REXROTH EcoDrive Cs - Operation on 400;480 V Mains; Basics; Selecting the Mains Transformer

6-16 Mains and Supply Voltage Connection Rexroth EcoDrive Cs Drives
DOK-ECODR3-DKC**.3-CS*-PR02-EN-P
6.6 Operation on 400/480 V Mains
Basics
Operation on the mains with voltages above 240 V requires a mains
transformer. This applies both to single-phase operation and to three-
phase operation.
Note: There are often only the 3 phases (L1, L2, L3) available in the
control cabinet so that the resulting voltage is 400 V (480 V)
even with single-phase mains connection (L1, L2)!
Selecting the Mains Transformer
When selecting the mains transformer, the total mains connection power
S
N1
and the total phase current I
N1
of all drive controllers to be supplied
has to be taken into account (see table below).
Connection P
mech
[W]
η [%]
P
DC
[W] S
N1
[VA] Form
factor F
I
N1
[A] I
Ein
[A]
100 61 140.3 400 2.436 1.5 78.6
200 71 253.2 700 2.471 2.7 78.6
400 83 457.1 1400 2.905 5.3 78.6
single-
phase
750 90 796.2 2400 2.848 9.1 78.6
100 61 140.3 400 2.436 0.9 78.6
200 71 253.2 700 2.471 1.6 78.6
400 83 457.1 1400 2.905 3.1 78.6
three-phase
750 90 796.2 2400 2.848 5.3 78.6
P
mech
: Power at the driven shaft of the motor
η: Efficiency
P
DC
: Continuous DC bus power
S
N1
: Mains connection power
I
Ein
: Inrush current
I
N1
: Phase current of the mains
T: Time constant of RC element (T = R
Softstart
x C
Zwischenkreis
)
Fig. 6-19: Overview of phase currents and inrush current peaks of the devices
for single-phase and three-phase operation
6 drive controllers of the DKC0x.3-W0008 (400 W) type are to be supplied
in a three-phase way via a transformer. The resulting mains connection
power is 6 x 1400 VA = 8400 VA. This means that a transformer of
8.4 kVA has to be used if all axes can load the mains simultaneously. As
often not all axes require power at the same time, a respective
coincidence factor can be taken into account, if necessary.
Note: Rexroth supplies appropriate transformers (see chapter 10
Additional Components).
Example
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