Tweco HMC-410 - Manual (Page 61)

HMC-410
July 27, 2005 4-19
Spot Hold Operation — Recycle count is
programmed to one
Trigger pull and release through the first second of the
weld segment (otherwise the mode defaults to the Spot
Deadman mode of operation). Pulling the trigger before
the end of the weld segment advances to crater fill.
Stitch Hold Operation — Recycle count is
programmed to more than one
Trigger pull and release through the first second of the
weld segment (otherwise the mode defaults to the Stitch
Deadman mode of operation). Pulling the trigger before
the end of the weld advances to crater fill and stops the
current stitch.
Operational Faults
During operation of the control panel, several factors can
create an operational fault. Faults for the HMC-410 are
grouped into three classifications:
Ground fault
Feeder fault, and
Tolerance fault
The ground fault is activated whenever a large current is
sensed through the earth ground from the power source
to the HMC-410 chassis. Since this is a significant safety
hazard, the control will immediately shut down all systems
under its control, excite the error light and relay, and
display “gnd Err” on the front panel. This will stay on
until the power is cycled on the control panel. This
situation should be researched and fixed before welding
is continued.
The feeder fault will be noticed by the fact that wire will
not feed during welding or during the INCH execution. If
there are no obvious impediments to the wire feeding
(e.g., blocked tip), then the feeder fault may have activated.
This occurs if the current through the motor exceeds
specifications. This could be from a bind on the feed, bad
cabling or
various other causes. In order to clear the error, power
should be cycled on the control panel. If the problem
persists, the feeder control cable, feeder, gun/torch, and
wire feed should be thoroughly checked for blockage and
short circuits.
The tolerance fault will occur during welding. It will show
via a light on the front panel, the activation of the error
relay, and may terminate the weld cycle if the fault abort
function is enabled (See Soft Switch Description located
in the Operation chapter). This error is caused because
of arc voltage out of tolerance (± .5 Volt variance from
programmed value), wire feed speed out of tolerance (±
10 IPM variance from programmed value), or a loss of
arc established from the power source. The error will be
recognized if any of these conditions continuously persist
for more time than the fault delay time. This type of error
will clear itself once a new weld cycle is initiated.
NOTE
The error relay will close from the occurrence
of the error through .1 second after the weld
is done. It is envisioned that this relay will drive
a customer’s latching relay which can be reset
by the customer.