Connecting the frequency converter part 2

Connection of the frequency converter for fan speed control

To implement the rotation speed control of the three-phase asynchronous motor shaft using the analog signal from the controller, it is necessary to pre-configure the frequency converter, taking into account the specific features of the motor model.

Connection diagram

image_alt_vfd

Frequency converter configuration parameters

It is important to enter the following settings through the frequency converter menu:

Parameter Code

Parameter Name

Parameter Value

3-02

Minimum Setpoint

"0" – minimum speed setpoint

3-03

Maximum Setpoint

"50" – maximum speed setpoint

3-15

Setpoint Source 1

"1" – Analog in 53 (signal from the controller)

3-16

Setpoint Source 2

"0" – No function – not used

5-10

Function of digital input 18

"8" – Start – operation of the mechanism with a 24V signal on terminal 18

6-10
or
6-12

Terminal 53 low voltage
or Terminal 53 low current

"0" – V/mA – lower limit of the analog input range 1

5-12*

Function of digital input terminal 27 for the VLT HVAC Basic model

"0" – No function – not used

5-400

Relay Function 1

"2" – Drive Ready – drive is ready for operation

5-401

Relay Function 2 (available for the VLT HVAC Basic model)

"9" – Alarm – fault (red light)

8-30

Protocol

"2" – ModBus RTU – communication between the controller and the frequency converter

8-31

Address of the converter in the network

"2" – address of the frequency converter in the network

8-32

Communication speed for the protocol

"2" – 9600 bps – connection speed for the protocol

* The values of some parameters may differ from factory settings; they should be checked and set according to the specific connection scheme.