Danfoss VLT AQUA Drive Series - Page 151

5.8.2 Parallel Connection of Motors
The frequency converter can control several parallel-connected motors.
The total current consumption of the motors must not exceed the rated
output current I
INV
for the frequency converter.
NB!
When motors are connected in parallel, par. 1-29
Au-
tomatic Motor Adaptation (AMA)
cannot be used.
Problems may arise at start and at low RPM values if motor sizes are
widely different because small motors' relatively high ohmic resistance in
the stator calls for a higher voltage at start and at low RPM values.
The electronic thermal relay (ETR) of the frequency converter cannot be
used as motor protection for the individual motor of systems with parallel-
connected motors. Provide further motor protection by e.g. thermistors
in each motor or individual thermal relays. (Circuit breakers are not suit-
able as protection).
VLT
®
AQUA Drive Design Guide 5 How to Install
MG.20.N5.02 - VLT
®
is a registered Danfoss trademark 151
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