Thermal Dynamics PAK Master 150XL, Руководство по обслуживанию

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SERVICE TROUBLESHOOTING 4-4 Manual 0-2728
Indicator Meaning
D4
Power Enable - When ON PWM
Enable received from the Logic
PC Board.
D20
Reset - Normally ON, goes out
when torch switch is pressed.
Indicator will blink if primary over-
current is detected when torch
switch is pressed.
Gate Drive P C B oards
D. Pilot/Output Board Functions
NOTE
Refer to Appendix 6 for Pilot/Output PC Board
layout.
The Pilot/Output PC Board has an IGBT which is
turned on by the Logic PC Board for piloting. This
allows the DC to flow from the output (-) through
the pilot return (tip) to a Pilot Inductor and finally to
the work. This path is broken very quickly by the
IGBT when the main cutting arc is initiated. This
board also filters the torch shield back to the torch (-
) through the Capacitor.
Indicator Meaning
D5
IGBT is turned on from the logic signal
coming from the Logic Board PCR J5-6.
NOTE: This LED is on during piloting; it is
off during cutting.
Pilot PC Board
E. Current Sense PC Board Functions
NOTE
Refer to Appendix 11 for Current Sense PC Board
layout.
The Current Sense PC Board senses current in the
work lead (approximately 3 amps). When this hap-
pens, it sends a signal back to the Logic Board. This
in turn tells the Logic to change demand levels from
pilot current to main cutting current.
4.04 Common Operating Problems
WARNINGS
Disconnect primary power at the source before dis-
assembling the power supply, torch, or torch leads.
Frequently review the Important Safety Precau-
tions in Section 1. Be sure the operator is equipped
with proper gloves, clothing, eye and ear protec-
tion. Make sure no part of the operator’s body comes
into contact with the workpiece while the torch is
activated.
Sparks from the cutting process can cause damage
to coated, painted, and other surfaces such as glass,
plastic and metal.
Handle torch leads with care and protect them from
damage.
A. Piloting
Piloting reduces parts life more than actual cutting
because the pilot arc is directed from the electrode to
the tip rather than to a workpiece. Whenever pos-
sible, avoid excessive pilot arc time to improve parts
life.
B. Torch Standoff
Improper standoff (the distance between the torch
tip and workpiece) can adversely affect tip life as well
as shield cup life. Standoff may also significantly af-
fect the bevel angle. Reducing standoff generally re-
sults in a more square cut.
C. Edge Starting
For edge starts, hold the torch perpendicular to the
workpiece with the front of the torch tip at the edge
of the workpiece, not touching, at the point where
the cut is to start. When starting at the edge of the
plate, do not pause at the edge and force the arc to
“reach” for the edge of the metal. Establish the cut-
ting arc as quickly as possible.
D. Direction of Cut
The plasma gas stream swirls as it leaves the torch.
The purpose of the swirl is to maintain a smooth col-
umn of gas. The swirl effect results in one side of a
cut being more square than the other. Viewed along
the direction of travel, the right side of the cut is more
square than the left.