Rtech PLASMA P31C User manual

www.r-techwelding.co.uk
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PLASMA P31C
INVERTER PLASMA CUTTER
OPERATION INSTRUCTIONS
Version 2021-11

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Thank you for selecting the R-Tech Plasma 31C Inverter Plasma Cutter
The Plasma 31C has many benefits over traditional transformer plasma cutters, including infinite
power control, HF contact start and quick fitting cost effective torch, long-life cost-effective torch
consumables and a 35% industrial duty cycle
We want you to take pride in operating our Plasma 31C as much pride as we have taken in making
this product for you. Please read all information in this manual before operation
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.
PLEASE EXAMINE 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
data plate at rear of machine.
Product Plasma P31C
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 3 years parts and labour warranty, we will cover cost of collecting and
returning item to you (UK mainland only, other areas are RTB). External items, torch, earth lead etc. are
covered by 3 months warranty. Any faults/damage found caused by customer will be charged pro-rata

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Introduction
The R-Tech Plasma 31C 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. Infinite cutting power adjustment, allows fine tuning of cut characteristics
3. HF start – Enables easy arc starting
4. Digital amp meter
5. Quick fitting torch for easy torch fitment/replacement
6. Long life – Low-cost torch consumables
7. 35% Duty cycle at 30 Amps @ 40ºC
Recommended Processes
The R-Tech Plasma 31C is recommended for the plasma cutting processes within its output capacity of
30 Amps DC
Equipment Limitations
The R-Tech Plasma 31C is protected from overloads beyond the output ratings and duty cycle as per
machine specifications with thermostat protection of the output coils and rectifiers.
Cutting Capability – Duty Cycle
The R-Tech Plasma 31C is rated at 30 Amps at 35% 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
PLASMA
31C
Power Voltage
240V 50/60Hz
AC
Input Current
10.5amps I
-eff (13amp fuse slow blow)
Rated Output Current
30A
Current Adjusting Range
15
- 30A
No
-load Voltage
200V
Rated Duty Cycle
35%
Working Mode
HF Contact Start
Air Pressure
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0 PSI – Working Air Pressure (Air flowing)
Max. Cutting Thickness (Clean cut mild steel)
8mm
Max.
Cutting Thickness (Severance cut mild steel)
12mm
After Flow Time
10 Seconds
Dimensions
390 X 190 X 290

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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 plasma cutter 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 plasma cutter 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 plasma cutter. 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.
Always use recommended lifting equipment.
WARNING!
Falling Equipment can cause injury. Never lift plasma cutter 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 plasma 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.

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Electrical Installation
WARNING!
ELECTRIC SHOCK CAN
KILL
Machine grounding and High Frequency Interference Protection
This plasma cutter must be grounded to earth. See national electrical codes for 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 lead 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.
Make sure fuse or circuit breaker is correct rating.Using fuses or circuit breakers smaller than
recommended will result in ‘nuisance’ shut off from welder inrush currents even if cutting 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

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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 Plasma 31C Plasma Cutters requires a 240V 50/60Hz 1-Phase supply. It requires an 13A
supply. It comes with a mains cable attached.
Connect wires according to national coding.
Brown wire – Live, Blue wire – Neutral
Green/Yellow Wire – Earth (Ground)
Connecting to an Engine Driven Generator
If connecting this Plasma Cutter to an engine driven generator, please ensure
the following
Minimum Generator KVA Output – 5KVA 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.

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Connections for Plasma 31C
Air pressure connection / setting
1. Air pressure regulating knob
This regulates the air pressure as displayed in gauge on front of machine.
To adjust pressure, pull knob upwards and turn to adjust pressure, once correct pressure is
obtained press down knob to secure -Set air pressure to70psi when air is flowing through
torch.
2. Air inlet connector
Connect hose from air compressor onto standard male PCL fitting – Fitting can be changed
if required to suit.
Note: If regulator fills with water, unscrew thumbscrew underneath to slowly drain of water,
screw back tight once drained.

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Rear machine connections
1. On / Off Switch
Turns machine on and off, the switch illuminates when machine turned on
2. Mains input cable
Fit required plug as per your electrical installation
3. 2nd Earth Connector
This can be used to earth the machine to workbench if you are experiencing interference from the
HF – Sometimes required when using CNC automated machinery - Not normally used

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Front machine connections
1. Torch power connector
Connect the main torch cable and screw clockwise until tight
2. Torch switch socket
Connect the torch switch plug (2 pin) and screw on retaining ring to secure
3. Earth / Workpiece connector
Connect the earth lead to this connector.
Insert male connector into socket and twist clockwise until tight.
Secure other end of earth lead to Workpiece via the earth clamp