Lenze MCH Series - Manual (Page 64)

60 13435744_EDBMH01_v13
38 SLEEP BANDWID (SLEEP BANDWIDTH)
This parameter allows the PID feedback signal to determine when drive should "wake
up" when operating in Sleep Mode. In process systems that utilize Integral Gain
(Parameter 78), the drive may cycle in and out of Sleep Mode more often than desired,
due to the Integral function of the PID algorithm.
When SLEEP BANDWIDTH is used, the feedback signal must decrease or increase
(depending on whether the system is normal or reverse-acting) by the programmed
amount before the drive will "wake up". This parameter is set in PID units.
Example:
In a normal-acting system, the PID setpoint is 50 PSI, SLEEP THRESHOLD
is set to 20 Hz, and SLEEP BANDWIDTH is set to 5 PSI. The drive will
enter Sleep Mode when the commanded speed drops below 20 Hz for the
time defined in SLEEP DELAY. The drive will wake up when the feedback
signal drops below 45 PSI (50 PSI setpoint minus 5 PSI bandwidth = 45
PSI), even if the commanded speed is still below 20 Hz.
NOTE: If SLEEP BANDWIDTH is set to 0, this function is disabled, and the drive will
wake up when the commanded speed exceeds the SLEEP THRESHOLD
plus 2 Hz, as described in Parameters 36 and 37.
39 TB5 MIN FREQ
This parameter sets the output frequency of the drive that will correspond to the minimum
analog speed reference input (0 VDC or 4 mA). This parameter is used in conjunction
with Parameter 40 - TB5 MAX FREQ to define a speed range that corresponds to the
analog speed reference input (0-10 VDC or 4-20 mA).
40
TB5 MAX FREQ
This parameter sets the output frequency of the drive that will correspond to the maximum
analog speed reference input (10 VDC or 20 mA). This parameter is used in conjunction
with Parameter 39 - TB5 MIN FREQ to define a speed range that corresponds to the
analog speed reference input (0-10 VDC or 4-20 mA).
Example:
The drive is required to operate from 0 to 60 Hz in response to a 0-5 VDC
speed reference signal (rather than the “normal” 0-10 VDC). Because TB5
MAX FREQ is based on a 0-10 VDC (or 4-20 mA) signal, the drive will
operate at half of the TB5 MAX FREQ value if it is given a 5 VDC signal.
Therefore, setting TB5 MAX FREQ to 120 Hz will cause the drive to run at
60 Hz when it is given a 5 VDC speed reference signal.
NOTE: The drive can be programmed for inverse operation so that as the speed
reference increases, the drive speed will decrease, and as the speed
reference decreases, the drive speed will increase. This is accomplished
by setting TB5 MIN FREQ to the desired maximum output frequency, and
TB5 MAX FREQ to the desired minimum output frequency.
41 AN INPUT FLTR (ANALOG INPUT FILTER)
This parameter adjusts the filter on the analog input terminals (TB-5A and TB-5B) to
reduce the effect of any electrical noise that may be present on the analog input signals.
This filter works in both PID mode and standard speed control mode. It should be set to
the lowest value that yields acceptable performance, as setting it too high may cause
the drive to react too slowly to signal changes.