Lincoln Electric IM917-A Output CABLES, Connections and Limitations, Negative Electrode Polarity

A-3 INSTALLATION A-3

OUTPUT CABLES, CONNECTIONS AND LIMITATIONS

Connect a work lead of sufficient size and length (per table A.1) between the proper output terminal on the power source and the work. Be sure the connection to the work makes tight metal-to-metal electrical contact. To avoid interference problems with other equipment and to achieve the best possible operation, route all cables directly to the work or wire feeder. Avoid excessive lengths and do not coil excess cable.

CAUTION

When using an inverter type power source like the POWER WAVE®s, use the largest welding (elec- trode and work) cables that are practical. At least 2/0 copper wire - even if the average output cur- rent would not normally require it. When pulsing, the pulse current can reach very high levels. Voltage drops can become excessive, leading to poor welding characteristics, if undersized weld- ing cables are used.

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CABLE INDUCTANCE, AND ITS EFFECTS ON PULSE WELDING

For Pulse Welding processes, cable inductance will cause the welding performance to degrade. For the total welding loop length less than 50 ft.(15.24m), tradi- tional welding cables may be used without any effects on welding performance. For the total welding loop length greater than 50 ft.(15.24m)), the K1796 Coaxial Welding Cables are recommended. The welding loop length is defined as the total of electrode cable length

(A)+ work cable length (B) + work length (C) (See Figure A.3).

POWER		FIGURE A.3
		A
WAVE
		C
	B	WORK

For long work piece lengths, a sliding ground should be considered to keep the total welding loop length less than 50 ft.(15.24m). (See Figure A.4.)

POWER	FIGURE A.4	A		A
WAVE
		C	WORK	C
K1796 COAXIAL CABLE		BSLIDING	WORK	B
MEASURE FROM END
OF OUTER JACKET OF
CABLE

Output connections on some POWER WAVE®s are made via 1/2-13 threaded output studs located beneath the spring loaded output cover at the bottom of the case front.

Most welding applications run with the electrode being positive (+). For those applications, connect the elec- trode cable between the wire feeder and the positive

(+)output Twist-Mate terminal on the power source. Connect the other end of the electrode cable to the wire drive feed plate. The electrode cable lug must be against the feed plate. Be sure the connection to the feed plate makes tight metal-to-metal electrical con- tact. The electrode cable should be sized according to the specifications given in the output cable connec- tions section. Connect a work lead from the negative (-) power source output Twist-Mate terminal to the work piece. The work piece connection must be firm and secure, especially if pulse welding is planned.

For additional Safety information regarding the elec- trode and work cable set-up, See the standard "SAFE- TY INFORMATION" located in the front of the Instruction Manuals.

CAUTION

Excessive voltage drops caused by poor work piece connections often result in unsatisfactory welding performance.

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NEGATIVE ELECTRODE POLARITY

When negative electrode polarity is required, such as in some Innershield applications, reverse the output connections at the power source (electrode cable to the negative (-) Twist-Mate terminal, and work cable to the positive (+) Twist-Mate terminal.

When operating with electrode polarity negative the "Electrode Sense Polarity" DIP switch must be set to the "Negative" position on the Wire Drive Feed Head PC Board. The default setting of the switch is positive electrode polarity. Consult the Power Feed instruction manual for further details.

POWER WAVE® 405M