Installation And Maintenance Work - ABB ACS800 Series Hardware Manual

6

Installation and maintenance work

These warnings are intended for all who work on the converter, generator cable or
generator.
WARNING!
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Safety instructions
Only qualified electricians are allowed to install and maintain the converter.
Before any installation work, the stator of the generator and the supply line
input of the ACS800-67 must be isolated from the supply grid. It is also highly
recommended that the rotor of the generator is locked with a mechanical brake.
The stator and the converter are not to be reconnected until the installation is
complete.
Never work on the converter, the generator cable or the generator when power
is applied. After switching off the input power, always wait for 5 min to let the
intermediate circuit capacitors discharge before you start working on the
converter, the generator or the generator cable. Measure the voltage between
terminals UDC+ and UDC- with a multimeter (impedance at least 1 Mohm) to
ensure that the converter is discharged before beginning work.
Before working in the converter power cabinet:
Stop the fan, generator and converter. Lock the fan shaft mechanically. Switch
off the main breaker, contactor of the stator circuit and the breaker of the fan
transformer.
Lock the main breaker of converter.
Because the main breaker of converter is non-extractable, the isolation fan
transformer switch needed to be isolated and locked in isolation position to
ensure the safety.
Ensure by measuring that the main circuit of the converter and incoming cable
have been discharged (it takes 10 minutes after the power switch off).
Temporary ground the main circuit.
Apply temporary grounding before working on the unit.
Do not work on the control cables when power is applied to the converter or to
the external control circuits. Externally supplied control circuits can cause
dangerous voltages to exist inside the converter even when the main power of
the converter is switched off.
Control boards of the converter unit can be at the main circuit potential.
Dangerous voltages can be present between the control boards and the frame
of the converter unit when the main circuit voltage is on. It is critical that the
measuring instruments, such as an oscilloscope, are used with caution and
safety always as a priority. The fault tracing instructions give special mention of
cases in which measurements may be performed on the control boards, also
indicating the measuring method to be used.