Rockwell Automation 8510 AC Spindle Drive System User Manual - Manual (Page 118)

Troubleshooting
Chapter 11
11-114
Power Distribution and Control The initial power-up sequence is described below. Refer to Figure 11.2 for
the associated power distribution and control circuitry.
1. When AC power is applied to the drive, the cooling fans and all
internal control logic is immediately energized through AC control
power fuse sets F1, F2, and F3.
2. The external Coast to Stop input must be closed to allow any of the
following power-up sequence to be executed. Closing this contact will
close the coast to stop control relay (K10) and allow the main contactor
(KM) to close.
3. When the Drive Enable input is closed, the DC bus discharge control
relay (KM3) is energized. This disconnects the DC bus discharge
resistor and allows the main contactor (KM) to be closed.
4. After KM3 energizes, the DC bus precharge control relay (KM1) is
energized to allow the DC bus to charge through the precharge
resistors.
5. When the DC bus voltage exceeds the under voltage trip level (250V
DC), the pilot relay for the main contactor (KM2) will energize, which
closes the main AC contactor (KM). The precharge relay (KM1) will
also open at this time.
6. After the main contactor is closed, the IGBT output inverter is turned
on and the motor is ready to operate.
7. If the Drive Enable or Coast to Stop inputs are opened, the main
contactor (KM) will be opened (either after the motor has stopped or
immediately, depending on which input is opened). If the Coast to Stop
input is opened, the DC bus discharge relay (KM3) will be
de-energized which connects the bus discharge resistor across the DC
bus. A time delay guards against the relay being energized again until
the bus discharge current has decreased to a level that will not damage
the relay contacts.
ATTENTION: If an oscilloscope is used during troubleshoot-
ing, it must be properly grounded. The oscilloscope chassis may
be at a potentially fatal voltage if not properly grounded.
Always connect the oscilloscope chassis to earth ground.
When using an oscilloscope it is recommended that the test
probe ground be connected to the test point labeled “GND.”
!