Troubleshooting & repair, Main transformer (t1) voltage test (continued) – Lincoln Electric IDEALARC R3R-500 User Manual
Page 55
TROUBLESHOOTING & REPAIR
F-21
F-21
IDEALARC R3R
8. Read the meter.
a.
If proper voltage is present for all three
phases, proper main input supply volt-
age is being supplied.
b.
If proper voltage is not present in any
or all of the three phases, check input
fuses and leads.
9. Test with an AC voltmeter for proper main
input supply voltage from the output side of
the input contactor (CR1). See the Wiring
Diagram and Figure F.7.
a.
T1 to T2.
b.
T2 to T3.
c.
T1 to T3.
10. Read the meter.
a.
If the proper voltage is present for all
three phases, the input contactor is
working properly.
b.
If the proper voltage is not present for
any or all of the three phases, the input
contactor may be faulty. See appropri-
ate Input Contactor Test.
11. Test with an AC voltmeter for approximate-
ly 50VAC across each of the three main
secondary start leads located at the
SCR/Diode Rectifier Bridge. Remove the
red insulating paint to achieve good con-
tact if necessary. The transformer voltages
will vary with the input line voltages. See
Figure F.8. See the Wiring Diagram.
a.
If one or more of the above voltage
tests are incorrect, check for loose or
faulty connections.
b.
If the connections are good, then the
main transformer may be faulty. Re-
place the main transformer.
MAIN TRANSFORMER (T1) VOLTAGE TEST (continued)
FIGURE F.8 – MAIN SECONDARY LEAD TEST POINTS