Tormach PCNC 770 - Page 212

Chapter 10
212
UM10350_PCNC770_Manual_0916A
Troubleshooting
Spindle Drive Subsystem Checklist
Table 5.1 (...continued)
Spindle will not turn on in manual or auto
Possible Cause Probability Action to Identify Cause of Problem Discussion
Defective control
board
or
Defective cables
between the control
board and the
spindle VFD
or
Defective cables
between the control
board and VFD
Low
Check that all cables are seated properly
in their connectors on the board.
—
Attempt to run the VFD. If the display
reads Fr xy.z or Ld xy.z where xy and
z are numbers between 0 and 9, the
control board is sending a run (enable)
signal to the VFD. A reading of rd 0.0
indicates the VFD is ready but not
receiving a run command. Note that
the VFD may be displaying numbers on
the left side of the display. If the digits
on the right side of the display are
ashing, momentarily press and release
the M button just below the display to
cause the left side digits to ash. With
the left side digits ashing, press and
hold the M button for three seconds
and the display will change to Fr, Ld or
rd as described below.
If the display reads rd 0.0, see
Table 5.2 to measure DC
voltage. Be sure to measure
at both the control board
and at the VFD to determine
if there is a problem with the
wiring. It is not critical that
the measurement for reverse
be made, as it is not required
to make the spindle turn;
however, it may aid in further
troubleshooting. If your
measurements match those
in Table 5.2, the control
board and wiring to the VFD
are good.
Attempt to run in manual with the Spindle
Speed Dial in a mid-range position.
2-3.5 VDC measured on the
control board between wires
J1-2 (common) and J1-1
indicates the control board
speed output signal is OK.
Turning the Spindle Speed Dial
from minimum to maximum
should cause the voltage to
range from <1 to >4.5 VDC.
Return Spindle Speed Dial to
mid-position.
Determination of defective VFD or
control board.
If the voltage measurements
in the two tests above are
not good, the control board
is defective; if correct the
VFD is defective.
(connued on next page...)