ABB ACS850-04 series, Руководство по оборудованию

Страница: 55 / 164

Planning the electrical installation
55
Additional data for calculating the rise time and the peak line-to-line voltage
The peak line-to-line voltage at the motor terminals generated by the drive as well as
the voltage rise time depend on the cable length. The requirements for the motor
insulation system given in the table are “worst case” requirements covering
installations with 30 meter and longer cables.
If you need to calculate the actual peak voltage and voltage rise time considering the
actual cable length, proceed as follows:
• Peak line-to line voltage: Read the relative Û
LL
/ U
N
value from the appropriate
diagram below and multiply it by the nominal supply voltage ( U
N
).
• Voltage rise time: Read the relative values Û
LL
/ U
N
and (d u /d t )/U
N
from the
appropriate diagram below. Multiply the values by the nominal supply voltage
(U
N
) and substitute into equation t = 0.8 · Û
LL
/(d u /d t ).
Additional note for sine filters
Sine filters protect the motor insulation system. A factory-installed sine filter is
available for the cabinet-installed units. The peak phase-to-phase voltage with the
sine filter is approximately 1.5 ×
U
N
.
Additional note common mode filters
Common mode filter is available as a plus code option (+E208).
l Motor cable length
A Graph for calculating the rise time of units with du/dt filter
B Graph for calculating the rise time of units without du/dt filter
Û
LL
/ U
N
du/dt
U
N
-------------(1/

s)
1.0
2.0
5.0
4.0
3.0
1.5
2.5
3.5
4.5
100 200 300 100 200 300
0.0
0.5
1.0
1.5
2.0
2.5
3.0
l (m)
du/dt
U
N
-------------(1/

s)
Û
LL
/ U
N
5.5
l (m)
A
B