Lincoln Electric IDEALARC DC-1500 Service Manual page 52

F-18
MAIN TRANSFORMER (T5) VOLTAGE TEST (continued)
FIGURE F.3 – Primary Output Of Contactor T1, T2, T3 (Not Shown)
T 1 , T 2 , T 3 ( U N D E R S I D E ) P R I M A R Y O U T P U T O F C O N T A C T O R F R O N T O F W E L D E R R I G H T S I D E
P R I M A R Y I N P U T L 1 , L 2 , L 3 O F C O N T A C T O R I N P U T S U P P L Y L I N E
FRONT OF WELDER
PROCEDURE
1. Disconnect main AC input power to the
machine.
2. Inspect the Input Contactor, Reconnect Panel,
and primary leads to the Main Transformer for
loose or faulty connections. See Figure F.3.
3. Apply input power, push start button, and make
sure the Input Contactor (1CR) energizes.
4. Carefully test with an AC voltmeter for proper
main AC input voltage to the line side of the
Input Contactor (1CR). See wiring diagram.
L1 to L2.
L2 to L3.
L1 to L3.
a. If proper voltage is not present in any or
all of the three phases, check input
fuses and leads.
TROUBLESHOOTING AND REPAIR
PRIMARY INPUT L1, L2, L3
RIGHT SIDE
IDEALARC® DC-1500
OF CONTACTOR
5. Test with an AC voltmeter for proper main AC
input voltage from the output side of the Input
Contactor. (1CR). See wiring diagram.
T1 to T2.
T2 to T3.
T1 to T3.
a. If correct voltage is present, the
Contactor is working properly.
b. If the correct voltage is not present for
any or all of the three phases, the con-
tactor may be faulty.
6. Carefully test with an AC voltmeter for approx-
imately 70.0 Volts on the six main transformer
secondary leads. Check from each of the six
secondary leads, where they are connected to
the SCR bridge, to the negative output termi-
nal. Note that the negative leads also pass
through the interphase reactor coils. See
Wiring Diagram. See Figure F.4.
7. If one or more of the secondary voltages are
incorrect, check for loose or faulty leads and
connections. It the leads and connections are
good, then the main transformer may be faulty.
INPUT SUPPLY LINE
PRIMARY OUTPUT OF CONTACTOR
T1, T2, T3 (UNDER SIDE)
F-18