Cable Inductance and ITS Effects on Welding

A-8

INSTALLATION

A-8

CABLE INDUCTANCE AND ITS EFFECTS ON WELDING

Excessive cable inductance will cause the welding performance to degrade. There are several factors that contribute to the overall inductance of the cabling system including cable size, and loop area. The loop area is defined by the separation distance between the electrode and work cables, and the overall welding loop length. The welding loop length is defined as the total of length of the electrode cable (A) + work cable

(B) + work path (C) (See Figure A.6).

To minimize inductance always use the appropriate size cables, and whenever possible, run the electrode and work cables in close proximity to one another to minimize the loop area. Since the most significant fac- tor in cable inductance is the welding loop length, avoid excessive lengths and do not coil excess cable. For long work piece lengths, a sliding ground should be considered to keep the total welding loop length as short as possible.

REMOTE SENSE LEAD

SPECIFICATIONS

Voltage Sensing Overview

The best arc performance occurs when the Power Wave S350 has accurate data about the arc condi- tions.

Depending upon the process, inductance within the electrode and work cables can influence the voltage apparent at the studs of the welder, and have a dra- matic effect on performance. Remote voltage sense leads are used to improve the accuracy of the arc volt- age information supplied to the control pc board. Sense Lead Kits (K940-xx) are available for this pur- pose.

The Power Wave S350 has the ability to automatically sense when remote sense leads are connected. With this feature there are no requirements for setting-up the machine to use remote sense leads. This feature can be disabled through the Weld Manager Utility (available at www.powerwavesoftware.com) or through the set up menu (if a user interface is installed into the power source).

CAUTION

If the auto sense lead feature is disabled and remote voltage sensing is enabled but the sense leads are missing, improperly connected extreme- ly high welding outputs may occur.

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General Guidelines for Voltage Sense Leads Sense leads should be attached as close to the weld as practical, and out of the weld current path when possible. In extremely sensitive applications it may be necessary to route cables that contain the sense leads away from the electrode and work welding cables.

Voltage sense leads requirements are based on the weld process (See Table A.2)

	TABLE A.2
Process	Electrode Voltage Sensing (1)	Work Voltage Sensing (2)
	67 lead	21 lead
GMAW	67 lead required	21 lead optional (3)
GMAW-P	67 lead required	21 lead optional (3)
FCAW	67 lead required	21 lead optional (3)
GTAW	Voltage sense at studs	Voltage sense at studs
SMAW	Voltage sense at studs	Voltage sense at studs

(1)The electrode voltage sense lead (67) is automatically enabled by the weld process, and integral to the 5 pin arclink control cable (K1543- xx).

(2)When a work voltage sense lead (21) is connected the power source will automatically switch over to using this feedback (if the auto sense feature is enable).

(3)Negative polarity semi-automatic process operation WITHOUT use of a remote work sense lead (21) requires the Negative Electrode Polarity attribute to be set.

FIGURE A.6

POWER

WAVE

S350

WORK

POWER WAVE® S350