Theory Of Operation - Lincoln Electric INVERTEC V300-PRO SVM105-B Service Manual

E-2
1ø OR 3ø DETETCTION (H5)
INPUT
LINE
RECTIFIER
SWITCH
1
AC1
2
AC2
3
AC3
3A
A-LEAD
24VDC
AUXILIARY
FAN
TRANSFORMER
18VAC
24VAC
TO
WIREFEEDER
INPUT LINE VOLTAGE & AUXILIARY
TRANSFORMER
The V300-PRO can be connected for a variety of three
phase or single phase input voltages. Power is applied
through the Line Switch to the Input Rectifier and the
Auxiliary Transformer.
The Reconnect Panel has switches to select high or
low operating voltage. The "A" lead must then be set for
the proper input voltage. It is important to set the
switches and "A" lead to the proper positions before
applying input power. Changing the switch position
with the power applied will result in major damage
to the machine
NOTE: Unshaded areas of block logic diagram are the subject of discussion

THEORY OF OPERATION

FIGURE E-2 --- INPUT CIRCUITS
POWER SWITCH
SECTIONS
20KHZ
LEFT SWITCH BOARD
FET MODULES
CAP
FET MODULES
PRE-CHARGE
DRIVER
BOARD
CR1
PROTECTION
PULSE
BOARD
TRAIN
CR2
PRE-CHARGE
RIGHT SWITCH BOARD
2ND STEP PWM
FET MODULES
CAP
POWERBOARD
FET MODULES
<1 VDC
LOCAL
METER MODE POT
REMOTE
1ST STEP PWM VOLTAGE
15VDC-CONTROL BOARD FUNCTION VOLTAGE
24VAC-THERMOSTATS-GUN TRIGGERING
V300-PRO
MAIN
TRANSFORMER
TOP
CURRENT
TRANSFORMER
CONTROL
BOARD
BOTTOM
Y-Y FEEDBACK
TOP
VOLTAGE FEEDBACK
POT
CURRENT FEEDBACK-PROTECTION
The auxiliary transformer provides 18v.a.c. and
24v.a.c. supplies to the Control and Power Boards. It
also provides 115v.a.c., 42v.a.c. and 24v.a.c. supplies
to the wirefeeder amphenol. (CE machines do not have
115v.a.c. supply)
The Power Board provides a 15v.d.c. supply to the
Control Board and a 24v.d.c.supply to the Driver Board
to operate the Pre-charge Relays.
E-2
RECTIFIER
CHOKE
HEATSINK
1 DIODE
5 DIODES
5 DIODES
1 DIODE
CHOKE
CHOKE
SHUNT