I. Use and Characteristics II. Safety Precautions

I. Use and Characteristics
The manufacturing of the inverter-type DC submerged arc welding machine of MZ series conforms to the
standard GB15579.1-2004 Part I for arc welding equipment: welding power source.
The inverter-type DC submerged arc welding machine of MZ series is a novel highly efficient
energy-saving equipment, which includes multiple specifications such as MZ-630, MZ-800, MZ-1000,
MZ-1250, etc., can be used for welding the materials such as the carbon structure steel, the stainless steel,
the heat resistant steel and the compound steel and is widely applied in various industries such as the
shipbuilding, the boilers, the chemical vessels, the bridges, the hoisting machinery, the metallurgical and
mechanical manufacturing, etc.
The inverter-type DC submerged arc welding machine of the series has the ideal static characteristics and
good dynamic characteristics, and has complete control function. It is mainly characterized in that:
The IGBT inverter technology is adopted, thus assuring that the welding current is highly stable and
smooth under the circumstances that the network voltage fluctuates and the arc length varies. The arc
has strong self-adjusting ability;
The function of adjusting the current of arc is provided. It can regulate the current of arc according to
the requirement of the welding process, thus greatly enhancing the successful rate of striking arc;
The function of adjusting the push current, thus assuring the weld shaping, being convenient for the
penetration adjustment and resulting in that the submerged arc welding machine adapts more strongly to
the welding process;
It is compatible with the function of manual arc welding and can be used for the carbon arc air gouging,
the manual arc welding, etc.;
The range of current regulation is wide and the minimum current is 60A;
It has a small weight, a small size and is convenient for being moved;
With high efficiency and high power factor delivered, it is a highly efficient and energy-saving
equipment.
II. Safety Precautions
※ General safety precautions
Observe the precautions stipulated in this instruction manual, or accident may occur.
Observe the related standard and regulations in design and construction of the input power supply, the
selection of the installation site, and the use of the high pressure gas.
Irrelative persons are not allowed to enter the welding operation site.
The installation, maintenance, and operation of the welder should be done by the professional and
qualified personnel.
Never use this welder for purpose other than welding, such as charging, heating, and pipe unfreezing,
etc.
Avoid the welder from being toppled over when the ground is not flat.
※Avoid the welding arc, splashing and welding dregs from harming person.
Wear glasses of sufficient light shielding degree. Arc can produce eye inflammation, whereas the
splashing and welding dregs can burn eyes.
Use the protection appliance such as the welding leather gloves, long sleeve clothes, caps, hose, and
apron, etc. to avoid the arc, splashing and welding dregs from hurting your skin.
※Avoid the welding fume, dust, and gas from hurting person.
Use the stipulated ventilation equipment to avoid accident such as gas poisoning and suffocation, etc.
When work at the bottom of a container, the protection gas can be aggraded around to cause
suffocation. Pay particular attention to ventilation.
※Avoid electrical sock or burnt.
Never contact the part with electricity.
The welder should be grounded with copper wire of stipulated section area by the professional
personnel.
The welder should be connected to the power supply with copper wire of stipulated section area by
the professional personnel. The insulation protection sleeve of the wire should not be damaged.
When work in a wet place limiting action, ensure there is insulation between your body and the
material.
When work overhead, use the safety protection net.
Turn off the power supply when it is not used.
※Avoid accident such as fire, explosion, or cracking.
Flammable matters are avoided from the welding site as the splashing and the hot welding seam can
cause fire.
The connection between the cable and the material should be tight, or its heat can cause fire.
Never weld in flammable gas or on a container containing flammable material, or fire can be caused.
Never weld a sealed container, or cracking can be caused.
Work with a fire extinguisher at hand, just in case.
※ Prevent the rotating part from hurting person.
Never put your finger, hair, or clothes near the rotating part of cooling fan, etc.
※Avoid the welder from hurting person when it is moving.
When move the welder with a forklift or a crane, never stand under the welder or in the front of its
way to avoid the welder from squashing person if it is falling down.
During lifting, the lift rope should have sufficient pull without breaking. The inclination at the lifting
hook of the rope should not exceed 30°.
III. Welder Installation
1.
Installation surroundings
(1) It should be installed in a room not under direct sunshine and with rainwater proofing, low
temperature, and less dust. The surrounding air temperature should be -10 to +40 .
(2) The floor slope should not exceed 15°.
(3) The welding position should not be ventilated. If yes, shield it.
(4) The welder should leave wall at least by 20cm, and the distance between welders should be
above 10cm.
2.
Voltage quality of the power supply
(1) Its waveform should be a standard sine wave with an effective value 380V±10% and frequency
50Hz/60Hz.
(2) Unbalance of the three phases of the voltage should be ≤5%.
3.
Input of the power supply.
MZ-630
Welder type
MZ-800
Input power supply
MZ-1250
Three phase 380V~50Hz
Min. capacity of the transmission-line
system of electric power
Fuse
Input
protection
Circuit breaker
Min. cable
sectional area
MZ-1000
53KVA
66KVA
83KVA
120KVA
60A
70A
90A
130A
100A
100A
2
2
2
35mm2
10mm
Output side
95mm ×1
50mm ×2
70mm ×2
95mm ×2
Grounding wire
10mm2
16mm2
16mm2
16mm2
2
25mm
160A
Input side
2
16mm
120A
2
2
Note: The capacities of the fuses and circuit breakers in the table above are for reference only.
4. Equipment installation
4.1 The external wire splice when the equipment is mounted is shown as Figure 1.
4.2 The user shall be delivered with the corresponding distribution panel or electric power distribution
cabinet, connects the three-phase 380V/50Hz alternating current to the terminal box for input cable of
the submerged arc welding machine and reliably connects it with the grounded bolt grounding wire of
the submerged arc welding machine.
Submerged arc
welding trolley
Air switch
Control box
Arc welding
power source
Work piece
Walking trolley
Control cable
Output cable at the
positive electrode
Flux hopper
Output cable at the
negative electrode
(Figure 1) external wire splice
4.3 The submerged arc welding machine is connected with the submerged arc welding trolley using the
output cable at the positive electrode.
4.4 The submerged arc welding machine is connected with the welded workpiece
4.5 The submerged arc welding machine is connected with the control box for the submerged arc welding
trolley using the control cable.
Ⅳ.Model compilation and Direction
The model compilation and direction for the inverter-type DC submerged arc welding machine of MZ
series are shown as Figure 2:
Rated Welding Current
Automatic welding
Submerged arc welding machine
(Figure 2) model compilation and direction for the inverter-type DC submerged arc welding machine of MZ series
Ⅴ. Brief description for Principles
The principles for the inverter-type DC submerged arc welding machine of MZ series are shown as Figure
3:
Three-phase rectification
High frequency inversion
High frequen
Rectification and filtering
Control circuit
(Figure 3) Principle block diagram for inverter-type DC submerged arc welding machine of MZ series
The IGBT high-frequency inverter technology is adopted for this equipment. The power frequency
three-phase 380V power source is input, and is delivered to the inverter composed of devices such as IGBT,
etc after being rectified with being changed into the high-frequency current, which is output as the direct
currents suitable for welding after being processed by the high-frequency transformer with lowered voltage
and rectified and filtered by the high-frequency rectifier. Through this process, the dynamic response
ability of the DC submerged arc welding machine is enhanced and the volume and weight of the
transformer and the reactor.
The closed loop control of the overall machine is realized for the design of the control circuit, thus
enabling the submerged arc welding machine to assure that the welding specification is stable, the arc
ignition is easy to be conducted, the electric arc is stable and the weld is shaped well when the external
conditions vary (for example, the network voltage fluctuates, the lengths of the output cables differs, etc.)
and simultaneously realizing that the welding current, the push current and the current of arc are
continuously adjustable.
The output characteristics of the inverter-type DC submerged arc welding machine of MZ series are shown
as Figure 4:
(Figure 4) Output characteristics of inverter-type DC submerged arc welding machine of MZ series
Ⅵ.Directions for use and operation
1.Function introduction
1.1 Front panel
The front panel of the inverter-type DC submerged arc welding machine of MZ series (take example
for MZ-1000) is shown as Figure 5:
(Figure 5) Front panel of inverter-type DC submerged arc welding machine of MZ series
(1) Ammeter (A) indicates the preset value of the current of the submerged arc welding machine and
the actual value of the welding current;
(2) Voltmeter (V)indicates the value of the welding voltage of the submerged arc welding machine;
(3) Power indicator lamp
it indicates that the three-phase 380V power supply has already been
connected in when the power indicator lamp illuminates;
(4) Busy indicator it indicates that the submerged arc welding machine has already been started
when the busy indicator illuminates;
(5) Protection indicator lamp
it indicates that the submerged arc welding machine stops working
due to that the interior temperature is too high when the protection indicator lamp illuminates;
(6) When the operating switch switches on “1”, the submerged arc welding machine starts to
work;When it switches on “0”, the submerged arc welding machine stops working;
(7) Adjusting knob for welding current
(8) Adjusting knob for push current
and improve the weld shaping;
used to adjust the welding current;
used to adjust the push current, control the weld penetration
(9) Adjusting knob for current of arc
used to adjust the current of arc, change the arcing
performance of the power supply and enable the welding machine to be suitable for the
requirements of various welding specifications;
(10) Selection switch for control mode
when this switch is switched on “close control”, the
welding current is adjusted on the control panel; when this switch is switched on “remote
control”, the submerged arc welding control box can be used to adjust the welding current;
(11) Operational mode selector switch
when this switch is switched on “manual arc welding”, the
manual arc welding can be carried out; when this switch is switched on “submerged arc welding”,
the submerged arc welding can be carried out;
(12) Protector for control box (5A) has an effect of safety on the 120V power supply of the control
box;
(13) Output positive electrode of submerged arc welding machine;
(14) Socket for control cable used to connect the submerged arc welding machine with the control
box, provide the working power of the control box and transmit the control signal between the
submerged arc welding machine and the control box;
(15) Output negative electrode of submerged arc welding machine.
1.2 Rear panel
The rear panel of the inverter-type DC submerged arc welding machine of MZ series (take example
for MZ-1000) is shown as Figure 6:
(Figure 6) rear panel of inverter-type DC submerged arc welding machine of MZ series
(1) Terminal box for input cable
used for connecting the three-phase 380V alternating current;
(2) Nameplatemarks the parameters of the submerged arc welding machine;
(3) Fanused for cooling the heat emitting devices in the submerged arc welding machine;
(4) Grounded bolt In order to assure the personal safety and the normal use of the equipments,
please be sure to ground this bolt using wires.
2.
Check before use
2.1 Check the submerged arc welding machine with the power supply disconnected. The main check
items are as follows:
(1) Whether input cables of the submerged arc welding machine are correctly and reliably connected;
(2) Whether the operational mode selector switch and the selection switch for control mode on the
front panel are correctly switched;
(3) Whether the output cables are correctly and reliably connected;
(4) Whether the control cables are correctly and reliably connected;
(5) Whether grounded bolt grounding wire is correctly and reliably connected.
2.2 Noload check with the power supply connected
The noload check with the power supply connected can be put into practice only after the “check with
the power supply disconnected” mentioned above ends. The check steps and methods are as follows:
(1) Switch the power switch on the distribution panel or electric power distribution cabinet ON and
connect the 380V power supply, then the power indicator lamp on the control panel of the
submerged arc welding machine illuminates;
(2) Switch the operating switch on “1”, then the busy indicator illuminates and the cooling fan runs.
When the operational mode selector switch is switched on “manual arc welding”, the voltmeter
indicates a no-load voltage; the operational mode selector switch is switched on “submerged arc
welding”, a no-load voltage indication of zero is delivered by the voltmeter;
(3) Adjust the knob for welding current, then the preset current displays the due corresponding
variations;
(4) Toggle the operating switch to be set on “0”, then the busy indicator is turned off and the fan
stops running.
The normal welding can be implemented only after the above steps all go into practice.
3.
Normal use
3.1 Used as the manual arc welding
(1) Well connect the input cables of the submerged arc welding machine;
(2) Well connect the grounding wire;
(3) Switch the operational mode selector switch on “manual arc welding”;
(4) The welding rod holder is connected with the positive electrode of the submerged arc welding
machine;
(5) The negative electrode of the submerged arc welding machine is connected with the welded
workpieces using the output cable at the negative electrode;
(6) The control cables between the submerged arc welding machine and the control box are well
connected according to the requirements;
(7) Select the control mode according to the requirement and determine “remote control” or “close
control”;
(8) Switch the knob for current of arc and the knob for push current on the appropriate position;
(9) Connect the input three-phase cable on the air switch of the distributor or electric power
distribution cabinet and then switch ON;
(10)Adjust the knob for welding current, preset the welding current and then conduct the welding.
Annotation: When the manual arc welding is carried out, you can refer to the welding specification in
Table 1 if the operational mode selector switch is switched on “submerged arc welding”,the user can
refer to the welding specifications in Table 1 whenno current is output from the welding machine and
the user implements the manual arc welding.
Table 1 Welding process specification for manual arc welding (reference)
Weldment thickness (mm)
<1
2
3
4~5
6~12
≥13
Diameter of welding wire (mm)
1.5
2
3.2
3.2~4
4~5
5~6
Welding current (A)
40
40~50
90~120
90~120
160~250
250~400
3.2 Used as the submerged arc welding
(1) Well connect the input cables;
(2) Well connect the grounding wire;
(3) Switch the operational mode selector switch on “submerged arc welding”;
(4) Connect the positive electrode of the submerged arc welding machine with the trolley using the
output cable at the positive electrode;
(5) Connect the negative electrode of the submerged arc welding machine with the welded
workpieces using the output cable at the negative electrode;
(6) Well connect the control cables between the submerged arc welding machine and the control
box;
(7) Select the control mode according to the requirements and determine “remote control” or “close
control”;
(8) Determine the welding specification according to the workpieces and switch the adjusting knobs
for current of arc and push current on the appropriate positions;
(9) Connect the input three-phase cable on the air switch of the distributor or electric power
distribution cabinet and then switch ON;
(10)Adjust the knob for welding current, preset the welding current and then implement the welding.
Caution: the welding machine shall be turned OFF when the welding cables and wires and the current
contact nozzle are changed.
3.3 Parameter setting and directions for matching relationship of the welding specifications
The output static characteristic curve for the inverter type DC submerged arc welding machine is
shown as Figure 7.
Output current(A)
(Figure 7) Output characteristics of inverter type DC submerged arc welding machine of MZ series
M-A-B-C is the output static characteristic curve.
N-B is the load curve
(1) The current adjusting knob is used for adjusting the welding current, namely adjusting the distance
between AB segment and the longitudinal axis on the output characteristic curve.
The curve of the AB segment is the constant current output segment of the submerged arc welding
machine and the adjustment range covers from the minimum current to the rated welding current.
(2) The adjusting knob for push current is used for adjusting the push current, which corresponds to the
DC segment of the output characteristic curve. When the thrust potentiometer is adjusted, namely the
slop of the DC segment is changed (shown as the straight line with Point B as the axis in Figure 7).
When the submerged arc welding machine is in the state of the manual arc welding, the thrust
adjusting range: 0~150A; when it is in the state of the submerged arc welding, the thrust adjusting
range: 0~450A.
(3) The adjusting knob for current of arc is used for adjusting the additional current when the arc ignition
of the welding is carried out. The reasonable current of arc can effectively prevent the stick from
being stuck and enhance the success rate of the arc ignition. The current adjustment range covers from
80±10A to I/4 (I is the rated current of the submerged arc welding machine).
(4) Weld shaping and specification adjustment
The weld shaping is densely and tightly related to the welding specifications, which usually follows
the following laws:
When the specification is within the constant current area (when the push current is zero), the
penetration is shallow, the reinforcement is large and the weld is narrow;
When the specification is within the descent area (when the push current is not zero), the penetration
is large, the reinforcement is small and the weld is wide;
When the welding current is adjusted to be stronger, the penetration is large and the weld is wide;
When the push current is adjusted to be stronger, the penetration is increased and the reinforcement
becomes smaller;
When the welding voltage for submerged arc welding is adjusted to be higher, the penetration is
reduced, the weld becomes wider and the reinforcement becomes smaller;
When the travel speed of the welding torch is adjusted to be slower, the penetration is increased and
the weld becomes wider;
The above parameters need to be comprehensively adjusted, and then a good weld can be generated.
When the user uses the submerged arc welding machine, he or she can refer to the welding
specifications in Table 2~8. When a welding defect occurs, it can be usually eliminated according to
the causes in Table 9 and the prevention measures.
Table 2: Welding current range suitable for welding wires of different diameters
Diameter of welding wire (mm)
2
3
4
5
6
Current density (A/mm )
63~125
50~85
40~63
35~50
28~42
Welding current (A)
200~400
350~600
500~800
700~1000
820~1200
2
Table 3 Specifications for double-sided automatic welding of flux rim strip groove
Weldment
thickness
(mm)
Groove diagram
Diameter
of welding
wire (mm)
14
φ5
16
φ5
18
φ5
φ6
φ5
φ6
φ5
22
24
φ6
30
ι/κ(mm)
Arc
voltage
(V)
Welding
current (A)
Welding
speed
(m/h)
6
-
7
-
8
-
13
-
14
14
10
10
36~38
36~38
36~38
36~38
36~38
36~38
38~40
36~38
38~40
36~38
36~40
36~38
830~850
600~620
830~850
600~620
830~860
600~620
1050~1150
600~620
1100
800
1000~1100
900~1000
25
45
20
45
20
45
18
45
24
28
18
20
Size of groove
Weld
order
α(°)
Front
Back
Front
Back
Front
Back
Front
Back
Front
Back
Front
Back
80
-
70
-
60
-
55
-
40
40
80
60
Table 4 Specifications for automatic welding with forming in double faces through welding in single face
on flux backing
Weldment
thickness (mm)
Assembly
clearance
(mm)
Diameter of
welding wire
(mm)
Welding
current (A)
Arc voltage
(V)
Welding speed
(m/h)
Pressure of
flux backing
MPa
2
0~1.0
φ1.6
120
24~28
43.5
0.08
3
0~1.5
φ3
400~425
25~28
70
0.08
4
0~1.5
φ4
525~550
28~30
50
0.10~0.15
5
0~2.5
φ4
575~625
28~30
46
0.10~0.15
6
0~3.0
φ4
600~650
28~32
40.5
0.10~0.15
7
0~3.0
φ4
650~700
30~34
37
0.10~0.15
8
0~3.5
φ4
725~775
30~36
34
0.10~0.15
Table 5 Welding specifications for fillet welding in the flat position
Fillet height (mm)
Diameter of welding wire
(mm)
Welding current (A)
Arc voltage (V)
Welding speed
(m/h)
6
φ5
450-475
34-36
40
8
φ5
550-600
34-36
30
8
φ5
575-625
36-36
30
10
φ5
600-650
34-36
23
10
φ5
650-700
34-36
23
12
φ5
600-650
34-36
15
12
φ5
725-775
36-38
20
12
φ5
775-825
36-38
18
Table 6 Specifications for gantry pressure frame type welding with self forming in double faces through
welding in single face on copper wall
Thickness of steel
plate (mm)
Assembly
clearance (mm)
Diameter of welding wire
(mm)
Welding current
(A)
Arc voltage
(V)
Welding speed
(m/h)
3
2
φ3
380-420
27-29
47
4
2-3
φ4
450-500
29-31
40.5
5
2-3
φ4
520-580
31-33
37.5
6
3
φ4
550-600
33-35
37.5
7
3
φ4
640-680
35-37
34.5
8
3-4
φ4
680-720
35-37
32
9
3-4
φ4
720-780
36-38
27.5
10
4
φ4
780-820
38-40
27.5
12
5
φ4
850-900
39-41
23
14
5
φ4
880-920
39-41
21.5
Table 7 Specifications for automatic welding by both sides with pre-welding gap on flux backing
Thickness of steel
plate (mm)
Assembly
clearance (mm)
Diameter of welding wire
(mm)
Welding current
(A)
Arc voltage
(V)
Welding speed
(m/h)
14
3-4
φ5
700-750
34-36
30
16
3-4
φ5
700-750
34-36
27
18
4-5
φ5
750-800
36-40
27
20
4-5
φ5
850-900
36-40
27
24
4-5
φ5
900-950
38-42
25
28
5-6
φ5
900-950
38-42
20
30
6-7
φ5
950-1000
40-44
16
Table 8 Specifications for hanging automatic welding by both sides
Diameter of welding wire
(mm)
Thickness of steel
plate (mm)
Welding order
φ4
6
φ4
φ4
φ4
φ4
φ4
φ4
φ4
φ4
φ4
Welding current
(A)
Welding
voltage (V)
Welding speed
(m/h)
Front
Back
380-420
30
34.6
430-470
30
32.7
8
Front
Back
440-480
30
30
480-530
31
30
10
Front
Back
530-570
31
27.7
590-640
33
27.7
12
Front
Back
620-660
35
25
680-720
35
24.8
14
Front
Back
680-720
37
24.6
730-770
40
22.5
15
Front
Back
800-850
34-36
38
850-900
36-38
26
17
Front
Back
850-900
35-37
36
900-950
37-39
26
18
Front
Back
850-900
36-38
36
900-950
38-40
24
20
Front
Back
850-900
36-38
35
900-1000
38-40
24
22
Front
Back
900-950
37-39
32
1000-1050
38-40
24
Table 9 weld defects of the submerged arc automatic welding, causes and prevention measures
Defect category
Morphological characteristic
Cause
Prevention measure
The weld is not
uniform
The weld widths differ from
each other
(1) The welding speed is not uniform
(2) The wire feed is not stable
(3) The contact of the current contact
nozzle is not stable
(1) Clear the circuit faults
(2) Adjust the wire feed rolling wheel
(3) Replace the current contact nozzle
Undercutting
(1) The welding speed is too high
(2) The welding current is too strong
(3) The arc voltage is too high
(4) The wire ends are not accurately
aimed
(1) Lower the welding speed or adopt
double-arc or multi-arc welding
(2) Reduce the welding current
(3) Lower the welding voltage
(4) Correct the position of the welding
wire
Inflection
The pressure over the flux backing is too
large
满溢
Brim over
(1) The wire extention of the welding
wire is too large
(2) The groove is too small
(3) The arc voltage is too low
(4) The wire ends are not accurately
aimed
Improve the flux backing
(1) Reduce the wire extention
(2) Change the size of the groove
(3) Increase the arc voltage
(4) Correct the position of the welding
wire
Weld penetration
and the weld on
the back is too
high
(1) The welding current is too strong
(2) The welding speed is too low
(3) The groove gap is too large
(4) The gasket is not tightly attached
(1) Reduce the welding current
(2) Increase the welding speed
(3) Improve the assembly quality
(4) Improve the holding apparatus
Incomplete
penetration
(1) The welding current is too weak
(2) The welding speed is too high
(3) The arc voltage is too high
(4) The wire ends are not accurately
aimed
(5) The net voltage fluctuation is too
large
(1) Appropriately increase the current
(2) Lower the welding speed
(3) Lower the arc voltage
(4) Straighten the welding wire and
adjust the welding head
(5) Avoid the peak period of the power
consumption
Stomata
(1) The parent materials are sullied
or not cleaned
(2) The rust or oil of the welding
wire is not completely
eliminated
(3) The flux is humid
(4) The
components
or
performances of the flux are
not good
(1) Intensify the clear work
(2) Dry the flux
(3) Change the appropriate flux
(1) Cylindrical ditch form
(2) Distributed along the
center of the weld
(3) Single or in group
Thermal crack
Slag inclusion
(1) Generated along the
longitudinal
or
transverse
grain
boundary of the weld
(2) Generated
at
the
beginning end or tail
end when the forming
in two faces through
welding by on side is
carried out
(1) The low melting point sulphide
is excessively segregated
(2) No sufficient binding force is
delivered when the weld at the
beginning end or tail end is
crystallized.
(1) The slag between layers is not
completely cleared when the
welding by multi-layer is
carried out
(2) The wire end is not accurately
aimed when the rear-pass
welding is carried out
(1) Select the welding wire with
low carbon and sulphur
contents and a high manganese
content and the low-silicon
high-manganese flux
(2) Appropriately increase the
widths of the end table and the
run-off tab and the welding
fasteness and adopt the notch
end tab.
(1) Completely clear the slag
between layers
(2) Adjust the position of the
welding head
Ⅶ.Service and Maintenance
The professionals shall be in charge of the maintenance of the DC submerged arc welding machine. When
the user encounters with the problems that can not be solved, he or she shall contact with the goods supply
candidate of our company in time.
Cautions: the maximum voltage in the machine is up to 600V. In order to assure the safety, that the casing
is arbitrarily opened is strictly prohibited. When the maintenance is put into practice, the air switch shall be
turned off in the machine and the safety protection work of preventing the electric shock shall be well
prepared.
1.
Normal phenomenon easy to be misunderstood
The following phenomenon of the DC submerged arc welding machine occurring in the work all is
normal:
1.1 When the input voltage is too low, the DC submerged arc welding machine does not work;
1.2 When the DC submerged arc welding machine is used in a high-temperature environment for a long
time or works with a strong current for a longer period of time, the thermal relay in the machine will
automatically makes the equipment stopped from working, and then the protection indicator lamp
illuminates. When this condition occurred, As long as it works without load (does not need to be shut
down) for several minutes, the equipment will automatically go back to normal.
2.
Application notice
2.1 When the equipment is used, it shall be put in the place where it is dry and the ventilation equipment
is mounted and should not be stored in the high-temperature humid place.
2.2 The line voltage of the three-phase power supply ranges from 340V to 420V and there should not be
the open-phase.
2.3 The grounding wire shall be correctly and reliably connected
2.4 Various connection cables and wires shall be periodically checked. If the joints are found to be
loosened, they shall be screwed tightly at any time, or the joints will be burned down and the
instability in the process of welding will be caused.
2.5 After the welding ends, the power supply shall be turned OFF.
3.
Faults and Elimination
3.1 Carry out the following checks before the maintenance
(1) Whether the line voltage of the three-phase power supply ranges from 340V to 420V and there
is an open phase;
(2) Whether the connection of the input cables of the power supply is correct and reliable;
(3) Whether the protective earthing is correct and reliable;
(4) Whether the output cables are correctly connected and well contacted.
3.2 See Appendix A for information of the common fault phenomenon, fault causes and elimination
method.
4.
Periodical check and maintenance
4.1 The professionals eliminate the dust of the DC submerged arc welding machine using the compressed
air for one time each season. Simultaneously pay attention to checking whether the phenomenon that
the fastener is loosened exists in the machine. If it exists, it shall be immediately eliminated. The
contact conditions of the input and output wiring terminals shall be frequently checked and carry out
the check for at least one time each month.
4.2 Check whether the remote control plug and the adjusting knobs are loosened, the control cable is
disrepaired and the switches on the panel are flexibly used in time.
Ⅷ.Technical data
1.
Main technical parameters
Model
MZ-630
Input voltage/frequency
MZ-800
MZ-1000
MZ-1250
Three phase 380V ~50/60Hz
Rated output capacity
27KW
35KW
44KW
55KW
Rated input current
52A
66A
83A
120A
60~1000A
60~1250A
Rated duty cycle
Current adjustment range
Nonloaded voltage
100%
60~630A
60~800A
Submerged arc welding:90V
Full load efficiency
92%
Full-load power factor
0.88
Welding wire diameter
1.6-4mm
3-5mm
Manual arc welding:67V
3-6mm
3-6mm
Main transformer
H
Power transformer, output reactance, etc.
B
Insulation grade
2. Circuit diagram of main circuit
Ⅸ.Common fault phenomenon, fault causes and elimination methods:
No.
1
2
3
Phenomenon
Cause
Measure
After the machine is
started, the indicator lamp
does not illuminates, the
welding machine does not
work and the fan does not
rotate
① Lack of one phase
② The protective tube (5A) in the
machine is broken
③ Disconnection
④ The air switch in the machine
is under voltage trip.
The following devices might be
damaged:
IGBT
module,
three-phase
rectifier
module,
output diode module, other devices
① Check the power supply
② Check whether the fan, the power
transformer and the main control board are
in good condition
③ Check the wires
④ The professionals carry out the check and
maintenance.
When the IGBT is damaged, various elements
of the output part of the driver board might be
usually also damaged and need to be checked
and changed.
The welding current is not
stable
① Lack of phase
② The following elements might
be
damaged:
various
potentiometers on the front
panel
③ The main control board is
damaged
① Check the power supply
② Check and replace
The welding current can
not be adjusted
① The wires in the machine are
disconnected
② The main control board is
damaged
③ The control cable is damaged
Check and replace
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