Lenze 8200 vector series, Mounting Instructions

Page: 94 / 250

Safety instructions
Thermal motor monitoring
2
94
EDK82EV222 DE/EN/FR 13.0
Thermal motor monitoring
Description
With the I
2
t monitoring you can monitor self−ventilated three−phase AC motors thermally without
sensors.
Note!
ƒ
The I
2
xt monitoring is based on a mathematical model which calculates a thermal
motor utilisation from the motor currents measured.
ƒ
However, the I
2
xt monitoring is no full motor protection, since other influences on
the motor utilisation cannot be detected, like changed cooling conditions (e.g.
cooling air flow interrupted or too warm).
ƒ
You can only obtain full motor protection if the motor is equipped with a PTC
thermistor or a thermal contact.
Warnings!
If you use the I
2
xt function in UL−approved systems for thermal motor monitoring:
ƒ
The I
2
xt function is UL−approved.
ƒ
In UL−approved systems no additional protective measures for the motor are
required.
For devices from software version V3.9 (nameplate data: E82xV... xx 39), an additional
setting is required!
ƒ
Activate the starting value 50% for the I
2
xt function:
–
Add 128 to the value displayed in Code C0311.
ƒ
Example:
–
C0311 = 1 (Lenze setting)
–
Setting for UL−approved systems: C0311 = 129