Multiple Ac Input; Charging Current - ABB ACS850 Application Manual

22
R values (R
The following condition must be fulfilled:
R
•
tot
If the condition cannot be fulfilled, more than one drive module must be connected to
the AC supply.

Multiple AC input

Define R
follows:
R
•
min
values (R
R
min
modules connected to the AC supply.
The following condition must be fulfilled:
R
•
tot

Charging current

A typical AC input line current waveform and the DC link voltage during charging are
shown in the figure below.
Check that the AC supply side components (fuses, contactors, etc.) can withstand the
peak current.
The peak current I
I
•
ac
Common DC configurations
, R ,...) are the charging resistances of each drive module.
1 2
> R
min
as in the previous case. Define the effective total minimum resistance as
tot
1
=
1 1
+ +
L
R R
1 2
min min
, R ,...) are the individual minimum resistance values of the drive
min1 min2
> R
min
is calculated as follows:
ac,peak
×
2
U
=
ac
, peak
R
tot
1
+
R
n