Lenze i510 - Motor Protection; Motor Overload Monitoring (I²*T)

7.7 Motor protecon
•
Mot
or o
v
erload monit
oring (i²*t)
^ 92
•
Current limits ^ 93
•
Ulmate motor current ^ 94
•
Motor phase failure detecon ^
94
•
Motor speed monitoring ^ 95
7.7.1 Motor overload monitoring (i²*t)
This funcon monitors the thermal ulisaon of the motor, taking the motor currents recor-
ded and a mathemacal model as a basis.
DANGER!
Fire hazard by overheang of the motor.
Possible consequences: Death or sev
ere injuries
▶
To achieve full motor protecon, an addional temperature monitoring funcon with a sep-
arate evaluaon must be installed.
▶
When actuang motors that are equipped with PTC thermistors or thermal contacts, always
acvate the PTC input.
Details
This funcon only serves to funconally protect the motor. It is not suitable for the safety-rele-
vant protecon agains
t energy-induced hazards, since the implementaon is not fail-safe.
•
When the thermal motor ulisaon calculated reaches the threshold set in 0x2D4B:001
(PAR 308/001), the response set in 0x2D4B:003 (PAR 308/003) is triggered.
•
With the seng 0x2D4B:003 (PAR 308/003) = "No response [0]", the monitoring funcon is
deacvated.
To ensure a UL-compliant operaon, 0x2D4B:002 (PAR 308/002) and 0x2D4B:
003 (PAR 308/003) hav
e to be le to Lenze seng! (speed compensaon = "On
[0]" and error response = "error [3]".)
Parameter Name / value range / [default seng] Info
0x2D4B:001
(PAR 308/001)
Motor overload monit
oring (i²*t): Maximum
ulisaon [60 s]
(Motor overload: Load at 60 sec)
30 ... [150] ... 200 %
Maximum permissible thermal motor ulisaon (max. permissible motor
current for 60 seconds).
•
100 % ≡ rated motor current 0x6075 (PAR 323)
•
If the motor is actuated with the current set here for 60 seconds, the
maximum permissible thermal motor ulisaon is reached and the
response set in 0x2D4B:003 (PAR 308/003) is executed.
•
If the motor is actuated with a dierent current, the me period unl
the motor overload monitoring funcon is acvated is dierent. Gen-
erally the following applies: the lower the current, the lower the ther-
mal ulisaon and the later the monitoring funcon is triggered.
0x2D4B:002
(PAR 308/002)
Motor overload monit
oring (i²*t): Speed
compensaon
(Motor overload: Speed comp.)
Use this funcon to protect motors that are actuated at a speed below
40 Hz.
•
UL-compliant operaon requires the seng "On [0]"!
0 On Release me for motor overload monitoring is reduced in order to com-
pensate for the reduced cooling of naturally venlated AC inducon
motors during operaon at low speed.
1 O Funcon deacvated, no reducon of the motor overload monitoring
release me.
0x2D4B:003
(PAR 308/003)
Motor overload monitoring (i²*t): Error response
(Motor overload: Error response)
•
For possible sengs see descripon for
0x2D45:001 (PAR 310/001). ^ 94
Selecon of the response to the triggering of motor overload monitor-
ing.
•
UL-compliant operaon requires the seng "Error [3]"!
3 Error
Motor control
Motor protecon
Motor ov
erload monitoring (i²*t)
92
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