Motor 2 Motor Rated Frequency; Motor 2 Motor Rated Current; Motor 2 Motor Rated Full Load Rpm - Emerson 2202 Advanced User's Manual

Parameter Parameter
Introduction
x.00 description format
21.06

Motor 2 motor rated frequency

Bit SP
Coding
Range 0.0 to 550 Hz
Default Eur: 50.0, USA 60.0
First motor
Pr 5.06
parameter
Update rate Background
The motor rated frequency and the motor rated voltage (Pr 21.09) are used to define the voltage to frequency characteristic applied to the drive (see
Pr 21.09). The motor rated frequency is also used in conjunction with the motor full load rpm to calculate the rated slip for slip compensation (see
Pr 21.08 on page 191).
21.07

Motor 2 motor rated current

Bit SP
Coding
Range 0 to RATED_CURRENT_MAX A
Default Drive rated current (Pr 11.32)
First motor
Pr 5.07
parameter
Update rate Background
The motor rated current should be set at the machine nameplate value for rated current.
This value is used in the following:
• Current limit, see Pr 21.29 on page 195
• Motor protection system, see Pr 21.16 on page 195
• Slip compensation, see Pr 21.08
• Vector mode voltage control, see Pr 21.09
• Dynamic V to f control, see Pr 5.13 on page 78
21.08

Motor 2 motor rated full load rpm

Bit SP
Coding
Range 0 to 9999 rpm
Default Eur: 1500, USA 1800
First motor
Pr 5.08
parameter
Update rate Background
The rated full load rpm is used with the motor rated frequency and No. of motor poles to calculate the rated slip of the induction machine in Hz.
Rated slip Motor rated frequency
=
The rated slip is used to calculate the frequency adjustment required to compensate for slip from the following equation:
Slip compensation = Rated slip
If slip compensation is required, Pr 5.27 must be set to On(1) and this parameter should be set to the nameplate value, which should give the correct
rpm for a hot machine.
Sometimes it will be necessary to adjust this when the drive is commissioned because the nameplate value may be inaccurate. Slip compensation will
operate correctly both below rated speed and within the field weakening region. Slip compensation is normally used to correct for the motor speed to
prevent speed variation with load. The rated load rpm can be set higher than synchronous speed to deliberately introduce speed droop. This can be
useful to aid load sharing with mechanically coupled motors.
NOTE
If Pr 21.08 is set to 0 or to synchronous speed, slip compensation is disabled.
NOTE
If the full load speed of the motor is above 9999rpm, slip compensation should be disabled. This is because a value above 9999 cannot be entered in
Pr 21.08.
Commander SK Advanced User Guide
Issue Number: 9
Keypad and Serial
display communications
FI DE Txt VM DP ND
1
FI DE Txt VM DP ND
1 2
FI DE Txt VM DP ND
( No. of motor pole pairs
–
× ⁄
Active current Rated active current
www.controltechniques.com
CT Modbus PLC Ladder
RTU programming
RA NC NV PT US RW BU
1 1
RA NC NV PT US RW BU
1 1 1
RA NC NV PT US RW BU
1 1
× Motor full load rpm 60 ⁄
Advanced parameter
CTSoft Menu 0
descriptions
PS
1
PS
1
PS
1
) Pr 21.06 [ ( Pr 21.11 2 ⁄ )
= –
Menu 21
× ( Pr 21.08 60 ⁄ ) ]
191