NFO Drives NFO 3A4D3490D, Operating And Installation Manual



NFO

Drives

AB

2021

201013

‐

2

Operating

and

Installation

Manual

31

If rotation is required in both directions (e.g. at ±10V or ±20mA, stopping in the middle), set 

Min Ain Frq

 to negative 

(–) 

Max Ain Frq

. 

5.10  RPM regulation with speed estimation, 

Speed 

mode 

Speed

 mode is designed to be used for more complex operating conditions when precise RPM regulation is 

required. The inverter compensates for the motor's slip. The setpoint and the value in the display is the rotor RPM 
(the speed the shaft is rotating at). The inverter's internal speed regulator (set via parameters 

Kp-speed

 and 

Ti-

speed

) ensures the motor follows the speed setpoint as accurately as possible. 

The parameters described below can be found in the parameter group 

Speed

, which are only displayed when this 

mode is selected. 

5.10.1   Setpoint source for Speed Mode 

Speed setpoint source is selected by the parameter 

Op Mode (Setp Source)

. 

Op Mode 

Setpoint source for Speed mode 

Terminal 

Any of the alternatives below, selected from terminal as in Table 7 

Analog 1 F 

Analogue input 1, clockwise. 

Analog 1 R  Analogue input 1, counter-clockwise. 
Analog 2 F 

Analogue input 2, clockwise. 

Analog 2 R  Analogue input 2, counter-clockwise. 
Fix-1 F 

Speed from parameter Fix Spd 1, clockwise. 

Fix-2 F 

Speed from parameter Fix Spd 2, clockwise. 

Fix-3 F 

Speed from parameter Fix Spd 3, clockwise. 

Fix-4 F 

Speed from parameter Fix Spd 4, clockwise. 

Fix-5 F 

Speed from parameter Fix Spd 5, clockwise. 

Fix-6 F 

Speed from parameter Fix Spd 6, clockwise. 

Fix-7 F 

Speed from parameter Fix Spd 7, clockwise. 

Fix-1 R 

Speed from parameter Fix Spd 1, counter-clockwise. 

Fix-2 R 

Speed from parameter Fix Spd 2, counter-clockwise. 

Fix-3 R 

Speed from parameter Fix Spd 3, counter-clockwise. 

Fix-4 R 

Speed from parameter Fix Spd 4, counter-clockwise. 

Fix-5 R 

Speed from parameter Fix Spd 5, counter-clockwise. 

Fix-6 R 

Speed from parameter Fix Spd 6, counter-clockwise. 

Fix-7 R 

Speed from parameter Fix Spd 7, counter-clockwise. 

PI-reg F 

Frequency from process regulator, clockwise. 

PI-reg R 

Frequency from process regulator, counter-clockwise. 

Table 13. Speed mode setpoint source parameter settings 

There are seven fixed speed setpoint parameters, 

Fix Spd 1

 - 

Fix Spd 7

. These are set between 0 - 9000rpm. 

However, the maximum speed is governed by the motor type and is set at three times the motor's nominal 
frequency up to a maximum of 150Hz. Thus a 4-pole motor with nominal frequency of 50Hz can have a maximum 
of 4500rpm. 

5.10.2   Analogue speed setpoint range, 

Min Ain Spd

 and 

Max Ain Spd

Parameters 

Min Ain Spd

 and 

Max Ain Spd

 indicate the RPM range in which the inverter is to work when an 

analogue input is designated as setpoint source. The terminal and scaling to be used are indicated by the 
parameter 

Ain Set

, see Table 8. 

Max Ain Spd

 applies at maximum analogue input signal and 

Min Ain Spd

 at 

minimum input signal. The settings apply for both rotational directions. 

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