Most MasterCut 120 CNC User manual

Operaon Manual
MasterCut 120 CNC
Operaon Manual
rev. 1.1 of 19.11.2018
MasterCut 120 CNC MOST
Before starting work every person using or responsible for maintenance work on
this device should familiarize with the entire content of these operating manual.
is will optimize the use of device potential.
Attention! Prior commencing work, familiarize yourself with the user manual.

Operaon Manual
rev. 1.0 of 19.11.2018
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MasterCut 120 CNC MOST
Plasma Cuer
Table of contents:
1. Introducon 3
2. Health and Safety Manual 3
3. Installaon and use 7
4. Technical data and accessories 8
5. Requirements for compressed air supply 9
6. The main parts of the device 10
7. Torches 11
8. Starng work 17
9. Cung (ps) 17
10. Problems occurring during work resulng in poor cung quality 19
11. Electrical scheme 20
12. Spare parts 21
CE Declaraon Of Conformity 23

Operaon Manual
rev. 1.0 of 19.11.2018
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MasterCut 120 CNC MOST
Plasma Cuer
1. Introducon
Thank you for buying the Inverter Plasma Cuer MasterCut 120 CNC MOST. Prior commencing work please
familiarize yourself with the user manual. MasterCut 120 CNC is designed for quality plasma jet cung of
metal sheets of up to 20 mm thick (for black steel). We do believe that this product will meet your require-
ments. This manual may be supplemented with a training conducted by our qualied personnel. If you are
interested, please contact the nearest branch of the RYWAL-RHC Group.
Recykling
In accordance with Direcve 2012/19 / EU WEEE 11 (WEEE - Waste Electrical and Elec-
tronic Equipment), aer decommissioning, the device must be recycled by a specialized
company.
Do not dispose of worn-out equipment with domesc waste!
2. Health and Safety Manual
Use and maintenance of plasma cuer may be dangerous. To avoid accidents user must
observe health and safety regulaons. Cung machines may be used only by qualied
personnel. Keep up to date with the naonal regulaons regarding the device operaon
and accident prevenon.
Remove all combusble materials from the cung zone before starng work. Do not cut
in tanks where ammable liquids (fuel) were stored previously. Place all combusble ma-
terials away from cung spaer. Cung may be carried out in properly venlated rooms
equipped with permanent or mobile ltering devices.
Electricity. Correct operaon of the device is possible only aer a correct installaon.
Disconnect the device before longer breaks in its usage. Do not leave the equipment unat-
tended. Always make sure that the installaon is grounded.

Operaon Manual
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MasterCut 120 CNC MOST
Plasma Cuer
Operator’s skin is exposed to a risk of contact with plasma arc radiaon and aggressive
substances. Wear suitable protecve clothing. Pay aenon to the protecon of bystan-
ders against UV radiaon emied by the plasma arc. During the cung process, harmful
gases and fumes are generated. Use respiratory protecon. Noise generated during cut-
ng may damage your hearing. Use personal hearing protecon.
Persons with a pacemaker are not allowed to work with this device.
Danger of burns. Never touch the materials while cung or shortly aer nishing witho-
ut protecve (welding) gloves. Avoid skin contact with parcles oang in the air. Do not
direct the plasma torch against other persons.
Keep a re exnguisher close to the cung locaon. Aer nishing cung check work
staon against re hazard.
Do not cut without proper eye protecon. Pay aenon for providing safety for bystan-
ders against welding radiaon. Applied eye protecon should have minimum 10 DIN safe-
ty glasses. Do not direct the plasma torch against faces of other persons.
Electromagnec interference
The device may inuence other devices sensive to electro-magnec interference (ro-
bots, computers, etc.) Always ensure that the devices within the cung work staon are
resistant to interference. For the purpose of liming interference, it is recommended to
use cables as possible and arranged in parallel. Always work in a distance at least 100 m
from other sensive devices. Always make sure that the installaon is grounded. In case
of interference issues with other devices, properly shield the cables oruse appropriate
lters.

Operaon Manual
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MasterCut 120 CNC MOST
Plasma Cuer
ATTENTION!
The following user manual should be read prior installing and starng the device. Manual
OSH manual should be known to every operator and employee responsible for equipment maintenance.
Aenon!
Commissioning and normal operaon are possible only aer reading the carefully reading following manual.
Cung with plasma arc requires fullment of condions resulng from re regulaons. The operator of se-
mi-automac cuer should be supplied with protecve clothing and equipment in accordance with current
regulaons. It is necessary to use a set of personal protecve equipment (PPE) in accordance with according
to provisions of the Council Direcve 89/686/EEC. Personal protecve equipment (PPE) includes: welding
mask, welding glasses, welding gloves, welding apron, leather shoes, hearing protectors. Despite the high
technical standard of the device, the personnel should represent considerable discipline in approach to
health and safety requirements to protect against harmful and health hazardous factors developed from
cung technology.
OPERATING CONDITIONS
This device can operate under severe condions. It is however important to apply simple prevenve measu-
res to ensure long and reliable work:
• do not place or use this device on an inclined surface (of more than 15°),
• do not use the device for pipe defrosng,
• the device needs to be located in a place with free clean air circulaon free clean air circulaon (to and
• from the fan without obstacles). When connected to electrical network
• the device must not be covered e.g. with a lt,
• minimize the amount of dirt and dust that can get into the device,
• device has an IP23S protecon rang of housing, keep it dry and not locate
• on wet surfaces or in a puddle.
• do not use the device for cung tanks previously used for ammable substances storing, as there is a
• risk of explosion,
• device is designed to work in industrial condions and is marked as class A according to PN-EN 60974-10
GASES AND FUMES
Plasma cung techniques produce harmful gases and fumes containing ozone and hydrogen as well as oxi-
des or metal parcles. Therefore, the cung work staon should be ed with very good venlaon (dust
and smoke extracon or airy locaon) Metal surfaces intended for cung should be free from chemical
contaminaon, especially degreasers (solvents) that decompose during welding process and produce toxic
gases. Cung of galvanized, cadmium-coated or chromium-plated parts is permied only when a sucon
and ltering device is ed, and with introducon of fresh air to the cung work staon.
RADIATION
Ultraviolet emission radiated when cung is harmful to eyesight and skin. Therefore a welding mask with
protecve lters is required.

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MasterCut 120 CNC MOST
Plasma Cuer
Cung work staon should meet certain requirements and include:
• adequate lighng system,
• xed or movable protecon screens, governing bystanders (depending on requirements),
• against radiaon eects
• locaon with wall colour providing appropriate for radiaon absorpon.
FIRE PROTECTION
Cung work staon should be located at a safe distance from ammable materials placed especially on the
oor or walls. All ammable materials need re protecon against hot metal drops. It is recommended to t
the work staon with re blankets and re exnguishers eg powder or snow type.
PROTECTION AGAINST ELECTRIC SHOCK
It is unacceptable to connect the device to an improper installaon or to an installaon with unveried zero-
ing eciency. It is prohibited to use of device with shields removed or remove the external shields while the
device is connected to electric network. It is not allowed to work on a suspended device (e.g. using a crane or
a gantry). Only authorized persons should perform maintenance and repair works keeping it in compliance
with the safety condions applicable to renovaon equipment. The device is marked with the [S] sign which
means the possibility of working in an environment with an increased risk of electric shock.
ATTENTION!
Device idling voltage U0 = 380 V, which complies with PN-EN 60974-1 for plasma cuers. Be especially care-
ful when replacing spare parts or the welding torch.
MAINTENANCE
ATTENTION!
In order to carry out any repair or maintenance acvity, it is recommended to contact your nearest technical
support of RYWAL-RHC - a list of authorized service shops is located on the last page of this manual. Any
signs of damage should be reported immediately.
The most important issue is the maintenance of the plasma torch. Regularly remove splashes that sck to
the cover and the nozzle. Worn parts should be replaced immediately with new ones (electrodes, nozzles,
swirl ring - diuser, covers). Regularly check the patency of channels in the swirl ring. If clogged - should be
cleaned (e.g. with compressed air), if it does not bring any improvement, the diuser should be replaced
with a new one. Poor condion of the diuser aects the cung quality and may cause damage to the
device.
In case the torch cables are damaged, it should be replaced immediately with new ones, as there is a risk
of electric shock (high voltage of idling).

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MasterCut 120 CNC MOST
Plasma Cuer
General maintenance (daily):
• check the condion of cables and connecons, replace if necessary,
• check the condion of high-speed torch parts. If necessary, replace it with new ones. It is recommen-
ded that simultaneous replacement of used nozzles and electrodes is performed.
• check condion of plasma torch, replace if necessary,
• check condion and operaon of the cooling fan; keep the cooling air inlet and outlet openings clean,
• keep the device clean.
Periodic maintenance (every 3 months at least)
Periodic maintenance frequency can be increased depending on the environment condions
of the device locaon:
• using the vacuum cleaner to remove dust from the outside of the housing and from the inside of the
cuer - do not use compressed air cuer for cleaning,
• check and ghten all the screws,
• check the state of all electrical contacts and correct if necessary.
Mandatory device checks
According to the Labour Code provisions: „All responsibility for the safe use of machinery and equipment
shall be borne by the owner.”
This results in the obligaon to perform periodic and post-repair checks and inspecons of equipment. The
scope of these tests is dened by PN-EN 60974- standard.
Periodic tests are carried out at least once a year (legal basis PN-EN ISO 17662 clause
4.2), and post-repair tests aer each repair that restored welding funconality (legal basis: PN-EN 60974-4
clause 4.6).
All above services re performed by the technical support of RYWAL-RHC.
UWAGA!
Sieć zasilająca i sprężone powietrze musi być odłączona od urządzenia przed każdą czynnością konserwacyj-
ną i serwisową. Po każdej naprawie wykonać odpowiednie sprawdzenie w celu zapewnienia bezpieczeństwa
użytkowania.
3. Installaon and use
The user is responsible for connecng the cuer in accordance with the operang instrucons. In the event
of electromagnec interference, the user should recfy the cause. In the event of repeated problems, con-
tact the manufacturer.
Before using the equipment, operator should esmate the possible impact of disturbances on the environ-
ment, in parcular the presence of persons with pacemakers or hearing aids.
Work with a plasma generator is acceptable, but it must meet certain requirements. It is recommended to
use a unit with an asynchronous generator. If the aggregate does not provide adequate power, this results in
lowering the arc parameters or turning o the cuer.
Ground cable
It is recommended to use wires as short as possible, placed close to each other, preferably on the oor level
or as close to it as possible.

Operaon Manual
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MasterCut 120 CNC MOST
Plasma Cuer
Locaon of plasma cuer
Observe the following rules:
• ensure easy access to connecons, wires and switches.
• do not place the cuer in small, conned spaces.
• do not place the cuer on surfaces with an inclinaon greater than 15 degrees.
Device installaon:
• connecon or repair of the device may only be carried out by trained personnel,
• connecon of several cuers (in series or in parallel) is forbidden,
• before removing the covers of the device, always disconnect the charger from the power supply,
• periodically carry out the necessary cleaning and maintenance,
• ensure that power and ground are sucient and adequate.
• before cung starts, check the condion of the cables and repair or replace them
• in case of damage.
• make sure to use correct spare parts for your plasma torch,
4. Technical data and accessories
Technical parameters Unit
Electrical power supply [V/Hz] 3x400/50-60
Network security [A] 32 A
Max current I1[A] 34,7
Max eecve current I1e [A] 27,8
Idling gear voltage U0[V] 380
Cung current (DC=100%) 12[A] 100
Cung current (DC=60%li) 12[A] 120
Cung current (DC=60%) 1.10[A] 120
Maximum thickness of qualitave cung for black
steel
[mm] 20
Air work pressure [bar] 5,5
Max air pressure [bar] 8,5
Air consumpon [l/min] 295
Arc ignion pneumac-contact
Current adjustment steeples
Housing protecon class IP23S
Class according to standard EN 60974-1; -10 Class A
Dimensions (H x W x L) [mm] 240x440x675
Weight [kg] 32,4
Table 1: MasterCut 120 CNC MOST. Technical parameters

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MasterCut 120 CNC MOST
Plasma Cuer
5. Requirements for compressed air supply
• recommended compressed air pressure 5.0 to 8.5 bar.
• approx. air consumpon <300 l/min.
• compressed air must be dry and clean.
• compressed air minimum temperature: 3°C.
• maximum oil content is 0.1 mg/m3.
• maximum parcle size in the air: 15 microns.
• compressor tank minimum size: 100 litres.
• do not use oil-lubricated air. It may damage the plasma torch.
ATTENTION!
It is recommended to use an addional air dryer at the device inlet, e.g. AT-1000. Complaints on quick
parts wears or short circuit in plasma cuer torch, where no addional air dryer was installed will be
considered negavely.
Accessories available:
Figure 1: AT-1000 lter and the way of xing it to the device gas quick coupling.
1AT-1000 air lter with xing 617610 5302
2 Paper insert for AT-100 617610 5303
3 AT-1000 lter adaptor (Inlet-outlet ngs) 617610 5304
Accessories available for ordering in each RYWAL-RHC branch (see page 24)
Table 2: MasterCut 120 CNC MOST. Accessories available.
ATTENTION!
Using of improperly cleaned or moist air will result in shorter service life of parts or may damage the torch.

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MasterCut 120 CNC MOST
Plasma Cuer
6. The main parts of the device.
Panel przedni i tylni
Figure 2: Main parts
Pos. Descripon
A1 Mass wire socket
A2 Remote control connector (on request)
A3 Plasma torch socket
A4 Cung current knob (A)
A5 Power ON LED - ON
lights up when device is connected to the network
A6 Cung current values display
A7 LED indicates overheang of the device. In this case - leave the device turned ON to
cool down
A8
Error LED:
1. Flashing - no nozzle cover or cover ed incorrectly
2. Lit - low compressed air pressure
A9 Manometer
A10 Acvity LED of the plasma torch Lights up when buon is pressed, the torch is energized
A11
Work mode switch
Seng the compressed air pressure
Cung
A12 Air connecon
A13 Pressure regulator with lter
A14 Power cord mounng
A15 ON/OFF switch
Table 3: MasterCut 120 CNC MOST. Device construcon

Operaon Manual
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MasterCut 120 CNC MOST
Plasma Cuer
7. Torches
Machine torch M-125
Gas cooling
Duty Cykle 60% 125 [A]
Gas Air/N2
Gas pressure 5,0-6,0 [bar]
Gas ow 295 [l/min]
Ignion without HF
607610 6071 Start kit M-125 MasterCut 120 CNC
Pos. Code Name Quanty
3 607610 5792 Swirl ring - 45-85A Max Life 1
5* 607610 5794 Electrode - 45-125A 10
6607610 5795 Nozzle 45A PrecisionCut 2
7 607610 5796 Nozzle 45A 2
8 607610 5797 Nozzle 65A 2
9 607610 5798 Nozzle 85A 2
10 607610 5799 Nozzle 105A 2
10* 607610 5800 Nozzle 125A 5
13 607610 5803 Torch cover 5A 1
14 607610 5804 Torch cover 45-85A TM 1
Figure 3: Machine torch
M-125 MOST
Table 4: MasterCut 120 CNC MOST. Torch start
kit M-125 (607610 6071)

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MasterCut 120 CNC MOST
Plasma Cuer
Pos. Code Descripon
607610 6130 Machine torch M-125 1.3 m Coax MasterCut 120 CNC
607610 6132 Cable Package 6,7m M-125
607610 6071 Starter kit M-125
1* 607610 5789 Torch Head M-125
1a* 607610 5790 O-Ring Torch Head M-125
2* 607610 5791 Fibreglass Posioning M-125
3 607610 5792 Insulang diuser 45-85A Max Life M-125
4* 607610 5793 Swirl Ring 105-125A Max Life M-125
5* 607610 5794 Electrode 45-125A M-125
6607610 5795 Cung Tip 45A Precision Cut M-125
7 607610 5796 Cung Tip 45A M-125
8 607610 5797 Cung Tip 65A M-125
9 607610 5798 Cung Tip 85A M-125
10 607610 5799 Cung Tip 105A M-125
10* 607610 5800 Cung Tip 125A M-125
11 607610 5801 Shield Cup Body 45-85A M-125
12* 607610 5802 Shield Cup Body 100-125A M-125
13 607610 5803 Deector Precision Cut 45A M-125
14 607610 5804 Shield Cap Machine 45-85A M-125
15* 607610 5805 Shield cap machine 100-125A M-125
16 607610 5806 Fibreglass Posioning Tube with Rack M-125
*standard torch equipment
Table 5: Torch operang elements M-125 MOST

Operaon Manual
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MasterCut 120 CNC MOST
Plasma Cuer
Machine torch M-70
Gas cooling
Duty Cykle 60% 70 [A]
Gas Air/N2
Gas pressure 5,0-5,5 [bar]
Gas ow 185 [l/min]
Ignion bez HF / without HF
607610 6271 Start kit M-70 MasterCut 120 CNC
Pos. Code Name Q-ty
5607610 5832 Nozzle 20-50A M-70 5
5* 607610 5937 Nozzle 70A M-70 5
3* 607610 5830 Electrode M-70 10
7* 607610 5833 Torch cover M-70 1
1a* 607610 5790 Torch cover M-70 1
4* 607610 5831 Gas distributor M-70 1
Pos. Code Descripon
607610 6131 Machine Torch M-70 1,3m Coaxial MasterCut 120
607610 6132 CNC
1* 607610 5934 Cable Package 6,7 m M-70
1a* 607610 5790 Machine Torch Head M-70
2* 607610 5791 O-Ring Torch Head M-70
3* 607610 5830 Fibreglass Posioning Tube M-70
4607610 5936 Electrode M-70
4* 607610 5831 Swirl Ring M-70
5607610 5832 Swirl Ring M-70 Maximum Life
5* 607610 5937 Cung Tip 20-50A M-70
6* 607610 5834 Cung Tip 70A M-70
7* 607610 5833 Shield Cup body M-70
8 607610 5806 Shield Cap M-70
9 607610 5938 Fibreglass Posioning Tube with Rack M-70
Shield Cap Machine OHMIC M-70
*standard torch equipment
Table 7: Torch operang elements M-70 MOST
Figure 4: Machine torch
M-70 MOST
Table 6: MasterCut 120 CNC MOST . Torch start
kit M-125 (607610 6271)

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MasterCut 120 CNC MOST
Plasma Cuer
Hand torch H-125
Gas cooling
Duty Cykle 60% 40-125 A
Gas Air/N2
Gas pressure 5,0-6,0 bar
Gas ow 295 l/min
Ignion bez HF / without HF
Figure 5: Manual torch H-125 MOST

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MasterCut 120 CNC MOST
Plasma Cuer
607610 6071 Pakiet startowy H-125 MasterCut 120 CNC
Pos. Code Name Q-ty
3 607610 5792 Swirl ring - 45-85A Max Life 1
5* 607610 5794 Electrode - 45-125A 10
6607610 5795 Nozzle 45A Precision Cut 2
7 607610 5796 Nozzle 45A 2
8 607610 5797 Nozzle 65A 2
9 607610 5798 Nozzle 85A 2
10 607610 5799 Nozzle 105A 2
10* 607610 5800 Nozzle 125A 5
13 607610 5803 Torch cover 5A 1
14 607610 5804 Torch cover 45-85A TM 1
Poz./pos. Kod/Code Nazwa / Descripon
5926 Hand Torch H-125 6m Coaxial
6071 MasterCut 120 CNC
15816* Starter kit M-125
1a 5790* Torch Head H-125 handle
2 5927* O-Ring Torch Head M-125
2a 5011* Handle with switch H-125
3 5967 Switch H-125
3 5792 Insulang diusor 45-85A H-125
45968 Insulang diuser 45-85A Max Life M-125
45793* Life H-125
55794* Swirl Ring 105-125A H-125
65795 Swirl Ring 105-125A Max Life M-125
7 5796 H-125
7 5797 Electrode 45-125A M-125
7 5798 Cung Tip 45A Precision Cut M-125
8 5799 Cung Tip 45A M-125
8 5800* Cung Tip 65A M-125
9 5801 Cung Tip 85A M-125
10 5802* Shield Cup Body 100-125A H-125
11 5803 Deector Precision Cut 45A H-125
Table 8: MasterCut 120 CNC MOST .
Torch start pack H-125 607610 6071

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MasterCut 120 CNC MOST
Plasma Cuer
12 5817 Shield Cap 45-85A H-125
13 5818* Shield Cap 100-125A H-125
14 5916 Tip 65/85A, gouging H-125
15 5917 Tip 100A, gouging H-125
15 5918 Tip 125A, gouging H-125
16 5919 Shield, gouging H-125
17 5872 Bevel Tolls for H-125
*standard torch equipment
Table 9: Torch operang elements H-125 MOST

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MasterCut 120 CNC MOST
Plasma Cuer
8. Starng the work
ATTENTION!
Cuer may only be operated by authorized personnel:
1. Before starng work, it is necessary to prepare an appropriate network connecon (3x400V, 50-60 Hz).
2. Check completeness of parts mounted torch. Nozzle, electrode and nozzle cover should be compable
with each other pre-set set cung current.
3. Connect plasma torch holder to socket (A3).
4. Check the power cord (A14) connecon.
5. Connect compressed air to the a spigot (A12) on the back of the device.
6. Connect grounding cable plug to socket (A1).
7. Set air pressure using pressure knob (A13) to 5.5 - 6 bar.
8. Aer switching on with ON / OFF (A15) switch, the (A6) display turns on.
9. Set potenometer (A) to desired value of cung current.
10. Press the torch trigger and gas will start to ow out of it and the plasma arc will ignite (cung with a
hand torch).
11. To end the cung process, release the torch trigger (cung with a hand torch).
ATTENTION!
The device is ready to perform cuts in 15 seconds aer being switched on by pressing the buon (A15)
(cung with a hand torch).
Cuer operates according to the following scheme:
A. Starng the device with (A12) switch and cung current seng with the knob (A3).
B. Automac compressed air test for 10 s.
C. Automac device test for 6 s.
D. Press the plasma torch buon.
E. Air ows for approx. 2 s.
F. Pilong arc appears..
G. Aer reaching the material with the pilot arc, a cung arc should appear.
H. If the arc gets too far away from material, than the pilot arc will reappear.
I. Release the plasma torch buon.
J. Cung arc should go out.
K. Gas post-ow (cooling the torch) for approx. 1 min - during this me do not switch the device OFF.
9. Cung (ps)
ATTENTION!
The device is ready to perform cuts in 15 seconds aer being switched on by pressing the buon (A15).
• Press the plasma torch buon. Pilong arc will appear. Immediately approach with nozzle p to the
material being cut. At this point, a plasma cung arc between the torch and the material will appear.
• Guide the torch at a constant speed. The cung speed depends on many factors, such as cung cur-
rent, thickness and type of material to be cut and operator’s skills. The purpose of repeve element’s

Operaon Manual
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MasterCut 120 CNC MOST
Plasma Cuer
quality cung is to use a rule or a callipers set.
• For best cung performance, a distance of 2 mm is recommended between the nozzle p and the cut
material being held by the guide. A longer distance leads to a slower cung - up to the breaking of the
arc. Too short distance can cause faster parts wear.
• Plasma cung can take place at any posion of the torch, but it is recommended to cut in a down
posion. For forced posions, operator and torch can be exposed to chipping and drops of molten
material.
• It is recommended to start cung from a material edge. Should the cung be started not from mate-
rial edge, it is advised to cut out a hole in start locaon. If it is necessary to start plasma cung in the
center of the material - start cung with a burner inclined at an angle (Figure 6) and gradually raise
it to the vercal seng unl it breaks through. This procedure is necessary if the material thickness
exceeds 3mm.
Figure 6: Holes piercing method in the material surface and in the corners
• For cung corners, it is recommended to use a long nozzle and electrode. Cung speed is smaller
when cung in corners
Operaonal observaons
• Pilot arc can only be started for a limited me. It aects the wear of spare parts signicantly.
• Never switch o the device immediately aer nishing the cut, let the torch cool down with oulow of
air. Switching o the device immediately aer cung is only possible in case of danger to the operator.
• Grounding clamp must be in good contact with the cut material. Check and if necessary, replace, the
quickly wearing parts. Their lifeme is limited to several hours of cung me and strictly depends on
following the instrucons in this manual. When replacing a part or disconnecng the plasma torch,
always switch the device o from the mains
• MasterCut 120 CNC device is designed to work with MOST torch types M-125 and M-70 and H-125
according to PN-EN 60974-7: 10.1.4. Manufacturer is not responsible for faults resulng from using
cuer combined with other torches.
• Improperly dried air can cause quick wear of parts and dicules in pilot arc development.

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MasterCut 120 CNC MOST
Plasma Cuer
10. Problems occurring during work resulng in poor cung quality
Aer starng the device, the pilot arc does not appear: Wait for 15 seconds for air test and device test. Then
press the torch buon.
Figure 7: Problems occurring during cung.
Incorrect penetraon of plasma arc: The cung quality is low due to too high speed. Make sure that
plasma arc angle does not exceed 15 ° (see Figure 7):
• excessive cung current for the parts in use.
• excessive material thickness.
• incorrect connecon of the grounding cable with material.
Plasma arc is unstable and „shoots” or suddenly goes out:
• nozzle (see gure 7) or electrode worn out.
• excessive air pressure.
• polluon in compressed air.
• humidity in compressed air.
Edges of the cut are not perpendicular (see Figure 7):
• switch the device o, unscrew the torch cover and rotate the nozzle 1/4 in relaon to the previous
posion and try to restart the cung.
• nozzle or electrode damaged - replace.
• posion of the torch during cung not vercal in relaon to the material.
• nozzle being too far from the material being cut.

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MasterCut 120 CNC MOST
Plasma Cuer
11. Electrical scheme
Figure 8: MasterCut 120 CNC MOST Electrical scheme