BENSHAW Rsi S Series, Instruction Manual, Page: 214 / 398

Learning Advanced Features
202
Code Description
2 FDT-2 FDT-2 compares the reference frequency to the
detect frequency OU.57, FDT frequency. Relay1 (or
Q1) closes when the reference frequency and the
detect frequency are within ½ of the FDT Band,
OU.58.
Eq: [Absolute value (set frequency-detected
frequency) < detected frequency width/2]&[FDT-1]
Ex: OU.57, FDT Frequency = 30 Hz.
OU.58, FDT Band = 10 Hz.
FDT-2 functions as shown in the graph below.
3 FDT-3 FDT-3 compares the output frequency to the detect
frequency OU.57, FDT Frequency. Relay1 (or Q1)
closes when the output frequency and the detect
frequency OU.57 are within ½ the FDT Band, OU.58.
Eq: Absolute value (output frequency
–
operation
frequency) < detected frequency width/2.
Ex: OU.57, FDT Frequency = 30 Hz.
OU.58, FDT Band = 10 Hz.
FDT-3 functions as shown in the graph below.
4 FDT-4 FDT-4 compares the output frequency to the detect
frequency OU.57, FDT Frequency. Relay1 (or Q1)
closes when the output frequency reaches the detect
frequency OU.57, FDT Frequency and remains closed
above the detect frequency (does not consider the
FDT Band frequency). During deceleration, Relay1 (or
Q1) closes when the output frequency reaches the
detect frequency OU.57, FDT Frequency and is below
½ the FDT Band, OU.58.
Q1
25Hz
30Hz
50Hz
Frequency
reference
Frequency
Run cmd
30Hz
35Hz
25Hz
Q1
Frequency
Run cmd