Lincoln Electric CV-250 manual General Maintenance, Machine and Circuit Protection

D-1 MAINTENANCE D-1

SAFETY PRECAUTIONS

WARNING

ELECTRIC SHOCK can kill.

•Only qualified personnel should perform this maintenance.

•Turn the input power OFF at the disconnect switch or fuse box before working on this equipment.

•Do not touch electrically hot parts.

GENERAL MAINTENANCE

1.The fan motor has sealed bearings which require no service.

2.In extremely dusty locations, dirt may clog the air channels causing the welder to run hot with prema- ture tripping of thermal protection. Blow out the welder with low pressure air at regular intervals to eliminate excessive dirt and dust build-up on inter- nal parts.

MACHINE AND CIRCUIT PROTECTION

The CV-250 Control PC Board has built-in diagnostic routines to alert the operator when trouble exists. When a trouble condition occurs, the CV-250 meter will display an error code, in the form "EXX", where "XX" refers to a specific error. See TROU- BLESHOOTING section for an explanation of the error codes.

The power source is thermostatically protected against overload or insufficient cooling. If the machine is overloaded, the thermostat will open, thermal pro- tection indicator light will turn on, and the output will be zero. The fan will continue to run and auxiliary power will still be available. The thermostat will remain open until the machine cools, at which time it will close and the output will again be available.

The CV-250 is electronically protected against over- loads and accidental short circuits. The overload pro- tection circuit automatically reduces the output current to a safe value when an overload is detected. If the circuitry senses a short circuit, it will shut off the CV- 250 output. The short circuit protection circuit can be reset by turning the CV-250 Power switch OFF for at least 10 seconds. Remove the short before turning the Power switch ON again.

CV-250