Lincoln Electric SVM194-A service manual B4.3, Selector setting and lower open circuit voltage

Return to Section TOC Return to Master TOC

Return to Section TOC Return to Master TOC

Return to Section TOC Return to Master TOC

Return to Section TOC Return to Master TOC

B4.3			OPERATION			B4.3
ENGINE BREAK-IN				DUTY CYCLE
Lincoln Electric selects high quality, heavy-duty industrial				The NEMA output rating of the Classic® 300D Perkins is 300
engines for the portable welding machines we offer.				amperes at 32 arc volts on a 60% duty cycle (consult
While it is normal to see a small amount of crankcase oil				Specifications	in this manual for alternate ratings). Duty
consumption during initial operation, excessive oil use,				cycle is based on a ten minute period; thus, the welder can
wet stacking (oil or tar like substance at the exhaust port),				be loaded at rated output for six minutes out of every ten
or excessive smoke is not normal.				minute period.
Larger machines with a capacity of 350 amperes and				CONTROL OF WELDING CURRENT
higher, which are operated at low or no-load conditions for					CAUTION
extended periods of time are especially susceptible to the
conditions described above. To accomplish successful				DO NOT TURN THE “CURRENT RANGE SELECTOR”
engine break-in, most diesel-powered equipment needs				WHILE WELDING because the current may arc between
only to be run at a reasonably heavy load within the rating				the contacts and damage the switch.
of the welder for some period of time during the engineʼs				-------------------------------------------------------------------------------
early life. However, if the welder is subjected to extensive				The “Current Range Selector” provides five overlapping cur-
light loading, occasional moderate to heavy loading of the				rent ranges. The “Fine Current Adjustment” adjusts the cur-
engine may sometimes be necessary. Caution must be				rent from minimum to maximum within each range. Open cir-
observed in correctly loading a diesel/generator unit.				cuit voltage is also controlled by the “Fine Current
1. Connect the welder output studs to a suitable resis-				Adjustment” permitting control of the arc characteristics.
				A high open circuit voltage setting provides the soft “butter-
tive load bank. Note that any attempt to short the
output studs by connecting the welding leads togeth-				ing” arc with best resistance to pop-outs preferred for most
er, direct shorting of the output studs, or connecting				welding. To get this characteristic, set the “Current Range
the output leads to a length of steel will result in cat-				Selector” to the lowest setting that still provides the current
astrophic damage to the generator and voids the				you need and set the “Fine Current Adjustment” near maxi-
warranty.				mum.
2. Set the welder controls for an output current and volt-				For example:	to obtain 175 amps and a soft arc, set the
age within the welder rating and duty cycle. Note that
any attempt to exceed the welder rating or duty cycle				“Current Range Selector” to the 190-120 position and then
for any period of time will result in catastrophic dam-				adjust the “Fine Current Adjustment” for 175 amps.
age to the generator and voids the warranty.				When a forceful “digging” arc is required, usually for vertical
3. Periodically shut off the engine and check the
crankcase oil level.				and overhead welding, use a higher “Current Range
WELDER OPERATION				Selector” setting and lower open circuit voltage.
				For example: to obtain 175 amps and a forceful arc, set the
		WARNING		“Current Range Selector” to the 240-160 position and the
				“Fine Current Adjustment” setting to get 175 amps.
	ELECTRIC SHOCK can kill.			Some arc instability may be experienced with EXX10 elec-
	•	Do not touch electrically live parts or		trodes when trying to operate with long arc techniques at set-
	•	electrode with skin or wet clothing.		tings at the lower end of the open circuit voltage range.
		Insulate yourself from work and ground.			CAUTION
	FUMES & GASES can be dangerous.
-------------------------------------------------------------------------------				DO NOT attempt to set the “Current Range Selector” between
	• Keep your head out of the fumes.
	• Use ventilation or exhaust to remove			the five points designated on the nameplate.
		fumes from breathing zone.		--------------------------------------------------------------------------------
-------------------------------------------------------------------------------				These switches have a spring loaded cam which almost elim-
	WELDING SPARKS can cause fire or
	explosion.			inates the possibility of setting this switch between the des-
	• Keep flammable material away.			ignated points.
-------------------------------------------------------------------------------
	ARC RAYS can burn.
	• Wear eye, ear, and body protection.

-------------------------------------------------------------------------------

CLASSIC® 300D & 300G