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ID300/302 Integrated Motor Drive |
Overview of the ID300/302 Integrated Motor & Drive
2.6.2 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.
2.7 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 IEC 61000-6-2: (1 kV
surge), provided the 0 V connection is not grounded.
In applications that may be exposed to high-energy 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 in which the ID300/302 is located, or if
cable runs within a building exceed 100ft (30 M), some of the following techniques should be used:
A.
Galvanic Isolation
-
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.
B.
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 (7 AWG), 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.
C.
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 one of the two Zener
diodes BZW50-15).
If a digital port experiences a severe surge, its protective trip may operate (‘I/O Overload’ trip).
