Lincoln Electric R3R 375-I, R3R 500-I manual Troubleshooting

E-4		TROUBLESHOOTING			E-4
	Observe all Safety Guidelines detailed througout this manual
	PROBLEMS		POSSIBLE CAUSE		RECOMMENDED
	(SYMPTOMS)				COURSE OF ACTION
			FUNCTION PROBLEMS
E. Machine does not have		1.	Input fuse blown. Machine is	1.	Replace fuse or repair input line.
maximum output (67 to 71 volts).			single phased.		Check reason for fault.
		2.	One phase of main transformer	2.	Repair.
			windings open.
		3.	Defective power bridge.	3.	Check bridge per
					Troubleshooting Procedures
					Section J and check snubber per
					Section F.
F. Machine comes on but soon trips		1.	Improper ventilation.	1.	Make sure all case openings are
off while under load and High					free for proper circulation of air.
Temperature Warning Light
glows. (Thermostat tripped)		2.	Loaded beyond rating.	2.	Operate at rated current and
					duty cycle.
		3.	Fan inoperative.	3.	Check leads and motor bearings.
					Fan can be tested on 115 volt
					line.
		4.	Shorted diode or SCR in power	4.	Refer to Troubleshooting
			rectifier bridge.		Procedures Section J and
					Snubber, Section F.
G.Machine comes on but reduces		1.	Excessive load causing the over-	1.	Reduce load.
to low output under load and			load protection on control board
remains there until the load is			to operate.
broken and arc restarted. See
Fault Protection Troubleshooting		2.	Machine output shorted causing	2.	Turn machine off and remove
Section E.			overload protection on control		short.
			board to operate.
		3.	Control circuit defective.	3.	Replace per PC board,
					Troubleshooting, Section A.

CAUTION

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your Local Lincoln Authorized Field Service Facility for technical troubleshooting assistance before you proceed.

IDEALARC® R3R 375-I, 500-I AND 600-I