30 VIX AE SERVO DRIVE USER GUIDEControl of I2t Parameters
The drive internal I2t parameters are always enabled and cannot be adjusted by the user.
However, the motor I2t settings can be influenced by the choice of parameters used for the
MOTOR command. To disable the motor I2t settings, set the thermal time constant of the
motor to zero.
Note: If you select a motor from the list of ‘standard motors’ using EASI-V, worst case
configuration data will be used. This prevents reporting a too optimistic view of the motors
thermal performance.
Where a motor is fitted with a temperature sensor built into its windings the motor I2t
threshold protection will not be required. In this case, set the thermal time constant of the
motor to zero (see MOTOR command).
Motor Voltage Ratings
Motors with a withstand voltage rating from phase to earth of 1000V AC should be used. An
insulation withstand rating of 500V AC is acceptable if an isolating transformer with earthed
screen is used to power the system, and X1 pin9 (0V/GND) input is earthed, as specified.
Motor Safety Earth/Ground Connection
It is recommended that the motor is independently bonded to a local safety earth point. The
safety earth lead should be at least 2.5mm2 in area.
Short Circuit Protection
The motor outputs are protected against overload and short circuits. Overload is protected
by the I2t circuit, and 300% of continuous drive current rating is only permitted for 2 seconds.
A current level just above rated current is only permitted for a maximum of 20 seconds.