Technical data

15
• DOK-POWER*-KDV*2.3****-ANW1-EN-E1,44 • 06.97
3. Guidelines for installation and electrical connections
3.5. Power supply requirements
Voltages can be adapted to grounded mains systems, either star systems with
a grounded neutral or a system with a grounded phase (TN or TT mains), by
using an autotransformer. The KDV 2.3 can be directly connected to 3 x AC
220 V mains.
There is the increased danger in ungrounded mains (IT mains) that overvoltages
can occur between phases and housing. The KDV 2.3 should only be operated
with such systems, if:
• it is connected across an isolation transformer, or,
• the installation is protected with an overvoltage conductor.
Grounded threephase
mains
Ungrounded
threephase mains
Connecting the KDV 2.3 via an isolation transformer offers the best
protection against overvoltage and the greatest operating safety!
Permissible
overvoltage levels
The voltage levels between the outer conductors (L1, L2, L3, 1L1, 3L3) and
the KDV 2.3 housing can equal 230 V (effective).
Non-periodic overvoltages per VDE 0160 between phases and housing are
permissible for the KDV 2.3 (see following diagram).
0.1 0.2 0.4 0.6 1 1.3 2 4 6 10 20
T (ms)
T
U
N
+∆U
U
N
U
N
∆U
∆U
2
3_05DGUEBSPG
3
2.6
2.4
2.3
2.2
2
1.8
1.6
1.4
1.2
1.15
1.1
1
Figure 3.6: Permissible non-periodic overvoltages per VDE 0160
The KDV 2.3 can be connected to 3 x AC 230 V - input power systems.
This means that the maximum permissible, non-periodic overvoltage may
equal: 230 V x √ 2 x 2.3 = 745 V.