Planning the electrical installation
61
The stress on motor insulation can be avoided by using optional ABB du/dt filters.
du/dt filters also reduce bearing currents.
To avoid damage to motor bearings, the cables must be selected and installed
according to the instructions given in this manual. In addition, insulated N-end (non-
driven end) bearings and output filters from ABB must be used according to the
following table. Two types of filters are used individually or in combinations:
• du/dt filtering (protects motor insulation system and reduces bearing currents).
• common mode filtering (CMF) (mainly reduces bearing currents).
Requirements table
The following table shows how to select the motor insulation system and when an
optional ABB du/dt filter, insulated N-end (non-driven end) motor bearings and ABB
common mode filters are required. The motor manufacturer should be consulted
regarding the construction of the motor insulation and additional requirements for
explosion-safe (EX) motors. Failure of the motor to fulfil the following requirements
or improper installation may shorten motor life or damage the motor bearings.
Manufacturer
Motor type Nominal mains
voltage (AC line
voltage)
Requirement for
Motor insulation
system
ABB du/dt filter, insulated N-end bearing and ABB common mode
filter
P
N
< 100 kW
and
frame size < IEC 315
100 kW <
P
N
< 350 kW
or
frame size >
IEC 315
P
N
> 350 kW
or
frame size >
IEC 400
P
N
< 134 HP
and frame size
<NEMA500
134 HP <
P
N
< 469 HP
or frame size
>
NEMA 500
P
N
> 469 HP
or frame size
>NEMA580
A
B
B
Random-
wound M2_
and M3_
U
N
< 500 V Standard - + N + N + CMF
500 V < U
N
< 600 V Standard + du/dt + du/dt + N + du/dt + N + CMF
or
Reinforced - + N + N + CMF
600 V < U
N
< 690 V Reinforced + du/dt + du/dt + N + du/dt + N + CMF
Form-wound
HX_ and AM_
380 V < U
N
< 690 V Standard n.a. + N + CMF P
N
< 500 kW:
+ N + CMF
P
N
> 500 kW:
+ N + CMF + du/dt
Old* form-
wound HX_
and modular
380 V < U
N
< 690 V Check with the
motor
manufacturer.
+ du/dt with voltages over 500 V + N + CMF
Random-
wound HX_
and AM_ **
0 V < U
N
< 500 V Enamelled wire
with fibre glass
taping
+ N + CMF
500 V < U
N
< 690 V + du/dt + N + CMF
To Next Page
Loading...
