Technical data

PD_OpManPS-4_06_us.fm
page 44 PacDrive PS-4 / PD-8 ELAU AG
6 Project definition
Hard-copy for correction
6.2.2 Transformer dimensioning
The following formula can be used for the power of the DC-circuit:
P
DC
= DC-circuit power in W
M
EFF
= effective torque in Nm
n
average
= average torque in min
-1
k = factor for motor and controller efficiency = 1.25
a = number of PacDrive SCL’s
g = percentage of PacDrive SCL’s simultaneously in
control (min 0.2 ...1)
The transformer connection power is calculated as follows:
S
AT
= transformer connection power in W
P
DC
= DC-circuit power in W
F = factor for connection power = 2
Calculation of phase currents on the mains side:
Single-phase connection:
Three-phase connection:
I
TS
= transformer secondary phase current in A
S
AT
= transformer connection power in VA
With the detected current value, an autotransformer can be selected
from the table below.
If motion developments and mechanical ambient conditions can only
be determined insufficiently or not at all, the transformer or choke
should be dimensioned for the permanent current of the PacDrive
PS-4. A measurement on the machine can supply the actual mains
burden and thus the necessary performance sizes.
P
ZK
M
eff
n
Mittel
2 π⋅
60
----------
kag⋅⋅⋅⋅⋅=
S
AT
P
ZK
F⋅=
I
TS
S
AT
230V
-------------
=
I
TS
S
AT
230V 3⋅
-------------------------
=