Lincoln Electric LN-25 SVM179-B Service Manual page 40

E-2
ELECTRODE
INPUT
CONTACTOR CURRENT TRANSDUCER
INPUT
21
1
14 PIN AMPHENOL
21
DIGITAL
RUN IN
DISPLAY
BOARD
GENERAL DESCRIPTION
Several models of the LN-25™ PRO are offered to best
meet the individual welders needs. The Extra Torque
model features additional torque for reliable feeding of
large diameter FCAW wire. The standard and control
cable models feature wire drive gearing for optimal per-
formance with both FCAW and GMAW wires of com-
mon sizes. All the models include a gas solenoid and
flow meter for the flexibility to run most wire processes.
Control Cable models also includes digital meters and
remote voltage control.
The plastic case is molded from high impact, flame
retardant plastic for durability and low weight. The
patent pending design keeps the internal components
protected and dry.
THEORY OF OPERATION
FIGURE E.2 — GENERAL DESCRIPTION
SOLENOID
POLARITY
V M
CONTROL BOARD
CC
COLD
CV
FEED
NOTE: Unshaded areas of Block Logic
Diagram are the subject of discussion
LN-25™ PRO
67
TIMER OPTION
MOTOR
MOTOR
OVERLOAD
ARMATURE
TACH FEEDBACK
GUN TRIGGER
TRIGGER GAS
INTERLOCK PURGE
The heart of the LN-25™ PRO is a 2 roll MAXTRAC
wire drive system. The patented features on the wire
drive offer tool-less changing of the drive rolls and wire
guides for quick changeovers. A tachometer controlled
motor powers the patent pending drive rolls for smooth,
steady feeding without slippage.
With only one p.c. board, the LN-25™ PRO is designed
to be simple, reliable and easy to service. The p.c.
board is manufactured with Lincoln's industry leading
environmental design protection which involces mount-
ing the board in a plastic tray and potting it with epoxy.
With a 325 amp, 100% duty cycle rating, these feeders
are ready for heavy duty welding.
FEEDPLATE
TACH
GUN
REMOTE
WIRE
VOLTAGE
SPEED
E-2