Hobart Welding Products OM-227 978B manual Duty Cycle And Overheating, Volt-Ampere Curves, Amperes

4-2. Duty Cycle And Overheating

								Duty Cycle is percentage of 10
								minutes that unit can weld at rated
								load without overheating.
		200						If unit overheats, thermostat(s)
								opens, output stops, and cooling
		175						fan runs. Wait fifteen minutes for
		130						unit to cool. Reduce amperage or
	Amperes							duty cycle before welding.
		100
								Y Exceeding duty cycle can
		80
								damage unit or gun and void
		60						warranty.
	Output	40
		20
		10
		10	20	30	40	60	70 80	100
				Duty Cycle %
			30% duty cycle at 150 amps
			3 Minutes Welding		7 Minutes Resting
Overheating
				0				A or V
					15			OR
				Minutes			Reduce Duty Cycle
								duty1 4/95 − 227 953-A
4-3.	Volt-Ampere Curves

																								The volt-ampere curves show the
																								minimum and maximum voltage
	35																							and amperage output capabilities of
																								the welding power source. Curves
																								of other settings fall between the
	30																							curves shown.
	25										7
											6
Voltage											5
	20										3
											4
	15										2
											1
	10
	5
	0
	0	10	20	30	40	50	60	70	80	90	100	110	120	130	140	150	160	170	180	190	200	210	220	230
												Amperage
																								ssb1.1 10/91 − 227 954-A
OM-227 978 Page 10