in the right--hand
column of the table below.
Note: The voltages measured at e, f and g below depend on the mains voltage.
a.
b.
c.
d.
e.
f.
g.
Switch on the mains. LEDs MAINS, TEMP and DC FAIL will briefly light up, and
then all except MAINS will go out.
Switch position
1: OFF
2: TEST ON
3: CHANGED POL
4: MOD ON
5: MOD AND AUX
6: MOD CHA. POL
Voltmeter
reading
0V
+17 to +20V
--17 to --20V
+70 to +90V
+100 to +120V
--70 to --90V
Voltmeter reading
with 5.6kΩ in //
0V
+17 to +20V
--17 to --20V
+60 to +75V
+95 to +120V
--60 to --75V
If all test values are correct, reset the machine for normal operation and make a test weld.
If some tests fail and it is unclear whether the fault is in the AC or DC part of the machine,
convert the machine to a DC machine, as described on page 66.
Then perform the softstarting procedure above, except that items 10, 13, 14.d and 14.g are
not relevant for a DC machine.
When working as a DC machine, circuit boards AP07, AP09 and AP10 are bypassed.
cdte1de1
-- 59 --
Gate pulses to the AC IGBTs
This instruction applies to items 9 and 10 on pages 58--59.
Measure the voltages at connector XE when the selector switch on the test board is in
position 2: TEST ON. Measure as shown in the diagram below.
Gate voltages when electrode (XS13) is positive
Measure the voltages at connector XE when the selector switch on the test board is in
position 3: CHANGED POL. Measure as shown in the diagram below.
Gate voltages when electrode (XS13) is negative
If the voltages are within the tolerance, the gate drive circuits are healthy.
To check the temperature monitoring of the IGBTs: Disconnect connector XB (= temp. sensor
ST02). All measurements above must now show --9V to --13V. The temperature monitoring is
described on page 47.
cdte1de1
-- 60 --
DC IGBT, test and fitting instructions
DTE 200 / DTE 255
Make all measurements listed below with the machine disconnected from the mains.
Generally, if the IGBT module has burnt out, one or both of the high--speed fuses on the
protection boards will also have blown. To check the fuses, disconnect connector XI from
circuit board AP01. Measure as shown in the diagram below. If the fuses are healthy the
meter will display 10kΩ..
Checking gate fuses
To make a complete check of the IGBT module, remove the screws at C1, E2 and C2E1, then
remove circuit board AP02. Use a multimeter in diode test position to measure as shown in
the diagram below.
Warning: The IGBT module is sensitive to ESD.
Test measuring the DC IGBT module
Fitting instructions for Q05
Follow the fitting instructions for Q01 - Q04 on page 62.
cdte1de1
-- 61 --
AC IGBT DTE 255, test and fitting instructions
Disconnect cables 2, 3, 4, 5, wire 010 and 011 from the AC unit. Use a multimeter in diode
test position to measure as shown in the diagram below.
Generally, if the IGBT module has burnt out, one or more of the high--speed fuses on AP09
and AP10 will also have blown. Check the fuses. The circuit diagrams for AP09 and AP10
are on page 53 and 54.
Warning: The IGBT modules are sensitive to ESD.
Test measuring AC IGBT modules, DTE 255
Fitting instructions for Q01 -- Q04
The IGBTs are extremely sensitive to ESD. Never touch an IGBT having an open gate input.
Apply appropriate ESD protection measures when fitting the IGBT’s.
Start by cleaning the heat sink, and then apply a thin, even layer of thermally conducting
grease to the contact surface of the IGBT. The purpose of this grease is to fill any hollows in
the surface of the IGBT and the heat sink: those parts of the IGBT and the heat sink that are
in true metallic contact may have such contact.
The order number for the thermally conducting grease is given under item 412 in the spare
parts list. Only the grease recommended by us may be used.
Fit the IGBT and tighten the screws to a torque of 1 Nm. Further tighten the screws to a
torque of 3.0 Nm, tightening them alternately.
Warning: An incorrectly fitted IGBT module can lead to failure. Do not tighten the screws
harder than 3.0 Nm.
cdte1de1
-- 62 --
AC IGBT DTE 200, test and fitting instructions
Remove the AC unit from the machine and remove Circuit board AP09 from the two IGBT
modules. Use a multimeter in diode test position to measure as shown in the diagram below.
Generally, if the IGBT module has burnt out, one or more of the high--speed fuses on AP09
will also have blown. Check the fuses. The circuit diagram for AP09 is on page 56.
Warning: The IGBT modules are sensitive to ESD.
Test measuring AC IGBT module, DTE 200
Instructions for reconnection of the cables to the IGBT modules and circuit board AP09 are
on page 67.
Fitting instructions for Q01 and Q02
The IGBT modules are extremely sensitive to ESD. Never touch a module having an open
gate input. Apply appropriate ESD protection measures when fitting the modules.
Start by cleaning the heat sink, and then apply a thin, even layer of thermally conducting
grease to the contact surface of the module. The purpose of this grease is to fill any hollows
in the surface of the module and the heat sink: those parts of the module and the heat sink that
are in true metallic contact may have such contact.
The order number for the thermally conducting grease is given under item 412 in the spare
parts list. Only the grease recommended by us may be used.
Fit the module and tighten the screws to a torque of 1 Nm. Further tighten the screws to a
torque of 3.0 Nm, tightening them alternately.
Warning: An incorrectly fitted IGBT module can lead to failure. Do not tighten the screws
harder than 3.0 Nm.
cdte1de1
-- 63 --
Test circuit board
The test board is mainly intended to be used when soft starting the machine. It can also be
used for fault tracing. For more information about the circuits which may be checked with the
test board, see the description of those circuits.
Circuit diagram for the test circuit board and its connections to the machine
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-- 64 --
Component positions for the test circuit board
The test board has 5 LEDs, as follows:
LED
MAINS
On in positions 1 to 6
MOD
On in positions 4 to 6
TEMP
On if the thermal sensors ST01, ST02 or ST03 are activated, and when the
discharge circuit in the AC unit is overloaded.
TEMP
On if the primary IGBT, Q5, and/or its control circuits do not work, or if the
DC FAIL thermal sensors ST01 or ST03 are activated.
The TEMP and DC FAIL LEDs are on or off at the same time.
AC FAIL
cdte1de1
On if the secondary IGBTs, and/or their control circuits, do not work.
On if the thermal sensor ST02 is, and when the discharge circuit in the AC unit
is overloaded.
-- 65 --
Conversion to DC machine
Follow the instructions below:
1.
Disconnect connector AP04:X4. (Control signals to/from AP07.)
2.
Disconnect connector XS22 from XP22. (42V AC supply to AP07.)
3.
Disconnect connector XS21 from XP21. (Supply to fans EV02 and EV03.)
4.
DTE 255: Disconnect wire 010 and 011 from the copper rails.
DTE 200: Disconnect connectors XC and XB (wire 010 and 011) from AP09.
5.
Remove the shunt cable (2) and the workpiece cable (5) from their connections to the
rails. Connect the two cables to each other and to wire 011.
Note: mark up the cables and the rails before you start disconnecting.
6.
Remove the other two cables and connect them to each other. (Cable 4 from L02 and
cable 3).
Remove varistor R10, which is connected between the connections for cable 3 and 5. It is
not used now but must be reconnected when the machine is used as a normal AC/DC
machine.
If you want to measure the arc voltage signal from AP01 (UNORM), connect wires 010
and 011 to cables 3 and 5.
7.
It is now possible to remove the whole AC unit of the machine, but it is not neccesarry
for this test.
Note: take care when removing the unit, there is a sharp screw end at the bottom of the
unit.
8.
Make a soft start and check the DC functions, see page 58 - 59.
9.
When reconnecting the AC unit, make sure that the copper bars are parallel and properly
tightened to the IGBTs.
cdte1de1
-- 66 --
The AC unit in the DTE 255 and its cable connections
Circuit board AP09 in the DTE 200 and the cable connections to the AC IGBT modules
cdte1de1
-- 67 --
INSTRUCTIONS
This chapter is an extract from the DTE 200 and DTE 255 instruction manuals.
SAFETY
Users of ESAB welding equipment have the ultimate responsibility for ensuring that anyone who
works on or near the equipment observes all the relevant safety precautions.
Safety precautions must meet the requirements that apply to this type of welding equipment.
The following recommendations should be observed in addition to the standard regulations that apply
to the work place.
All work must be carried out by trained personnel well familiar with the operation of the welding equipment.
Incorrect operation of the equipment may lead to hazardous situations which can result in injury to the
operator and damage to the equipment.
1.
Anyone who uses the welding equipment must be familiar with:
S
its operation
S
location of emergency stops
S
its function
S
relevant safety precautions
S
welding
2.
The operator must ensure that:
S
no unauthorized person is stationed within the working area of the equipment when it is
started up.
S
that no--one is unprotected when the arc is struck
3.
The work place must:
S
be suitable for the purpose
S
be free from draughts
4.
Personal safety equipment
S
Always wear recommended personal safety equipment, such as safety glasses, flame--proof
clothing, safety gloves.
S
Do not wear loose--fitting items, such as scarves, bracelets, rings, etc., which could become
trapped or cause burns.
5.
General precautions
S
Make sure the return cable is connected securely.
S
Work on high voltage equipment shall only be carried out by a qualified electrician.
S
Appropriate fire extinquishing equipment must be clearly marked and close at hand.
S
Lubrication and maintenance must not be carried out on the equipment during operation.
cdte1de2
-- 68 --
INTRODUCTION
The DTE 200 and DTE 255 are welding power sources for two different welding methods welding with tungsten electrodes (TIG) and manual metal arc welding with coated electrodes
(MMA), using direct or alternating current.
They are is available in two designs:
S
with OKC connection for the TIG torch
S
with central connection for the TIG torch
Note:
Remove the TIG torch when using the MMA method.
When TIG welding, remove the electrode holder.
The machines are delivered with:
S
Mains cable (5 m)
S
Gas hose
S
Return cable (5 m)
S
Hose clamps
INSTALLATION
The installation shall be executed by a professional.
WARNING
This product is intended for industrial use. In a domestic environment this product may cause
radio interference. It is the user’s responsibility to take adequate precautions.
The machines have mains voltage compensation, which means that ±10% variation in the
supply voltage produces only ±0.2% variation in the welding current.
To reduce the voltage drop resulting from the use of long welding cables, a cable with a larger
sectional area than the one indicated under Technical Data on page 6 could be used.
When the machine is started, the fan works at a reduced rotation speed, partly to reduce the
amount of dirt being sucked in, partly to reduce the noise level.
Only when the load is high does the fan work at full rotation speed.
Location and connection
S
Place the welding power source so that the cooling air in-- and outlets remain free.
S
Connect the shielding gas (see fig. on next page).
S
Connect the TIG torch and the torch return cable, alternatively the welding and return
cable of the electrode holder (see fig. on next page).
S
Make sure the welding power source is connected to the right mains voltage and that it is
properly fused. Connect to earth according to applicable regulations.
Rating plate with connection data is located on the rear of the welding power source.
The machine is now ready for use.
cdte1de2
-- 69 --
OPERATION
General safety regulations for the handling of the equipment appear from page 68. Read
through before you start using the equipment!
Controls and connections
Central connection
A
Mains switch ON/OFF
H
Mains voltage ON, LED
B
Connection for remote control unit
J
Welding voltage ON, LED
C
Torch connector
L
Error / Overheating, LED
D
Connection for electrode holder (MMA)
M
Flow guard, LED
(In operation when the cooling unit is
connected)
E
OKC connection for TIG torch
N
Connection for shielding gas to the machine
F
Return cable connection
O
Control unit, digital display
G
Shielding gas connection
P
Central connection for TIG torch
N.B. The positions C and G are dropped when the central connection is used.
When the mains switch is switched on, the LED (H) goes on.
When open circuit voltage is applied LED (J) goes on.
When an error occurs, for example overheating, LED (L) goes on.
When there is no water flow LED (M) goes on.
When there is a fault that can cause temporary high output voltage, the LED (J) switches off,
(output voltage has been switched off). When idling for longer than 30 minutes, the output
voltage is switched off and LED (J) goes out.
Restart by turning the switch (1) to TIG mode and then back to MMA mode.
Remote control unit
For both the TIG and MMA methods the welding current can be adjusted by way of a remote
control unit. The welding power source registers automatically when a remote control unit is
connected.
cdte1de2
-- 70 --
If the remote control is to include the whole current range, the current must be set to max. on
the welding power source. Max. value = The reference value set on the welding power
source. This is also the value shown by the display on the DTE 255 prior to serial no.
844--950--xxxx. For other DTE 255 machines and DTE 200 the value set by the remote
control is shown by the display.
Protection against overheating
Three thermal cut--outs prevent the power source being overloaded as a result of too high
temperature. If this should happen, the welding current is interrupted and the yellow diode
(L) goes on. (See page 70.)
When the temperature has gone down, the welding current circuit is reclosed and the diode
goes out.
Control panel
1
2
3
4
Method selection switch
S
MMA welding (hand welding electrodes)
(SW3)
S
TIG, two--stroke (also for remote control)
S
TIG, four--stroke
S
TIG four--stroke with the possibility to shift between
two currents (shift function). See items 8 and 9
below for setting of the two currents.
Ignition selection switch
S
HF ignition
(SW2)
S
Lift--Arc ignition, see page 73.
Pulsing selection switch
S
Non--pulsed welding, d.c. and a.c.
(SW4)
S
Welding with square--wave pulsing; d.c. and a.c.
S
Welding with trapezi--form pulsing; d.c. and a.c.
Polarity selection switch
S
Alternating current
(SW1)
S
Square--wave alternating current
S
Direct current, negative electrode (normal in TIG
welding)
S
Direct current, positive electrode
S
Direct current, negative electrode, but with positive
electrode at the start (for example for 3.2 mm
electrodes, TIG welding).
cdte1de2
-- 71 --
5
Potentiometer, Hot Start time
(R3)
S
For setting and optimising the starting cycle with
regard to the electrode size.
TIG welding ( 10 -- 500 ms )
MMA welding (0.1 -- 2 s)
6
Potentiometer, Arc Force
(R9)
S
For setting and optimising the Arc Force function
(Anti Stick), for MMA welding only.
7
Potentiometer, Slope Up
(R6)
S
For setting the slope--up time of the welding current
(0 to 10 seconds).
8
Potentiometer I1
(R1)
S
For setting the non--pulsed welding current and the
current pulse when welding with pulsed current.
9
Potentiometer I2
(R2)
S
For setting the background current for pulsed
welding and the lower current level when using the
shift function.
10 Potentiometer, Slope down
(R7)
S
For setting the welding current slope--down (0 to 10
seconds).
11
S
For setting the gas postflow time (3 to 30 seconds).
Potentiometer, Gas Post Flow
(R8)
12 Potentiometer, Frequency
(R4)
This potentiometer has double functions:
S
For setting the pulse frequency between 0.3 and
300 Hz for pulsed welding with direct current.
For setting the a.c. frequency between 30 and 300
Hz for non--pulsed welding with alternating current.
N.B. When welding with pulsed alternating current,
the a.c. frequency is automatically set to 100 Hz!
The max. pulse frequency to be set is then 100 Hz!
S
13 Potentiometer, Balance
(R5)
This potentiometer has double functions:
S
For setting the relationship between positive and
negative half wave when welding with alternating
current to optimise the cleaning or the penetration.
(Turning right =>increased penetration.)
For setting the time relation between the
background and the peak current when welding
with direct current.
(Turning right =>longer pulse current time.)
N.B. When welding with pulsed ac the time balance
between the pulse current and the base current will
automatically be 50/50%. The relationship between
positive and negative halfwave is adjustable as for
unpulsed ac welding.
S
cdte1de2
-- 72 --
Position
= MMA
In this position the welding power source is prepared for welding with coated electrodes. The
HF unit and the Lift--Arc are disconnected, and the hot--start function is activated in order to
supply increased current at the start.
Position
= HF unit ON
When pressing the torch trigger the gas starts flowing, the HF unit goes on, generating an
electric spark between the electrode and the welding material, the gas is ionised and an arc is
produced. When the arc is stable, the HF unit will automatically be disconnected.
Position
= Lift Arc
By Lift--Arc is meant that you place the torch with the electrode on the spot where you want
to start the welding, press the torch trigger and lift up the torch. In doing so an arc is
produced.
By way of the slope--up function the current now goes up to the set value. When you want to
terminate the welding, release the switch and the current goes down slowly according to the
slope--down time set.
Place the electrode against the workpiece
Press the torch trigger
Tilt the torch a little, lift and an arc is produced
To stop, release the torch trigger
Position
Two/four stroke
Two stroke means that the arc is struck when the torch trigger is pressed and extinguished
when it is released.
Four stroke means that it is not necessary to keep the torch trigger pressed while the welding
is going on. The arc is struck by pressing an releasing the switch and is extinguished by
repeating the action.
Four stroke with the possibility to shift between two currents (Shift function).
By activating the torch trigger for less than 0.5 seconds, the shift function permits switching
between the set current and the background current. Keeping the torch trigger down, the
current will start dropping (slope down).
cdte1de2
-- 73 --
MMA welding (Hand welding electrodes)
Adjusting the control panel for MMA welding
Connect the welding and return cable to the OKC terminals D and F.
Set switch (1) to the position for hand welding electrodes. If the machine is in MMA
mode when the mains is switched on, there will be no open circuit voltage. Activate the
machine by turning the switch (1) to TIG mode and then back to MMA mode.
The LED (J) indicates that open circuit voltage is available on the welding terminals.
S Set the desired value for welding current using potentiometer (8).
It is also possible to use pulsed welding current. The settings are made in the same way
as for pulsed TIG welding.
S Potentiometer (5) is used for stepless setting of the Hot--Start time (0.2 to 2 s),
potentiometer (6) for stepless setting of the Arc--Force function, and thereby the control
dynamics.
S Depending on the electrode type to be used, direct current and polarity or one of the
alternating current alternatives can be selected by way of switch (4) without shifting the
welding cables.
The welding current can be set over a hand--operated remote control unit.
S
S
The DTE has an inbuilt energy saving function. When the machine is in the MMA mode and
not used for 25 minutes, the open circuit voltage is switched off.
Restart by turning the switch (1) to TIG mode and then back to MMA mode.
cdte1de2
-- 74 --
TIG welding
In TIG welding the torch trigger has three different functions:
S
Two--stroke.
S
Four--stroke.
S
Four--stroke with the possibility to shift between two currents (shift function).
Adjusting the control panel for TIG welding
S
Connect the welding cable and the respective return cable to the OKC terminals E and F,
(for central connection: terminals F and P).
S
Set switch (1) to the desired position.
If a foot--operated remote control unit is to be used, set switch (1) to position two--stroke.
NB. For direct current control over the foot--operated remote control unit, the
potentiometer (7) and (10) must be set to position 0.
A hand--operated remote control unit can be used for both two-- and four--stroke to set the
welding current.
S
Select the desired striking method using switch (2).
S
Adjust the welding current using potentiometer (8).
S
Select the desired type of pulsing using switch (3).
S
For the shift function or pulsing, adjust the lower current value using potentiometer (9).
cdte1de2
-- 75 --
Procedure for welding with TIG 4-- stroke and shift function
1.
The gas preflow time is preset to 10 ms. *
2.
Hot start:
S
The start current is preset to 100 A. *
S
The time is adjusted on the front panel: Between 20 and 500 ms.
(For MMA welding: 200 to 2000 ms.)
3.
The start current is preset by the software to 10 A in the DTE 200 and 15 A in DTE 255.
4.
The slope--up time is adjusted on the front panel: 0 - 10 s.
5.
The pulse current is adjusted on the front panel: 5 - 200 A, 250 A in DTE 255.
6.
The background current is adjusted on the front panel: 10 - 90% of the pulse current.
7.
The slope--down time is adjusted on the front panel: 0 -- 10 s.
8.
The end current is preset to 5 A. *
9.
The gas postflow time is adjusted on the front panel: 3 - 30 s.
*
Instructions for the setting of the trim potentiometers for gas preflow time, hot start
current and end current are on page 34 and 36.
cdte1de2
-- 76 --
Setting direct and alternating current
Direct current:
S
Set switch (4) to the position for direct current with negative polarity.
If pulsing has been selected:
S
Set the pulse current value using potentiometer (8).
S
Set the background current in per cent of the pulse current value using
potentiometer (9).
S
Set the pulse frequency using potentiometer (12).
S
Set the time relation between pulse and background current using
potentiometer (13).
Alternating current:
Two different types of alternating current can be set over switch (4):
S
A sine--wave type, characterised by low noise and a soft arc. Effective when low
frequencies are used!
S
A square--wave type, characterised by a hard and stable arc, resulting in a somewhat
higher noise level.
The arc is always struck by way of direct current which is then automatically switched
over to alternating current.
Increased alternating current frequency gives a concentrated and stable arc, suitable above all
when a low amperage is used and when welding in extremely thin plate. The displacement
(balance) of the half--wave in positive direction leads to increased cleaning, and in negative
direction to increased penetration.
(Turn potentiometer (13) more to the right for increased penetration!)
Forced disconnection
If the torch trigger or the foot--operated remote control unit has been activated and no arc has
been generated, the open circuit voltage is automatically disconnected after 2 seconds. The
same applies in the event of an arc interruption.
This function protects from:
S Uncontrolled arc strike
S
Shielding gas drop out
Material damage
S
Accidents
S
cdte1de2
-- 77 --
Maintenance
Note:
All warranty undertakings given by the supplier cease to apply if the customer attempts
to rectify any faults on the machine during the warranty period.
Check--up and cleaning
Clean the welding power source once a year using dry
compressed air (reduced pressure). The dust filter is to
be checked up and cleaned regularly.
If the welding power source is used in a dusty and dirty
environment, the cleaning should be performed more
frequently.
For maximal service reliability it could be advisable
to let an authorised retailer service the machine once
a year.
bt07d109
SPARE PARTS
The spare parts lists are published in separate documents.
Product
filename / ordering no.
DTE 200
0458 234 990
DTE 255
0457 784 990
cdte1de2
-- 78 --
NOTES
notes
-- 79 --
ESAB subsidiaries and representative offices
Europe
AUSTRIA
ESAB Ges.m.b.H
Vienna--Liesing
Tel: +43 1 888 25 11
Fax: +43 1 888 25 11 85
BELGIUM
S.A. ESAB N.V.
Brussels
Tel: +32 2 745 11 00
Fax: +32 2 726 80 05
THE CZECH REPUBLIC
ESAB VAMBERK s.r.o.
Prague
Tel: +420 2 819 40 885
Fax: +420 2 819 40 120
DENMARK
Aktieselskabet ESAB
Copenhagen--Valby
Tel: +45 36 30 01 11
Fax: +45 36 30 40 03
FINLAND
ESAB Oy
Helsinki
Tel: +358 9 547 761
Fax: +358 9 547 77 71
FRANCE
ESAB France S.A.
Cergy Pontoise
Tel: +33 1 30 75 55 00
Fax: +33 1 30 75 55 24
GERMANY
ESAB GmbH
Solingen
Tel: +49 212 298 0
Fax: +49 212 298 204
GREAT BRITAIN
ESAB Group (UK) Ltd
Waltham Cross
Tel: +44 1992 76 85 15
Fax: +44 1992 71 58 03
ESAB Automation Ltd
Andover
Tel: +44 1264 33 22 33
Fax: +44 1264 33 20 74
HUNGARY
ESAB Kft
Budapest
Tel: +36 1 20 44 182
Fax: +36 1 20 44 186
ITALY
ESAB Saldatura S.p.A.
Mesero (Mi)
Tel: +39 02 97 96 81
Fax: +39 02 97 28 91 81
THE NETHERLANDS
ESAB Nederland B.V.
Utrecht
Tel: +31 30 248 59 22
Fax: +31 30 248 52 60
NORWAY
AS ESAB
Larvik
Tel: +47 33 12 10 00
Fax: +47 33 11 52 03
POLAND
ESAB Sp.z.o.o
Warszaw
Tel: +48 22 813 99 63
Fax: +48 22 813 98 81
PORTUGAL
ESAB Lda
Lisbon
Tel: +351 1 837 1527
Fax: +351 1 859 1277
SLOVAKIA
ESAB Slovakia s.r.o.
Bratislava
Tel: +421 7 44 88 24 26
Fax: +421 7 44 88 87 41
SPAIN
ESAB Ibérica S.A.
Alcobendas (Madrid)
Tel: +34 91 623 11 00
Fax: +34 91 661 51 83
SWEDEN
ESAB Sverige AB
Gothenburg
Tel: +46 31 50 95 00
Fax: +46 31 50 92 22
ESAB International AB
Gothenburg
Tel: +46 31 50 90 00
Fax: +46 31 50 93 60
SWITZERLAND
ESAB AG
Dietikon
Tel: +41 1 741 25 25
Fax: +41 1 740 30 55
North and South America
Asia/Pacific
CHINA
Shanghai ESAB A/P
Shanghai
Tel: +86 21 6539 7124
Fax: +86 21 6543 6622
INDIA
ESAB India Ltd
Calcutta
Tel: +91 33 478 45 17
Fax: +91 33 468 18 80
INDONESIA
P.T. Esabindo Pratama
Jakarta
Tel: +62 21 460 01 88
Fax: +62 21 461 29 29
MALAYSIA
ESAB (Malaysia) Snd Bhd
Selangor
Tel: +60 3 703 36 15
Fax: +60 3 703 35 52
SINGAPORE
ESAB Singapore Pte Ltd
Singapore
Tel: +65 861 43 22
Fax: +65 861 31 95
ESAB Asia/Pacific Pte Ltd
Singapore
Tel: +65 861 74 42
Fax: +65 863 08 39
Representative offices
BULGARIA
ESAB Representative Office
Sofia
Tel/Fax: +359 2 974 42 88
EGYPT
ESAB Egypt
Dokki--Cairo
Tel: +20 2 390 96 69
Fax: +20 2 393 32 13
ROMANIA
ESAB Representative Office
Bucharest
Tel/Fax: +40 1 322 36 74
RUSSIA-- CIS
ESAB Representative Office
Moscow
Tel: +7 095 937 98 20
Fax: +7 095 937 95 80
ESAB Representative Office
St Petersburg
Tel: +7 812 325 43 62
Fax: +7 812 325 66 85
Distributors
For addresses and phone
numbers to our distributors in
other countries, please visit our
home page
www.esab.com
SOUTH KOREA
ESAB SeAH Corporation
Kyung--Nam
Tel: +82 551 289 81 11
Fax: +82 551 289 88 63
UNITED ARAB EMIRATES
ESAB Middle East
Dubai
Tel: +971 4 338 88 29
Fax: +971 4 338 87 29
ARGENTINA
CONARCO
Buenos Aires
Tel: +54 11 4 753 4039
Fax: +54 11 4 753 6313
BRAZIL
ESAB S.A.
Contagem--MG
Tel: +55 31 3369 4333
Fax: +55 31 3369 4440
CANADA
ESAB Group Canada Inc.
Missisauga, Ontario
Tel: +1 905 670 02 20
Fax: +1 905 670 48 79
MEXICO
ESAB Mexico S.A.
Monterrey
Tel: +52 8 350 5959
Fax: +52 8 350 7554
USA
ESAB Welding & Cutting Products
Florence, SC
Tel: +1 843 669 44 11
Fax: +1 843 664 44 58
ESAB AB
SE-- 695 81 LAXÅ
SWEDEN
Phone +46 584 81 000
www.esab.com
031021
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