ESAB PC 120 Plasma Instruction manual

PC 120 PLASMA

INVERTER PLASMA
Power Source

Instruction manual

1

PC 120 PLASMA

INVERTER PLASMA POWER SOURCE

Instruction manual

For

Installation, Operation & General maintenance

2

CONTENTS

Item Page No

SAFETY ……………………………………………………………… 3

OVERVIEW…………………………………………………………… 5
TECHNICAL DATA …………………………………………………. 6
INSTALLATION……………………………………………………… 7
OPERATIONS……………………………………………………….. 8

TROUBLESHOOTING……………………………………………… 11

WARING DIAGRAM………………………………………………… 13

PARTS LIST AND EXPLODED VIEW……………………………. 14

ESAB INDIA LOCATIONS AND CONTACT DETAILS…………. 19

3

SAFETY

Users of ESAB plasma 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
plasma equipment. The following recommendations should be observed in addition to
the standard regulations that apply to the workplace.

Trained personnel well acquainted with the operation of the plasma equipment must
carry out all the work. 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 plasma equipment must be familiar with:

• its operation

• location of emergency stops

• its function

• relevant safety precautions

• cutting

2. The operator must ensure that:

• no unauthorized person is stationed within the working area of the equipment

when it is started up.

• no one is unprotected when the plasma arc is struck

3. The workplace must:

• be suitable for the purpose

• be free from drafts

4. Personal safety equipment

• Always wear recommended personal safety equipment, such as safety glasses,
flameproof clothing, and safety gloves.

• Do not wear loose—fitting items, such as scarves, bracelets, rings, etc., which
could become trapped or cause burns.

5. General precautions

• Make sure the return cable is connected securely.

• Only a qualified electrician may carry out work on high voltage equipment.

• Appropriate fire extinguishing equipment must be clearly marked and close at

hand.

• Lubrication and maintenance must not be carried out on the equipment during
operation.

ESAB can provide you with all necessary cutting protection and accessories.

Dispose of electronic equipment at the recycling facility!

In observance of European Directive 2002/96/EC on Waste Electrical and Electronic
Equipment and its implementation in accordance with national law, electrical and/or
electronic equipment that has reached the end of its life must be disposed of at a

recycling facility.
As the person responsible for the equipment, it is your responsibility to obtain information
on approved collection stations.

For further information contact the nearest ESAB dealer.

4

Read and understand the instruction manual before installing or operating.
ESAB can provide you with all necessary Cutting protection and accessories.

WARNING

Cutting can be injurious to yourself and others. Take precautions when cutting.
Ask for your employer’s safety practices which should be based on manufacturers’
hazard data.

ELECTRIC SHOCK – Can kill

• Install and earth the plasma unit in accordance with applicable
standards.

• Do not touch live electrical parts or electrodes with bare skin, wet
gloves or wet clothing.

• Insulate yourself from earth and the workpiece.

• Ensure your working stance is safe.

FUMES AND GASES – Can be dangerous to health

• Keep your head out of the fumes.

• Use ventilation, extraction at the plasma arc, or both, to take fumes

and gases
away from your breathing zone and the general area.

PLASMA ARC RAYS – Can injure eyes and burn skin.

• Protect your eyes and body. Use the correct screen and filter
lens and wear protective clothing.

• Protect bystanders with suitable screens or curtains.

FIRE HAZARD

• Sparks (spatter) can cause fire. Make sure therefore that there are no
inflammable materials nearby.

NOISE – Excessive noise can damage hearing

• Protect your ears. Use earmuffs or other hearing protection.

• Warn bystanders of the risk.

MALFUNCTION – Call for expert assistance in the event of malfunction.
PROTECT YOURSELF AND OTHERS!

CAUTION!
This product is solely intended for Plasma

Do not dispose of electrical equipment together with normal waste!
In accordance with national law, electrical equipment that has
reached the end of its life must be collected separately and returned
to an environmentally compatible recycling facility. As the owner of
the equipment, you should get information on approved collection
systems from the local representative. By applying this Directive you
will improve the environment and human health

5

OVERVIEW

Purpose and characteristics

The PC 120 inverter air plasma arc cutting machine can cut various metal materials
(stainless steel, carbon steel, alloy steel, aluminum, copper, nickel and titanium) using
only compressed air and three-phase (AC415V) power supply.
It has the characteristics of fast cutting speed, narrow incision, small deformation and
material saving, and can be widely used in the plate blanking and assembly
processing of ships, vehicles, automobiles, boilers, chemical machinery, pressure
vessels, environmental protection, purification, kitchens and other equipment, the
control circuit adopts integrated circuit control, with reliable control procedure, low fault
and convenient maintenance.

• The PC 120 inverter air plasma arc cutting machine is a kind of newly designed
metal processing equipment, which is designed and manufactured using advanced
insulation gate high power transistor (IGBT) and pulse width modulation (PWM)
technology.

• The cutting machine can cut all metal materials, especially applicable to cut high
alloy steel and non-ferrous metal which cannot be cut by flame cutting method

• Excellent external and dynamic characteristics meet the cutting process
requirements to a greater extent, providing a reliable guarantee for obtaining
high-quality cutting.

• High frequency plasma arc striking mode is adopted. The success rate of
arcing is high.

• Unique transferred plasma arc circuit is adopted. The transferred plasma arc is
continuous and stable, and the interference is small (with the transferred arc
cutting machine).

• Adopt inner loop characteristic control. The system has a fast response speed,
which can quickly respond to plasma arc length changes, to ensure continuous
arc.

• Output Hall sensor feedback is adopted. The output current is stable and the
effect of external characteristic sag is good (with transferred arc cutting
machine).

• Adopt the peak current control mode. Even if the mis-operation causes the
cutting gun to be short circuited, the power device can work reliably.

• The surface of circuit board is coated with insulating paint. Effectively prevent
the corrosion of humid and corrosive gases.

• It has knob adjustment. The operation is simple and the output is accurate.

• Digital display meter. Intuitive display.

• Novel inverter cutting, small size, light weight and energy saving.

6

TECHNICAL DATA

PC 120

Mains Voltage, V/Ph, Hz

415±15% /3,50

Rated Input Power, KVA

20

Rated Input Current, A

27.5

Current Range, A

30-120

Rated Output Voltage, V

128

No Load Voltage, V

374

Gas Supply

Clean, dry, oil-free air

Required Air Pressure, Bar

4-6

Recommended Cut, mm

20

Pierce Cut, mm

<14

Maximum Cut, mm

40

Permissible load at 100% Duty Cycle, A

120

Power factor at maximum current

0.9

Efficiency at maximum current

≥90%

Operating temperature, Deg C

-10 to + 40

Insulation class

H

Enclosure class

IP21S

Dimension (LXWXH), mm

687×315×581

Weight, Kg

52

Duty Cycle

The duty cycle refers to the time as a percentage of a ten-minute period that you can
weld or cut at a certain load without overloading. The duty cycle is valid for 40 °C / 104
°F, or below.

Enclosure class

The IP code indicates the enclosure class, i.e. the degree of protection against
penetration by solid objects or water.

7

INSTALLATION

The complete installation for Plasma application should consist of the following items:

Sl. No

Description

Type

Quantity

1.

Power Source

PC 120

1

2.

Plasma Torch

1

3.

Earth cable with clamp

1

4.

Compressed Air

CAUTIONS FOR INSTALLATION

− Provide a Switch Box for every Power Source, and use designated fuse

− Tolerance of Power Voltage Variation is  10% of rated input voltage.

a) Installation place

− Install in the place where less moisture and dust exist. Avoid direct sunlight and
rain, and maintain ambient temperature within –10o to +45

o

C as much as

possible.

− Keep the power source at least 20 cm. away from the wall (if any).

− In case of installation of more two units side by side, a distance of more than 20

cm is recommended between the two power sources.

− Use a shield to protect the plasma arc in case of excessive air draft.

b) Ventilation

Adequate ventilation is recommended at the place of installation. For example

the following guideline should be followed:

a) In case of the area being more than 300 square meters (per unit), no

ventilation is required, provided the room is not completely airtight.

b) In case of the area being less than 300 square meters and the cutting is

continuously performed, adequate ventilation is recommended with the
help of vent fan or exhaust duct.

c) While performing the grounding work, it is recommended that a skilled

electrician does the work.

8

OPERATIONS

Front Panel

Rear Panel

• Connect the electric circuit and air circuit of the cutting machine and check
whether they are correct.

• Check whether the placement, installation and operator protection of the cutting
machine meet the requirements.

• Check whether the cutting torch accessories are installed correctly. Install the
electrode, gas distributor, nozzle and ceramic protective sleeve in the order .

• Start the air compressor, turn on the air compressor outlet switch, then turn the
power switch of the cutting machine to the "on" position, then the power
indicator light will be on, select the cutting/gas testing selection switch to the
gas testing position, at this time, there is gas from the cutting torch, adjust the
pressure reducing valve of the cutting machine to the required pressure, then
select it to the cutting position, and the current is also adjusted according to

9

the required position according to the material and thickness of the plate
(Panel potentiometer).

• At the beginning of cutting, make the support wheel of the cutting gun contact
the workpiece, meanwhile, adjust the height of the support wheel to maintain a
proper distance between the nozzle and the workpiece. Press the cutting
torch switch to start plasma arc. If the arc is not ignited, release the cutting
torch switch, and press the cutting torch switch again. After the plasma arc is
struck successfully, move the cutting torch at a constant speed for normal
cutting (the moving speed shall be changed according to the thickness of the
plate, if the spark flips upward, it indicates that the moving speed is too fast or
the current or air pressure is not adjusted properly).

• At the time when the cutting is terminated and the workpiece is about to be cut
off, the cutting speed shall be slowed down (to prevent the workpiece from
deforming), and the cutting can be completed by releasing the cutting torch
switch.

• Thickness of the plate cut by choke hole: PC-120≤14mm

The plate whose thickness is corresponding to the cutting torch can be directly
subject to choke hole cutting. The cutting torch shall be inclined down 10°-20°
when choke hole cutting strikes plasma arc. After arc striking, the cutting torch
shall be restored to normal state.

• For hole cutting, when the plate thickness is greater than the above specified
thickness and the hole cannot be choked and it cannot be cut at the edge, a
pinhole (φ 3-φ 5) can be drilled at the starting point of cutting, and the pinhole
can be used as the starting point for cutting. If the hole is forced to choke, it will
cause "frost boiling" and burn the electrode cutting nozzle of the cutting gun.

• If there are splashes on the surface of the nozzle, it will affect the cooling effect
of the nozzle. It shall be removed in time, and the dust and splashes on the
head of the cutting torch shall be removed frequently. Keep good heat
dissipation effect.

• Replacement of electrode and nozzle

The electrode and nozzle shall be replaced in case of the following conditions.
(1) When the consumption depth of electrode and hafnium wire is more than

2.5mm.
(2) Irregular deformation of nozzle aperture.
(3) The cutting speed slows down obviously and green flame appears in the
plasma arc.
(4) Plasma arc striking is difficult.
(5) The incision is slanted or widened.
In case of the above phenomena, the electrode and nozzle shall be replaced in
time, or strong plasma arc will be generated in the nozzle, which will break
through the electrode and nozzle, or even burn the cutting torch. The nozzles
of different models are different. When replacing nozzles, it shall be ensured to
match the models.

• The electrode and nozzle in the cutting torch shall not be loosed during use.
The ceramic protective sleeve shall be screwed tightly by hand, and it must be
checked before use every time. If it is loose, it shall be screwed tightly by hand
at any time (please wear protective gloves)

• During replacement, the electrode must be completely cooled (blown with
compressed air), otherwise, the electrode base will be relatively tight after being
heated and expanded. Before replacing the electrode and nozzle, it is

10

necessary to check whether the inner cavity is clean, and it shall be used after
the impurities are removed.

• The compressed air used shall be dry and clean. Due to the water gas and oil
stains are easy to conduct electricity, there are spiral black stripes on the
electrode, which indicates that there are too much water gas and oil stains, that
will short circuit the plasma arc of electrode and nozzle, easily damage the
cutting torch, and cannot work normally.

• In the normal use process, the "pu" sound is heard suddenly, the plasma arc
light is red, and the arc chirps upward. Stop the use immediately, and check
whether the electrode and nozzle are installed correctly before use.

• During cutting, the cutting gun shall be kept as straight as possible. If the space
is not allowed, it shall not form a dead bend. At the same time, do not step on
or squeeze the cutting gun with your feet to avoid air flow is blocked and too
small to burn the cutting gun. The cutting gun shall not contact with sharp tools
to avoid damage and affecting normal use.

• After dismantling the nozzle protective sleeve, nozzle, electrode and starting
the machine, select the cutting/gas test selection switch to the gas testing
position. At this time, there is gas ejecting from the air jet pipe hole of the
cutting torch to clean up the dirt in the air pipe. Use or clean it once a day for
about 15 seconds each time. During cleaning, do not touch the conductive part
of the cutting gun to avoid electric shock.

• Since the cutting torch head is a consumable part, it shall be operated in strict
accordance with the instructions during use, otherwise the service life of the
cutting torch will be shortened.

• It is forbidden to use the cutting torch head as a slogging tool.

• It is necessary to pay attention to avoid unnecessary repeatedly closing

(pressing) the cutting torch switch, which may cause power failure or reduce
the service life of the electrode.

Main Supply

Make sure that the plasma power source is connected to the correct supply voltage
and that it is protected by the correct fuse rating. A protective earth connection must
be made in accordance with regulations.

The power source will automatically adjust to the supplied input voltage
Recommended input cable, grounding wire and fuse protector or circuit breaker are as

follows:

Machine model

PC 120

Input power supply

Three-phase AC415V

Equipment capacity

Network source

25kVA

Input protection

Device

Fuse protector

45A

Non-fuse circuit breaker

45A

Cable

Sectional area

Cutting power supply input line

3mm2

Input grounding wire

＞6mm2

11

Connection of cutting and return cable

The power source has two outputs, a positive terminal (+) and a negative terminal (-).
Connect the return cable to the negative terminal on the power source. Secure the

return cable's contact clamp to the work piece and ensure that there is good contact
between the work piece and the output for the return cable on the power source

Recommended output cable specifications are as follows:

Machine model

PC 120

Sectional area of cable (mm2)

≥16

TROUBLESHOOTING

Common failure reasons and troubleshooting methods of PC 120 inverter air plasma
arc cutting machine

S/N

Fault phenomena

Causes

Treatment measures

1

When the "power
switch" is closed,
the power
indicator light is
not on.

1. No three-phase power supply.

2. Power supply defaults phase.

3. Timing drive board is damaged.

4. "Power switch" is broken.

5. Control panel is damaged.

1. Maintain the power supply lines and
switches.

2. Maintain the power supply lines and
switches.

3. Overhaul or replace.

4. Replace.

5. Overhaul or replace.

2

The overheating
indicator light is
on, and the nixie
tube shows hot

1. Temperature in the machine is too high.

2. Thermal protector is damaged.

3. The wiring of thermal protector is not
standard.

1. Wait for the machine to cool down.

2. Replace the damaged elements.

3. Twisted pair of thermal protector harness.

3

The power
indicator light is
on, but there is no
air flow after
pressing the
cutting gun switch.

1. Air supply system is abnormal.

2. Pressure reducer of gas filter is out of
order, or the filter is damaged.

3. Solenoid valve is damaged.

4. Control panel doesn't work properly.

1. Turn the handle of the pressure reducer
clockwise, and raise the pressure to 0.4MPa.
If the pressure reducer of the filter is
damaged, repair it.

2. Replace.

3. Overhaul or replace.

4. Overhaul or replace.

4

When cutting,
there is no
transferred arc.

1. Cutting torch head and electrode are in
contact with the conductive nozzle.

2. Control panel doesn't work properly.

3. Gap of spark arrester is too small or too
large.

4. High frequency arc striking board is not
working normally.

5. Fast recovery diode is damaged.

6. Drive board is not working properly.

7. IGBT module is damaged.

1. Adjust or replace the electrode and
conductive nozzle.

2. Overhaul or replace.

3. Adjust the clearance distance.

4. Overhaul or replace.

5. Overhaul or replace.

6. Overhaul or replace.

7. Replace.

5

Cutting torch
control switch fails

1. Cutting torch is damaged.

2. Cutting torch switch is disconnected.

1. Replace.

2. Wiring.

6

The cutting seam
is askew or too
wide.

1. Electrode nozzle is damaged.

2. The moving speed of cutting torch is
improper.

3. The core of cutting torch is deformed,
and the degree of different axes
decreases.

1. Replace.

2. If the movement is too fast, the cutting
seam will be skewed. If it is too slow, the
cutting seam will be too wide.

3. Replace the cutting torch.

12

7

It can cut at first,
but can't cut in a
few seconds

1. The air supply flow is too small, and the
flow cannot keep up with the operation,
resulting in excessive pressure drop.

2. The electric contact between "cutting
grounding wire" and workpiece is poor.

1. Make large flow to required parameters.

2. Reconnect to ensure good electric contact.

8

Cutting torch is
easy to damage.

1. The moisture content of the air supply is
too high, which causes the insulation
resistance to drop.

2. When installing the electrode, the
ceramic protective sleeve is not screwed
tightly.

1. Add stages of filter pressure reducer.

2. Be sure to screw tightly it every time.

9

Transferred arc is
on and off or there
is no transferred
arc

1. Quick-wear parts are seriously
consumed.

2. Main circuit fails (fast recovery diode,
IGBT or three-phase rectifier bridge fails).

3. High frequency control circuit of control
panel fails.

4. Transferred arc circuit fails.

5. High frequency arc striking board fails.

1. Replace quick-wear parts.
2 Remove the HF plug from the control panel
and measure the no-load voltage. If there is
no no-load voltage or the no-load voltage is
80-120v, check the fast recovery diode,
three-phase rectifier bridge or IGBT. If there
is any abnormality, replace it.

3. Press the cutting gun, if there is no
discharge phenomenon of the high frequency
arc striking discharge chip or between the arc
striking device, the high frequency control
circuit on the control panel fails, and replace
the control panel.

4. Disassemble the arc striking line of the
cutting gun and contact the workpiece for arc
striking. If the arc striking cutting can be
carried out and the arc transfer circuit fails,
forcibly close the contact point of the
contactor and press the cutting gun switch. If
there is a transferred arc, replace the
contactor. Forcibly close the contact point of
the contactor, press the cutting gun switch, if
there is no transferred arc, the main control
panel fails, and replace the main control
panel.

5. Disassemble the arc striking line of the
cutting gun and contact the workpiece for arc
striking. If the arc cannot be struck, adjust the
distance between the discharge plate or the
arc striking device to make it between 1­2mm. If the arc cannot be struck, replace the
high frequency arc striking board.

10

There is
transferred arc,
but it cannot cut.

1. Grounding cable is not connected or in
poor contact.

2. Power supply defaults phase.

3. Three-phase rectifier module is
damaged (one or multiple groups of its six
groups of diodes are open circuit).

4. Fast recovery diode module is
damaged.

1. Check the grounding cable connection and
tighten it.

2. Overhaul.

3. Disassemble the input and output wiring of
the three-phase rectifier module and use the
diode position to measure. If there is any
problem, replace it.

4. Disassemble the diode absorption board
on the fast recovery diode and use the diode
position to measure. If there is any problem,
replace it.

13

WIRING DIAGRAM

14

PART LIST & EXPLODED VIEW

Front View

S/N

Name

Item code

1

Pneumatic-to-current connector

30501891

2

Aviation connector: Socket

12002029

3

Binding post

40138065

4

Aviation socket

12001039

5

Output terminal

40214018

6

Potentiometer knob (large)

11603056

7

Control panel

30101810

8

Pressure gauge

10901045

9

Regulator of pressure reducer

10901044

10

High frequency arc striking board

30101246

15

Side View (Left)

S/N

Name

Item code

11

Fast recovery diode module (common cathode)

12102039

12

Diode absorption board

30101261

13

Fast recovery diode module (common cathode)

12102040

14

Reactor

30901151

15

Absorption board

30101698

16

Hall current sensor

11301007

17

Auxiliary inductor

31001127

16

Rear View

S/N

Name

Item code

18

Filter gas cylinder of pressure reducer

10901039

19

Axial flow fan

11702012

20

Miniature circuit breaker

11501003

21

Aviation socket

12001042

22

Aviation socket

12001039

23

Combined connection terminal

60701065

17

Side View (Right)

S/N

Name

Item code

24

Primary side inductor

31001128

25

Matching transformer

30801603

26

Main transformer

30801626

27

Current transformer

11303021

28

Three-phase rectifier bridge

12103013

29

IGBT module

12101028

30

Drive board

30101591

18

Medium Septum

S/N

Name

Item code

31

Hall sensor filter inductor assembly

30502171

32

Timing drive board

30101696

33

Solenoid valve

11001028

34

Three-phase input cable

31001126

35

Arc voltage sampling board

30101697

36

Voltage sampling inductor assembly

30502170

37

Control transformer

60101255

38

AC contactor

11103008

39

Transferred arc absorption board

30101307

19

ESAB INDIA LIMITED

Registered and Head Office

13, Industrial Estate, III Main Road
Ambattur, Chennai - 600058
Telephone: + 91 44 42281100
Fax: + 91 44 4228 1107
Email: [e-mail]

Web: www.esabindia.com