Tormach PCNC 770 - Page 216

Chapter 10
216
UM10350_PCNC770_Manual_0916A
Troubleshooting
If the right side digits are ashing, momentarily press and release the M buon just below the
display to cause the le side digits to ash. Now with the le side digits ashing, press and hold the
M buon for three seconds and the display will change to display diagnoscs.
If frequency is displayed and it is desired to display load, or vice versa, press and hold the M buon
for three seconds.
Do not change any parameter values in the VFD. There are no operator seable parameters available.
Spindle Drive Subsystem Checklist
Table 5.3
Spindle VFD Trips
Trip Code Condition Likely Cause
UU DC bus undervoltage This happens every time the VFD is powered down.
OU DC bus overvoltage
Braking resistor failed open or wiring connection
open between the VFD and the resistor. Resistance to
measure 75 ohms.
OI.AC
VFD output instantaneous over
current.
Phase to phase or phase to ground short on output of
VFD to motor.
OI.br
Braking resistor instantaneous over
current.
Braking resistor shorted or partially shorted out
or short in wiring between the VFD and the resistor.
Resistance to measure 75 ohms.
It.br I2t (power) on braking resistor
Excessive braking resistor energy caused by too frequent
and too severe deceleration cycles or AC supply voltage
too high.
It.AC
I
2
t (power) on VFD output current
(used to protect motor).
Spindle motor working too hard. Consider running the
spindle motor at half speed for 10 minutes with no load
to cool the motor down.
O.ht1
VFD is working too hard and stops
to prevent failure.
Spindle motor working too hard. Stop running the
spindle but leave the VFD power on and let the power
electronics cool down.
O.ht2
Heat sink temperature is too high
because the VFD is working too
hard and stops to prevent failure.
Cabinet may also be too hot.
Spindle motor working too hard or it is too hot in work
location. Stop running spindle but leave VFD power on
and let power electronics cool down. Check to see if fan
on the VFD is running and check lters on cabinet. Cool
work location down if required.
Hf.29 Cooling fan is not cooling. Failed drive