ABB ACS880-204LC, Hardware Manual

Page: 102 / 278

Isolation from common DC bus
In case of units with DC voltage remaining: if there are several power sources for the DC
bus, the supply unit which shall be isolated must be equipped with a DC switch-disconnector.
In order to isolate the supply unit from the live DC bus, open the DC switch-disconnector
[Q11] and also the charging switch [Q10] in EVERY cubicle containing supply modules. In
addition, open the DC switch-disconnector of the AC circuit [Q40].
1. Clearly identify the work location.
2. Disconnect all possible voltage sources. Note that energy to the DC bus can also be
fed back by motors, energy storages, etc.
• Make sure that reconnection is not possible. Lock the disconnectors to open position
and attach a warning notice to them.
• Disconnect any external power sources from the control circuits before you do work
on the control cables.
• After you disconnect the drive, always wait for 5 minutes to let the intermediate
circuit capacitors discharge before you continue.
3. Protect any other energized parts in the work location against contact.
4. Take special precautions when close to bare conductors.
5. Measure that the installation is de-energized.
• Use a multimeter with an impedance of at least 1 Mohm.
• Make sure that the voltage between the drive input power terminals and the
grounding (PE) busbar is close to 0 V.
6. Install temporary grounding as required by the local regulations. Connect the DC busbars
to PE with a temporary grounding tool.
7. Ask for a permit to work from the person in control of the electrical installation work.
General notes
￭ Printed circuit boards
WARNING!
Use a grounding wrist band when you handle printed circuit boards. Do not touch
the boards unnecessarily. The boards contain components sensitive to electrostatic
discharge.
￭ Optical components
WARNING!
Obey these instructions. If you ignore them, damage to the equipment can occur.
• Handle the fiber optic cables with care.
• When you unplug the fiber optic cables, always hold the connector, not the cable itself.
• Do not touch the ends of the fibers with bare hands as the ends are extremely sensitive
to dirt.
• Do not bend the fiber optic cables too tightly. The minimum allowed bend radius is
35 mm (1.4”).
102 Electrical installation