ABB ACS880-04F-504A-3, Hardware Manual

Page: 59 / 202

￭
Protecting the motor insulation and bearings
The drive employs modern IGBT inverter technology. Regardless of frequency, the
drive output comprises pulses of approximately the drive DC bus voltage with a very
short rise time. The pulse voltage can almost double at the motor terminals, depending
on the attenuation and reflection properties of the motor cable and the terminals.
This can cause additional stress on the motor and motor cable insulation.
Modern variable speed drives with their fast rising voltage pulses and high switching
frequencies can generate current pulses that flow through the motor bearings. This
can gradually erode the bearing races and rolling elements.
d
u/dt filters protect motor insulation system and reduce bearing currents. Common
mode filters mainly reduce bearing currents. Insulated N-end (non-drive end) bearings
protect the motor bearings.
￭
Requirements tables
These tables show how to select the motor insulation system and when a drive d u/dt
and common mode filters and insulated N-end (non-drive end) motor bearings are
required. Ignoring the requirements or improper installation may shorten motor life
or damage the motor bearings and voids the warranty.
Requirements for ABB motors,
P
n
< 100 kW (134 hp)
See also Abbreviations (page 62) .
Requirement for Nominal AC line
voltage
Motor type
ABB d u/dt and common mode filters, insulated
N-end motor bearings
Motor insula-
tion system
P
n
< 100 kW and frame size < IEC 315
P
n
< 134 hp and frame size < NEMA 500
- Standard U
n
≤ 500 V Random-wound
M2_, M3_ and M4_
+ d u/dt Standard 500 V < U
n
≤ 600 V
- Reinforced
+ d u/dt Reinforced 600 V < U
n
≤ 690 V
(cable length ≤
150 m)
- Reinforced 600 V < U
n
≤ 690 V
(cable length >
150 m)
N/A Standard 380 V < U
n
≤ 690 V Form-wound HX_
and AM_
+ N + d u/dt with voltages over 500 V + CMF Check with
the motor
manufac-
turer.
380 V < U
n
≤ 690 V
Old
1)
form-wound
HX_ and modular
+ N + CMF Enamelled
wire with
fiber glass
taping
0 V < U
n
≤ 500 V
Random-wound HX_
and AM_
2)
+ N + d u/dt + CMF 500 V < U
n
≤ 690 V
Consult the motor manufacturer. HDP
1) manufactured before 1.1.1998
2) For motors manufactured before 1.1.1998, check for additional instructions with the motor manufacturer.
Guidelines for planning the electrical installation 59