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Installation and quick start commissioning guide - Commander ID300/302
5511 en - 2017.06 / a
GENERAL INFORMATION
1.6 -
Thermal overload protection and
typical overload limits
As standard, the Commander ID300/302 integrates
internal functions to protect motor and drive against
overloads.
Motor protection:
Current in the lower IGBTs is continuously measured.
The drive software uses these measurements to
calculate the actual I²t value for the motor. If the actual
motor I²t exceeds the rated motor I²t, the drive will trip.
By default, the internal thermal protection of the drive
is set to 150% of the full rated output current for 60
seconds, and 180% for 3 seconds.
All drive models are provided with thermal memory
retention.
However, an optional PTC probe can be added in
motor windings in order to get an additional thermal
protection.
NOTE
In the case a PTC probe is used to protect the motor,
the user may ensure it is connected to an analog input
of the drive control board and that it is correctly mana-
ged by the drive (parameter setting). For more details,
please refer to section 3.6.
Drive protection:
An overload on the output of the drive will cause the
junction temperature of the IGBT to rise. This junction
temperature is estimated by the IGBT thermal model,
taking into account the operating conditions. When the
estimated junction temperature reaches its limit, the
drive will trip.
1.7 - Surge immunity of control circuits
The input/output ports for the control circuits are
designed for general use within machines and small
systems without any special precautions. These circuits
meet the requirements of EN 61000-6-2:2005 (1 kV
surge) provided the 0 V connection is not grounded.
In applications where they may be exposed to high-
ene rgy voltage surges, some special measures may
be required to prevent malfunction or damage. Surges
may be caused by lightning or severe power faults in
association with grounding arrangements which permit
high transient voltages between nominally grounded
points. This is a particular risk where the circuits extend
outside the protection of a building.
As a general rule, if the circuits are to pass outside
the building where the Commander ID300 is located,
or if cable runs within a building exceed 30 m, some
additional precautions are advisable. One of the
following techniques should be used:
1. Galvanic isolation, i.e. do not connect the control 0 V
terminal to ground. Avoid loops in the control wiring, i.e.
ensure every control wire is accompanied by its return
(0 V) wire.
2. Shielded cable with additional power ground
bonding. The cable shield may be connected to ground
at both ends, but in addition the ground conductors at
both ends of the cable must be bonded together by a
power ground cable (equipotential bonding cable) with
cross-sectional area of at least 10 mm2, or 10 times the
area of the signal cable shield, or to suit the electrical
safety requirements of the plant. This ensures that fault
or surge current passes mainly through the ground
cable and not in the signal cable shield. If the building or
plant has a well-designed common bonded network this
precaution is not necessary.
3. Additional over-voltage suppression - for the analog
and digital inputs and outputs, a zener diode network
or a commercially available surge suppressor may be
connected in parallel with the input circuit as shown
below (performances must be at least equal to ones of
the two zener diodes BZW50-15).
0 V
0 V
Signal from plant
Signal to drive
30 V Zener diode
e.g. 2xBZW50-15
If a digital port experiences a severe surge its protective
trip may operate (‘I/O Overload’ trip). For conti nued
operation after such an event, the trip can be reset
automatically by setting Pr
10.034
to 5.
