Tweco 3000 Merlin - Manual (Page 17)

Manual 0-2532 2-3 INTRODUCTION
E. RF Shielding
All machine torch systems are shielded to minimize ra-
dio frequency (RF) interference which results from the
high frequency arc initiation. These shielded systems
are designed with features such as a wire for establish-
ing an earth ground and shielded torch and control leads.
F. Interlocks
The system has several built-in interlocks to provide safe
and efficient operation. When an interlock shuts down
the system, the torch switch (or control device) must be
used to restart the system.
1. Parts-In-Place (PIP) Interlock
The Power Supply has a built-in parts-in-place inter-
lock that prevents accidental torch starting when torch
parts are not properly installed. A flow switch on the
coolant return lead detects reduced coolant flow
caused by improper torch assembly. If not satisfied,
the switch interrupts power to the tip and electrode.
2. Gas Pressure Interlock
Pressure switches act as an interlock for the gas sup-
plies. If supply pressure falls below minimum re-
quirements the pressure switches will open, shutting
off the power to the contactors, and the GAS indica-
tor will go out. When adequate supply pressure is
available the pressure switches close, allowing power
to be resumed for cutting.
3. Thermal Interlock
Thermal overload sensors are located in the trans-
former and main heatsink in the power supply. If
one of these components is overheated the appro-
priate switch will open up, causing the temperature
light to turn from green to red and shutting off power
to the main contactor. When the overheated com-
ponent cools down the switch will close again and
allow operation of the system.
G. Plasma Torches
Plasma torches are similar in design to the common au-
tomotive spark plug. They consist of negative and posi-
tive sections which are separated by a center insulator.
Inside the torch, the pilot arc is initiated in the gap be-
tween the negatively charged electrode and the positively
charged tip. Once the pilot arc has ionized the plasma
gas, the superheated column of gas flows through the
small orifice in the torch tip, which is focused on the metal
to be cut.
The Maximizer 300 Torch uses an internal closed-loop
cooling system. Deionized coolant is distributed from a
reservoir in the Power Supply through the coolant supply
lead. At the torch, the coolant is circulated around the
torch tip and electrode, where the extra cooling helps to
prolong parts life. Coolant then circles back to the power
supply through the return lead. The Maximizer 300 also
can use secondary gases such as compressed air, nitro-
gen (N2), water, and carbon dioxide (CO
2
).
2.05 Options And Accessories
These items can be used to customize a standard sys-
tem for a particular application or to further enhance per-
formance. Torch accessories are listed in the separate
Torch Instruction Manual.
NOTE
Refer to Section 6, Parts Lists, for ordering
information.
A. RC6010 Remote Control
For mechanized systems, this low profile unit pro-
vides full CNC capability and allows the operator to
control all system functions from a remote location.
B. Computer Control Cable Kits
For interfacing the power supply with a computer or
auxiliary control device. Available in various cable
lengths.
C. SC-10 Standoff Control
For machine torch systems, the SC-10 automatically
finds height and maintains torch standoff with a high
speed torch lifter motor.
D. High Pressure Regulators
Available for air, oxygen, argon/hydrogen, nitrogen,
CO
2
, and water.
E. High Flow Water Shield (HFWS) Assembly
Reduces arc glare, noise, and fumes during the cut-
ting process.
F. Two Stage Air Line Filter
Removes damaging contaminants as small as 0.5
microns from the plasma stream when using com-
pressed air.