Lust CDA3000 - Short-Circuit and Ground Fault Proofing; Motor Cable Length

Engineering Guide CDA3000
3-29
3 Selection of inverter module
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EN
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7
A
Note on AC-3 contactors
Note: If contactors of usage category AC-3 are used (conforming to
IEC 947-4-1, EN 60947 or VDE 0660 Part 102), the number
of actuations must not exceed five per minute and 10 every
10 minutes. For higher actuating rates different switching
elements should be selected accordingly.
Activation of energized motors or direct switching of the number of
poles in variable-pole motors, and reversing the direction of the
motor - such as by means of a reversing contactor - is not permitted
during operation.
3.2.10Short-circuit
and ground
fault proofing
The inverters of series CDA3000 are fitted with one current sensor per
motor phase. In the event of a short-circuit or ground fault in the motor
cable, the power stage is disabled and an appropriate error message is
delivered.
The CDA3000 inverter modules are short-circuit and ground fault
proof.
3.2.11Motor cable
length
The maximum motor cable length depends on a number of different
factors (see following table).
Voltage drop on the motor cable
In designing a drive solution it should be noted that the mains voltage can
fall by 10% and the components used (line choke, inverter, motor cable,
etc.) cause a voltage drop.
The system undervoltage (-10%) and the voltage drops mean that, in cer-
tain operating states, the full motor torque is not attained and the field
weakening begins earlier.
Factor Section
Standard EN 55011 A/B Section 6.4
Clock frequency of power stage Section 3.2.14
Voltage drop on the motor cable See explanation below
Connection of a motor choke du/dt Section 6.3
Table 3.20 Motor cable length