ABB ACSM1 - Page 19

Start-up
19
Multimotor drives
Ie, more than one motor is connected to one drive.
Check that the motors have the same relative slip (only for
asynchronous motors), nominal voltage and number of poles. If the
manufacturer motor data is insufficient, use the following formulas to
calculate the slip and the number of poles:
where
p = number of pole pairs (= motor pole number / 2)
f
N
= motor nominal frequency [Hz]
n
N
= motor nominal speed [rpm]
s = motor slip [%]
n
S
= motor synchronous speed [rpm].
Set the sum of the motor nominal currents.
99.06 MOT NOM
CURRENT
Set the nominal motor frequencies. Frequencies must be the same.
99.08 MOT NOM FREQ
Set the sum of the motor nominal powers.
If the motor powers are close to each other or the same but the
nominal speeds vary slightly, parameter 99.09 MOT NOM SPEED can
be set to an average value of the motor speeds.
99.10 MOT NOM
POWER
99.09 MOT NOM SPEED
External control unit power supply
If the control unit of the drive is powered from an external power
supply (as specified in Hardware Manual), set parameter 95.01 CTRL
UNIT SUPPLY to EXTERNAL 24V.
95.01 CTRL UNIT
SUPPLY
External mains choke
If the drive is equipped with an external choke (specified in Hardware
Manual), set parameter 95.02 EXTERNAL CHOKE to YES.
95.02 EXTERNAL
CHOKE
Motor overtemperature protection (1)
Select how the drive reacts when motor overtemperature is detected.
45.01 MOT TEMP PROT
Select the motor temperature protection: motor thermal model or
motor temperature measurement. For motor temperature
measurement connections, see section Temperature sensors on
page 45.
45.02 MOT TEMP
SOURCE
s
n
S
n
N
–
n
S
------------------
100%⋅=
n
s
f
N
60⋅
p
----------------
=
p Int
f
N
60⋅
n
N
---------------


=