Lenze EVS9332xK - Manual (Page 265)

Configuration
Monitoring
Current load of motor (I 2 x t monitoring: OC6, OC8)
8
8.2
8.2.8
l
8.2−7 EDSVS9332K EN 8.0−07/2013
8.2.8 Current load of motor (I 2 x t monitoring: OC6, OC8)
From software version 8.0 onwards, the 9300 controllers are provided with
an I
2 xt function for sensorless thermal monitoring of the connected motor.
)
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.
Behaviour of the I 2 x t monitoring Condition
The I 2 x t monitoring is deactivated.
C0066 is set = 0 % and
MCTRL−LOAD−I2XT is set = 0.00 %.
When C0120 = 0 % and C0127 = 0 %, set
controller inhibit.
I 2 x t monitoring is stopped.
The current value in C0066 and at the
MCTRL−LOAD−I2XT output is frozen.
When C0120 = 0 % and C0127 = 0 %, set
controller enable.
I 2 x t monitoring is deactivated.
The motor load is displayed in C0066.
Set C0606 = 3 (off) and C0127 > 0 %.
)
Note!
An error message OC6 or OC8 can only be reset if the I 2 x t load
falls below the set trigger threshold by 5 %.