ABB ACS850 series, Application Manual

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33
Selection of AC supply fuses
The standard selection table for the AC supply fuses in the single drive configuration
can be found in the relevant hardware manual. That selection guideline can be used
when the AC supply line current of the drive module(s) connected to the AC supply is
according to the table.
The general guidelines for the selection of AC supply fuses are the following:
•
IEC fuse classes gG and aR, and UL class T are suitable for AC supply side.
•
Fuse voltage rating of 500 V should be selected for 380…500 V AC supply.
•
Fuse nominal current
) i ( ave , mot N , F
I . I
× ≈
6 1
Where factor 1.6 covers the influence of cyclic load and ambient conditions. If the
average motoring line current
I
mot,ave
is not exactly known, the nominal power ratings of
the drive module can be used. However, the selected fuse current rating and the
operation curve should be in line with the supply cable cross section to meet the
regulations for the cable protection.
Selection of DC connection fuses
In the common DC system, each DC connection must be equipped with fuses. Fuses
are needed in both branches (+ / -). The general guidelines for the selection of DC link
fuses are the following:
•
AC fuse class aR (so called high speed fuses) should be used.
•
Fuse voltage rating should be 690 V.
•
Fuse nominal current
) i ( ave , dc N , F
I . I
× ≈
6 1
where the
average DC link current I
dc,ave
can be defined with:
dc
) i ( ave , dc
ave , dc
U
P
I
=
• P
dc,ave(i)
is the maximum average (during the 3 min time window) DC link power in
the DC connection terminals of the individual drive module.
• U
dc
is the actual DC link voltage
ac dc
U . U
× ≈
35 1
The factor 1.6 covers the influence of the cyclic load and ambient conditions. If the
average DC current
I
dc,ave
is not exactly known, the power ratings of the drive module
can be used. However, the selected fuse current rating and the operation curve should
be in line with the used cable cross section to meet the regulations for the cable
protection.
The recommended fuse current ratings based on the DC power ratings of the drive
modules are shown in the table below.
Common DC configurations