MK Products Cobramatic 120VAC - Manual (Page 15)

Cobramatic ® Owner’s Manual - page 8
Remove spatter build-up from inside of nozzles with a hardwood stick.
The only parts on the Cobramatic® system that are subject to normal wear
are the conduit, contact tips, gas cups, front body liners, wire guides, drive
and idler rolls. A supply of these parts should be maintained on hand.
If repairs do become necessary, any part can easily be replaced by qualifi ed
maintenance personnel.
Your Cobramatic® is designed to provide years of reliable service. Normal
wear and component failure may require occasional service.
The number of units in operation and the importance of minimal “down time”
will determine to what extent spare parts should be stocked on hand.
Testing the Feeder
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 con-
tactor signal.
Testing the Input Power Circuits
The AC circuits are protected by fuse F3. If F3 continually blows, disconnect
J4 (Brake Solenoid), J7 (Slave Motor) and J5-3 & 4 - if connected (AC Con-
tactor Out.) from the PC board. Replace fuse and re-trigger system. If fuse
does not blow, isolate problem by reconnecting J4, J7 and J5-3 & 4 one at a
time until the fuse blows.
Testing the Speed Control
NOTE:
The torch should be tested fi rst 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.