Lenze E82EV 8200 - Manual (Page 94)

Safety instructions
Thermal motor monitoring
2
l
94 EDK82EV113 DE/EN/FR 11.0
Thermal motor monitoring
Description
With the I
2 t monitoring you can monitor self−ventilated three−phase AC motors thermally without
sensors.
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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.
J
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