Lincoln Electric IM318 IDEALARC DC1500 - Manual (Page 15)

B-6 OPERATION B-6
Operation When Connected to the LAF-3
and the K783 NL Option Kit
For proper arc striking and welding when using the
LAF-3 with the DC-1500 and K783 NL Option Kit, fol-
low the instructions below (Turn the input power off at
the fuse box before working inside the machine.):
1. Connect the DC-1500 NL option, and LAF-3 per
the Connection Diagram M13321 in the Diagram
Section.
2. Remove the cover from the LAF-3 control box.
3. Remove the blue jumper lead connected between
#1 on the coil of the main relay and #7 on the coil
of the transfer relay. (The main relay is the upper
right relay when facing the left end of the control
box. The transfer relay is just to the left of the main
relay.)
4. Replace the LAF-3 control cover.
5. Set the “POS — NEG” switch (on both the NL
Option and the DC-1500) to correspond to the
polarity of the electrode cable connection.
6. Set the mode switch on the front of the DC-1500 to
“Variable Voltage”.
7. Set the toggle switch on the front of the DC-1500 to
“Output Control Remote”.
8. Set the DC-1500 welding current as required by
the procedures using the K775 Remote Output
Control shipped with the NL Option.
9. Set the LAF-3 “Inch Speed” control near minimum
so the electrode touches the work lightly before
starting the arc. The NL Option “Inch Speed” con-
trol is not in the circuit.
10. Set the “Hot Start Control” on the NL Option at
#2. This setting does not change the open cir-
cuit voltage, but it will improve starting, particu-
larly at low currents. Adjust the control for opti-
mum starting.
NOTE: The “Hot Start Control” does not affect the
starting method of the LAF-3, i.e., “cold” start, “hot”
start, etc. See IM198-B, Sec. 2.4.9.
11. Set the NL Option “Contactor Drop-Out Delay”
switch to “On”. This circuit delays opening of
the output contactor for a fixed length of time
after wire feeding stops to prevent sticking.
Operation When Connected to the LT-3 or
LT-34
Follow the same instructions as above except in Step
1, connect per M13322. Omit Steps 2, 3 and 4. Set
the “Inch Speed” control on the NL Option as low as
possible so the electrode touches the work piece light-
ly before starting the arc.
Overload Protection
The NL Option kit includes two fuses on the front
panel. The upper fuse (2 amp slow blow) protects the
inching circuit when the option is used with LT-3 and
LT-34 wire feeders. The lower fuse (2.8 amp slow
blow) protects the 115 volt DC circuit (#1 and #2). If
replacing either fuse use the same size and type.
IDEALARC ® DC-1500