MK Products MK Cobramatic Pro Series - Manual (Page 12)

Cobramatic ® Pro Series Owner’s Manual - Page 5
Wire Size Selector Switch
The wire size selector switch changes the torque of the slave motor for the
wire you are using. When in the .030-.035 aluminum only position, the slave
motor produces approximately 1 1/2 lbs/inch of torque and approximately 4
1/2 lbs/inch when in the all other wires position.
NOTE:
Operating the cabinet with the switch in the wrong
position will cause wire feed difficulties.
PosaStart Switch & Run In Speed Setting
The Posa Start Run-in Speed Control, located on the front panel, provides
wire speed adjustment for slow wire run-in. This setting tracks as a percent-
age of the welding wire speed setting. Once the arc has been established,
the wire feed speed automatically changes from the slow run-in speed to the
welding wire speed set on the gun potentiometer.
PosaStart operation and configuration is explained later in this section.
Trigger Normal/Trigger Latched
This switch configures the electronic Trigger Latching mechanism. In the
Trigger “Normal” mode, pull and hold the trigger to start welding functions -
release trigger to stop welding functions. In the Trigger “Latched” mode pull
and release trigger, to start welding functions- pull trigger again and release,
to stop welding functions.
NOTE:
Most guns require Modified Gas Valve Assy (p/n 003-2199) for
Pre & Postpurge functions.
The Pre-Purge/Post-Purge functions are pre-configured to provide a preset
amount of pre & postpurge gas time; 0.25 and 2.0 second respectively. The
default factory position of this jumper is horizontal (top right) across pins.
Changing the position of the JP3 jumper changes the configuration of the pre
& postpurge sequences. Refer to Figure 5 for the desired pre and postpurge
sequence. Once the desired sequence is selected, relocate on JP3 jumper
from its horizontal default pattern (top right) to its new vertical sequence posi-
turn.
Pre-Purge Settings & Adjustments (JP2)
The Pre-Purge Jumper/Pot Configuration at JP2 has 3 available settings:
0.25 sec. fixed, variable from 0-1 sec. or variable from 0-5 seconds.
By default, the twin two-pin jumpers, across rows 1 & 3, are configured for
0.25 sec. Just to the left of the jumpers is a ¾-turn potentiometer (pot) which
is used with both variable settings. For the 0-1 sec. range, move the jumpers
across rows 3 & 5. For the 0-5 second range, move the jumpers across rows
5 & 7 (Figure 6a).
Timing adjustment for the variable settings are as follows: Move the jumpers
to either variable setting location. Turn potentiometer screw (Small flat or
cross-head) half way. Pull gun trigger and count time between red contactor
Figure 5