Rtech MMA 160S User manual

MMA 160S ARC/MMA WELDER
OPERATION INSTRUCTIONS
www.r-techwelding.co.uk

2

3
Thank you for selecting the R-Tech MMA160S Inverter Arc Welder.
The MMA160S has many benefits over traditional Arc welders, including an industrial 60%
duty cycle, Anti-stick hot start technology, portable and lightweight
We want you to take pride in operating our MMA160S as much pride as we have taken in
making this product for you. Please read all information in this manual before operation
PLEASE EXAMINE THE CARTON AND EQUIPMENT FOR DAMAGE IMMEDIATELY
When this equipment is shipped, title passes to the purchaser upon receipt from the courier.
Consequently all claims for material damaged in shipment must be made by purchaser against
the transportation company used.
Please record your equipment identification below for future reference. This information can be
found on the data plate at rear of machine.
Product: MMA160S
Serial No. ___________________________________
Date of Purchase _____________________________
Where Purchased _____________________________
Whenever you request replacement parts or information on this equipment please always
supply information you have recorded above.
This product is covered by a 2 year parts and labour warranty; we will cover the cost of collecting and
returning the item to you. External items, (torch, earth lead etc…) are covered by a 3 month warranty. Any
faults/damage found caused by a customer will be charged accordingly.
Pay particular attention to the safety instructions we have provided you for your protection
The level of seriousness to be applied to each section is explained below
WARNING
This statement appears where the information must be followed exactly to avoid serious personal injury.
CAUTION
This statement appears where the information must be following to avoid a minor personal injury or damage
to this equipment.

4
Introduction
The R-Tech MMA160S is a member of our field acclaimed family of welding products.
Premium features include:-
1. Inverter power source – more efficient to operate, provides smoother weld characteristics.
2. Anti-stick hot start technology for easy arc starting
3. Digital amp meter
4. Industrial 60% Duty cycle at 180 Amps @ 40C
5. Portable and lightweight
Recommended Processes
The R-Tech MMA160S is recommended for the Arc (MMA) welding processes within its output
capacity of 160 Amps
Equipment Limitations
The R-Tech MMA160S is protected from overloads beyond the output ratings and duty cycle as per
machine specifications with thermostat protection of the output coils and rectifiers.
Welding Capability – Duty Cycle
The R-Tech MMA160S is rated at 160 Amps at 60% duty cycle on a ten minute basis. If the duty
cycle is exceeded a thermal protector will shut machine off until the machine cools.
Technical Specifications
Model No. R-Tech MMA160S
Input 240V AC 50/60Hz Fuse rating 26amp
MMA No-load Voltage 60V – 80V
Current Range 10A – 160A
Rated Output Current 160A
Duty Cycle 60%
Gross Weight 12 KG
Insulation IP21S
Dimensions mm 425 x 195 x 310

5
Safety Precautions
Read entire section before starting installation
WARNING!
Electric Shock can kill – Only qualified personnel should perform this installation. Turn off input
power at the fuse box before working on this equipment. Do not touch electrically live parts. Always
connect the machine to an earthed mains supply as per national recommended standards.
Select suitable location
Place the welder where clean cooling air can freely circulate in and out of the front & rear louver
vents. Dirt, dust or any foreign material that can be drawn through vents into welder must be kept to
a minimum. Failure to observe these precautions can result in excessive operating temperatures
which can lead to plant failure.
Grinding
Do not direct grinding particles towards the welder. An abundance of conductive material can cause
plant failure.
Stacking
This machine cannot be stacked.
Transport – Unloading
Never underestimate the weight of equipment, never move or leave suspended in the air above
people. Use recommended lifting equipment at all times.
WARNING!
Falling Equipment can cause injury. Never lift welder with gas bottle attached. Never lift above
personnel.
Tilting
Machine must be placed on a secure level surface or on a recommended undercarriage/trolley.
This machine may topple over if this procedure is not followed.
Environmental Rating
The welding power source carries the IP21S rating. It may be used in normal industrial and
commercial environments. Avoid using in areas where water / rain is around.
Read and follow the ‘Electric Shock Warnings’ in the safety section if welding must be performed
under electrically hazardous conditions such as welding in wet areas or water on the work piece.

6
Electrical Installation
WARNING!
ELECTRIC SHOCK CAN KILL
Machine grounding and High Frequency Interference Protection
This welder must be grounded to earth. See national electrical codes fro proper grounding
methods.
The high frequency generator being similar to a radio transmitter may cause interference to radio,
TV and other electronic equipment. These problems may be the result of radiated interference.
Proper grounding methods can reduce or eliminate this.
Radiated interference can develop in the following ways
1. Direct interference from welder power source
2. Direct interference from the welding leads
3. Direct interference radiated from feedback into power lines
4. Interference from re-radiation by un-grounded metallic objects.
Keeping these contributing factors in mind, installing equipment as per following instructions should
minimize problems.
1. Keep the welder input power lines as short as possible and enclose as much of them as
possible in metal conduit or equivalent shielding. There should be a good electrical contact
between this conduit and ground (Earth).
2. Keep the work and electrode leads as short as possible. Tape the leads together where
practical.
3. Be sure the torch and earth leads rubber coverings are free from cuts and cracks that allow
welding power leakage
4. Keep earth lead connection to work in good condition – Clean area on workbench where
earth clamp is situated on a regular basis.
Input Connections
Make sure the voltage, phase and frequency of input power is as specified on machine rating plate
located at rear of machine.
Have a qualified electrician provide suitable input power as per national electrical codes. Make sure
machine is earthed / grounded.

7
Make sure fuse or circuit breaker is correct rating for machine. Using fuses or circuit breakers
smaller than recommended will result in ‘nuisance’ shut off from welder inrush currents even if
welding at low amperages.
Failure to follow these instructions can cause immediate failure within the welder and void
machines warranty.
Turn the input power OFF at the mains switch & fuse box before working on this equipment.
Have a qualified electrician install & service this equipment.
Allow machine to sit for 5 minutes minimum to allow the power capacitors to discharge before
working inside this equipment. Do not touch electrically live parts
The MMA160S Inverter Arc Welder requires a 240V 50/60Hz supply. It requires a 32A supply for. It
comes with a 3 metre mains cable attached.
Connect wires according to national coding.
Brown wire – Live
Blue wire – Neutral
Green/Yellow Wire – Earth (Ground)
Connecting to a mains electrical supply
THIS MACHINE IS OF AN INDUSTRIAL SPECIFICATION AND MUST BE
FITTED TO A 32AMP 240V MAINS INPUT
Connecting to an Engine Driven Generator
If connecting this machine to an engine driven generator please ensure the
following
Minimum Generator KVA Output – 9 KVA continuous
Generator to be fitted with AVR (automatic voltage regulation)
DO NOT USE ON A GENERATOR WITHOUT AVR
Connecting to a generator without the above minimum requirements will in-
validate your warranty.

8
Connections for MMA160S
Rear machine connections
Fig 1
1. On/Off Switch
Switches main on and off
2. Earth for chassis
If experiencing localized interference when using machine, connect workbench to this point
using correct graded earth wire (not normally used)
3. Mains input cable
Fit required plug as per your electrical installation

9
Connections for STICK MMA (SMAW) Welding
Fig 3
1. Negative power connector -
Connect the earth lead to by inserting and twisting until tight and the earth clamp to
work/bench.
2. Positive power connector +
Connect the electrode holder by inserting and twisting until tight

10
Controls and Settings
Fig 4
1. LED Display
3 digit LED meter is used to display the actual amperage (when welding).
2. Main current control
This adjusts the main welding current and is shown in L.E.D (Fig 4.1) when welding is in
process.

11
Operating machine
SAFETY PRECAUTIONS
WARNING!
ELECTRIC SHOCK CAN KILL
Do not touch electrically live parts or electrode with skin or wet clothing.
Insulate yourself from work and ground
Always wear dry insulating gloves
WARNING!
FUMES AND GASES can be dangerous
Keep your head out of fumes & gases produced from welding.
Use ventilation or exhaust to remove fumes & gases from breathing zone and general area.
WARNING!
WELDING SPARKS can cause fire or explosion
Keep flammable material away from work area.
Do not weld on containers that have held combustibles
WARNING!
ARC RAYS can burn
Wear eye, ear and body protection – Make sure work area is protected by proper shielding to
avoid injury to passers by.
1.

12
Welding in STICK MMA (SMAW) Mode
1. Fit MMA electrode holder to machine
2. Fit earth lead to machine and to work piece
3. Select MMA on MMA/TIG switch
4. Place electrode in holder
5. Select desired welding base current
6. Strike arc and weld
Notes: When machine is switched on, output terminals are always live, take care and do not touch
electrode and earth by person at same time, otherwise electric shock will occur.
Maintenance
Routine and periodic maintenance
WARNING!
ELECTRIC SHOCK CAN KILL
Turn the input power OFF at the mains switch & fuse box before working on this equipment.
Have a qualified electrician install & service this equipment.
Allow machine to sit for 5 minutes minimum to allow the power capacitors to discharge before
working inside this equipment.
Do not touch electrically live parts
1. Periodically remove the side/top panels of machine and clean out machine with a low
pressure dry air line paying particular attention to PC Boards, Fan blades, HF points
2. Inspect input and output cables & hoses for fraying, cuts & bare spots
3. Keep tig torch and cables in good condition
4. Clean air vents to ensure proper air flow and cooling
5. The fan motor has sealed bearings which requires no maintenance

13
Troubleshooting
Service & repair should only be performed by R-Tech welding trained personnel. Unauthorised
repairs performed on this welding equipment may result in danger or injury to the technician and
machine operator and will invalidate your warranty.
For your safety and to avoid electric shock, please observe all safety notes and precautions
detailed throughout this manual
The troubleshooting guide is provided to help you locate possible machine malfunctions
If fault / problem is not listed below check our Arc Welder Support page on our website
www.r-techwelding.co.uk/support.php
or contact R-Tech by phone. Contact details can be found on front of this manual and our website
Welding problems
•No output - Power light is not lit
Check machine on/off switch is in the ‘on’ position
Check Input power to machine
Check plug wiring
Check mains trip / fuses
•No output - Fan runs - Power light is lit
Check power cable connections and condition of earth clamp assy.
•No output - Power light is lit - Warning light is lit
Welding application may have exceeded recommended duty cycle, allow machine to cool
down until the warning light goes out.
•Machine keeps overheating - Warning light is lit on machine
Check if fan is running – if not contact R-Tech for repair
Check the cooling vents for obstruction, blow out machine with clean dry low pressure air
supply. Check for adequate ventilation around machine
•Poor weld penetration
Check condition of earth lead and clamp and ensure clamp is connection via a clean area
on work piece

14
Check condition of tig torch, try other tig torch
MMA Stick welding problems
•Stick electrode ‘blasts off’ when arc is struck
Welding current set to high, reduce amperage or use thicker electrode
Contaminated electrodes or material
•Electrode sticks in weld puddle
Welding current is set too low
Arc is too short, keep electrode further away from work
•Excessive splatter
Too long an arc, keep electrode closer to work
•Poor penetration
Travel speed too fast
Too much welding current, reduce welding amperage
•Porosity in weld
Electrodes are damp
Arc too long, get electrode closer to work

15 15

16

17