Machine Protection

B-5

OPERATION

B-5

3.42VAC 10 AMP CIRCUIT BREAKER - This breaker protects the 42VAC auxiliary circuits locat- ed in the terminal strip and MS-receptacle.

4.14 PIN MS-RECEPTACLE - This connector pro- vides easy connection for a wire feeder control cable. It provides connections for auxiliary power, output switching, remote output control, wire feeder voltmeter sense lead and ground. Refer to 14 Pin MS Type Receptacle in the Installation Section of this manual for information about the circuits made available at this receptacle.

5.TERMINAL STRIP COVER PANEL - Remove this panel to gain access to the circuits made available at the terminal strip and the 4-pin receptacle for the optional paralleling kit. This terminal strip contains the same circuits as the 14 pin MS-receptacle. The cover also provides for installation of cable strain relief clamps.

6.POSITIVE OUTPUT TERMINAL - This output ter- minal is for connecting a welding cable. To change welding polarity and for proper welding cable size refer to Electrode and Work Cables in the Installation Section of this manual.

7.NEGATIVE OUTPUT TERMINALS - These output terminals are for connecting a welding cable to either the High Inductance or Low Inductance Terminal for desired arc characteristics. (Low induc- tance is recommended only for NR203Ni 1%). To change welding polarity and for proper welding cable size refer to Electrode and Work Cables in the Installation Section of this manual.

CASE BACK CONNECTIONS

220VAC AUXILIARY RECEPTACLE

(European and Export Models)

This receptacle provides up to 2 amps of 220VAC auxiliary power for a water cooler.

220VAC 2 AMP CIRCUIT BREAKER

(European and Export Models)

This breaker protects the 220VAC auxiliary circuit located in the 220VAC receptacle.

DC-655 machines can also supply 115 volt AC auxil- iary power through the wire feeder receptacle. A 20 amp circuit breaker on the Domestic and Canadian models, except for a 15 amp on Canadian Code 10502 and Export models protects the 115 volt circuit from overloads. 115VAC is not available in the MS- receptacle on the European models.

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 DC-655 auxiliary power for that equip- ment.

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THERMAL FAN CONTROL

The machine’s cooling fan remains off when the tem- perature of the rectifiers and windings inside the machine are below that requiring air flow cooling, as determined by electronic monitoring of several thermal sensors and the welding current of the machine. The fan may remain off until welding begins, but once the fan is activated, it will remain on for at least 5 minutes to assure proper cooling. This feature saves energy and also minimizes the amount of dirt and other air borne particles being drawn into the machine.

FAN MOTOR FUSE (EUROPEANMODEL)

A 10 amp slow blow fuse protects the fan motor cir- cuit. This fuse is located inside the DC-655 mounted on the fan motor bracket.

MACHINE SHUTDOWN

The DC-655 provides shutdown modes for thermal over-heating, excessive load currents and faults. It also provides an idle timer shutdown feature for addi- tional operating economy.

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.

DC-655