Tweco SLICE - Manual (Page 8)

8
When using the battery supplied with
this unit, the three-position switch on
the face of the battery box must be in
the "CUT" position when igniting the
rod.
To check the charge on the battery,
push the mode switch to the "TEST"
position. The meter will register the
charge level. The mode switch must
be put in the "CHARGE" position
when the battery is recharged.
The battery should be recharged
when the indicator is close to or in the
red zone of the meter. Recharge
time depends on the level of battery's
discharge level. A fully discharged
battery will take 12 hours to recharge.
FIGURE 5 SLICE Battery Box
Assembly
IMPORTANT PROCESS
VARIABLES AND THEIR
EFFECTS
Process Variables
Exothermic cutting is easier than
most cutting processes to do. It can
be done improperly though.
Variables can reduce the efficiency of
this process, resulting in poor cutting.
Major variables requiring attention are
listed and discussed below.
Oxygen Pressure
The oxygen in this process maintains
the exothermic burn and removes the
molten material from the cut. 80 psi
yields the most efficient cutting rates
(amount of cut per inch of rod
burned), on materials up to 3" thick.
Using pressures less than 80 psi on
such materials reduces cutting rates
because there is not enough pressure
to remove the molten material.
Using pressures under 80 psi is
advantageous for scarfing. Lower
pressures offer a more controllable
scarfing action. With material thicker
than 3", pressures over 80 psi can be
used to give the oxygen enough
velocity to blow away molten material
at the bottom of the cut. Using higher
pressures on thicker materials causes
a more forceful oxygen jet and faster
rod consumption. A sawing motion
with 80 psi or a larger-diameter rod
may help cut these materials more
efficiently.
80 psi is the best pressure to use
when piercing. To pierce, an
operator should reduce the pressure
slightly to control the distance the
molten material travels. Once there is
a hole, full pressure should be used.
The operator can vary pressure by
using the torch's oxygen lever. The
only time pressures above 80 psi are
used in piercing is when the thickness
of the material - usually more than
12" - needs added pressure to blow
the molten material out of the pierce
hole.
Amperage
In exothermic cutting electrical
current increases the heat from the
reaction, allowing faster cutting. 200
amps yields the most efficient cutting
rates with power. When cutting with
power and using less than 200 amps,
the amount of cut per minute will be
lower. Amperage above 200 amps
consumes the rod faster, reducing the
cut per inch of rod burned.
Exothermic cutting equipment uses
CUT
CHARGE TEST
GOOD RECHARGE
STRIKER
TORCH
CUT
CHARGE TEST
GOOD RECHARGE
CUT
CHARGE TEST
GOOD RECHARGE
SWITCH IN TEST POSITION
SWITCH IN CHARGE POSITION
ARCAIR SLICE BATTERY ASSEMBLY
SWITCH IN CUT POSITION
2