Description; Introduction - Siemens 6SE2101–1AA01 Operating Manual

1. DESCRIPTION

WARNING
SIMOVERT P transistorised voltage–source inverters operate with high voltages.
Connection, commissioning and fault–finding should only be carried out by qualified personnel
who are fully conversant with the relevant documentation, installation regulations, etc.
Only permanently–wired input power connections are allowed. This equipment must be
grounded (IEC 536 Class 1, NEC and other applicable standards).
Safety Note:
Do not apply input power to the equipment when the plastic cover has been removed.
Dangerous voltages are present within the equipment which could cause serious injury or death
if touched. After removing mains power, always allow a minimum of five minutes for the internal
capacitors to discharge before removing the cover.
When the 3–phase mains input is protected by a current–operated earth–leakage breaker, the
input to the innverter must be isolated from the mains if the earth–leakage breaker is to operate
effectively.
The dc–link capacitors remain charged to dangerous voltages for up to five minutes after the
incoming power has been switched off.
When the motor is not running, dangerous voltages are still present on the power input terminals
AND motor output terminals and also on the dc–link terminals.
Under certain set–up conditions, the inverter may restart automatically after an input power
failure.

1.1 Introduction

SIMOVERT P inverters of the 6SE21 series are designed for low–loss speed control of three–phase motors. This
is achieved by rectifying input voltage to establish a dc link voltage, and modulating this link voltage with a
three–phase transistor bridge to produce a Pulse–Width Modulated (PWM) three–phase output voltage (see
Figure 1) . The inductance of the motor windings converts this PWM voltage to a sinusoidal motor current. By
varying the frequency of this sinusoidal current, the rotational speed of the motor is controlled without
significantly affecting the losses in the motor. The output frequency can be adjusted between 0 and 400 Hz.
1/1 English