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

Low output, low OCV, or erratic welding

Turn

control dial to

minimum

Check OCV

OCV is 35-55V

OCV is 40-45V

OCV is 0

Rated

OCV but

OCV less

than

rated

erratic welding

but more than

55V

OCV 45-55V

OCV 35-45V

Possible machine

Check leads 76, 77,

Possible

Loose lead

Possible intermittent

Possible

Possible wrong connection

Possible defective

is being

212, 213, 210, 211

defective

connections

or loose connections

defective

of gate leads if recent

PC board

single phased

& SW2 for open

PC board

on shunt

in control circuit.

PC board

PC board or rectifier

Check

voltages

Check PC board con-

stack change.

aux.

IDEALARC®

on PC board

nector, switches,

potentiometers, etc.

201-202 = 120V ± 10%

Replace

Retighten

Replace

See

wiring

diagram

Replace

201-202 = 120V ± 10%

leads

and correct

202-203 = 120V ± 10%

Remove and replace Gate leads

G-1, G-2, G-3 from PC board

one at a time.

R3R

If aux. voltages

375

are incorrect,

If

aux. voltages

If

removing

each

gate lead

If removing and

replacing

check & repair.

are OK

one

at a time changes OCV

each gate lead

one at a

-I, 500-I AND600-I

time does NOT change OCV

CONTROLCIRCUIT TROUBLESHOOTING

follows:

77-

Replace

GND 12K minimum

Codes below 9500

with power off, remove leads from

Identify

gate lead that, when

Codes above 9500

75, 76, 77 terminal strip and

removed,

OCV did not change.

with power off, disconnect

welding leads from output terminals

Remove gate lead. Voltage

remote control amphenol

between gate lead and 204 must be 13-17V.

and welding leads from

output terminals.

Check

resistance of

each

If voltage

OK

If voltage is

terminal on this terminal

not correct

strip to ground. Resistance

Check

the following

pins

must be as follows:

Defective power SCR

for

resistance to ground.

75-GND 2K minimum

Possible defective

Resistance must be as

76-GND 2K minimum

PC board

GND 2K min.

CHART

GND 2K min.

Replace.

GND 12K min.

If not, clear terminal strip

If

resistance is OK,

and leads, and also check

possible defective

SW2 and R1 for dirt.

PC board.

If not,

examine amphenol

If resistance is OK,

possible

assembly for faults.

defective PC board.

If fault found, repair or

If amphenol

OK, possible

replace amphenol assembly.

defective PC board.

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TROUBLESHOOTING

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