Lenze ECSEAxxx - Manual (Page 76)

Safety instructions
Thermal motor monitoring
2
l
76 EDKCSEX064 DE/EN/FR 6.0
2.2 Thermal motor monitoring
)
Note!
ƒ I 2 x t monitoring is based on a mathematical model which
calculates a thermal motor load from the detected motor
currents.
ƒ The calculated motor load is saved when the mains is switched.
ƒ The function is UL−certified, i.e. no additional protective
measures are required for the motor in UL−approved systems.
ƒ However, I 2 x t monitoring is no full motor protection as other
influences on the motor load could not be detected as for
instance changed cooling conditions (e.g. interrupted or too
warm cooling air flow).
Die I 2 x t load of the motor is displayed in C0066.
The thermal loading capacity of the motor is expressed by the thermal motor
time constant (
t , C0128). Find the value in the rated motor data or contact the
manufacturer of the motor.
The I
2 x t monitoring has been designed such that it will be activated after 179
s in the event of a motor with a thermal motor time constant of 5 minutes
(Lenze setting C0128), a motor current of 1.5 x I
N
and a trigger threshold of
100 %.
Two adjustable trigger thresholds provide for different responses.
ƒ Adjustable response OC8 (TRIP, warning, off).
– The trigger threshold is set in C0127.
– The response is set in C0606.
– The response OC8, for instance, can be used for an advance warning.
ƒ Fixed response OC6−TRIP.
– The trigger threshold is set in C0120.