Fuji Electric FRENIC-AQUA series, User Manual

Page: 566 / 751

6.3 Details of Function Codes
6-285
Chap. 6
FUNCTION C
ODES
Selecting Feedback Terminals
For feedback control, determine the connection terminal according to the type of the sensor
output.
• If the sensor is a current output type, use the current input terminal [C1] of the inverter.
• If the sensor is a voltage output type, use the voltage input terminal [12] of the inverter, or
switch over the terminal [V2] to the voltage input terminal and use it.
For details, refer to the descriptions of E61 through E63.
Application example: Process control (for air conditioners, fans and pumps)
The operating range for PID process control is internally controlled as 0% through 100%. For
the given feedback input, determine the operating range to be controlled by means of gain
adjustment.
(Example) When the output level of the external sensor is within the range of 1 to 5 V:
• Use terminal [12] designed for voltage input.
• Set the gain (C32 for analog input adjustment) at 200% in order to make the maximum
value (5 V) of the external sensor's output correspond to 100%. Note that the input
specification for terminal [12] is 0 to 10 V corresponding to 0 to 100%; thus, a gain factor
of 200% (= 10 V
÷
5 V
×
100) should be specified. Note also that any bias setting does not
apply to feedback control.
(Example 1) When the output level of the external sensor is
±
7 VDC:
• Use terminal [12] since the voltage input is of bipolar.
• When the external sensor's output is of bipolar, the inverter controls the speed within the
range of
±
100%. To convert the output
±
7 VDC to
±
100%, set the gain (C32 for analog
input adjustment) at 143% as calculated below.
10 V
7 V
≈
143%