Lincoln Electric IM944 POWERTORCH PLASMA 20 - Manual (Page 10)

B-1 OPERATION
POWERTORCH™ PLASMA 20
B-1
SAFETY PRECAUTIONS DESCRIPTION
The POWERTORCH™ PLASMA 20 is a constant cur-
rent, continuous control plasma cutter power source.
The POWERTORCH™ PLASMA 20 comes standard
with an air regulator and pressure gauge. The unit is
powered from a 115Vac, 20 amp input circuit with a
40% duty cycle rating on a 10 minute basis, with 20
amp output. The unit includes a hand-held torch with
consumables and a work cable with clamp.
The POWERTORCH™ PLASMA 20 utilizes a 3 sec-
ond delay after pressing the trigger before arc initia-
tion to ensure that the operator is ready. The unit will
not function if consumables are not installed correctly
or missing, protecting the user. The unit uses pneu-
matic-action touch starting for arc initiation and does
not use high-frequency.
Plasma is a gas that is heated to an extremely high
temperature and ionized so that is becomes a conduc-
tor of electricity.
This cutting procedure utilizes the plasma to transfer
the electric arc to the metal workpiece. The arc melts
a small amount of the work piece and the compressed
air blows away the molten metal there by producing
the cutting action.
The torch uses compressed air from a single source,
for both the plasma, cooling and protective gas.
The start of the cycle is determined by an arc, called
the pilot arc, which is struck between the moveable
electrode (negative polarity) and the torch nozzle
(positive polarity) due to a short circuit between these
two elements.
When the torch is brought into direct contact with the
workpiece to be cut (connected to the positive polarity
of the power source) the pilot arc is transferred
between the electrode and the workpiece thus striking
a plasma arc, also called the cutting arc.
The duration of the pilot arc is set in the factory at 3
seconds; if the transfer has not been made within this
time, the cycle is automatically stopped except for the
cooling air which is kept on.
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.
FUMES AND GASES
can be dangerous.
• Keep your head out of fumes.
• Use ventilation or exhaust to
remove fumes from breathing
zone.
WELDING, CUTTING and
GOUGING SPARKS
can cause fire or explosion
• Keep flammable material away.
• Do not weld, cut or gouge on contain-
ers that have held combustibles.
Observe additional Safety Guidelines detailed in
the beginning of this manual.
WARNING
ARC RAYS
can burn.
• Wear eye, ear and body
protection.
PLASMA ARC
can injure
• Keep your body away from nozzle
and plasma arc.
• Operate the pilot arc with caution. The
pilot arc is capable of burning the
operator, others or even piercing
safety clothing.