Lincoln Electric V300-PRO manual Periodic Maintenance, Troubleshooting

PERIODIC MAINTENANCE

Overload Protection

The machine is electrically protected from producing high output currents. Should the output current exceed 340-360A, an electronic protection circuit will reduce the current to approximately 150A. The machine will continue to produce this low current until the protection circuit is reset. Reset occurs when the output load is removed.

Thermal Protection

Thermostats protect the machine from excessive operating temperatures. Excessive temperatures may be caused by a lack of cooling air or operating the machine beyond the duty cycle and output rating. If excessive operating temperature should occur, the thermostat will prevent output voltage or current. The meter will remain energized during this time.

Thermostats are self-resetting once the machine cools sufficiently. If the thermostat shutdown was caused by excessive output or duty cycle and the fan is operating normally, the Power Switch may be left on and the reset should occur within a 15 minute period. If the fan is not turning or the air intake louvers were obstructed, then the power must be switched off for 15 minutes in order to reset. The fan problem or air obstruction must also be corrected.

Filter Capacitor Conditioning

A protection circuit is included to monitor the voltage across filter capacitors C1 and C2 (also C14 and C15 on 575 VAC units). In the event that the capacitor volt- age is too high, the protection circuit will prevent out- put. The protection circuit may prevent output provid- ing all these circumstances are met:

1.Machine is internally connected for 380 VAC, or higher input voltage.

2.Machine did not have power applied for many months.

3.Machine did not produce output when power was first switched on.

If these circumstances apply, the proper action is to switch the machine on and let it idle for up to 30 min- utes. This is required to condition the filter capacitors after an extended storage time. The protection circuit will automatically reset once the capacitor conditioning and resultant voltage levels are acceptable. It may be necessary to turn the power switch off and back on again after this period.

TROUBLESHOOTING

WARNING

ELECTRIC SHOCK can kill.

•Have an electrician install and service this equipment.

•Turn the input power off at the fuse box before working on equipment.

•Do not touch electrically hot parts.

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EXPLODING PARTS can cause

injury.

• Failed parts can explode or cause other parts to explode when power is applied.

•Always wear a face shield and long sleeves when servicing.

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Visual Inspection

Clean interior of machine with a low pressure airstream. Make a thorough inspection of all compo- nents. Look for signs of overheating, broken leads or other obvious problems. Many problems can be uncovered with a good visual inspection.

Open Circuit Voltage

The open circuit voltage of the Invertec V300-PRO is 60 to 75 VDC and cannot be adjusted by the output control.

Test Conditions

Perform all testing at the lowest input voltage avail- able, except where a higher voltage is required by a test step. Make ohmmeter checks only after power has been disconnected from machine and after capacitors have been discharged.

Certain high voltage connections have been insulated with RTV sealant. It is necessary to break through the sealant with a sharp probe in order to make voltage or resistance checks.

Disconnect any control cables from remote control receptacle.

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