Adjust the LN-9 Controls

B-19

OPERATION

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1.Set the "Electrode Polarity" switch to same polarity as the electrode lead.

2.Connect the "Direct Work Lead" if it is going to be used.

3.Check that "Feed Direction" is set to forward.

4.Set the "Trigger Interlock" switch as desired.

5.Set the "Meter Reading" switch to "Wire Speed" and adjust the "Wire Speed" rheostat so the meter reads the desired wire feed speed.

6.Set the "Meter Reading" switch to "Volts" and adjust the "Volts" rheostat so the meter reads the desired arc voltage. IMPORTANT: Make certain this setting is within the voltage output range of the power source setting.

7.Load the LN-9 with electrode.

VOLTAGE CONTROL RESPONSE

The LN-9 is provided with selectable voltage control response. Proper setting depends on the power source and process being used. Refer to the appropri- ate power source connection diagram for the proper connection of the jumpers located on the LN-9 Voltage PC Board and Start PC Board (only in models using L- 6084 Voltage PC Board).

To change the voltage control response:

1.Turn OFF the control power to the LN-9 at the power source.

2.Remove the screws holding the control section cover in place and swing open.

3.Position the jumper plugs on the Voltage Board and Start Board (where used) according to the appropriate power source connection diagram.

4.Reassemble.

STARTING CHARACTERISTICS

SELECT ACCELERATION

The LN-9 models can provide optimum starting for dif- ferent processes. The wire feeder is designed to start with two different speeds of controlled acceleration. As shipped, it is connected for fast acceleration, which is the best for most open arc procedures. However, the slower acceleration may be more desirable for Linc-Fill long stickout applications and most submerged arc

procedures. If the electrode being used does not give satisfactory starting because of "stubbing" or "blasting off," slower acceleration can be obtained by modifying the LN-9 models as follows:

1.Turn OFF the control power to the LN-9 at the power source.

2.Remove the screws holding the control section cover in place and swing it open.

3.Move the jumper plug on the Control PC board from pin "F" to pin "S."

4.Reassemble.

START VOLTAGE TRIM

The start voltage is the voltage provided by the welding power source before establishing the welding arc. This start voltage setting is a function of the open circuit voltage characteristic of the power source, the SET value of the weld voltage, and the start voltage trimmer (R41) setting on the LN-9 Voltage PC Board. As set at the factory, the start voltage trim level is typically about 20% higher than the LN-9 SET level. This generally gives good starting for steel cored and MIG processes using CO2 or Argon/CO2 blended shielding gas. If you are using "hotter" gases (such as Argon/Oxygen blends) and other processes (such as stainless steel MIG), arc flaring may occur at start, which requires low- ering the start voltage trim as follows:

1.Turn off the control power to the LN-9 at the power source.

2.Remove the screws holding the control section cover in place and swing it open.

3.On the voltage board, locate trimmer R41 (below R40 next to the 1/8 amp fuse) and labeled START.

4.The slot on the START trimmer is marked with a red seal for factory setting. To decrease the facto- ry setting, turn the slot CCW (opposite to the labeled arrow direction).

NOTE: If the start trim is set too low, stubbing may occur at start, requiring increasing the START trimmer by turning the slot CW (in the direction of the labeled arrow).

5. Reassemble.

Lincoln Electric SVM127-A Adjust the LN-9 Controls, Voltage Control Response, Select Acceleration

Models: SVM127-A

OPERATION