Safe Stop Of Fc 300 - Danfoss FC 300 Design Manual

FC 300 Design Guide
Motor-generated Overvoltage
The voltage in the intermediate circuit is increased when the motor acts as a generator. This occurs in
following cases:
1. The load drives the motor (at constant output frequency from the frequency converter), ie. the
load generates energy.
2. During deceleration ("ramp-down") if the moment of inertia is high, the friction is low and the
ramp-down time is too short for the energy to be dissipated as a loss in the frequency converter,
the motor and the installation.
3. In-correct slip compensation setting may cause higher DC link voltage.
The control unit may attempt to correct the ramp if possible (par. 2-17 Over-voltage Control.
The inverter turns off to protect the transistors and the intermediate circuit capacitors when a certain
voltage level is reached.
See par. 2-10 and par. 2-17 to select the method used for controlling the intermediate circuit voltage
level.
Mains Drop-out
During a mains drop-out, the frequency converter keeps running until the intermediate circuit voltage
drops below the minimum stop level, which is typically 15% below the frequency converter's lowest rated
supply voltage.
The mains voltage before the drop-out and the motor load determines how long it takes for the inverter
to coast.
Static Overload in VVC
When the frequency converter is overloaded (the torque limit in par. 4-16/4-17 is reached), the controls
reduces the output frequency to reduce the load.
If the overload is excessive, a current may occur that makes the frequency converter cut out after approx.
5-10 s.
Operation within the torque limit is limited in time (0-60 s) in par. 14-25.
Motor Thermal Protection
The motor temperature is calculated on the basis
of motor current, output frequency, and time or
thermistor. See par. 1-90 in the chapter How to
Programme.

Safe Stop of FC 300

The FC 302, and also the FC301 in A1 enclosure,
can perform the safety function Safe Torque Off
(As defined by draft CD IEC 61800-5-2) or Stop
Category 0 (as defined in EN 60204-1).
FC 301 A1 enclosure: When Safe Stop is included
in the drive position 18 of Type Code must be ei-
Introduction to FC 300
plus mode
MG.33.B7.02 - VLT is a registered Danfoss trademark
ther T or U. If position 18 is B or X Safe Stop
Terminal 37 is not included!
Example:
Type Code for FC 301 A1 with Safe Stop:
FC-301PK75T4Z20H4TGCXXXSXXXXA0BXCXXXX
D0
45