Lenze TCF Series User Manual

Page 59

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P83

CURRENT LOOP I GAIN

Normally, this parameter should not require adjustment . In special cases, however, it
may need to be adjusted to optimize performance . Do not change this parameter without
consulting Lenze-AC Tech .
P84

MOTOR STATOR RESISTANCE

This will be automatically adjusted when the AUTO CALIBRATION (Parameter 81) function
is performed . Once the AUTO CALIBRATION function is performed, this setting should not
be changed .
P85

MOTOR RATED SPEED

Enter the motor's nameplate RPM rating .
P86

MOTOR RATED CURRENT

Enter the motor's nameplate full-load current rating .
P87

MOTOR RATED VOLTAGE

Enter the motor's nameplate voltage rating . If the motor is dual-rated, enter the voltage that
matches the supply voltage being used .
P88

MOTOR BASE FREQUENCY

Enter the motor's nameplate frequency .
P91

MOTOR COSINE PHI (POWER FACTOR)

Use the following formulas to determine the appropriate value to enter, depending on the
available motor data:

1 . If the motor's power factor is known, simply enter that value .
2 . If the motor's magnetizing current is known:

COS F = COS

[

SIN

-1

(

Magentizing Current

)]

Motor Current

Example 1: A motor has a full-load current rating of 8 amps and a magnetizing current of 4
amps . Using the above formula yields a result of 0 .87:

4/8 = 0 .5

sin

-1

(0 .5) = 30

cos (30) = 0 .866 = 0 .87

3 . If the motor's power factor or magnetizing current is not available, but the

efficiency is known:

COS F =

Motor HP X 746

Motor Efficiency X Motor Voltage X Motor Current X 1 .732

Example 2: A 10 Hp 460 Vac motor has an efficiency of 85% and a full-load current rating
of 13 amps . Using the formula above yields a result of 0 .85:

10 X 746 = 7460

0 .85 X 460 X 13 X 1 .732 = 8804

7460/8804 = 0 .847 = 0 .85

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