Connection To Different Types Of Networks - HEIDENHAIN TNC 410 M Technical Manual

4.1.7 Connection to Different Types of Networks

Distribution
systems – types of
networks
4 – 6
HEIDENHAIN power supply units (UV, UVR, UR, UE) and their accessories
(line filter, KDR) can only be used in symmetrical three-phase networks with a
grounded and loadable star point, unless the line voltage is adjusted
separately. These are TN networks with a voltage of 3 x 400 V; 50 to 60 Hz
(± 10%). Other power supply networks (e. g. TT, IT networks) must be
adjusted via an isolating transformer, and other supply voltages must be
adjusted via an autotransformer (see "Adjustment to Different Types of
Networks" on page4 – 32 ).
The following illustrations show some of the possible types of networks:
1: Symmetrical three-phase network with a grounded, loadable star point
(= TN network). An isolating transformer for adjusting the line voltage is not
necessary.
2: Symmetrical three-phase network without a star point (= IT network). The
use of an isolating transformer is absolutely necessary. The star point must
be grounded on the secondary side.
3: Asymmetrical three-phase network with a grounded external line. The
use of an isolating transformer is absolutely necessary. The star point must
be grounded on the secondary side.
4: Symmetrical three-phase network with a non-grounded star point
(9 = TT network). The use of an isolating transformer is absolutely
necessary. The star point must be grounded on the secondary side.
5: Symmetrical three-phase network without a star point. The use of an
isolating transformer is absolutely necessary. The star point must be
grounded on the secondary side.
6: Asymmetrical three-phase network with midpoint tap. The use of an
isolating transformer is absolutely necessary. The star point must be
grounded on the secondary side.
HEIDENHAIN Technical Manual for Inverter Systems and Motors