Eaton Rapid Link RAMO5, Руководство пользователя

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2 Engineering
2.6 Power bus
Rapid Link 5 · RAMO5 · RASP5 10/19 MN034004EN www.eaton.com
45
Calculate the short-circuit current and the voltage drop as specified in
DIN VDE 0100 to make sure that the protection requirements are being met.
The power bus’ cable length can be calculated as follows:
Figure 18: Example: RAMO5
Requirements for the group protection device in the event of a short-circuit:
The short-circuit current I
k
must be greater than the tripping current of the
short-circuit tripping device I
rm
. The former depends on the impedance and
length of the power bus and the stub line.
Depending on the power bus’ length and the configuration of the power
branches, the total of all RAMO5 and RASP5 supply system currents during
continuous operation must not exceed 25 A (4 mm
2
power bus).
l =
U
0
x 1000
- Z
v
- (Z
stub
x l
stub
)
I
rm
Z
Power bus
l = Cable length (maximum 100 m)
U
0
= 230 V (single phase no-load voltage)
I
rm
= Tripping current of short-circuit release
Z
v
= External supply impedance (e. g. 100 m Ω )
Z
Stub
= 35.50 m Ω /m (stub cable 1.5 mm
2
)
Z
Power bus
= 13.40 m Ω /m (power bus 4.0 mm
2
)
21.50 m Ω /m (power bus 2.5 mm 2 )
￫
When selecting the cable cross-section, take into account the
voltage drop under load.
Consideration of other standards (e. g. VDE 0113, VDE 0289) is
the responsibility of the user.
3 AC 400 V∼, 50/60 Hz
I
rm
I
k
Q1
l
M
3 ∼
RAMO
1.5 mm
2
4 mm
2
I >
l
Stich
1.5 m
(4.92 ft)
1.5 m
(4.92 ft)