39 TB5 MIN (TERMINAL TB-5 INPUT)
This parameter selects 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 36 - TB5 MAX to
define a speed range for the drive that corresponds to the analog speed reference input (0 - 10 VDC or 4 -
20 mA).
40 TB5 MAX (TERMINAL TB-5 INPUT)
This parameter selects 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 35 - TB5 MIN
to define a speed range for the drive 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 is based on a 0-10 VDC (or 4-20 mA)
signal, the drive will operate at half of the TB5 MAX value if it is given a 5 VDC signal. Therefore, setting
TB5 MAX 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 minimum speed reference corresponds
to the maximum output frequency, and the maximum speed reference corresponds to the minimum output
frequency. This is accomplished by setting TB5 MIN larger than TB5 MAX. Therefore, as the speed
reference increases, the drive speed will decrease, and as the speed reference decreases, the drive speed will
increase.
Example: 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 ohm. 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.
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