Weldclass Weldforce 136S User manual

Weldforce 136S
Weldforce 181S
Edition 1.5
OPERATING INSTRUCTIONS
 IMPORTANT!
To qualify for full / extended warranty, you must register within 30 days of purchase. See inside for details.
Read these Operating Instructions Completely before attempting to use this machine. Save this manual and
keep it handy for quick reference. Pay particular attention to the safety instructions we have provided for
your protection. Contact your distributor if you do not fully understand anything in this manual.

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2© Weldclass | E.&O.E.
Congratulations & thank you for choosing Weldclass!
The Weldforce range from Weldclass provides market leading value, features and durability.
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To qualify for an extended warranty, you must register within 30 days of purchase.
Full details on warranty period and terms can be found at www.weldclass.com.au/WarrantyInfo
Please register your warranty now by going to:
www.weldclass.com.au/weldforcewarranty
You will need;
a) A copy of your purchase invoice / receipt.
b) Your machine serial number which can be found on the technical data plate on the back of the
machine, or on the outside of the box that your machine came in.
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Weldforce 136S & 181S
© Weldclass | E.&O.E. 3
1CONTENTS
1CONTENTS...............................................................................................................................................3
2BASIC SPECIFICATIONS ............................................................................................................................5
3KNOW YOUR MACHINE...........................................................................................................................6
3.1 Machine Front................................................................................................................................6
3.2 Machine Rear .................................................................................................................................6
3.3 Symbols chart.................................................................................................................................7
4CONTROLS EXPLAINED............................................................................................................................8
4.1 Setting Selection.............................................................................................................................8
4.2 Error/Over Temperature Indicator Light ........................................................................................8
5POWER SUPPLY .......................................................................................................................................9
5.1 Electrical Connection......................................................................................................................9
5.2 Extension Leads..............................................................................................................................9
5.3 Generator Use................................................................................................................................9
5.3.1 Generator Size............................................................................................................................9
5.3.2 Generator Quality & Warranty Limitations................................................................................9
5.3.3 3 Golden Rules of Generator use.............................................................................................10
6OPERATING ENVIRONMENT..................................................................................................................10
6.1Location........................................................................................................................................10
6.2 Ventilation....................................................................................................................................10
7BASIC OPERATION.................................................................................................................................11
7.1 Stick (MMA) Welding Operation ..................................................................................................11
8ACCESSORIES, SPARE PARTS & CIRCUIT DIAGRAMS..............................................................................12
8.1 Optional Accessories....................................................................................................................12
8.2 Machine Spare Parts: ...................................................................................................................12
8.3 Primary Schematic Circuit Diagram..............................................................................................15
9CARE & MAINTENANCE.........................................................................................................................16
9.1 Keep your Welding Machine in Top Condition.............................................................................16
9.2 Storing the Welder .......................................................................................................................16
10 GENERAL GUIDE TO WELDING .........................................................................................................17
10.1 Duty Cycle Rating .........................................................................................................................17
10.2 Stick (MMA) Process ....................................................................................................................17
10.3 Joint Preparations ........................................................................................................................18
11 STICK (MMA) BASIC WELDING GUIDE ..............................................................................................20
11.1 Size of Electrodes .........................................................................................................................20
11.2 Storage of Electrodes ...................................................................................................................20
11.3 Electrode Polarity.........................................................................................................................20

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11.4 Effects of Stick (MMA) Welding on Various Materials..................................................................20
11.4.1 High Tensile and Alloy Steels................................................................................................20
11.4.2 Manganese Steels................................................................................................................20
11.4.3 Cast Iron...............................................................................................................................20
11.5 Types of Electrodes ......................................................................................................................21
11.5.1 MILD STEEL: .........................................................................................................................21
11.5.2 CAST IRON:...........................................................................................................................21
11.5.3 STAINLESS STEEL: .................................................................................................................21
11.6 Suggested Settings for Typical Stick (MMA) Applications ............................................................21
11.7 MMA Welding Techniques ...........................................................................................................22
11.7.1 A Word for Beginners...........................................................................................................22
11.7.2 The Welder...........................................................................................................................22
11.7.3 Striking the Arc.....................................................................................................................22
11.7.4 Arc Length............................................................................................................................23
11.7.5 Rate of Travel .......................................................................................................................23
11.8 Making Welded Joints..................................................................................................................24
11.8.1 Butt Welds............................................................................................................................24
11.8.2 Fillet Welds...........................................................................................................................25
11.8.3 Vertical Welds ......................................................................................................................26
11.8.4 Overhead Welds...................................................................................................................27
11.9 MMA (Stick) Troubleshooting ......................................................................................................28
12 KNOWLEDGE & RESOURCES.............................................................................................................30
13 SAFETY..............................................................................................................................................30
13.1 Store and Retain this Manual.......................................................................................................30
13.2 Important Safety Information ......................................................................................................30
13.3 Welding Operation .......................................................................................................................30
13.4 Welding Safety Instructions & Warnings......................................................................................32
13.4.1 Personal Safety.....................................................................................................................33
13.4.2 Arc Rays can Burn Eyes and Skin..........................................................................................33
13.4.3 Noise Can Damage Hearing .................................................................................................33
13.4.4 Work Environment Safety ....................................................................................................34
13.4.5 Electricity Can Kill.................................................................................................................34
13.4.6 Fumes And Gases.................................................................................................................35
13.4.7 Fire & Explosive Risks...........................................................................................................36
13.4.8 Sparks & Hot Metal..............................................................................................................36
14 WARRANTY.......................................................................................................................................36
14.1 Warranty Information ..................................................................................................................36

Weldforce 136S & 181S
© Weldclass | E.&O.E. 5
2BASIC SPECIFICATIONS
Description
WeldForce 136S
WeldForce 181S
Part Number
WC-136S
WC-181S
Dimensions of Power Source (L x
W x H)
300 x 125 x 255mm
300 x 130 x 230mm
Weight of Power Source
2.8kg
4.1kg
Standard
AS 60974.1
Power Supply
240V +/- 15% 50hz Single Phase
Factory Fitting Supply Plug Rating
10A
15A
Effective Input Current (I1eff)
7A
15A
Maximum Input Current (I1max)
27A
34A
Output Terminals
Dinse™ style 10-25
Dinse™ style 10-25
Protection Class
IP21
IP23
Stick (MMA) Welding
Welding Current Output
10 – 130A
10 – 170A (max 180A)
Duty Cycle
125A / 25V @ 7%
35A / 21.4V @ 60%
30A / 21.2V @ 100%
170A / 26.8V @ 18%
105A / 24.2V % 60%
90A / 23.6V @ 100%
Nominal Open Circuit Voltage
72V
75V
MMA Electrode Size
1.6 – 3.2mm
1.6 – 4.0mm
Table 1
For full machine specifications, refer to technical data plate on back of machine – or go to:
www.Weldclass.com.au/136S / www.Weldclass.com.au/181S

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6© Weldclass | E.&O.E.
Figure 2
3KNOW YOUR MACHINE
3.1 Machine Front
1. Positive (+) Welding Power Output Connection Socket
2. Error/Over Temperature Indicator Light
3. Power On Indicator Light
4. Adjustment Knob
5. Negative (-) Welding Power Output Connection Socket
3.2 Machine Rear
1. Mains Power Switch
2. 240V AC Mains Power Input Lead
Figure 1

Weldforce 136S & 181S
© Weldclass | E.&O.E. 7
3.3 Symbols chart
I
Power On
O
Power Off
Power On
Indication
ꝇ
Fault Indication
Caution / Hazard
Read Instruction
Manual
Increase/Decrease
Single phase
Inverter power
source DC
Stick/MMA
(SMAW) Function
Power Supply
Connection
Single Phase
Direct Current (DC)
–
Negative
+
Positive
Hertz (cycles/sec)
Duty Cycle
Amperage
(Current)
Voltage
Table 2

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8© Weldclass | E.&O.E.
4CONTROLS EXPLAINED
4.1 Setting Selection
1. Rotate the Adjustment Knob (4) to adjust parameter for the chosen Setting
Figure 4
4.2 Error/Over Temperature Indicator Light
Error/Over Temperature Indicator Light (2) illuminates yellow to indicate that welding current has
stopped for one of the following reasons:
•Thermal Protection: when duty cycle is exceeded and thermal protection is activated. When
thermal protection is activated, welding output will be disabled until machines cools
sufficiently and overload indicator lamp goes out.
•Power Supply Voltage Protection: the machine will stop functioning if the input voltage
exceeds unsafe limits (over 15%).
•Anti-Stick Protection: automatically shuts down the welding machine if the electrode sticks
to the material being welded so that it can be removed manually without damaging the
electrode holder.
This may also activate if there are electronic circuit failure issues.
Figure 5

Weldforce 136S & 181S
© Weldclass | E.&O.E. 9
5POWER SUPPLY
5.1 Electrical Connection
Weldforce 136S
The Weldforce 140ST is designed to operate on a 10A 240V AC power supply.
Weldforce 181S
The Weldforce 181S is designed to operate on a 15A 240V AC power supply.
5.2 Extension Leads
If an extension cord must be used, it should be minimum cable core size 2.5mm2.
Using extension leads of over 50m is not recommended.
5.3 Generator Use
This machine is designed with generator use in mind and incorporates wide voltage tolerance and
intelligent voltage sensing technology to provide maximum protection from power fluctuations that
can occur with motor generators.
5.3.1 Generator Size
Weldforce 136S
Generator size should be not less than 6kva. An 6kVa generator may not provide enough power to
enable full output and duty of this welder.
To ensure full output and duty cycle of this welder a minimum recommended generator size is
minimum 7kVa or more.
Weldforce 181S
Generator size should be not less than 8kva. An 8kVa generator will not provide enough power to
enable full output and duty of this welder. However, it should provide sufficient power to run a
general purpose 3.2mm with reasonable duty cycle.
To enable full output and duty cycle of this welder a minimum recommended generator size is
minimum 10kVa.
5.3.2 Generator Quality & Warranty Limitations
Avoid using poor, low quality generators as these have the greatest risk of power spikes etc. A
suitable quality generator should have a THD (total harmonic distortion) rating of no more than 6%.
Most reputable generator suppliers will be able to specify the THD ratings on their product.
Any damage caused by poor quality generator power supply or incorrect use is not covered under
warranty.

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10 © Weldclass | E.&O.E.
5.3.3 3 Golden Rules of Generator use
When running an inverter welder off a generator there are 3 VERY IMPORTANT Golden Rules that
MUST be followed:
1. Do NOT plug welder into generator until AFTER generator has been started up and is running
smoothly
2. UNPLUG welder from generator BEFORE shutting generator down/turning generator off
3. NEVER let your generator run out of fuel whilst the welder is plugged in.
Following these Golden Rules will significantly reduce the risk of any damage resulting from
generator power supply.
6OPERATING ENVIRONMENT
6.1 Location
The machine has electrical components and control circuit boards which may be damaged by excessive
moisture, dust and dirt, so a clean and dry operating environment is important for reliable product life.
The enclosure design of this power source meets the requirements of IP23S as outlined in AS60529.
This provides adequate protection against solid objects (greater than 12mm), and direct protection
from vertical drops. Under no circumstances should the unit be operated or connected in a micro
environment that will exceed the stated conditions. For further information please refer to AS 60529.
6.2 Ventilation
Adequate ventilation is required to provide proper cooling for the machine. Ensure that the machine
is placed on a stable level surface where clean cool air can easily flow through the unit.

Weldforce 136S & 181S
© Weldclass | E.&O.E. 11
7BASIC OPERATION
7.1 Stick (MMA) Welding Operation
1. Connect the earth cable quick connector to the Negative (-) Welding Power Output Socket (5)
2. Connect the earth clamp to the work piece. Contact with the work piece must be firm contact
with clean, bare metal, with no corrosion, paint or scale at the contact point.
3. Insert an electrode into the electrode holder and connect the electrode holder and work lead to
the Positive (+) Welding Power Output Socket (1).
NOTE: This polarity connection configuration is valid for most GP (General Purpose)
MMA electrodes. There are variances to this, also many electrodes will run in either
polarity setting (electrodes positive or electrode negative, with slight difference in
performance. If in doubt, check the electrode specifications or consult the electrode
manufacturer.
4. Connect the machine to suitable power. Switch the mains power switch (1) to ‘on’ to power up
the machine.
5. Select the required output current using the Adjustment Knob (4).
6. You are now ready to weld!
Figure 6

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12 © Weldclass | E.&O.E.
8ACCESSORIES, SPARE PARTS & CIRCUIT
DIAGRAMS
8.1 Optional Accessories
Optional Accessories
Part No.
Accessory
WC-06235
Welding Trolley
WC-01775
Welding Gloves
Table 3
8.2 Machine Spare Parts:
For machine parts, go to www.weldclass.com.au/machines or contact your Weldclass distributor.
Weldforce 136S
Ref.
Description
1
Potentiometer
2
Resistor
3
Diode Kit
4
Capacitors
5
Relay
6
Thermostat
7
Adjustment Knob
8
Power Switch
9
Input Power Lead
10
Fan
11
Current Transformer
12
Pulse Transformer
13
Inductance Filter
14
Power Transformer
15
Front Panel
16
Back Panel
17
Handle
18
Guide
19
Dinse Socket
20
Complete PCB Kit
21
Cover Kit (Metal Panel)
22
Bottom Kit
23
IGBT & Diode Kit
24
Bridge & Thermal Switch Kit
Table 4
Weldforce 181S
Ref.
Description
1
Potentiometer
2
Resistor
3
Diode
4
Relay
5
Diode
6
Inductor
7
Mosfet N-ch
8
Capacitor
9
Adjustment Knob
10
Power Switch
11
Input Power Lead
12
Current Transformer
13
Pulse Transformer
14
Fan
15
Inductance Filter
16
Inductor
17
Power Transformer
18
Handle Set
19
Dinse Socket
20
Back Panel
21
Front Panel
22
Bottom Kit
23
IGBT & Diode Kit
24
Complete PCB Kit
25
Cover Kit (Metal Panel)
26
Bridge & Thermal Switch Kit
27
Switch Cover

Weldforce 136S & 181S
© Weldclass | E.&O.E. 13
Table 5
Weldforce 136S
Figure 7

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14 © Weldclass | E.&O.E.
Weldforce 181S
Figure 8

Weldforce 136S & 181S
© Weldclass | E.&O.E. 15
8.3 Primary Schematic Circuit Diagram
Weldforce 136S & 181S
Figure 9

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16 © Weldclass | E.&O.E.
9CARE & MAINTENANCE
9.1 Keep your Welding Machine in Top Condition
This WeldForce machine does not require any special maintenance, however the user should take care of
the machine as follows:
1. Regularly clean the ventilation slots
2. Keep the casing clean
3. Check all cables before use
4. Check electrode holders, work lead/clamps and welding torches before use
5. Replace worn electrode holders and earth clamps, which do not provide a good connection
6. Replace worn torch consumable parts in a timely manner
7. Use a soft cloth or brush to clean electrical components. Do not use liquid cleaning products,
water or especially solvents
8. Do not use compressed air to clean electrical components as this can force dirt and dust further
into components, causing electrical short circuits
9. Check for damaged parts
WARNING! Before performing cleaning/maintenance, replacing cables/connections,
make sure the welding machine is switched off and disconnected from the power
supply.
If damaged, before further use, the welder must be carefully checked by a qualified person to determine
that it will operate properly. Check for breakage of parts, mountings and other conditions that may affect
its operation.
Have your welder repaired by an expert. An authorised service centre should properly repair a damaged
part.
This appliance is manufactured in accordance with relevant safety standards. Only experts must carry out
repairing of electrical appliances, otherwise considerable danger for the user may result.
Use only genuine replacement parts. Do not use modified or non-genuine parts.
9.2 Storing the Welder
When not in use the welder should be stored in the dry, dust-free and frost-free environment.

Weldforce 136S & 181S
© Weldclass | E.&O.E. 17
10 GENERAL GUIDE TO WELDING
10.1 Duty Cycle Rating
WeldForce welding machines are fitted with thermal overload protection which means the machine will
cut out when it reaches a certain temperature, to prevent damage to components. The machine will then
re-start when it returns to a safe temperature.
Duty cycle is a measure of the percentage of time a machine will operate within a certain time period at a
given amperage. For example a duty cycle of 160A @ 25% means that a machine will operate at 160A for 2
½ minutes in a 10 minute time period. The machine will have to rest for the remaining 7 ½ minutes to
enable it to cool down.
The international standard for duty cycle rating is based on an ambient air temperature of 40°C with 50%
humidity, over a 10 minute period. In an environment with temperatures exceeding 40°C, the duty cycle
will be less than stated. In ambient temperature less than 40°C, duty cycle performance will be higher. There
are numerous other factors that can influence actual duty cycle performance.
10.2 Stick (MMA) Process
10.2.1.1 Description
The acronym MMA (or MMAW) stands for Manual Metal Arc Welding. ‘Manual’ refers to the fact
that the MMA process requires the operator to apply filler metal (in contrast to MIG ‘semi-automatic’
welding where the machine feeds the filler metal into the weld). ‘Metal’ refers to the fact that the
filler metal itself (the stick electrode) is used to conduct the welding current to the job. MMA welding
is commonly known as ‘stick-electrode’ or ‘arc’ welding.
10.2.1.2 Process
The MMA process involves the electrode being touched on the job to ignite the arc. The electrode is
held in the electrode holder and must be continually replaced as it is consumed. The electrode
consists of a metal core, which is the filler metal, covered by a flux coating which shields the weld
and prevents it from oxidising. During welding the flux forms into a slag covering the weld which is
chipped off after the weld has formed.
10.2.1.3 Advantages
MMA welding offers several advantages over alternative welding processes. Primarily it has a greater
capacity than MIG welding, or in other words it can weld heavier materials with the same amperage
output. For this reason small, portable inverter welders like the WeldForce machines, have the
capacity to weld with up to 3.2mm or 4mm electrodes making it suitable for a vast range of
applications without the complication of shielding gas or wire feeding. Moreover, MMA welding is
typically more ‘forgiving’ than MIG or TIG when welding rusty or dirty materials (which makes it ideal
for maintenance applications).
10.2.1.4 Limitations
Traditionally, welding thin materials whilst avoiding “blow-through” can be tricky with the MMA
process. This being said, however, welding thin materials with a WeldForce machine will be
noticeably easier because the arc is so stable and the output can be very finely adjusted down to
very low amps.
10.2.1.5 Materials
MMA welding can be used with a wide variety of electrodes including general purpose, low
hydrogen, stainless steel, iron powder, hard facing & cast iron just to name a few.

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18 © Weldclass | E.&O.E.
10.3 Joint Preparations
In many cases, it will be possible to weld steel sections without any special preparation. For heavier sections
and for repair work on castings, etc., it will be necessary to cut or grind an angle between the pieces being
joined to ensure proper penetration of the weld metal and to produce sound joints. In general, surfaces
being welded should be clean and free of rust, scale, dirt, grease, etc. Slag should be removed from oxy-cut
surfaces. Typical joint designs are shown in the following figures.
Figure 10
Figure 11
Figure 12
Figure 13
Figure 14
Figure 15
Figure 16
Figure 17
Figure 18

Weldforce 136S & 181S
© Weldclass | E.&O.E. 19
Figure 19

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20 © Weldclass | E.&O.E.
11 STICK (MMA) BASIC WELDING GUIDE
11.1 Size of Electrodes
The electrode size is determined by the thickness of metals being joined and can also be governed by the
type of welding machine available. Small welding machines will only provide current (amperage) to run
smaller sized electrodes. For thin sections, it is necessary to use smaller electrodes otherwise the arc may
burn holes through the job. A little practice will soon establish the most suitable electrode for a given
application.
11.2 Storage of Electrodes
Always store electrodes in a dry place and in their original containers. If electrodes have been exposed to
moisture or moist air then they will need to be dried out using an electrode drying oven.
11.3 Electrode Polarity
Electrodes are generally connected to the electrode holder with the electrode holder connected positive
polarity.
The work lead is connected to the negative polarity and is connected to the work piece. If in doubt consult
the electrode data sheet.
11.4 Effects of Stick (MMA) Welding on Various Materials
11.4.1 High Tensile and Alloy Steels
The two most prominent effects of welding these steels are the formation of a hardened zone in the
weld area, and, if suitable precautions are not taken, the occurrence in this zone of under-bead cracks.
Hardened zone and under-bead cracks in the weld area may be reduced by using the correct electrodes,
preheating, using higher current settings, using larger electrodes sizes, short runs for larger electrode
deposits or tempering in a furnace.
11.4.2 Manganese Steels
The effect on manganese steel of slow cooling from high temperatures causes embrittlement. For this
reason it is absolutely essential to keep manganese steel cool during welding by quenching after each
weld or skip welding to distribute the heat.
11.4.3 Cast Iron
Most types of cast iron, except white iron, are weldable. White iron, because of its extreme brittleness,
generally cracks when attempts are made to weld it. Trouble may also be experienced when welding
white-heart malleable, due to the porosity caused by gas held in this type of iron.