Lincoln Electric CV-250 manual Starting the Machine, Auxiliary Power, Overload Protection

B-6 OPERATION B-6

STARTING THE MACHINE

The power switch at the extreme right side of the con- trol panel energizes the CV-250.

ADJUSTING THE OUTPUT VOLTAGE USING THE DIGITAL METER

The digital meters in the CV-250 incorporate a voltage pre- set function. This allows the operator to set the desired welding voltage before striking an arc. The digital meters can also display welding current.

To make use of the voltage preset function, the Volts/Amps switch must be in the "Volts" position. Turn the Voltage Adjust knob until the digital meter displays the desired weld- ing voltage. (See below if an external power source remote control is installed.)

When an arc is struck, the digital meter displays the actual welding voltage, as measured at the CV-250 output termi- nals.

NOTE: The arc voltage at the electrode may be as much as two volts different from the CV-250 output terminal voltage. This is due to voltage drops present in the welding cables, cable connections, and welding gun. To minimize these drops, use cables of ade- quate capacity, and make sure all connections are clean and tight. Because of these voltage drops, you may have to preset the CV-250 for a slightly higher welding voltage than your procedure calls for.

To read welding current, set the Volts/Amps switch to the "Amps" position. The welding current will be displayed whenever an arc is struck.

LOCAL/REMOTE SWITCH OPERATION

If voltage control is desired at the CV-250, the Local/Remote switch must be in the "Local" position. The Voltage Adjust on the front panel can be used to adjust the CV-250 output. (The remote control, even if connected, will have no effect if the switch is in the "Local" position).

To use a remote control, such as the K857 (see INSTALLA- TION section), place the Local/Remote switch (see Figure B.1) in the "Remote" position. The remote control now con- trols the output voltage, in the manner described above. This control may be adjusted while welding to change the CV-250 output.

AUXILIARY POWER

42 volt AC auxiliary power, as required for some wire feeders, is available through the wire feeder recepta- cle. A 10 amp circuit breaker protects the 42 volt cir- cuit from overloads.

CV-250 machines can also supply 115 volt AC auxil- iary power through the wire feeder receptacle. A 5 amp circuit breaker protects the 115 volt circuit from overloads.

NOTE: Do not use circuits 2 or 4 for control of auxil- iary loads. (The 2-4 circuit is isolated from the 31-32 and 41-42 circuits.)

CAUTION

Note that some types of equipment, especially pumps and large motors, have starting currents which are significantly higher than their running current. These higher starting currents may cause the circuit breaker to open. If this situation occurs, the user should refrain from using the CV-250 auxiliary power for that equip- ment.

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OVERLOAD PROTECTION

This welder has thermostatic protection from exces- sive duty cycles, overloads, loss of cooling, and high ambient temperatures. When the welder is subjected to an overload or loss of cooling, a thermostat will open. This condition will be indicated by the illumina- tion of the yellow Thermostatic Protection Light on the case front (see Figure B.1).The fan will continue to run to cool the power source. No welding is possible until the machine is allowed to cool and the Thermostatic Protection Light goes out.

CV-250