Lenze MC1000 Series - Manual (Page 63)

13435742_EDBM101_v24 59
Example 2: The drive is being controlled by a pressure transducer that provides a
4-20 mA signal proportional to duct pressure. The minimum frequency desired is 20
Hz, and the maximum is 60 Hz. Set TB5 MIN for 60 Hz, and TB5 MAX for 20 Hz. As
the duct pressure rises, the output signal from the transducer will increase, causing
the speed of the drive to decrease. This results in a decrease in duct pressure and
a decreasing transducer signal. The drive responds to the decreasing signal by
increasing speed, which again raises the duct pressure. In this way, the average duct
pressure can be maintained at a certain level. If the acceleration and deceleration
rates are set too fast however, the drive will react quickly to signal changes which
will cause the drive speed to “hunt” up and down excessively.
41
AIN 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.
42
TB10A OUT (TERMINAL TB-10A OUTPUT)
The analog output signal at TB-10A is proportional to the output frequency of the
drive. This parameter selects whether that signal is 0-10 VDC or 2-10 VDC. The
2-10 VDC signal can be converted to a 4-20 mA signal by connecting a resistor
in series with the signal such that the total load resistance is 500 Ohms. If set to
NONE, the function is disabled.
NOTE: This output cannot be used with “loop-powered” devices that derive power
from a 4-20 mA signal.
43
@ TB10A (TERMINAL TB-10A SCALING)
This parameter scales the analog output signal at TB-10A. This setting is the output
frequency that is indicated when the TB-10A output measures 10VDC.
Example: The drive is part of a control system that requires a 0-5 VDC signal (rather
than 0-10 VDC) that is proportional to 0-60 Hz output frequency. The output signal
is linear, so setting this parameter to 120 Hz would yield 10 VDC at 120 Hz, and
5 VDC at 60 Hz.
44
TB10B OUT (TERMINAL TB-10B OUTPUT)
The analog output signal at TB-10B is proportional to the drive load. This parameter
selects whether that signal is 0-10 VDC or 2-10 VDC. The 2-10 VDC signal can be
converted to a 4-20 mA signal by connecting a resistor in series with the signal such
that the total load resistance is 500 Ohms.
NOTE: This output cannot be used with “loop-powered” devices that derive power
from a 4-20 mA signal.
45
@ TB10B (TERMINAL TB-10B SCALING)
This parameter scales the analog output signal at TB-10B. This setting is the load
(in %) that is indicated when the TB-10B output measures 10 VDC.
Example: The drive is part of a control system that requires a 0-10 VDC signal to
indicate 0-150% drive load. If this parameter were set to 150%, the drive would
output 10 VDC at 150% load (and about 6.7 VDC at 100% load).
NOTE: The output signal at TB-10B is affected by the setting of Parameter 34
- LOAD MLT.