ECO REFERENCE MANUAL
10-6
DIRECTION OF ROTATION
The direction of rotation of the motor can be
reversed during commissioning by changing over
two of the output connections on the Eco.
x
x
x
x
x
x
x
x
U
V
W
PE
U
V
W
PE
M
M
STAR OR DELTA MOTOR
CONNECTION
The MICROMASTER Eco & MIDIMASTER Eco
range can be used to control all types of three-
phase asynchronous standard motors.
The voltage and connection method should be
taken from the motor nameplate, but as a general
rule, larger motors (380/660 volt) are delta-
connected and smaller motors (220/380 volt) are
star-connected.
U
V
W
Z
X
Y
U
V
W
Z
X
Y
MULTI-MOTOR CONNECTION
The MICROMASTER Eco & MIDIMASTER Eco
range can be used to control several motors
connected in parallel.
If the motors to be controlled are to run at
different speeds from one another, then motors
with different rated speeds must be used.
Because motor speeds will change
simultaneously, the ratio between the rated motor
speeds will be consistent over the full range.
If motor sizes vary to any great extent, this could
cause problems at start-up and at low rpm. This
is because smaller motors need a higher voltage
during start-up, as they have a higher resistance
value in the stator.
Additional motor protection (e.g. thermistors in
every motor or individual thermal overload relays)
is essential in systems with parallel motor
operation. This is because the inverter’s internal
thermal protection cannot be used, as output
current must be programmed to match the overall
motor current.
Total motor current consumption must not
exceed maximum rated output current.
Parameter P077 should be set to multi motor
mode.
MOTOR OVERLOAD PROTECTION
When operated below rated speed, the cooling
effect of fans fitted to the motor shaft is reduced,
so that most motors require de-rating for
continuous operation at low frequencies.
However, variable torque loads such as pumps
and fans are generally not heavily loaded at low
speeds. To provide motors with additional
protection against overheating, a PTC
(thermistor) temperature sensor may be fitted to
the motor and connected to the inverter control
terminals. Note: to enable the motor overload
protection trip function, see parameter P087=1.
MOTOR
PTC
14
15
Inverter Control
Terminals
