Yeswelder CUT-55DS User manual

CUT-55DS
AIR PLASMA CUTTER
Note: Please read this user's manual carefully before using this product.

SAFETY
Precautions for installation
Beware of electric shock!
Install grounding device according to application standard.
Do not touch live parts with naked skin, wet gloves or wet clothes.
Be sure you are insulated from ground and workpiece.
Cover the cover plate of the machine before power on to avoid an
electric shock.
Confirm the safety of your working position.
Beware of fire hazard!
Please install the machine on non-combustible materials to avoid
a fire.
Make ensure there are no inflammables near the cutting position
to avoid a fire.
Beware of explosion!
Do not install the machine in an environment with explosive gas
to avoid an explosion.
Replacing the components can be dangerous.
Only professionals can replace the components of the machine.
Make sure the connecting wires inside the machine are correctly connected after replacing
the PCBs, and then the machine can be run. Otherwise, there is a risk of damage to
property.
Make sure there are no foreign bodies such as wire leads, screws, gaskets and metal bars
falling into the machine inside when replacing the components.

Pay attention to the following when discarding the cutting machine:
Burning the plastic parts such as the front panel may produce poisonous gas.
Dispose it as industrial waste.
Burning the electrolytic capacitors in the main circuit or on the PCBs may cause an explosion.
Smoke-may be harmful to your health!
Keep your head away from the smoke to avoid inhalation of waste gas
in cutting.
Keep the working environment well ventilated with exhaust or ventilation
equipment when cutting.
Arc radiation-may hurt your eyes and burn your skin!
Use proper mask and wear protective clothing to protect your eyes and
body.
Use proper mask or curtain to protect onlooker from being injured.
Magnetic field can make cardiac pacemaker a bit wonky!
Stay away from the power source to reduce the affect of magnetic filed.
Improper use and operation may result in a fire or an explosion!
Cutting spark may result in a fire, so please make ensure there are no
inflammables near the cutting position, and pay attention to fire safety.
Ensure there is fire extinguisher nearby, and make sure someone has
been trained to operate the fire extinguisher.
Do not weld closed container.
Do not use this machine for pipe thawing.
Hot workpiece can cause severe scald!
Do not touch hot workpiece with bare hands.
Cool the cutting torch for a while after continuously working.
Excessive noise does great harm to people’s hearing!
Wear ear covers or other hearing protectors when cutting.
Give warning to onlooker that noise may be potentially hazardous to
hearing.
Moving parts may injure your body!
Please keep away from moving parts (like fan).
Each door, panel, cover, baffle plate, and protective device the like
should be closed and located correctly.
Seek professional support when trouble strikes!
When trouble strikes in installation and operation, please inspect
according to related contents in this manual.
If you still cannot understand fully, or you still cannot solve the problem,
People with cardiac pacemaker should consult the doctor before carrying
out cutting.
please contact the dealer or the service center to obtain professional
support.
Precautions for discard
Precautions for operation

TABLE OF CONTENTS
GENERAL DESCRIPTION
1.1 Model coding.......................................................................................................................1
1.2 Technical parameters..........................................................................................................1
1.3 Size and weight ..................................................................................................................2
1.4 Composition and configuration of the cutting machine system...........................................3
1.5 Functions and characteristics of the cutting machine..........................................................4
1.6 System characteristics.........................................................................................................5
INSTALLATION AND CONNECTION
2.1 Installation requirements......................................................................................................6
2.2 Precautions...........................................................................................................................7
OPERATION
3.1 Panel functions......................................................................................................................9
3.2 Digital panel ..........................................................................................................................10
3.3 Operation method..................................................................................................................11
3.4 Notes for cutting operation.....................................................................................................11
3.5 Cutting parameters table........................................................................................................12
3.6 Replacement of electrode and nozzle....................................................................................12
MAINTENANCE
4.1 Daily maintenance..................................................................................................................13
4.2 Periodic check.........................................................................................................................14
TROUBLESHOOTING....................................................................................................................15

35
1
1. GENERAL DESCRIPTION
1.1 Model coding
Product code
Code for rated output current
Inverter air plasma cutter
Figure 1-1: Model coding
1.2 Technical parameters
Table 1-1: General technical parameters
1. GENERAL DESCRIPTION
CUT XX (XXXX)
CUT 55DS
7.4
35/94
100
265
HF
0.7
Single-phase AC220V 50Hz
20
0.5
Air cooling
IP21S
85
F
Single-phase AC110V 50Hz
29
55/96
60
265
Rated input power supply
Rated output (A/V)
Rated duty cycle(%)
No-load voltage(V)
Efficiency (%)
Cooling mode
Insulation grade
Power factor
Rated input capacity (KVA)
Output current range (A)
Arc ignition mode
Post-flow time (S)
Gas pressure range (Mpa)
Enclosure ingress protection

2
1.3 Size and weight
Table 1-2: Overall size and weight of the machine
Figure 1-2: Appearance and size of the machine (Unit: mm)
1. GENERAL DESCRIPTION
Weight(Kg)
Model
Overall size (L*W*H)
CUT 55DS
407X160X280 mm
7.8

第一章 产品概述
3
1.4 Composition and configuration of the cutting machine system
1) Composition
Figure 1-3: Composition of the cutting machine system
1. GENERAL DESCRIPTION

4
1.5 Functions and characteristics of the cutting machine
1. GENERAL DESCRIPTION
Advanced digital control mode
Plasma cutting machine CUT 55SD adopts international leading MCU intelligent digital control
technology, and all its major parts are performed through software. It is a digital control plasma
cutting machine, improved a lot in its function and performance when compared with the traditional
plasma cutting machine.
With PWM technology and high power component IGBT, it inverts the DC voltage, which is rectified
from 50Hz/60Hz input AC voltage, to 30K~100KHz AC high voltage. Then the voltage is dropped
and rectified to output the high power DC power supply for cutting. The machine adopts switching
power supply inverter technology, greatly reducing the volume and weight of the plasma cutter,
and obviously enhancing the conversion efficiency. Switching frequency is beyond audiorange,
which almost eliminates the noise pollution.
Good consistency and stable performance
Generally speaking, for a cutting machine with analogue circuit control or with analogue circuit &
digital circuit control, the performance characteristics are decided by the parameters of various
components. Cutting performance of the machines differ as a result of the inconsistent parameters
of the components, so even for the cutting machines of the same brand, their parameters often
differ from each other. In addition, cutting performance of the machine may change on some
extent, since parameters of the components may vary according to the environment such as
temperature and humidity, etc.
One of the characteristics of digital control is that it is not sensitive to the change of parameters;
the performance of cutting machine will not be affected by the change of the parameters of
certain parts. Therefore, the consistency and stability of digital control cutter is better than that
of traditional cutter.
Powerful cutting performance
This machine is economic and practical since it can cut metals by adopting compressed air as
the plasma gas source. The cutting speed has increased by 1.8 times when compared with
oxyacetylene cutting. It can cut thick steel plates such as stainless steel, copper, cast iron and
aluminum conveniently and quickly. It is easy to ignite arc by adopting HF arc ignition mode,
and post-flow function is available. With simple operation and high cutting speed, smooth cutting
surface can be obtained, and polishing is unnecessary.
Advanced inverter technology
The forward-looking design concept of this machine and the application of a large number of
advanced and mature technologies can protect user’s investment to the greatest extent.
This is a digital plasma cutting machine with perfect function, high performance and advanced
technology. CUT 55SD is an ultra-portable plasma cutting system suitable for a variety of application
requirements. It can be used in handheld cutting and robot cutting as well. CUT 55DS can cut
conductive metal, such as low carbon steel, stainless steel and aluminum. The cutting thickness
can reach up to 20 mm and perforating thickness can reach up to 12 mm.

5
1.6 System characteristics
Figure 1-4: Duty cycle
Figure 1-5: Output characteristic curves
1) Duty cycle
2) Output characteristics
External characteristic of maximum output
External characteristic of minimum output
Relationship with ratedload
1. GENERAL DESCRIPTION
Rated duty cycle refers to the percentage of the normal work time of the machine under rated
maximum current holding in the period when taking 10 minutes as a period. The rated duty
cycle of this machine is 35%.Using the cutting machine continuously overrunning the rated load
may lead to overheating of the machine, and frequently using the machine overrunning the rated
load may accelerate the aging of the machine or even burn the machine.
U2(V)
U0
I2(A)
0
Q(%)
100
I(A)
80
60
40
20
150120
90
60
30
0

6
INSTALLATION AND CONNECTION
2.1 Installation requirements
In order to ensure personal safety and avoid electric shock, please send the product power plug
the grounding ang wiring box grounding device,reliable giounding protection.
1) Connection of input cable
A primary power supply cable is available for this cutting machine. Connect the power supply
cable to the rated input power. The primary cable should be tightly connected to the correct
socket to avoid oxidization. Check whether the voltage value varies in acceptable range with a
multi-meter.
The cross section of the leads used in the switching box should meet the requirements of the
maximum input capacity of the machine.
2) Connection of output cable
2. INSTALLATION AND CONNECTION
CUT 55DS should be located close to the corresponding power socket.
Line disconnecting switch
Install a line disconnecting switch at each power supply,
so that the power supply can be cut off immediately in
case of an emergency. The disconnecting value of the
switch should be equal to or greater than the continuous
rating of the fuse. In addition, the switch should have the
following feature:
· The power is cut off when the switch is at “OFF” position.
Connection of cutting torch
Connect the center plug on the cutting torch
to the center socket of the power supply, and
tighten It clockwise to avoid gas leakage.
Connection of earth cable
Insert the quick plug on the earth cable into
the output terminal “+” on the front panel of
the machine, and tighten it clockwise.

7
2. INSTALLATION AND CONNECTION
3) Operation of the reducer valve
Figure 2-1: Embedded filter reducer
The embedded filter reducer is properly set when leaving factory, and users do not need to set
it themselves in general.
If users need to set the embedded filter reducer, the machine cover should be opened as shown
in the above figure. Steps are as follows: start the gas flow; lift the pressure control knob upward;
adjust the gas pressure to the desired value by rotating the knob (rotate to “+” direction to increase
gas pressure; rotate to “-” direction to reduce gas pressure); press down the pressure control
knob to get the knob locked. The water can be drained automatically for auto-drain function is
available for the embedded filter reducer.
4) Installation of the cutting torch
Insert one end of the electrode into the
torch head.
Insert the other end of the electrode into
the distributor.
Connect the nozzle with the electrode and
distributor.
Connect the protective sleeve with the
nozzle, screw it into the torch head, and
tighten it.
Figure 2-2: Installation of cutting torch head
2.2 Precautions
1) Make sure the place to install the machine can bear the weight of the cutting machine.
2) Do not install the machine at places where water droplet splash may be produced, such as
near water pipes.
3) Cutting should be carried out in dry environment with humidity of 90% or less.
4) The temperature of the working environment should be between -10℃ and 40℃.
5) Avoid cutting in the open air unless sheltered from sunlight and rain. Keep it dry at all times
and do not place it on wet ground or in puddles.
6) Avoid cutting in dusty area or environment with corrosive chemical gas.
7) Do not carry out cutting with the cutting machine placed on a platform with a pitch greater
than 10°.
Plasma handle
Electrode AG-60
External nozzle AG-60 with groove
Electrode nozzle AG - 60
Plasma spear AG - 60

8
2. INSTALLATION AND CONNECTION
Overcurrent/overvoltage/overheating protection circuit is installed in this machine. When the mains
voltage, output current or inner temperature exceeds the set standard, the machine will stop
automatically. However, excessive use (e.g. too high voltage) of machine may also damage the
machine, so please note:
This cutting machine can create powerful cutting current and has strict cooling requirements that
cannot be met with natural ventilation. Therefore the built-in fan is very important in enabling the
machine to work stable with effective cooling. The operator should make sure that the louvers be
uncovered and unblocked. The minimum distance between the machine and nearby objects
should be 25cm.
This machine is of automatic mains voltage compensation, which ensures that the cutting current
varies within the given range. In case that the input mains voltage exceeds the tolerance value,
it would possibly damage the machine. The operator should understand this circumstance fully
and adopt relevant precautions.
Remember to observe the max load current at any moment (refer to the corresponding duty
cycle). Make sure that the cutting current should not exceed the maximum load current. Overload
could obviously shorten the machine's lifespan, or even damage the machine.
A sudden halt may occur with the yellow LED on the front panel on while the machine is of
over-load status. Under this circumstance, it is unnecessary to restart the machine. Keep the
built-in fan working to lower the temperature inside the machine. Cutting can be continued after
the inner temperature falls into the standard range and the yellow LED is off.

Power switch
To control the ON/OFF of the input
power of the machine.
Figure 3-1: Front panel
Figure 3-2: Back panel
1
2
3
4
No. Part name Function
Current
control knob To adjust the output current value.
Quick socket To connect the earth cable.
To connect the cutting torch
Power cable To connect the power supply.
Gas-electric
connector
1
2
No. Part name Function
1
2
3
4
3
Cooling fan
Forced air cooling
2T/4T key
Two-step and Four-step" Welding Mode
Conversion
1
2
3
9
3. OPERATION
OPERATION
3.1 Panel functions of CUT55DS

10
3. OPERATION
3.2 Digital Panel of CUT 55 SD
No.
1
2
3
4
5
6
7
Symbol Function
Power indicator: It illuminates when the machine is powered on,
and it glitters after arc is successfully ignited.
Overheating indicator: It illuminates when the working temperature
of the IGBT is overly high. Meanwhile, the machine stops working.
Torch protection indicator: It illuminates when the consumable
parts of the machine are not well installed or the torch head is
shorted. Meanwhile the machine stops working.
2T indicator: It illuminates when the machine is under 2T status.
4T indicator: It illuminates when the machine is under 4T status.
Gas-check indicator: It illuminates when the machine is under
gas-check status. At this moment, the machine cannot cut.
Metal mesh cutting indicator: The machine can cut metal
mesh when this indicator illuminates.

11
3. OPERATION
3.3 Operation method
1) Turn on the power switch of the machine, and the power indicator illuminates.
2) Select proper working mode and proper function. There are two working modes available on
the machine panel: 2T and 4T. There are two functions available: normal cutting and metal mesh
cutting. The electrode and nozzle are more easily to wear out in metal mesh cutting.
3) Push the torch trigger on the cutting torch, the cutting machine works.
4) Set cutting current according to the thickness of workpiece.
5) Bring the copper nozzle of the cutting torch into contact with the workpiece (For models with
pilot arc function, keep a distance of about 2mm between the copper nozzle of the torch and the
workpiece.), and then push the torch trigger. After the arc is ignited and started, raise the cutting
torch to the position about 1mm above the workpiece, and start cutting.
3.4 Notes for cutting operation
It is recommended not to ignite the arc in the air if not necessary, for it
will shorten the lifespan of the electrode and nozzle of the torch.
It is recommended to initiate the cutting from the edge of workpiece,
unless penetration is needed.
Ensure spatters fly from the bottom of workpiece while cutting. If spatters
fly from the top of workpiece, it indicates that the workpiece can not be
fully cut because the cutting torch is moved too fast or the cutting current
is too low.
Keep the nozzle slightly touching the workpiece or keep a short distance
between the nozzle and workpiece. If the torch is pressed against the
workpiece, the nozzle may stick to the workpiece, and smooth cutting
is unavailable.
For cutting round workpiece or to meet precise cutting requirement,
molding board or other assistant tools are needed.
It is recommended to pull the cutting torch while cutting.
Keep the nozzle of cutting torch upright over the workpiece, and check
if the arc is moving with the cutting line. If the space is not enough,
don’t bend the cable too much, step on or press upon the cable to avoid
suffocating of gas flow. The cutting torch may be burned because the
gas flow is too small. Keep the cutting cable away from edge tools.
Clean up the spatters on the nozzle timely, for it will affect the cooling
effect of the nozzle. Clean up the dust and spatters on the torch head
after using everyday to ensure good cooling effect.

12
3. OPERATION
The workpiece is not cut fully. This may be caused by:
The cutting current is too low.
The cutting speed is too high.
The electrode and nozzle of the torch are burned.
The workpiece is too thick.
Molten slag drops from the bottom of workpiece. This may be caused by:
The cutting speed is too low.
The electrode and nozzle of the torch are burned.
The cutting current is too high.
3.5 Cutting parameters table
Select proper current according to the cutting parameters table, workpiece material, cutting
thickness and cutting speed, etc. (The figure in the below table is an approximation. )
Table 3-1: Cutting speed (m/min) when cutting current is 55A
3.6 Replacement of electrode and nozzle
When the phenomena below occur, the electrode and nozzle should be replaced. Otherwise,
there will be strong arc in the nozzle, which will break down the electrode and the nozzle, or even
burn the torch. Nozzles of different models are different, so ensure the nozzle is of the same
model when replacing it.
Electrode wear＞1.5mm
Distortion of the nozzle
Cutting speed declining, arc with green flame
Difficult in arc ignition
Irregular cut
9876543210.1
0.4
0.4
0.4
1.5
1.5
1.5
1.5
8
8
8
8
0.75
0.75
Cutting thickness (mm)
Mild steel
Galvanized steel
Stainless steel
Aluminum
Brass
Red copper

13
MAINTENANCE
WARNING
The power of the switching box and the cutting machine should be shut down before
daily checking (except appearance checking without contacting the conductive body)
to avoid personal injury accidents such as electric shock and burns.
Table 4-1: Daily checking of the cutting machine
Items Checking requirements Remarks
Front panel
Back panel
Cover
Chassis
Routine
Whether any of the components are damaged
or loosely connected;
Whether the output quick sockets are tightened;
Whether the abnormity indicator illuminates.
Whether the input power cable and buckle are
in good condition;
Whether the air intake is unobstructed.
Whether the bolts are loosely connected.
Whether the screws are loosely connected.
Whether the machine enclosure has color fading
or overheating problems;
Whether the fan sounds normal when the machine
is running;
Whether there is abnormal smell, abnormal
vibration or noise when the machine is running.
Earth cable
Cutting cable
Whether the grounding wires (including workpiece
GND wire and cutting machine GND wire) break off.
Whether the insulating layer of the cable is worn,
or the conductive part of the cable is exposed;
Whether the cable is drawn by an external force;
Whether the cable connected to the workpiece
is well connected.
Items Checking requirements Remarks
Table 4-2: Daily checking of the cables
If unqualified, check the interior
of the machine, and tighten or
replace the components.
If unqualified, tighten or replace
the components.
If abnormal, check the interior
of the machine.
If unqualified, tighten or replace
the components.
4. MAINTENANCE
Use appropriate methods
according to the work site
situation to ensure safety
and normal cutting.
4.1 Daily maintenance
1) Daily checking is very important in keeping the high performance and safe operation of this
cutting machine.
2) Do daily checking according to the table below, and clean or replace components when necessary.
3) In order to ensure the high performance of the machine, please choose components provided
or recommended when replacing components.

14
4. MAINTENANCE
WARNING
Periodic check should be carried out by qualified professionals to ensure safety.
Thepower of the switching box and the cutting machine should be shut down
before periodic check to avoid personal injury accidents such as electric shock
and burns. Due to the discharge of capacitors, checking should be carried out
5 minutes after the machine is powered off.
4.2 Periodic check
Tips:
All maintenance and checking should be carry out after the power is
completely cut off. Make sure the power plug of the machine is pulled
out before uncovering the cutting machine.
When the machine is powered on, keep hands, hair and tools away from the
moving parts such as the fan to avoid personal injury or machine damage.
Avoid rain, water and vapor infiltrating the machine. If there is, dry it and check
the insulation of the cutting machine (including that between the connections
and that between the connection and the enclosure) with an ohmmeter. Only
when there are no abnormal phenomena anymore, can the machine be used.
Put the machine into the original packing in dry location if it is not to be used
for a long time.
Generally, periodic check should be carried out every 6 months, and it should
be carried out every 3 months if the cutting environment is dusty or with heavy
oily smoke.

15
5. TROUBLESHOOTING
Malfunction Phenomena Cause and Solution
TROUBLESHOOTING
The abnormity indicator on the front panel would illuminate in case of any failures inside the
cutting machine.
Turn on the machine, the
power indicator illuminates,
the control PCB keys do
not function, and there is
no response when pushing
the torch trigger.
Turn on the machine, the
power indicator illuminates,
the control PCB keys work
normally, but there is no
response when pushing the
torch trigger.
Turn on the machine, the
power indicator illuminates,
and the fan works. When
pushing the torch trigger,
the solenoid valve functions,
but there is no HF discharge
rustling.
Arc can not be ignited.
The cutting machine crashes: Shut down the machine, and
restart it.
1) The LED1 on the main board is on: The control PCB is
damaged.
2) The LED1 on the main board is of f: Check the torch
trigger and torch trigger wire.
The arc ignition part fails:
1) The interelectrode distance of the discharge nozzle is too
long.
2) There is leakage of the HF capacitor 102/10KV.
3) The relay is damaged.
4) The input voltage is too low.
The air pressure is overly high or overly low.