Troubleshooting & repair, Protection circuit test (continued), Protection circuit (simplified) – Lincoln Electric INVERTEC V250-S User Manual
Page 69
F-37
TROUBLESHOOTING & REPAIR
F-37
4. The following tests will be performed
with the input power applied to the
V250-S. BE CAREFUL. ALWAYS
REMOVE INPUT POWER AND
PERFORM FILTER CAPACITOR
DISCHARGE PROCEDURE
BEFORE TOUCHING ANY
MACHINE COMPONENT.
5. Apply input power and turn ON the
V250-S.
6. Check for 0 to 1 VDC at leads
#311(4J6)+ to #313(5J6)- at the
power board. If the correct voltage
is present go to step #7.
If 15VDC is present the overvoltage
protection circuit has not been satis-
fied. Perform the
Test. If the capacitor balance is
good and the overvoltage protection
circuit has NOT been satisfied the
power board may be faulty. Replace.
7. Check for 0 to 1VDC at leads
#311(2J2)+ to #313(8J2)- at the con-
trol board. If the correct voltage is
present go to step 8.
If the correct voltage is present at
the power board but not at the control
board check associated leads and
connections.
8.
Check for 15VDC at leads
#309(1J2)+ to #310(6J2)- at the con-
trol board. If the correct voltage is
present check for 15VDC at leads
#309(6J6) + to #310(3J6)- at the
power board.
If the correct voltage is present at the
control board but not at the power
board check the associated leads
and connections.
If the correct voltage, 15VDC, is not
present at the control board the con-
trol board may be faulty. Perform the
Control Board Voltage Test.
9. If 15VDC IS present at leads
#309(6J6)+ to #310(3J6)- at the
power board the input relay
(1CR), should activate (pull-in) and
apply full input power to the filter
capacitors.
If this does not take place the power
board may be faulty. Replace.
PROTECTION CIRCUIT TEST (continued)
INVERTEC V250-S
(4J6)
5J6
(
)
(2J2)
(8J2)
#311
#313
+15VDC
TIMER
(6J2)
#310
(1J2)
+15VDC
#309
(6J6)
(3J6)
1CR
CHARGE
RELAY
O
V
E
R
V
O
L
T
A
G
E
D
E
T
E
C
T
I
O
N
PROTECTION CIRCUIT (SIMPLIFIED)
POWER BOARD
CONTROL BOARD