Selection Of Winding Insulation For Acs800-Converters; Selection Of Winding Insulation With All Other Converters; Thermal Protection Of Windings; Bearing Currents - ABB ACS800 Serie Manuel D'installation

5.3.3 Selection of winding
insulation for ACS800-
converters
In the case of ABB ACS800 single drives with a diode
supply unit, the selection of winding insulation and
fi lters can be made according to table below:
Nominal supply
voltage U of
N
the converter Winding insulation and fi lters required
U ≤ 500 V ABB Standard insulation
N
U ≤ 600 V ABB Standard insulation + dU/dt fi lters
N
OR
ABB Special insulation
(variant code 405)
U ≤ 690 V ABB Special insulation
N
(variant code 405)
AND
dU/dt-fi lters at converter output
For more information on resistor braking and converters
with controlled supply units, please contact ABB.
5.3.4 Selection of winding
insulation with all other
converters
The voltage stresses must be limited below accepted
limits. Please contact the system designer to ensure the
safety of the application. The infl uence of possible fi lters
must be taken into account while dimensioning the
motor.
5.4 Thermal protection of
windings
All cast iron ABB Ex motors are equipped with PTC
thermistors to prevent the winding temperatures from
exceeding the thermal limits of used insulation materials
(usually Insulation Class B or F).
NOTE!
If not otherwise indicated on the rating plate, these
thermistors do not prevent motor surface tempera-
tures exceeding the limit values of their temperature
classes (T4, T5, etc.).
ATEX-countries:
The thermistors must be connected to a thermistor
circuit relay functioning independently and that is
dedicated to reliably trip off the supply to the motor
according to the requirements of the "Essential Health
and Safety Requirements" in Annex II, item 1.5.1 of the
ATEX Directive 94/9/EC.
Non-ATEX countries:
It is recommended that the thermistors are connected to
a thermistor circuit relay functioning independently and
that is dedicated to reliably trip off the supply to the
motor.
ABB/Low Voltage Motors/ Ex manual 01-2007
NOTE!
According to the local installation rules, it may be
possible to also connect the thermistors to equipment
other than a thermistor relay; for example, to the
control inputs of a frequency converter.

5.5 Bearing currents

Bearing voltages and currents must be avoided in all
variable speed applications to ensure the reliability and
safety of the application. For this purpose insulated
bearings or bearing constructions, common mode fi lters
and suitable cabling and grounding methods must be
used.
5.5.1 Elimination of bearing currents
with ABB ACS800 converters
In the case of the ABB ACS800 frequency converter
with a diode supply unit (uncontrolled DC voltage), the
following methods must be used to avoid harmful
bearing currents in the motors:
Frame size
250 and smaller No actions needed
280 – 315 Insulated non-drive end bearing
355 – 450 Insulated non-drive end bearing
AND
Common mode fi lter at the converter
ABB uses insulated bearings which have aluminum
oxide coated inner and/or outer bores or ceramic rolling
elements. Aluminum oxide coatings are also treated
with a sealant to prevent dirt and humidity penetrating
into the porous coating. For the exact type of bearing
insulation, see the motor's rating plate. Changing the
bearing type or insulation method without ABB's per-
mission is prohibited.
5.5.2 Elimination of bearing currents
with all other converters
The user is responsible for protecting the motor and
driven equipment from harmful bearing currents. In-
structions described in Chapter 5.5.1 can be followed,
but their effectiveness cannot be guaranteed in all
cases.

5.6 Cabling, grounding and EMC

To provide proper grounding and to ensure compliance
with any applicable EMC requirements, motors above
30 kW must be cabled using shielded symmetrical
cables and EMC glands, i.e. cable glands providing
360° bonding. Also for smaller motors symmetrical and
shielded cables are highly recommended. Make the
360° grounding arrangement at all the cable entries as
described in the instructions for the glands. Twist the
cable shields into bundles and connect to the nearest
ground terminal/busbar inside the terminal box, con-
verter cabinet, etc.
13 – EN