2 optimisation of motor-current control, Commissioning – Lenze 8240 HVAC Series User Manual
Page 50
Commissioning
5-10
UOOuhäáã~_^NMMO
5.4.2.2
Optimisation of motor-current control
Codes required
Code
Name
Possible settings
IMPORTANT
Lenze
Selection
Info
C015 V/f rated frequency
50.00 7.50
{0.02Hz}
960.00
C021 Slip compensation
0
-50.0
{0.1 %}
50.0
C088 Rated motor current
*
0.0 ... 2.0
¡
rated output current
* depends on
the unit
Input only necessary
when motors not
C091 Motor cos
j
*
0.4
{0.1}
1.0
the unit
when motors not
adapted.
Setting sequence
D
Drives with matching 4 pole standard motors 230/400 V in star connection do not need to be
adapted.After having started the drive, the controller itself detects all further motor data.
D
The following drives can be optimized by entering the nameplate data ”rated motor current” and
”cos
j” under C088 or C091:
- Motor one power class smaller than the motor assigned to the controller.
- Motor one or two power classes smaller than the motor assigned to the controller.
- Drives with 2, 6, 8, 10 and 12 pole standard motors.
- Drives with special motors.
D
With the slip compensation C021, you can optimize the ”sensorless speed control” for your
application.
1.If necessary,
select C014 = -4-.
(factory setting)
2.Select V/f-rated frequency
(C015).
Motor voltage
Motor
connection
C015
(
)
220/380 V
Y
52,6 Hz
230/400 V, 265/460 V, 280/480 V
Y
50 Hz
220/380 V, 230/400 V, 265/460 V, 280/480 V
D
87 Hz
380/660 V
D
52,6 Hz
400/690 V
D
50 Hz
3.If necessary, enter the motor
data of unadapted motors
(C088, C091).
4.Set slip compensation
Rough setting by means of the motor data:
p
p
(C021):
л =
е
клуе
− е
к
е
клуе
⋅ NMMB
е
клуе
=
С
Зк
⋅ SM
é
s
Slip constant (C021)
n
rsyn
synchronous motor speed [min
-1
]
n
r
rated speed to motor nameplate [min
-1
]
f
dr
rated frequency to motor nameplate [Hz]
p
Number of pole pairs
Precise setting:
Change C021 under constant load until the speed is near the synchronous speed.
If C021 is set to too high values, the drive may become instable (overcompensation).
Important
D
The change from V/f-characteristic control to motor-current control should only be carried out
when the controller is inhibited.
D
The idle current of the motor (magnetizing current) must not exceed the rated current of the
controller.
D
With very small friction values it is possible that an angle offset of up to 180
° occurs when
enabling the controller.
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