Taurus CUT-70I User manual

IGBT Inverter Plasma
Cutter
Operation Manual
CUT-70I
CUT-80I
CUT-100I
CUT-120I
Read this manual carefully before installing,
operating and maintaining the machine.

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Description: This machine is used to cut ferrous or nonferrous metals.
Disclaimer: The information, illustrations and instructions described in this manual
are based on the latest product information available at the time of publication. The
manufacturer and distributors reserve the right to modify the contents of the
brochure at any time which modifications may result following product modifications
and the manufacturer and distributors are not obliged to notify any organization or
individual of such modifications. Cutting work must be executed only by
professionally trained and qualified individuals. Therefore, the manufacturer and
distributors will only accept responsibility for product quality. No liability, joint or
several, shall be accepted for incidents including but not limited to loss of profit
resulting from omissions or misdirection that may be printed in this operating
manual. This manual will contain as far as possible preventive and safe operation
measures related to the equipment but cannot exclude the occurrence of accidents.
Therefore, the manufacturer and distributors shall not be liable for any direct or
indirect, joint or several liability for any incidental or consequential damages which
may occur. For detailed health and safety information, the relevant professional
agencies and manufacturers of consumables such as welding materials should be
contacted.
Warranty exclusions:
✓Consumable items such as cutting nozzles, electrodes and current dividers.
✓Machine damages caused by incorrect voltage input or power surges.
✓Machine or parts malfunction owing to incorrect connections or user operation.
✓Illegal disassembly or re-fitment of the machine without permission of the
manufacturer, resulting in damage or malfunction.
✓Accidental damage during shipment, transportation and storage.
✓Damage owing to incorrect handling, natural disaster and other force majeure
occurrences.

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CONTENTS
Safety precautions..........................................................................3
Warnings.........................................................................................4
Packaging and transportation ................................................................7
Parameters.............................................................................................8
Product description.................................................................................8
Working principle..................................................................................11
Installation and wiring...........................................................................12
Brief instruction for cutting operation....................................................14
Maintenance .........................................................................................16
Common machine malfunctions and solutions ....................................16

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Safety precautions
The equipment is designed for use by qualified personnel who have completed
professional training and have obtained a qualification certificate as a welder/cutter.
The operator shall have sufficient professional knowledge of welding, cutting and
circuitry. The machine should be operated only after having read and fully understood
all the safety precautions and warnings contained in this manual and those generally
applicable to welding operations. The risk of personal injury and damage to
equipment is reduced by safety precautions being followed when using tools and
equipment. This machine is easy to operate and the selection of its functions is
straight forward. Improper use and maintenance will reduce the safe operation of the
machine and the following safety precautions must be followed:
1. The operator must have the relevant certificate before operating the equipment.
2. A qualified professional should be employed to ensure that the machine and all
cables are properly connected, grounded and installed.
3. Personal protective equipment approved by the local safety authority must be
used. All relevant safety procedures must be adhered to.
4. Before operation insulation layers on wires and cables as well as connection
sequences should be inspected and corrected if required.
5. Repairs and maintenance should be carried out by qualified technicians only
after the machine has been disconnected from the electricity supply.
6. Operating the machine in a humid environment may result in a short circuit or
may cause an electric shock to the operator.
7. Modifications to the machine or equipment are not allowed.
8. The disposal of scrap machine parts and equipment must comply with local
regulations.

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Warnings
Welding and cutting is a special type of work, with a certain degree of danger.
Professional training, correct operation and necessary protective measures can
effectively avoid and reduce the damage and loss caused by machine accidents.
Personal Safety Protection
Welding and cutting operations generate noise, bright light and
high-temperature sparks which will cause harm to human hearing,
eyes and skin unless personal protective measures are
implemented and proper operational instructions are adhered to.
1
A helmet with the correct shading filter will protect eyes, face, neck and ears
from bright (radiating) light and arc sparks. This applies to the operator as
well as any person observing the welding or cutting operation.
2
Wear flame retardant gloves, overalls, shoes and aprons to protect against
thermal radiation, sparks and hot metal particles.
3
Hot sparks and metal fragments can cause skin damage. Avoid clothes with
front pockets and button-up sleeves and collars.
4
Use appropriate flame-retardant shields or curtains to protect bystanders
from arc radiation and high temperature sparks. Bystanders also need to
wear a protective helmet fitted with a shading filter to protect face and eyes
or a pair of spectacles fitted with shading filters if only eye protection is a
requirement.
5
Avoid burns and scalds by not touching a welded work piece with bare
hands.
Fire and explosion precaution
Welding and cutting operations generate high-temperature flames
and arc which can cause fires and explosions. The same applies to
welding slag and sparks.
1
Operators and bystanders must be protected from arc, sparks and metal
fragments.
2
The welding/cutting area should be free from flammable and explosive
materials. Should these materials be required in the welding/cutting process,
flame retardant covers should be applied.

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3
Care should be taken to avoid fire hazards from cracked floors and walls.
4
Welding and cutting on sealed gas tanks will cause explosions. These
operations are prohibited.
5
Welding and cutting areas must be provided with adequate fire extinguishing
equipment. Regular testing for efficiency of this equipment is compulsory as
is training of staff in the use of the equipment.
6
Once the welding/cutting operation is completed, check for any high
temperature spark or metal which might cause a fire and immediately
dispose of it. If necessary, seek help from a firefighter.
Electricity hazards
Electric shock can cause serious injury or even death to the
individual when contact is made with live wires. Humid conditions
can add to the risk and great care should be taken when welding or
cutting machines are used in these conditions.
1
Reliable grounding of machine and work piece as well as a secure ground
clamp, is important.
2
Insulation layers of electric wires and cables must be checked regularly for
wear and replaced if necessary.
3
All equipment used and clothing worn during the welding/cutting operation
should be free from moist and kept dry.
4
Do not make direct body contact with any live electrical parts.
5
Wearing rubber-insulated shoes and standing on an insulated platform
greatly reduce the risk of accidental shock.
6
Refrain from replacing the ground cable on the machine with wires not
suitable for the task.
7
The machine operates on high voltage and capacitors remain charged even
after power is switched off. Removing covers for maintenance procedures
must only be executed by qualified professionals.
Effects of Electromagnetic Fields
Electric current flowing through a conductor produces magnetic
fields (EMF). The discussion on the topic of the effects of EMF on
the human body is ongoing worldwide and up to the present no
evidence has been forthcoming proving negative effects on health.

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However, it would be wise to limit exposure to EMF as far as
possible and the following procedures are suggested:
1
Welders and cutters with cardiac pacemaker implants should obtain medical
advice on the effects of EMF on the implant.
2
Users should minimise the possibility of electromagnetic field damage
through the following methods
2.1
Route the electrode and ground cables together and, where possible, secure
them with tape.
2.2
Do not wrap wires and cables around arms or coil power cables around body
parts. If possible, keep cables away from the body.
2.3
Keep the distance between the ground clamp to the workpiece and the
electrode as short as possible.
2.4
Keep a safe distance between the operator and the welding/cutting machine.
Protection from fumes and gases
During the welding or cutting process, fumes can be produced
which may be detrimental to health.
1
The working area should be well ventilated and welding/cutting activities
should not be executed in confined spaces. Eye, nose or throat discomfort
can be the result of inadequate ventilation.
2
Welding and cutting in or near locations where chlorinated hydrocarbon
vapours are produced such as degreasing, cleaning and spraying
operations, should not be undertaken since phosgene, a highly toxic gas as
well as other irritants can be reaction products.
3
The industry offers a variety of respiratory masks and must be used in
conditions where clean breathing air is required.
Gas Cylinder Safety
Gas leaks can occur on cylinders connected to welding/cutting
operations if the system is not properly managed and maintained.
A ruptured cylinder or relief valve can cause serious injury or can
even be fatal.
1
Gas cylinders should be kept away from extreme temperatures and fire
sources. Scratching on cylinder walls with hard objects should be avoided.

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2
A pressure regulator should be installed on the gas cylinder in use in
accordance with the manufacturer's operating instructions. Quick-coupling
connectors must not be used and gas hose fitting should be tested for leaks.
3
Gas cylinders must always be kept upright and chained or belted to a
cylinder trolley, base, wall, post or shelf. Never fix a gas cylinder to a
worktable or machine: It can become party to an electrical circuit and
explode.
4
Ensure that the cylinder valve is closed when not in use. If there is no hose
connected to the cylinder regulator then cover the outlet with a dust cap.
Protection Against Moving and Rotating Parts
Moving parts, such as fans, rotors and belts, can be
hazardous.
1
Ensure that all protective covers, doors and panels on the machine are
closed or securely intact before starting an operation.
2
Ensure that maintenance on machines is only carried out by qualified
technicians.
3
Ensure that hands, hair, clothing and tools are safely out of range from
moving and rotating parts.
Packaging, Transportation and Handling
1. Pay attention to and comply with packaging, storage and transportation
instructions which are clearly identified on the containers.
2. Always handle all containers with care.
3. Equipment must be stored in waterproof, moisture proof and well-ventilated
facilities within the temperature range -25°C - 55°C.

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Parameters
Product Description
The plasma cutting machines in this range invert 50Hz power supply to a
high-frequency, high-voltage power supply of up to 200KHz. The inversion process is
facilitated by a powerful IGBT device followed by step-down rectification and
pulse-width modulation (PWM) technology producing a high-power DC output
suitable for cutting. The advanced inverter technology allows the construction of a
smaller volume and light-weight, stable and reliable transformer with a 30% improved
efficiency. This series of plasma cutting machines produce a concentrated, stable,
powerful and fast-cutting arc at an ionized state of 10000-15000°C. The result is a
super-smooth cutting surface on a reduced heat affected area which facilitates further
processing.
Model
CUT-70I
CUT-80I
CUT-100I
CUT-120I
Item
Value
Rated input voltage：
AC 3PH-380V±15% 50/60Hz
Rated input power:
10.0KVA
14.0KVA
16.5KVA
20KVA
Rated input current:
13.9A
21.5A
25.5A
32.5A
Rated duty cycle:
60%
Output current range:
30-70A
30-80A
30-100A
30-120A
Open circuit voltage:
285V
285V
300V
300V
Insulation grade:
F
IP grade:
IP21S
Max. cutting thickness :
25mm
30mm
40mm
45mm
Package dimensions :
595*315*530
（mm）
710*385*630（mm）
N.W./G.W.（kg）:
23.5/30.0
30.0/38.7
31.3/40.0
32.3/41.0

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The machine can be used for cutting various metals including stainless steel,
aluminium, copper, cast iron and carbon steel. A narrow and clean-cut seam is
produced with less effort and low deformation. The machines are suitable for use in
the manufacturing industry, installation and maintenance, plate cutting, cutting holes,
patching, beveling, pipe cutting and various other metal cutting applications.
The machines in this series are manufactured in accordance with IEC60974-1<Arc
Welding Equipment-Part 1: Welding Power Sources>, Safety Requirements for Arc
Welding Equipment.
1. Features of this cutting machine series:
1.1. Arc ignition system uses high-frequency oscillation to create a pilot arc which
allows an easy non-contact start arc.
1.2. Air flow detection ensures that a sufficient volume is delivered before cutting is
commenced.
1.3. Accurate preset cutting currents ensure energy efficiency and allow for cutting
various material thicknesses.
1.4. Overheat, over-current and over-voltage protection facility.
1.5. Adjustable Pre-flow and post-flow cooling.
1.6. The IP21S protection grading guarantees reliable operation even under harsh
environmental conditions.

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2. Appearance Diagram:
Panel:
1
Control panel
2
Cutting torch control socket: Connects the control line of the cutting torch
switch.
3
Air and electric hybrid socket: Connects to the air and electric plug to the
cutting torch.
4
Pilot arc terminal block: Connects to the pilot arc line of the cutting torch.
5
Cutting cable coupling device (positive pole): Connects to the workpiece
via the earth clamp.
8
6
9
7
1
1
2
1
3
1
4
1
5
1

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6
Gas check & cut selection button: When the 'AIR’ mode is selected, air is
ejected from the torch head and it is determined automatically whether the air
volume is sufficient to ensure a smooth cutting process. When restarting the
machine, it is advisable to remove overnight condensation from the torch by
blowing for approximately 30 seconds through the cutter handle in the 'TEST'
position. This action will facilitate the starting process and extend the life of the
cutter nozzle. Selection of the 'Cut' mode allows normal cutting.
7
2T/4T selection: Switch between 2t and 4T modes.
2T - two-stroke mode: When this mode is selected, press the button on the
torch handle, ignite the arc and continue cutting with the button depressed.
Release the button when the cut is complete.
4T - four-stroke cutting mode: When this mode is selected, press the button
on the torch handle, ignite the arc, release the button, complete the cut and
press the button again.
8
LED display: Shows real-time current output and values during parameter
settings
9
Parameter selection and adjustment knob: Press the knob to select pre flow
time, post flow time or cutting current for adjustment. Once the corresponding
indicator lights up to your selection, turn the knob to set the parameter.
Working Principle
1. Working principle diagram
1.1. A bridge rectifier converts AC to DC;
1.2. Controlled by PWM, the IGBT inverts the DC to 20kHz AC and transmits it
1through a high-frequency transformer;
1.3. After secondary rectification the output cutting current is sufficient to meet the
cutting requirements;

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1.4. The in-time protection circuit provides signals to the PWM warning for overheat
and over-current situations;
1.5. A closed-loop control system ensures a good anti-grid fluctuation ability and an
excellent cutting performance.
Installation and wiring
1. Location Requirements
1.1. The machine should not be installed in an area where it is exposed to direct
sunlight or rain but where the humidity is as low as possible and the ambient
temperature is within the range of -10°C - 40°C.
1.2. The machine should be installed on a flat, preferable level surface but, in any
case not on a surface with an inclination of more than 10 degrees.
1.3. The machine should not be operated in a work station exposed to wind. Should a
windy environment be unavoidable, suitable screening should be installed.
1.4. In order to allow for efficient ventilation, a clear space of at least 20cm should be
allowed in front of and behind the machine as well as at least 10cm at each side.
2. Requirements of power input
The power supply waveform should be the standard sine wave with rated voltage
AC380V±15% 50Hz. Three phase, phase unbalance voltage should be ≤5%.
Model
CUT- 70I
CUT- 80I
CUT- 100I
CUT- 120I
Parameters
Value
Power supply：
AC 3PH-380V±15% 50/60Hz
Rated input current：
13.9A
21.5A
25.5A
32.5A
Input cable：
≥2.5mm2
≥2.5mm2
≥4.0mm2
≥4.0mm2
Output cable：
10mm2
10mm2
16mm2
16mm2
Ground cable：
≥2.5mm2
≥2.5mm2
≥4.0mm2
≥4.0mm2

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3. Main Power Supply Connection
Pay attention to prevent electric shock
Wear goggles
Warning: Take note of the following when the cutting machine is connected to
the main power supply:
3.1. The connection must be carried out by a qualified electrician or technician.
3.2. The connection must be in compliance with national and local regulations.
3.3. Before the connection is carried out, the main power supply to the control box
must be switched off.
3.4. The yellow green earth wire of the machine must be reliably connected with the
grounding cable.
3.5. Ensure that the required power supply of the machine (as printed on its
nameplate) corresponds to the main power supply.
3.6. The connection screws on the terminal block must be tight ensuring a solid
connection between the machine cable wires and the main power supply.
3.7. The correct wiring procedure is explained in the following diagram:
Wiring of three phase 50/60Hz welding machine
2b
3
7
6
4
5
1
2c
2d
2a

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No.
Item
No.
Item
1
Cutting machine
3
Terminal block
2
Power cord
4
Electric control box
2a
Live wire L1
5
Earth wire terminal block
2b
Live wire L2
6
GND
2d
Earth wire
Brief instruction for cutting operation
1. Before cutting
1.1. Wear the necessary and approved personal protective equipment (PPE) required
for the task: Such as helmet, mask, goggles, earplugs, protective clothing, gloves
and insulating shoes.
1.2. Ensure that the electrical grid connected to the cutting machine complies with the
allowable power supply of the machine.
1.3. Ensure that insulating layers of all wires and cables are sound and correctly
connected to the machine.
1.4. Ensure that the machine is freely vented and that the vents on the machine are
not obstructed.
1.5. Connect and tighten the air hose to the inlet on the rear panel of the machine.
Ensure the air source provides dry air with sufficient pressure and flow rate.
1.6. Install and tighten the air and electricity connectors of the cutting torch to the
corresponding interfaces on the cutting machine panel. Connect the air plug and
pilot arc wire securely to the corresponding interfaces on the machine panel.
Insert the quick-plug of the work cable into the panel socket and tighten
clockwise. Secure the workpiece to the other end with the ground clamp.
1.7. Turn the machine on - the LED lights up and the fan becomes operational.
1.8. Set the parameters for the cutting job and commence cutting.
1.9. Complete the cutting operation following the normal procedure. During the
operation the cutting parameters can be adjusted to suit the situational demands.
1.10. After completion of the cutting operation, turn off the power using the switch on
the rear panel of the machine. Then switch off the power at the main distribution
box.

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2. Schematic Diagram
No.
Item
No.
Item
1
Cutting power supply
4
Earth clamp
2
Air pressure reducing valve
5
Workpiece
3
Air compressor
6
Torch
3. Setting cutting parameters
Cutting current
Max cutting
thickness(mm)
Quality cutting
thickness(mm)
40A
10
6
50A
15
10
60A
20
15
70A
25
20
80A
30
20
100A
40
25
120A
45
30
3
6
4
1
5
2

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Maintenance
Safe operation of the machine is dependent on regular maintenance and replacement
of parts, if required.
1. Daily Precautionary Checks:
1.1. Abnormal vibrations, sounds or odours.
1.2. Signs of overheating on cable connections.
1.3. Smooth fan operation.
1.4. Power switch efficiency.
1.5. Proper cable connection, insulation and damage.
1.6. Cable integrity and insulation.
2. Three to six monthly check list
Remove the side cover plate and clean off all parts with dry compressed air. Since the
effective cooling of the machine is dependent on a designed air flow pattern, it is
important to return the side cover plate after the cleaning operation. Not paying
attention to this detail, will result in over-heating of and consequent damage to the
transformer and semi-conductor parts.
Common machine malfunctions and solutions
Warning：
Machine maintenance and repair must be carried out by qualified technical
individuals. The operating voltage in the machine can be up to 600V and it is
important that power be cut at the machine and at the control box before
covers are removed and repairs carried out. A cooling-down period of at least 5
minutes is required before commencement of any inspection and repairs. This
will allow the capacitor to fully discharge.

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1. Inspection Before Overhaul
1.1. Check if the line voltage on the single-phase power supply is within the range of
360V - 440V and, that all phases on a three-phase system are intact.
1.2. Check if the power cable as well as the earth wire is firmly connected.
1.3. Check whether the wiring connections are correct and firmly connected.
2. Common Machine Problems and Troubleshooting
No.
Problem
Root cause
What to do
1
The “machine-on”
light is off. No
digital display. Fan
doesn’t work. No
no-load output.
Power switch was turned off
or damaged
Check or replace the
power switch
Power supply phase missing
Check power input if phase
loss
Whether there is electricity in
the grid connected to the
output cable
Check the grid voltage
Filter capacitor and bridge
rectifier have been damaged,
resulting in failure to start the
machine
Replace filter capacitor
and bridge rectifier
Control board damaged
Replace control board
2
No digital display
or the ''machine
on'' light not
active. Fan
operational. No
load output.
Digital display meter
damaged.
Replace meter or indicator
light.
Loose wire connection.
Check and reconnect the
wire.
Control board damaged.
Check problem on control
board or replace control
board.

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No.
Problem
Root cause
What to do
3
The ''machine-on''
light is lit. Digital
display meter
functional and fan
operational. Error
indicator light is
off. No
high-frequency
discharge sound
when torch trigger
is activated. No
no-load output.
Insufficient torch-trigger
contact and the torch-trigger
connecting wire is loose.
Re-connect the torch
trigger and fasten the
torch-trigger connecting
wire.
Control wire on the cutting
torch broken or torch trigger
damaged.
Replace torch trigger.
Problems with control circuit.
Check control circuit.
4
Fan, digital display
meter and
solenoid valve
operational. No
pilot arc output.
Error indicator
light off. No
high-frequency
discharge sound.
Poor contact between the
primary wire of the arc ignition
coil and the arc ignition plate.
Fasten the connecting
wire.
Oxidized spark gap.
Remove oxide film on
spark gap surface.
Damaged high-frequency arc
ignition device.
Determine which parts are
damaged and replace.
Poor contact of high
temperature wire terminal of
main transformer.
Tighten the terminal
blocks.
5
Fan, digital display
meter and
solenoid valve
operational. No
pilot arc output.
High-frequency
discharge sound.
Poor interface contact of pilot
arc wire on torch.
Fasten the connection of
pilot arc wire
Poor connection of the
connecting wire inside the
machine.
Check and re-tighten the
connecting wire inside the
machine
High-frequency board or
control board damaged.
Replace high frequency
board or control board

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No.
Problem
Root cause
What to do
6
The ''machine on''
light is lit. Digital
display meter and
fan operational.
No high-frequency
discharge sound
when torch trigger
is pressed. Gas
out. No load
output.
Poor contact on primary wire
of arc ignition coil.
Fasten the connecting wire.
Oxidation of the spark-gap
assembly or spark gap too
great.
Remove oxide layer from
spark gap surface or
re-adjust the gap to 1mm.
Damaged high-frequency arc
ignition device.
Determine which parts are
damaged and replace.
Poor contact of high
temperature wire terminal of
main transformer.
Tighten the terminal blocks.
7
The ''machine
light'' is lit. Digital
display and fan
operational.
Overheating and
over-current lights
are lit. No no-load
output.
Over-current protection.
Shut off the machine and
reboot.
Overheating protection.
Auto-recovery after 5 to 10
minutes.
Failure of inverter circuit
Replace IGBT
Secondary rectifier damaged.
Replace IGBT tube.
Failure of feedback circuit.
Control board problem.
Replace control board.
8
During the cutting
process the
current is unstable
or not controlled by
the potentiometer.
Current regulating
potentiometer faulty.
Replace the potentiometer.
Bad contact at the connecting
wire of the current regulating
potentiometer or a loose
terminal of the connecting
wire.
Check the connecting wire
and fasten the terminal.