BBV28581 05/2010 87
Configuration Mode - Complete menu (FULL)
Zero flow detectionThis function is only active when the auxiliary pump is stopped and the motor frequency is below threshold FFd.
This function is used in applications where zero flow cannot be detected by the sleep function alone. It forces the drive frequency reference
to LSP + LFd periodically (at each time interval nFd) in order to test for zero flow.
• If the request is still present, the PI error increases, causing the drive to restart.
• If the request is no longer present (zero flow), the PI error will not increase.
• Set the sleep function so that the drive switches to sleep mode when zero flow is detected (LFd ≤ SLE).
FFd
LSP + LFd
nFd
LSP t
t
nFd
PI feedback
PI error
Frequency reference
LSP
LSP + LFd
nFd tLS
FFd
t
t
HSP
PI feedback
Frequency reference
Sleep threshold LSP + SLE