Rexroth EcoDrive Cs Drives
Mains and Supply Voltage Connection
6-11
DOK-ECODR3-DKC**.3-CS*-PR02-EN-P
Computing Phase Current on the Mains
To select a suitable mains contactor and fuses for the power connections
it is necessary to first compute the phase current I
N
at the mains.
The mains-side phase current I
N1
is determined out of the mains
connecting power S
N1
.
Selecting the mains connecting power in the list or compute it according
to the following formula. With multiple controllers, add the individual
powers.
The mains connecting power can be determined
•
by selecting the mains connecting power in the list resp. the technical
data
- or -
•
by computing it according to the following formula.
Note
:
With multiple controllers, add the individual powers and, if
necessary, take a coincidence factor into account, because
often not all servo axes require full power simultaneously.
k
⋅
⋅
⋅
⋅
60
2
MITTEL
EFF
ZWD
π
n
M
P
=
P
ZWD
:
required DC bus continuous power in W
M
EFF
:
rms torque in Nm
n
MITTEL
:
mean speed in min-1
k:
factor for motor and controller efficiency
Fig. 6-13: Computing DC bus power
F
P
S
⋅
ZWD
N1
=
S
N1
:
connected load in VA
P
ZWD
:
DC bus continuous power in W
F:
connected load factor due to the non-sinusoidal phase current
Fig. 6-14: Computing mains connected load
Single-phase load:
N1
N1
N1
U
S
=
I
Three-phase load:
3
U
S
=
I
N1
N1
N1
⋅
I
N1
:
mains-side phase current in A
S
N1
:
connected load in VA
U
N1
:
voltage between phases of the mains in V
Fig. 6-15: Computing mains-side phase current
Courtesy
of
CMA/Flodyne/Hydradyne
▪
Motion
Control
▪
Hydraulic
▪
Pneumatic
▪
Electrical
▪
Mechanical
▪
(800)
426-5480
▪
www.cmafh.com
