Altivar 71 And Altivar 71 Plus Variable Speed Drives Page 17 Application Information

17 Altivar 71 variable speed drives Using special motors Special brake motors: tapered rotor or flux bypass The magnetic field releases the brake. This type of operation with the Altivar 71 drive requires application of the voltage/frequency ratio. Note: The no-load current may be high, and operation at low speed can only be intermittent. ATEX motors in an explosive atmosphere explosive Use of the "Power Removal" safety function enables the variable speed drive to provide thermal protection in the event of excessive temperature rise of the ATEX motor, but it does not enable it to control and regulate the tempera- ture of the ATEX motor. All motor types ATEX certified for use in zones 1, 21, 2 or 22, which are equipped with ATEX thermal sensors, can be protected by the Altivar 71 variable speed drive. Resistive rotor asynchronous motors Different motor control ratios available on the Altivar 71 drive make it possible to apply specific settings when using high-slip motors. Switching the motor at the drive output The drive can be switched when locked or unlocked. If the drive is switched on-the- fly (drive unlocked), the motor is controlled and accelerates until it reaches the reference speed smoothly following the acceleration ramp. This use requires configuration of the automatic catching a spinning load ("catch on the fly") and the motor phase loss on output cut functions. Typical applications : loss of run circuit at drive output, bypass function, switching of motors connected in parallel. On new installations, it is recommended that the Power Removal safety function is used. Test on a low power motor or without a motor In a test or maintenance environment, the drive can be tested without having to use a motor with the same rating as the drive (particularly useful in the case of high power drives). This use requires deactivation of the output phase loss function. Application Information

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