For Altivar 312/32/61/71 range of drives, Is it possible to continue motor operation at same speed even if 4-20 mA analog signal is lost during drive is running.

Yes, it is possible to maintain the speed of the motor even if 4-20 mA analog signal is lost during the drive running and so it prevents the motor from stopping or trip on a fault such
as LFF2 , LFF3 & LFF4 (4-20 mA loss fault detected on AI2, AI3 and AI4 terminals respectiviely) .

To have this function, set parameter LFL2 [ AI2 4-20 mA loss] to rLS [ Spd maint.] Same function can be made available for AI2 and AI3 by setting LFL3 [ AI3 4-20 mA loss]
and LFL4 [ AI4 4-20 mA loss] parameters respectively. These parameters are at FLt [ Fault Management] menu, LFL- [ 4-20 mA loss] sub-menu.

When 4-20 mA signal loss is detected on analog input terminals, the drive will continue at the speed which is at the instance 4-20 mA signal loss is detected and
continued till the 4-20 mA signal is restored back. Once the 4-20 mA signal is restored, the drive automatically follows the speed in accordance with it.

Note, if the drive is powered OFF in the condition of 4-20 mA signal is lost then after the power cycle, the drive frequency reference will remain at 0 hZ.
To resume the speed, 4-20 mA signal has to be restored first.

Released for:Schneider Electric India