Tormach PCNC 770 - Control Power Subsystem

Chapter 10
185
UM10350_PCNC770_Manual_0916A
Troubleshooting
10.5.2 Control Power Subsystem
Control power enables running of the mill. When control power is o, some components in the cabinet
are live but none of the motors and drives are powered on. Turn control power on when you desire
to run the mill by pressing the green Start buon, and power o control power by pressing the red
E-stop when you are not running. The red E-stop is a twist-lock device and must be released by turning
it clockwise unl it pops out. The Machine LED illuminates when control power is on (see Figure 10.7).
Control Power Subsystem Checklist
Table 2.1
Control power cannot be turned on
Possible Cause Probability Action to Identify Cause of Problem Discussion
Red E-stop is in
the lock position
High
Twist the head of the red E-stop to
release
—
Breaker turned off
in electrical cabinet
supplying PCNC
Medium Check the breaker Turn it on if required
Disconnect switch
in off position
Low Check the switch
Turn it on if required. Measure
for 120 VAC nominal between
wires 91 and 100 if required.
Fuse FU3 blown Low
Measure for 120 VAC nominal
between wires 102 and 100.
Power off Main Disconnect before
checking or replacing fuses.
Contactor C1 has
a defective coil
Low
Push the manual override button on
middle of contactor.
If the control power turns on
then the C1 contactor coil is
defective or there is a loose wire
connection on 100, 103 or 104.
Contactor C1
contacts are
defective
Low
Measure continuity across the
contacts.
If high resistance is found, the
contactor is defective or there is
a loose wire connection on 103,
104, 100, 120 or 160.
Find the relevant poron of the electrical schemac highlighted in Figure 10.8 and Figure 10.9. For
more detail, view electrical schemac inside back cover.