Operating instructions

Issue B1 3 Commissioning
MICROMASTER 420 Operating Instructions
6SE6400-5AA00-0BP0
45
External motor thermal overload protection
When operated below rated speed, the
cooling effect of fans fitted to the motor
shaft is reduced. Consequentially, most
motors require de-rating for continuous
operation at low frequencies. To ensure
that the motors are protected against
overheating under these conditions, a
PTC temperature sensor must be fitted to
the motor and connected to the inverter
control terminals. P0601 must also be set
to 1.
NOTE
To enable the trip function, set parameter P0701, P0702 or P0703 = 29.
1 k Ω
Motor
PTC
8
9
5, 6
or 7
Inverter
Control
Terminals
Figure 3-8 Motor Overload PTC
Connection