Hobart 6T28-600CL Operation And Maintenance Manual page 38

OM-2244 / Operation and Maintenance Manual
DCS-600/ Series 500082 / Solid State Transformer-Rectifiers
3. Line contactor chatters
Trouble, Symptom, Condition
Machine Will Not Operate, continued
4. Contactor operates and trips
power source circuit breaker or
blows fuses
Trouble, Symptom, Condition
Unit Turns Off After Starting
1. Unit delivers power but soon
shuts down (Thermal overload,
electronic overload or over-
voltage circuit trips)
December 15, 2014
a. Input cables too small or too
long
b. Faulty contactor coil
c. Low line voltage
Probable Cause
a. Wrong line voltage
b. Breaker incorrect size or type or
fuse
c. Links on voltage changeover
board incorrectly connected
d. SCR failure or shorted fly-back
diode
e. Short circuit in primary
connections
Probable Cause
a. Power supply overloaded
b. Duty cycle too high
Use input cables of sufficient
capability for proper operation of
the machine. Refer to Section 1-2,
Figure 1 for proper cable size to be
used.
Check coil voltage. If correct,
replace contactor.
Check line voltage. Correct
problem as necessary.
Test, Check, and/or Remedy
Check nameplate of machine for
line voltage to be used. Then
measure line voltage. If line voltage
is of improper value, correct this
condition as is necessary to
provide proper voltage input to the
machine.
Refer to Section 1-2, Figure 1 for
input current requirements. Make
sure the breaker is appropriate for
a high inrush current – use a
breaker designed for motor starting
applications.
Check appropriate voltage
changeover diagram in Chapter 5
for proper link positions. Make
correction as necessary.
Refer to detail troubleshooting
instructions.
Remove short circuit.
Test, Check, and/or Remedy
Reduce load, overload can be
carried only for a short time.
Do not operate continually at
overload currents.
Chapter 2-1
Page 6