Danfoss iC2 Application Manual page 111

Application Guide | iC2-Micro Frequency Converters
Selection number Selection name
0 No Function
1 Ctrl. Ramp-down
2 Ctrl. Ramp-down, Trip
3 Coasting
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Selection description
The frequency converter does not compensate for a mains
interruption. The voltage on the DC link drops quickly, and the
motor is lost within milliseconds to seconds. Trip lock is the
result.
The frequency converter retains control of the motor and does a
controlled ramp down from P 2.3.7 Power Loss Controller Limit.
The ramp follows the setting in P 5.7.7 Quick Stop Ramp Time.
This selection is useful in pump applications, where the inertia is
low and the friction is high. When mains is restored, the output
frequency ramps the motor up to the reference speed (if the
mains interruption is prolonged, the controlled ramp down
might take down the output frequency to 0 RPM, and when the
mains is restored, the application is ramped up from 0 RPM to the
previous reference speed via the normal ramp up). If the energy
in the DC link disappears before the motor is ramped to 0, the
motor is coasted.
This selection is similar to selection [1] Ctrl. ramp-down, except
that in [2] Ctrl. ramp-down, Trip a reset is necessary for starting
up after power-up.
Centrifuges can run for an hour without supply. In those
situations, it is possible to select a coast function at mains
interruption, together with a flying start, which occurs when the
mains is restored.
AB413939445838en-000301 / 130R1254 |
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