ABB 81EU01E-E GJR2391500R1210 logic input module
Note 7: Resistor braking of the drive
When the drive is in braking mode for a large part of its operation time, the
intermediate circuit DC voltage of the drive increases, the effect being similar to
increasing the supply voltage by up to 20 percent. The voltage increase should be
taken into consideration when determining the motor insulation requirement.
Example: Motor insulation requirement for a 400 V application must be selected as if
the drive were supplied with 480 V.
Note 8: 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 metre and longer cables. The rise time can be calculated as
follows: t = 0.8 · ÛLL/(du/dt). Read ÛLL and du/dt from the diagrams below. Multiply
the values of the graph by the supply voltage (UN). In case of drives with an IGBT
supply unit or resistor braking, the ÛLL and du/dt values are approximately 20 %
higher.
Note 9: Sine filters protect the motor insulation system. Therefore, du/dt filter can be
replaced with a sine filter. The peak phase-to-phase voltage with the sine filter is
approximately 1.5 × UN.
Note 10: Common mode filter is available as a plus code option (+E208) or as a
separate kit (one box including three rings for one cable).
Supply connection
Disconnecting device
Install a hand-operated input disconnecting device between the AC power source
and the drive. The disconnecting device must be of a type that can be locked to the
open position for installation and maintenance work.
EU
To meet the European Union Directives, according to standard EN/IEC 60204-1,
Safety of Machinery, the disconnecting device must be one of the following types:
• switch-disconnector of utilization category AC-23B (EN 60947-3)
• disconnector that has an auxiliary contact that in all cases causes switching
devices to break the load circuit before the opening of the main contacts of the
disconnector (EN 60947-3)
• circuit breaker suitable for isolation in accordance with EN 60947-2.
US
The disconnecting device must conform to the applicable safety regulations.
Fuses
See section Thermal overload and short-circuit protection.
Main contactor
If used, dimension the contactor according to the nominal voltage and current of the
drive. The utilization category (IEC 947-4) is AC-1.

Thermal overload protection of the drive and the input and motor cables
The drive protects itself and the input and motor cables against thermal overload
when the cables are dimensioned according to the nominal current of the drive. No
additional thermal protection devices are needed.
WARNING! If the drive is connected to multiple motors, a separate thermal overload
switch or a circuit breaker must be used for protecting each cable and motor. These
devices may require a separate fuse to cut off the short-circuit current.
Thermal overload protection of the motor
According to regulations, the motor must be protected against thermal overload and
the current must be switched off when overload is detected. The drive includes a
motor thermal protection function that protects the motor and switches off the current
when necessary. Depending on a drive parameter value, the function either monitors
a calculated temperature value (based on a motor thermal model) or an actual
temperature indication given by motor temperature sensors. The user can tune the
thermal model further by feeding in additional motor and load data.
The most common temperature sensors are:
• motor sizes IEC180…225: thermal switch (e.g. Klixon)
• motor sizes IEC200…250 and larger: PTC or Pt100.
See the firmware manual for more information on the motor thermal protection, and
the connection and use of the temperature sensors.
Protection against short-circuit in the motor cable
The drive protects the motor cable and motor in a short-circuit situation when the
motor cable is dimensioned according to the nominal current of the drive. No
additional protection devices are needed.