Lincoln Electric COBRAMATIC IM597 - Manual (Page 15)

K1587-1 Cobramatic® Owner's Manual - Page 15
8.1.2 TESTING THE POTENTIOMETER - “W” CLOCKED
Using the torch amphenol, check the resistance across pin “D” (wiper) and
pin “C”. The resistance should vary from 0 - 5K ohms.
Check the resistance across pin “D” (wiper) and pin “G”. The resistance
should vary from 5K - 0 ohms.
8.1.3 TESTING THE MICRO SWITCH
Using the torch amphenol, check for continuity across pins “E” and “F” when
the trigger is pressed.
8.2 RELAY K2 OPERATION
When the torch trigger is pressed, 24VAC is sent to the coil of relay K2.
When K2 is energized, AC is sent to the slave motor, spool brake, and the AC
contactor. Relay K2 is also responsible for sending 24VAC to the speed
control circuit and shorting the torch motor leads together when the trigger is
released for the dynamic braking system. K2 also provides the closing
contactor signal.
8.3 TESTING THE INPUT POWER CIRCUITS
The AC circuits are protected by fuses F2 and F3. If F2 and F3 continually
blow, remove J4 (Brake Solenoid), J7 (slave motor) and J5-3,4 (AC
Contactor) from the P.C. Board. Replace fuse, and retrigger system. If fuse
does not blow; isolate the problem by plugging in J4, J7, and J5-3,4 one at a
time until the fuse blows.
8.4 TESTING THE SPEED CONTROL
NOTE: The torch should be tested first and the amphenol must be connected to the
Cobramatic® to perform this test.
Place a voltmeter across diode D10 and press torch trigger. A reading of 0 -
24VDC should be observed, as the torch potentiometer varied.
+
_
24.0 24.0 24.0 24.0 24.0
VDC
D10