Yaskawa GPD 506/P5 Section One - Manual (Page 11)

PP.P5G5.01.Troubleshoot
Page 11
Rev. 06/11/2003
Before attempting any checks in this troubleshooting manual, make sure that the three
phase power is disconnected and locked out. With power removed from the unit, the DC
bus capacitors will stay charged for several minutes. The charge LED in the unit will glow
red until the DC bus voltage is below 10 VDC. To ensure that the DC bus is completely
discharged, measure between the positive and negative bus with a DC voltmeter set to
the highest scale.
Checking the inverter for power
Test Equipment - DC voltmeter set to the highest scale
This test is a mandatory safety check! Before touching any components inside the
inverter, perform the following test. Look at the charge LED on the inverter. If high voltage
is present on the DC bus, the charge LED will glow red. As the DC bus capacitors
discharge, the charge LED will fade out. There is a possibility that voltage will be present
on the DC bus even when the charge LED is off. To determine if the DC bus is completely
discharged, measure between the positive and negative portions of the DC bus with a DC
voltmeter. Set the meter to it’s highest scale and place the positive lead onto the positive
portion of the DC bus and place the negative lead onto the negative portion of the DC bus.
If the measured voltage is below 10 VDC, you can safely work inside the unit.
WARNING
LETHAL VOLTAGES ARE PRESENT!
!