OPERATION MANUAL for the GOODWIN P18 AIR

OPERATION MANUAL for the GOODWIN P18 AIR
OPERATION MANUAL
for the
GOODWIN P18
AIR PLASMA CUTTING SYSTEM
The Company reserves the right to make such changes to the design or specification of the
equipment as it shall see fit. The information contained in this manual is issued for the guidance
of users and does not form part of any contract. It is strongly recommended that all users and
supervisors familiarise themselves with the contents...
PRIOR TO COMMENCING USE OF THE SYSTEM
...and in particular, the section on safety precautions which should be used as a guide to
safe operation in accordance with the requirements of the relevant Health and Safety at Work
legislation.
GOODWIN AIR PLASMA LIMITED
KERNAN DRIVE
LOUGHBOROUGH
LEICESTERSHIRE
LE11 5JF
ENGLAND
Tel No. ++(0) 01509 237369
Fax No. ++(0) 01509 234942
Email. [email protected]
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Issue 5
12th December 1997
Contents
1. .............................................................................................................................................. SAFETY
1.1 ................................................................................................................................................General
1.2 ................................................................................................................................... Safety Features
1.3 ..................................................................................................................................... Warning Signs
1.4 .....................................................................................................Packaging Handling and Transport
2. ........................................................................ INTRODUCTION TO THE PLASMA PROCESS
3. ............................................................................................................................... INSTALLATION
3.1 ...................................................................................................................................... Power Supply
3.2 .............................................................................................................................Earth Requirements
3.3 ........................................................................................................................... Phase Determination
4. ..................................................................................... PLASMA AND TORCH CONNECTIONS
4.1 ....................................................... Connecting the Torch and Plasma Earth Lead to the Power Unit
4.2 ........................................................................................................................ Control of Hand Torch
4.3 ...................................................................................................................Control of Machine Torch
5 ..................................................................................................................................... OPERATION
5.1 ..............................................................................................................................Machine Controls
5.2 ......................................................................................................................... Power Up Procedure
5.3 ............................................................................................................................. Cutting Procedure
5.3.1. ........................................................................................................ Starting and Finishing a Cut.
5.3.2, ................................................................................................................ Cutting With Stand Off.
5.3.3. .............................................................................................................................. Cutting Speed.
5.3.4. ............................................................................. Piercing Thicker Materials with a Hand Torch
5.3.5. ..................................................................................................... Piercing with a Machine Torch
5.4 ................................................................................................................................ Troubleshooting
5.5. ............................................................................................................................. Consumable Life.
5.5.1. ................................................................................................................................ Intrinsic Life.
5.5.2. .................................................................................................................................... Alignment.
5.5.3. ........................................................................................................................ Transient Damage.
5.5.4. .................................................................................................................... Operational Damage.
5.5.5. .............................................................................................................. Electrode “non-starting”.
5.6 .................................................................................................................... Changing Consumables
6. ........................................................................................................................ TECHNICAL DATA
6.1 ........................................................................................................................................ Power Unit
6.1.1. ............................................................................................................................. Electrical Input
6.1.2. ......................................................................................................................... Electrical Output
6.2 ........................................................................................................................... Torch and Hose Set
6.2.1 ................................................................................................................................... Hand Torch
6.2.2 .............................................................................................................................. Machine Torch
7. ............................................................................................................ SERVICE INFORMATION
7.1 ................................................................................................................................. The Power Unit
7.1.1. ............................................................................................................................ Circuit Diagram
7.1.2. ................................................................................................................... Diagnostic Indicators.
7.1.2. ............................................................................................................................ Machine Layout
7.2 ........................................................................................................ The Torch and Hose Set Repair
7.3 ...................................................................................................................................... Maintenance
8. .................................................................................................................................. Torch Blockage
8.1 .................................................................................................................................. Machine Torch
8.2 ....................................................................................................................................... Hand Torch
8.3 ............................................................................................................... Hand Torch exploded View
8.4 .......................................................................................................... Machine Torch exploded View
9. ..................................................................................................................................... Fault Finding
10. ................................................................................................................................................ Index
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1. SAFETY
1.1 General
Before any cutting operations are started, the user must ensure that the installation and
proposed working methods comply with all relevant safety regulations, environmental and
electricity standards.
The plasma arc produced at the torch head is a jet of high energy and is potentially
dangerous. Users unfamiliar with a plasma arc should seek basic training. Goodwin Air Plasma
can offer comprehensive training courses.
In addition, the following points are particularly important:
a)
b)
c)
d)
e)
f)
g)
h)
i)
j)
k)
The mains connection must be properly grounded and the supply lines fitted with fuses of
the specified rating. The mains cable must be properly secured and protected from possible
damage.
High voltage exists at the torch when power is applied and the pilot arc is struck (up to
300V), and when the main arc is cutting (150V). Under no circumstances should anyone
touch the nozzle with power applied to the torch. All adjustments and replacement of parts
should be done with the power unit supply isolated. The torch should not be used in
excessively wet conditions or if the torch or hose set are damaged in any way.
The mains supply should be isolated from the unit AT THE SUPPLY before removing any
panels from the unit. Only authorised service personnel should remove panels.
Keep the work area clear of all inflammable materials. Ensure that any material ejected
from the cut is not a hazard to the operator or to others.
Protection is necessary against ultraviolet radiation emitted from the arc. A helmet or
shield with shade glass is recommended. Wear gloves and adequate protective clothing
where appropriate. Adequate screening should be arranged to protect others in the vicinity
or passing by in a similar manner to that required for arc welding operations.
Adequate ventilation or fume extraction to remove the cutting fume and dust is required at
all times around any plasma cutting operation. When cutting flat sheet, a shallow water
bed cutting table will greatly reduce the fumes and dust which mainly occur below the cut.
The wheels on the unit are meant for ease of movement around the work place and should
not be used over rough surfaces nor at excessive speeds.
The plasma power unit should be positioned on stable level ground and if necessary
secured against any unwanted movement.
The operation of this equipment and the plasma cutting process can result in noise levels
that could be harmful, The employer should undertake a noise assessment to monitor
compliance with relevant legislation.
Material to be cut should be supported in such a way that any material cut from the work
piece will not be a hazard and fall onto the user, the equipment, or others in the vicinity.
Care should be taken when manoevering the hose set with either a hand held torch or one
connected to a robot arm or profiler, that it does not snag on objects or other equipment
which may result in damage to the hose set, or topple the objects or equipment. Hose sets
that are subject to excessive mechanical tension may result in damage to the hose set
connections at the machine or the hose set components themselves.
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1.2 Safety Features
The plasma unit includes the following features for the safety of the operator:
*
*
*
*
*
The body of the plasma torch is earthed.
The continuity of the torch earth and the voltage on the body is monitored.
Cutting current flowing in the supply earth is monitored.
The voltage on the torch nozzle is monitored.
In the event of a faulty condition of the above, the machine will switch off power to the
torch.
The emergency stop procedure is to turn the main isolator to the off position, which is located on
the lower front control panel.
A tool (flat bladed screw driver) is required to remove the canopy for access to the internal components. Under no circumstances should the canopy be removed whilst the mains supply is still
connected. Only suitably trained and authorised personnel should remove the canopy.
1.3 Warning Signs
The location of the warning signs fitted to the
plasma unit are:
a)
At the front of the machine Warning Open Circuit Voltage 300 volts.
b)
At each rear lower corner of the canopy Warning Disconnect the Mains Supply.....
These should be maintained in a legible condition.
1.4 Packaging Handling and Transport
Should the plasma unit need to be shipped, we recommend re-use of the original packing crate.
Also:a) That the hose set be disconnected to prevent any damage to the hose set / plasma connections.
b) That the control panel is adequately protected against potential damage.
c) Any lifting should be done using the eyebolt located in the top of the canopy together with
certified lifting equipment (not supplied). Precautions should be taken to prevent rotation about
the eyebolt.
d) The plasma unit should be shipped and stored in the upright position to avoid any heavy
internal components breaking free from their mountings.
e) Storage should be undercover, preferably in a clean dry environment.
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2.
INTRODUCTION TO THE PLASMA PROCESS
The plasma process is created by passing a stream of clean ionised air, provided by an oil free
compressor, through a NOZZLE in the torch. The air stream is ionised by a PILOT ARC,
initiated by a HIGH FREQUENCY unit (HF Unit) which passes from the ELECTRODE to the
nozzle when the torch is activated. When the PILOT ARC is brought close to the work piece,
MAIN ARC is TRANSFERRED to the work piece as a jet of high energy which rapidly melts
any metal with which it makes contact, providing fast cutting, low residual heat input, and low
material distortion.
The electrode and nozzle are cooled by air (and water in water cooled torches), and as the air is
passed through the nozzle it is caused to swirl around the arc by a SWIRL BUSH to aid stability
of the arc.
The HF unit operates automatically to establish an arc when power is applied to the torch and it
ceases to operate when the pilot or main arc is established.
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3.
INSTALLATION
May be carried out by a competent electrician. No specialist tools are required.
3.1 Power Supply
The power unit is provided with a length of flexible cable which must be connected to the
customers 3 phase and earth electrical supply. The supply should be fitted with fuses or circuit
breakers of appropriate rating and a means of isolating the power unit from the supply.
A plug should be fitted if appropriate. The machine is phase/rotation sensitive.
Refer to the rating plate on the machine and Technical Data section 6.1.1. for the correct voltage
and current requirements.
3.2 Earth Requirements
The installation should be arranged such that the only path to earth (or ground) from the work
piece is by way of the plasma earth lead connected to the front of the machine.
Where the material to be cut forms part of the structure which is earthed or grounded to the
mains electrical supply system, then the cutting current could flow through that route rather than
the plasma earth lead to the machine. Always ensure that there is a good connection between the
work piece and the machine via the plasma earth lead as a poor connection will cause excessive
current in the mains supply earth which will create a current trip fault condition.
In installations where it is not possible to avoid earth current trips, even though a good cutting
current earth path has been ensured, it will be necessary to check that the alternative mains earth
paths are substantial enough to carry higher currents than the current trip setting of 10 amps
without causing damage, as where the cutting earth is not connected to the work piece at all, this
would be the full cutting current. If the earth paths are not substantial they must be uprated or
rerouted to avoid the possibility of damage. Once the necessary checks and precautions have
been taken, the earth current trip circuit may be disabled by means of the switch on the Earth
Current Relay (ECR) located inside the power unit.
3.3 Phase Determination
Connect the torch to the machine (see section 4).
Switch on the machine by rotating the main isolator.
Correct phase connection is determined by checking that the cooling air flowing through the
power unit is from the front panel to the rear of machine. If this is incorrect, change two of the
three phase connections at the power supply and check again.
If there is any doubt regarding installation, consult your distributor or Goodwin Air
Plasma.
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4. PLASMA AND TORCH CONNECTIONS
4.1 Connecting the Torch and Plasma Earth Lead to the Power Unit
Note.
Do not run the power unit without the torch connected.
Torch connection to the power unit is made
by a "push in" connector plug to a socket on
the front of the power unit designed to
prevent accidental removal of the hose set.
A pointed tool is supplied in the tool kit for
the purpose of allowing the hose set to be
connected and disconnected.
To connect the hose set, insert the connector
plug into the socket and press the pointed
tool into the small hole (see illustration),
whilst rotating the knurled securing collar.
Note that a sealing ring is located in the base of the torch connector socket to form an air seal
with the centre power pin. Care should be taken to ensure that this seal is not displaced and that
the end of the pin is not damaged when the torch plug is removed.
The plasma earth lead is connected via the push in and twist clockwise socket.
POINTED TOOL
DIAGRAM TO SHOW POSITION OF EARTH AND TORCH CONNECTIONS.
PLASMA EARTH
AIR PRESSURE GAUGE
AIR REGULATOR
WATER FEED
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WATER RETURN
TORCH CONNECTOR
4.2 Control of Hand Torch
The hand torch is provided with a press on / release off control switch on the handle for
operation of the plasma arc.
Note.
Air will flow through the torch at all times when the machine is switched on.
If a hand torch is to be used in conjunction with a mechanical manipulator or tractor unit etc.,
when the operation of the handle mounted press on / release off control switch will not be
possible, plug the remote control switch unit into the remote control socket as for the machine
torch.
4.3 Control of Machine Torch
If the machine torch is used, plug the remote control plug into the remote control socket.
If the machine is to be interfaced to a profiling machine, robot or other automatic system, the
following remote control socket connections may be used.
REMOTE CONTROL
SOCKET
pin 1
Ground
Main Arc Signal
Latch
2 +12 volts on main arc transfer
plasma
off
(optionally switched to ground)
3
optional latch
Plasma On
plasma on
contacts
(12V dc
100mA)
4
Pilot arc relay contacts can also be provided when necessary. If in doubt contact Goodwin Air
Plasma for advice on interfacing to other equipment.
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5
OPERATION
5.1 Machine Controls
The front panel of the machine provides a range of displays and control gear to ensure correct
operation.
OUTPUT
VOLTAGE
OUTPUT
INDICATOR ON.
MAIN
REMOTE
ISOLATOR. CONTROL SOCKET
WARNING INDICATORS
POWER
READY
TEMPERATURE
WATER FLOW
CURRENT TRIP
AIR REGULATOR
AIR PRESSURE GAUGE
MAIN ISOLATOR.
Switches machine on and off.
OUTPUT “ON” NEON.
Indicates that power is applied to the torch.
OUTPUT VOLTAGE METER
Indicates output voltage. Typical values are:
Power applied but no arc
300v
Pilot arc
250/280v
Main arc
120/150/180v
POWER INDICATOR.
Indicates that power is available to the system control circuit.
READY INDICATOR.
Indicates that all system interlocks are operational and that the machine is ready to operate.
TEMPERATURE INDICATOR.
Indicates when the main transformer temperature is too high. Cutting operations will
immediately stop. Do not switch off supply, allow the fan to cool the machine
.
Note. This safety feature is not designed nor intended to be a means to control the duty
cycle. It is the user's resposibility to ensure the machine is operated within it's duty
capability such that the machine does not exceed its temperature limitations during cutting
operations.
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WATER FLOW INDICATOR.
Indicates the the loss of water pressure from the torch.
CURRENT TRIP INDICATOR.
Indicates excessive pilot arc current due to incorrectly installed or damaged consumables in the
torch, or insufficient air flowing through torch, or the main arc cutting current is flowing in a
secondary earth path.
AIR PRESSURE GAUGE.
Displays the back pressure in the system for setting the pilot arc air pressure, during pilot arc and
during cutting modes. Typical values would be:
For setting Pilot Arc
During Pilot Arc
During Main Arc
10 to 15 psi.(0.65 to 1.0 bar)
10 to 20 psi (0.65 to 1.4 bar)
35 to 45 psi (2.5 to 3.2 bar)
AIR REGULATOR.
Sets the air flow through the torch. Adjust for a stable pilot arc.
REMOTE CONTROL SOCKET.
For the connection of a machine torch remote control unit.
NOTE.
As plasma power units do not have a voltage stablised power supply, a fluctuation in the input
voltage will directly affect the output current. This may not be noticeable if the input voltage
rises slightly above the norm as it will provide more power for cutting. If the rise is excessive,
consumable life may suffer. However, when the input voltage falls, the output power also falls,
affecting both the pilot arc and main arc. In these circumstances it will be necessary to adjust the
air pressure regulator to reduce the airflow to obtain a stable pilot arc, and readjust it when the
mains voltage returns to normal.
5.2 Power Up Procedure
Having completed the mains and cutting earth wiring, connected the torch and checked the fan
rotation, the machine is ready for use.
To ascertain the absence of air leaks, the air regulator should be wound fully anti-clockwise and
the pressure gauge should indicate a back pressure of 1.7 bar.
It is now necessary to adjust the air pressure to give the highest possible reading consistent with
good arc starting and a stable pilot arc. Switch on the torch with the nozzle well clear of any
work piece, person or equipment, and adjust the air pressure until it is at maximum or the pilot
arc becomes unstable (very noisy, misfire, and the output showing 300 volts). At this point
reduce the pressure to restore stability (arc less noisy, stable arc, and the voltage indicator
showing 250/280 volts).
Always maintain as high an air pressure as possible for pilot arc as this gives the best
consumable life.
The output neon is “on” and the output reads between 250 vdc and 280 vdc at this stage.
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5.3 Cutting Procedure
5.3.1.
Starting and Finishing a Cut.
Where possible it is better to start a cut at a plate edge or hole because the piercing process
reduces consumable life.
Cuts can be started by either initiating the pilot arc and moving the torch into the proximity of the
work piece, or by positioning the torch over the edge of the work piece and starting the pilot arc.
Materials with a capacity to absorb heat energy, especially thicker sections, require more care and
technique when starting a cut. In these cases the cut will appear slow to start and pierce through
the material. Once a cut is established then cutting speeds may be increased.
Cutting can be stopped either by releasing the torch switch, switching off the power, or by withdrawing
from the workpiece (best done rapidly).
5.3.2,
Cutting With Stand Off.
Under normal cutting conditions the torch is designed
to operate with a STAND OFF of about 6 mm. This is
the distance between the end of the nozzle and the
work piece.
Where the work piece is rusty, scaly, or with thick
sections of steel or aluminium etc., a build up of dross
on the top of the work piece may occur which will
cause damage to the nozzle. In these conditions, the
stand off distance should be increased slightly.
A guide ring is avalable to assist the operator in
maintaining the desired stand off height. This can also
be used against a straight edge to maintain a straight
cut.
IMPORTANT
If the arc should “flare”, be coloured green, or emit any unusual noise, it is recommended that the
unit be immediately switched off and the condition of the consumables checked. Cutting under these
conditions may result in damage extending beyond the consumables to other parts of the torch.
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5.3.3.
Cutting Speed.
Best results are usually obtained by cutting at the optimum cutting speed.
OPTIMUM CUTTING SPEED
Correct cutting speed is judged by experience from
observing the angle at which the cut material leaves
the lower edge of the plate, either by observing the
ejected material or by studying the surface of a cut
after completing a test cut. The drag back of the arc is
aproximately 30 degrees.
CUTTING TOO SLOW
Arc appears to blow straight through the material.
Excessive dross may accumulate on the underside of
the material.
CUTTING TOO FAST
Arc fails to pierce the material. Blow back of dross
will damage the nozzle.
MAXIMUM CUTTING SPEED
Drag back of the arc is around 45°, but cut quality will
deteriorate.
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5.3.4.
Piercing Thicker Materials with a Hand Torch
Piercing will cause cut material to be ejected upwards which can be dangerous, and has a risk of
damaging the torch nozzle. This problem is worsened as material thickness increases because it
takes longer to pierce. If it is necessary to pierce, then it is best done by angling the torch and
gradually bringing it upright as piercing is completed.
X
X
Initiate the pilot arc and lay the torch over at approximately
60º
Imaginary pivot point. X
X
Begin twisting the torch slowly towards a vertical position
taking care to avoid ejected material from hitting the nozzle.
At the same time, the torch should be moved a small
distance along the work piece.
X
As piercing completes, the nozzle can be brought to vertical
and cutting can continue.
If the torch is pivoted about the nozzle there is a risk of material
being blown back onto the nozzle which will cause damage to
the nozzle or even to the torch itself.
*
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5.3.5.
Piercing with a Machine Torch
When using a machine torch, it is not generally possible to angle the torch for piercing.
Start the pilot arc above the work piece, and with the torch travelling at about half of the normal
cutting speed, lower the torch until main arc transfer occurs.
Once piercing is complete, the torch may be brought to normal stand off and cutting speed.
Goodwin Air Plasma offer an Automatic Height Control Unit as an optional extra for machine
torches integrated with profiling machines or robot arms. Ask your distributor or Goodwin Air
Plasma for further details.
ê
STAND
OFF
è
Position the torch around 20mm from the work
piece, start the pilot arc and torch manipulator
moving at half speed.
20MM
ê
Lower the torch until main arc transfers.
è
At this point, the descent speed of the torch is
important. If it is too fast, the ejected molten
metal will damage the torch.
15MM
ê
Continue to lower the torch slowly after arc
transfer until the nozzle is 10mm from the work
piece.
è
10MM
è è
NORMAL
Wait until the arc has completed piercing
through, then lower the torch and maintain a
normal stand off for the duration of the cut.
Cutting can now continue at the full
recomended speed.
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5.4 Troubleshooting
Excessive dross on lower Cutting speed too slow. Torch consumables worn or damaged.
Insufficient air flow.
edge of cut.
Double arcing.
Damaged torch consumables. Nozzle blocked by dross or too close
to work piece. Insufficient air flow.
Main arc not square to
work piece.
Nozzle orifice damaged. Electrode eroded “off centre”. Consumables
wrongly fitted.
Excessive bevel or
rounded cut surface.
Speed too high. Stand off too high. Arc not straight - consumables
damaged or misaligned.
Bevel is more noticeable on thinner sections and is more pronounced on the left hand side of a
cut. It is due to the clockwise swirling of the air induced by the swirl bush in the electrode
assembly. Bevel edges can be desirable as an aid to weld preparation, however it can be virtually
eliminated by reducing the cutting speed but at the expense of accumulated dross. For minimum
bevel cut clockwise around a component and anticlockwise in a hole.
5.5. Consumable Life.
A good consumable life is the single most important factor in achieving optimum cutting
economics of any plasma cutting unit. This life is dependent on the intrinsic life of the
consumables, correct alignment and the incidence of transient and operational damage.
5.5.1.
Intrinsic Life.
The intrinsic life of the consumables is determined by the rate at which they are eroded by the arc
process. This erosion rate is however low, and in practice, the life is limited by other factors. The
insert in the centre will be eroded slightly each time the arc is struck eventually creating a visible
crater. The crater can be more than 2mm deep before the electrode is considered to be expired.
5.5.2.
Alignment.
The alignment and construction of the Goodwin Air Plasma Torch is such that problems of
grinding and adjusting electrodes do not occur. With reasonable care taken in fitting the
consumables, alignment problems should not arise.
5.5.3.
Transient Damage.
On starting directly onto main arc, it is occasionally possible to erode some of the copper from
the electrode before the arc settles onto the insert material. This generates a crater in the
electrode and the insert burns back to become flush. Consumable life is thus reduced if there is a
high number of starts relative to the total cutting time.
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5.5.4.
Operational Damage.
This is the most likely cause of limited consumable life. Since the arc is quite capable of cutting
copper, anything which causes the arc to deviate from the centre of the nozzle will result in
damage to the orifice. In extreme cases the arc passes not through the orifice but from the
electrode to the nozzle and from the nozzle to the work piece - DOUBLE ARCING, causing the
rapid erosion of copper from both electrode and nozzle.
The most common cause of these problems is from ejected cut material entering the orifice
particularly when piercing or obstructing the nozzle with the work piece.
It is best to operate within the maximum speed capabilities of the machine and avoid unnecessary
piercing or stop-start cutting whenever possible.
5.5.5.
Electrode “non-starting”.
Occasionally, it may happen that it is difficult to start the pilot arc. This happens when the
oxidized material from the electrode insert is deposited over the surface of the copper electrode
and inside the nozzle. Starting can be improved by cleaning or scratching the surface of the
electrode with a wire brush or sharp implement. Always switch off the power unit before
removing the nozzle for this purpose. Once a “non-starting” electrode has been used a few times,
starting usually improves.
It is not good practice to fire the pilot arc continually in midair without striking the cutting arc as
this oxidizes the surface of the electrode and leads to “non-starting” problems.
Since cutting usually improves a non-starting electrode, it may be desirable to use a piece of scrap
material and start the main arc immediatly by positioning the torch close to the material before
switching on. Once started, continue to cut for as long as possible before trying to re-initiate the
pilot arc.
ILLUSTRATION TO SHOW ELECTRODE DAMAGE
NEW ELECTRODE
USED ELECTRODE
WORN OUT
EXPIRED
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5.6 Changing Consumables
The Goodwin Water Cooled torch carries a number of elements known as the CONSUMABLES
which are eroded during the cutting process. They consist of:
a)
b)
Nozzle.
Electrode Assembly comprising:
Electrode
Swirl Bush
O ring
Other parts that may be damaged and replaced by the user are:
Front Cap
Front Cap Retaining Ring
Contact Tube.
TORCH HEAD
FRONT CAP RETAINING RING
CONTACT TUBE
ELECTRODE ASSEMBLY
NOZZLE
FRONT CAP
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To renew the consumables, the following procedure should be adopted, remembering that care
and cleanliness are of the utmost importance.
1. Switch the machine off at the mains supply or Main Isolator.
2. Remove the Front Cap. The cap is a push fit over the O ring seated in a groove in the outer
diameter of the Torch Body.
3. Unscrew the Nozzle with the special
tool supplied. (See illustration left).
4. Check the condition of the Electrode
Assembly. If it is to be removed, grip the
Electrode Assembly with the special
Electrode Pliers provided, and pull firmly
out from the torch body. (See illustration
right).
5. Press a new Electrode Assembly carefully but firmly over the contact tube until it is fully home
and central. Use the handle of the Nozzle Tool which has been prepared for this purpose. THIS
IS VERY IMPORTANT ! If the Electrode is not pressed fully home onto the Contact Tube, the
Swirl Bush may be partly crushed by the Nozzle, and will interfere with the airflow.
6. Carefully screw the Nozzle into the Torch Head using the special tool until fully home. DO
NOT OVER TIGHTEN.
7. Apply a liberal quantity of Silicone Grease around the front of the torch.
8. Refit the push fit Front Cap. Apply additional grease over the outside of the front cap. The
grease will provide a first line of defence against material blown back from the cutting process.
Remember that cleanliness and care must be taken when fitting consumables. Do not allow dirt to
obstruct the threaded parts of the torch. Take care when engaging threaded parts not to damage
the threead.
CONTACT TUBE REPLACEMENT.
Should the Contact Tube need changing, it is removed by inserting the 1/8" allen key supplied into
the centre and unscrewing. Replacement is the reverse of removal but it is important not to over
tighten as this may cause subsequent electrode fitment to be off centre, producing bevel cuts.
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6. TECHNICAL DATA
6.1 Power Unit
6.1.1
Electrical Input
Input is via 3 core and earth flexible: 4 x 6mm2 3 metre length standard.
Machines are available for the following 3 phase supplies:
Note. When the power unit is connected to a generator it may be necessary to disconnect the power
factor correction capacitors (if fitted) in the power unit if they disturb the generator's automatic
voltage control. This does however increase supply current. See below or rating plate.
Input Voltage
Without correction
380v
50 Hz
60 amps
415v
50 Hz
55 amps
440/480v
60 Hz
50amps
Other voltages and frequencies available to order
With correction
6.1.2 Electrical Output
Open circuit voltage
Typical arc voltage
Main arc power
Pilot arc current
Duty cycle
300v dc
150v dc
18kW
15 - 20 amps nominal
60%
6.1.3 Miscellaneous
Compressor type
Water pump type
Water capacity
Oil free twin cylinder.
Regenerative type.
3 litre (aprox. dependant on hose length)
distilled or deionised water
6.1.4 Dimensions
Height
Width
Depth
Weight
660mm
540mm
1200mm
140kg
(26.0 in)
(21.3 in)
(47.3 in)
(310 lb)
6.2 Torch and Hose Set
6.2.1 Hand Torch
Torch body diameter
Torch head weight
Effective weight (inc. hose set)
Hose set lengths available
Hose set water capacity
40mm
1.0 kg
1.5 kg
7.5m, 15m, 20m, 30m, longer with Junction Box.
0.6 litres per 10m length
6.2.2 Machine Torch
Torch body diameter
Torch body length
Torch head weight:
Hose set lengths available
Hose set water capacity
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40mm
200mm
1.0 kg
7.5m, 15m, 20m, 30m, longer with Junction Box.
0.6 litres per 10m length
7. SERVICE INFORMATION
7.1 The Power Unit
Output power is supplied from a fan cooled transformer and rectifier with varistor diode protection.
The transformer is rated at 60% duty cycle and is protected by a thermostat.
The power is carried to the torch electrode by a cable within the hose set.
Pilot arc connection to the nozzle is made via a current limiting resistor in the rear of the machine
and a coaxial cable in the hose set. The HF arc ignition is fully automatic in operation, being
powered from the torch power lines.
The compressor, cooling fan, and water pump are the only “phase sensitive” components and it is
essential to ensure that their direction of rotation is correct according to the installation instructions
(see section 3).
These components are protected by thermal / magnetic overload switches. If an overload should
operate, it can be reset by first removing the machine cover then pressing the manual reset button on
the overload unit situated behind the instrument panel after establishing the reason for the trip (e.g.
missing supply phase).
The transformer, water radiator and the pilot arc resistor, are cooled by an electric fan. A temperature
sensing interlock inside the transformer windings protects the system against thermal overload should
the cooling fail or be obstructed hence it is essential to ensure adequate air circulation around the
machine at all times.
The air compressor is of the oil free, maintenance free, twin piston type fitted with two cleanable/
replaceable inlet filters contained in black screw-in housings with a snap open lids.
The high pressure water pump supplies cooling water to the torch through quick release, self sealing
couplings so that the torch can be disconnected without the loss of water from the system. There is
an interlocked flow sensor on the return line which shuts down the arc if the water flow should be
restricted.
The header tank must be kept full of distilled water at all times. If site conditions dictate that antifreeze
should be used, then up to 33% METHANOL may be added.
NOTE. Ethylene glycol or automotive type antifreeze fluids MUST NOT BE USED, as they will
cause rapid corrosion of the torch.
Whenever any of the interlocks come into operation the appropriate warning light on the front panel
will indicate to assist in the diagnosis of the problem.
7.1.1.
Main Circuits and Systems.
The Circuit Diagram is shown in drawing 1/D/10773
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7.1.1.
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Circuit Diagram
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7.1.2.
Diagnostic Indicators.
OUTPUT ON NEON
Indicates that power is applied to the torch.
POWER INDICATOR
Indicates that 12V power is available to the system control circuit.
READY INDICATOR
Indicates that all system interlocks are operational and that the machine is ready to operate.
TEMPERATURE INDICATOR
Indicates that the main transformer temperature is too high. Cutting operations will immediately
stop. Leave the machine running to allow the fan to cool the transformer. The safety systems will
automatically reset when the temperature drops.
WATER INDICATOR
Indicates no water in the system, a water leak, torch blockage, low pump supply pressure or
incorrect motor/fan rotation. See section 7.2 for torch blockage. When water flow is restored, the
system will reset automatically.
CURRENT TRIP INDICATOR
Indicates the main arc cutting current is flowing in a secondary path. System will stop until the
torch switch is released. (See section 3.2 for cutting earth requirements).
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7.1.2.
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Machine Layout
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7.2 The Torch and Hose Set Repair
The torch is a precise assembly of electrically conductive parts and P.T.F.E. insulators housed in a
stainless steel body. It is supplied with compressed air, water and electrical power at high voltage
which must not be allowed to escape from their designed confines.
Rebuilding torches requires special training and instruction and is not within the scope of this
manual. Users who wish to repair damaged torches themselves should consult their supplier or
Goodwin Air Plasma for detailed advice.
A torches should be removed from the power unit complete with hose set. Once removed, the
torch head may be serviced or repaired.
If a spare torch and hose set is available, the machine may be put back in service whilst repairs are
carried out.
TORCH BLOCKAGE.
The water flow in the torch can occasionally become blocked, usually with scale because
deionised / distilled water has not been used or has become contaminated. Also, copper deposits
can accure as a result of expiry of an electrode. See section 8 of this manual.
TORCH / HOSE JUNCTION BOX ON MACHINE INSTALLATIONS .
A Junction box is offered as an optional extra to provide a facility for the fast removal of the torch
head. Useful for service or change of use with minimum loss of production time, the junction box
links all the control services carried by the hose set to the torch. Another advantage of the
junction box is that it will allow the majority of the hose set, which may be lengthy and difficult to
remove from an automatic machine, to remain in situ.
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7.3 Maintenance
Daily
Check condition of the consumables.
Top up water reservoir with distilled /
demineralised water.
Monthly
(depending on usage)
Check for water and air leaks, clean the air
compressor intake filters.
Remove excessive dust from inside the machine
taking care not to damage any mechanical or
electrical component and avoid exposure to this
dust which may represent a health hazard. Use
personal protection as necessary.
Annually
more frequently in poor conditions or
with high usage
Replace the compressor air intake filter. Check
tightness of all electrical and mechanical
connections. Check the correct operation of all
controls and indicators.
Goodwin Air Plasma Cutting Systems are designed so that only a minimum amount of maintenance
is required. By following a regular and careful maintenance procedure, the equipment will give a
long productive life.
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8.2 Hand Torch
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
Remove the Front Cap, Nozzle and Electrode.
Remove Back Cap and Front Ring (using Special tool).
Remove Rear Cover by carefully tapping the side of the Torch on a piece of wood, this will
cause it to fall out. This will reveal the HF Strap and HF Screws.
Using a small flat bladed screw driver unscrew the two screws. This will allow the Nozzle
Holder to be removed.
Carefully ease out the Centre Insulator taking care not to lose the four Water Seals. This
will reveal the Cathode Block.
Clean out the two water galleries using a small drill bit by hand, taking care not to push the
blockage any further into the Cathode Block.
Clean holes in the Centre Insulator in the same way.
The Nozzle Holder is cleaned in the same way, however this may have a blockage within the
circular water gallery, (check this by blowing into one of the holes, if the air flows freely it is
ok to re-use) if it is blocked it will need replacing before rebuilding the torch.
Check Water Seals for damage. Replace if necessary and refit into Centre Insulator.
Check length of HF screws as they may have stretched. If they are over 35mm they should
be replaced.
Refit Centre Insulator to Cathode Block taking care not to dislodge Water Seals.
Refit Nozzle Holder to Centre Insulator taking care to aline screws with threaded holes and
tighten.
Refit Front Insulator over Nozzle Holder, if this is damaged replace it.
Refit Front Ring and Back Cap taking care not to cross thread.
Fit Nozzle and Electrode to torch.
Remove water return pipe connection from the Machine (Long water fitting) and start
Machine, allow water to run out until the air lock is released (the water jet will stop then
restart). Run machine for a further five seconds, this will allow any debris left in the torch
head to be ejected. Switch off Machine and reconnect hose set.
NOTE
If the jet of water coming out of the removed return water connection is not
between 300 to 500mm long then the torch may still be blocked and should be stripped down
completely or sent to Goodwin Air Plasma for repair.
Page : 28
9_W_BLK.P65
Issue 2
8th March 1998
8.4 Machine Torch exploded View
Page : 30
9_W_BLK.P65
Issue 2
8th March 1998
9.
Fault Finding
Below is a list of the most common reasons for non operation of a Goodwin Air Plasma Cutting
System.
Symptom
Probable cause
Remedy
No Pilot arc at torch head
a) Machine Ready Light not on Check for red indicator being
when torch button is depressed b) Output Indicator not on.
on (If so refer to Manual)
Check torch switch and 220v
fuse.
As above with output indicator c) Non starting electrode.
(Refer to manual)
on.
d) Volt meter not reading 300v Telephone Goodwin Air Plasma
As above with voltmeter reading e) No HF on P C Board
Telephone Goodwin Air Plasma
300v.
f) Broken HF cable on hose set Telephone Goodwin Air Plasma
Current trip indicator coming on a) Electrode incorrectly fitted Refit correctly
b) Low air flow through torch Increase flow, check for air leaks
c) An other path to mains earth Ensure workpiece is completely
isolated from mains earth
Misfiring pilot arc
a) Too much air flowing through Decrease flow
the torch
Telephone Goodwin Air Plasma
b) Blown diode
Tracking :- Spark appears at a) Slag build up on Front Cap
front of torch and no pilot arc. b) Front Insulator damaged
Clean slag from around Nozzle
Replace Front Insulator
Front Caps and Nozzles burning a) Incorrect operation of torch
b) Not using Silicone Grease
up rapidly.
See operating instruction pages
Apply Silicone Grease
a) Damaged Consumables.
b) Electrode eroded off centre
c) Misaligned Consumables
Change Consumables
Change Consumables
Change Contact Tube and
consumables
Clean air filters, check for air
leaks
See operating instruction pages
See operating instruction pages
Excessive bevel, poor cut
quality
d) Low air pressure
e) Cut speed too fast
f) Stand off too high
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6th March 1998
Page : 31
10. Index
A
Accessories
Automatic Height Contol 15
G
C
Goodwin Air Plasma 2
Guide Ring 12
Circuit diagram 23
CNC 15
Compressor 20, 21
Consumable
Damage to 12
Life of 16, 17
Replacement 18, 19
Contact Tube 18, 19
Controls
Air regulator 11
Hi Lo Output switch 10
Main Isolator 5, 10
Cutting
Bevel 16
Blow back 17
High Frequency (HF) 6
Main arc 6
Piercing 14, 15
Pilot arc 6
Power up procedure 11
Process explained 6
Robot 4
Speed 13
Stand off 12
Thick materials 14
Ventilation 4
Water table 4
S
H
Handling
Lifting 5
Packaging 5
Health and Safety 2
I
Identification
Warning signs 5
Indicator
Air pressure 11, 24
Bargraph 10
Current trip 11, 24
Output On 10, 11, 24
Power 10, 24
Ready 10, 24
Temperature 10, 24
Voltage 24
Voltage indicator 10
Installation
Earth lead connection 8
Earth requirements 7
Electrical supply 7, 11, 20
Phase determination 7
Remote control 9
Torch connection 8
D
M
Duty cycle 21
Maintenance 26
E
N
Earth Current Relay (ECR) 7
Electrode 18
Emergency stop 5
Nozzle. See Consumable: Replacement
Nozzle Holder. See Consumable:
Replacement
F
O
Fault Finding
Air leak 8, 11
Overload 21
Bevel 16
P
Current trip 7, 11
Dross 16
Plasma
Troubleshooting 16
Flare 12
Front Cap. See Consumable: ReplaceProcess 4
ment
Profiling. See CNC
Front Cap Retaining Ring. See
Consumable: Replacement
R
Remote control 11
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Retaining ring. See Consumable:
Replacement
Robot. See CNC
12th December 1997
Safety
General 4
Mains connection 4
Noise 4
Personal protection 4
Service
Hose 25
Removing canopy 5
Torch 25
Silicone Grease 19
T
Technical Data 20
Torch
Hand torch operation 9
Machine torch operation 9
Training 4
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