ABB ACS 601 - Page 11

Safety Instructions
ACS/ACC/ACP 601 Drives ACx=ACS/ACC/ACP vii
voltage of the pulses is approximately 1.35 times the input line voltage
with a very short rise time.
The voltage of the pulses can be almost double at the motor terminals,
depending on the properties of the cable between the drive and the
motor. This in turn can cause additional stress to the motor insulation.
The motor manufacturer should be consulted regarding the
characteristics of the motor insulation system. Failure of the motor to
fulfill the following requirements may shorten its life.
The following table lists the insulation requirements for motors used
with ACx 600 AC drives.
Motor Type
Nominal
AC Line Voltage
Motor Insulation Requirement
ABB Motors
(manufactured
from beginning of
1998)
V
N
< 500 V Standard insulation system
525 V <
V
N
≤ 690 V Standard insulation and dv/dt filter
or
special insulation system
Random-wound
Motors
V
N
≤ 420 V Motor insulation system must withstand V
PK
= 1300 V.
420 V <
V
N
≤ 500 V If motor insulation system withstands V
PK
= 1600 V and 0.2
µs rise time, a dv/dt filter is not needed.
With a dv/dt filter at the output of the ACx 600, motor
insulation system must withstand
V
PK
= 1300 V.
500 V <
V
N
≤ 600 V Motor insulation system must withstand V
PK
= 1600 V. A
dv/dt filter must be used at the output of the ACx 600.
600 V <
V
N
≤ 690 V Motor insulation system must withstand
V
PK
= 1800 V. A dv/dt filter must be used at the output of the
ACx 600.
Form-wound
Motors
V
N
≤ 690 V If motor insulation system withstands V
PK
= 2000 V and rise
time 0.3 µs, no dv/dt filter is needed.
Symbol Definition
V
N
nominal power line voltage
V
PK
peak line to line voltage at motor terminals
Rise time
:
t = 0.8 · V
PK
/(dv/dt)
Rise time is line to line voltage change rate
at motor terminals (the interval during
which the voltage changes from 10 % to
90 % of the whole voltage range)
V
PK
and t depend on cable length. Read
the values of
V
PK
and dv/dt from the
diagrams below.