Lincoln Electric R3R-500, R3R-300 Figure F.22 Pocket Amptrol Board Plug P6 and P7 Location

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F-33 F-33

TROUBLESHOOTING & REPAIR

POCKET AMPTROL CIRCUIT TEST (continued)

FIGURE F.22 – POCKET AMPTROL BOARD PLUG P6 AND P7 LOCATION

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P6P7

Pin 1 (Lead #218)

Pin 2 (Lead #219)

Pin 3 (Green)

Pin 1 (Green)

Pin 2 (Yellow)

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8.Connect the Pocket Amptrol unit from the work to the electrode welding output termi- nals. Jumper wires may be necessary.

WARNING

Electric Shock can kill.

• With the input power on, there are high volt-

ages inside the machine. Do not reach into the machine or touch any internal part of the machine while the power is on.

9.Turn on the R3 machine.

10.Check for the following voltages at plug P6 pin 1(+) (lead #218) to pin 2(–) (lead #219). Plug 6 is located on the Pocket Amptrol board. See Figure F.22.

a.With the Pocket Amptrol in position “1”, the voltage should be approximately 40.8mV.

b.With the Pocket Amptrol in position “10”, the voltage should be approximately 138.9mV.

If the correct AC voltages are applied to the PC board and the correct DC mV is sensed at plug P6 pins 1 and 2, the Pocket Amptrol circuit should function properly. If it does NOT, check the leads between the plug P6 (leads #75, #76 and #77) (see Figure F.24) and the local remote switch (SW2). See the Wiring Diagram. If the leads are OK, the PC board may be faulty.

If the correct AC voltages are applied to the PC board and the DC mV are not cor- rect, check the sensing resistor (R4). See Figure F.23 and the Wiring Diagram. Normal resistance is 0.4 ohms.

If the resistance at R4 is normal (0.4 ohms) the Pocket Amptrol board may be faulty.

IDEALARC R3R