Miller Electric KC237900 manual Overload Protection, Circuit Board Handling Precautions

WARNING: ELECTRIC SHOCK can kill.

• Do not touch live electrical parts.

•Shut down welding power source, and dis- connect input power employing lockout/tagging procedures before inspecting, maintaining, or servicing.

Lockout/tagging procedures consist of pad- locking line disconnect switch in open position, removing fuses from fuse box, or shutting off and red-tagging circuit breaker or other discon- necting device.

1.Remove top cover and right side panel, and locate spark gaps according to Parts List Views.

2.Loosen screws A on both sides.

3.Place feeler gauge of proper thickness between points C.

4.Apply slight pressure against points B so feeler gauge is held firmly in gap.

5.Tighten screws A.

6.Close and secure front panel access door.

C C

A

B A B S-0043

Figure 6-3. Spark Gap Adjustment

6-4. OVERLOAD PROTECTION

WARNING: ELECTRIC SHOCK can kill.

• Do not touch live electrical parts.

•Shut down welding power source, and dis- connect input power employing lockout/tagging procedures before inspecting, maintaining, or servicing.

Lockout/tagging procedures consist of pad- locking line disconnect switch in open position, removing fuses from fuse box, or shutting off and red-tagging circuit breaker or other discon- necting device.

INCORRECT FUSE can damage unit.

•Use only replacement fuse of same size, type, and rating (see Parts List).

The control circuit in the TIG-Unit is protected by a 15 ampere circuit breaker CB1 located under the front ac- cess door to the left of the duplex receptacle. Should this circuit breaker trip, it would be necessary to manually re- set it by depressing the button. The symptoms of a tripped breaker are no output at the duplex receptacle,

no flow of gas and coolant, and no high-frequency out- put.

A. Fuse F1

Fuse F1 is a 3 ampere, glass fuse located on the center mounting panel below terminal strip 1T. If this fuse should open, there would be no remote control of the contactor.

B. Fuse F2

When the unit is connected to 230 volts in the welding power source, the entire TIG-Unit is protected by a 600 volts, 10 ampere, cartridge type fuse F2. This fuse is lo- cated on the center mounting panel below terminal strip 1T. Should this fuse open, the TIG-Unit will completely shut down.

6-5. CIRCUIT BOARD HANDLING PRECAUTIONS

WARNING: ELECTRIC SHOCK can kill.

• Do not touch live electrical parts.

•Shut down welding power source, and dis- connect input power employing lockout/tagging procedures before inspecting, maintaining, or servicing.

Lockout/tagging procedures consist of pad- locking line disconnect switch in open position, removing fuses from fuse box, or shutting off and red-tagging circuit breaker or other discon- necting device.

CAUTION: ELECTROSTATIC DISCHARGE (ESD) can damage circuit boards.

•Put on properly grounded wrist strap BEFORE handling circuit boards.

•Transport circuit boards in proper static- shielding carriers or packages.

•Perform work only at a static-safe work area.

INCORRECT INSTALLATION or misaligned plugs can damage circuit board.

•Be sure that plugs are properly installed and aligned.

EXCESSIVE PRESSURE can break circuit board.

•Use only minimal pressure and gentle move- ment when disconnecting or connecting board plugs and removing or installing board.

6-6. TROUBLESHOOTING (Table 6-3)

WARNING: ELECTRIC SHOCK can kill.

• Do not touch live electrical parts.

•Shut down welding power source, and dis- connect input power employing lockout/tagging procedures before inspecting, maintaining, or servicing.

Lockout/tagging procedures consist of pad- locking line disconnect switch in open position, removing fuses from fuse box, or shutting off and red-tagging circuit breaker or other discon- necting device.

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