Motor Overload Calculation To Ul - Jetter JetMove D203 User Manual

JetMove D203
NOTICE
5.2.3
The UL standard prescribes a motor overload detection for a servo amplifier that
meets the following requirements:
The "trip current" is defined to 1.15 times the user-set nominal current.
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This protection (error message 31 will occur) can be parameterized only through the
nominal current value.
The motor overload protection is always active and cannot be deactivated.
NOTICE
Jetter AG
Because of the fact that after reset the I²t calculation always starts at zero,
the motor overload calculation is wrong if the motor is already hot when the
JetMove D203 is energized (that is, when parameterization of I²t calculation
is completed and 24 V logic power supply is applied).
Therefore wait until the motor is cold before enabling the axis again.

Motor overload calculation to UL

If the average motor current corresponds to the trip current the overload
protection must switch of the motor after a limited time
If the average motor current is 2 times higher than the trip current the overload
protection must switch of the motor after at least 8 minutes.
If the average motor current is six times higher than the trip current, the overload
protection must switch off the motor after at least 20 seconds.
Because of the fact that after reset the motor overload calculation always starts
at zero, the result is wrong if the motor is already hot when the JetMove D203 is
energized (that is, when the 24 V logic power supply is applied).
Therefore wait until the motor is cold before enabling the axis again.
5.2 Motor Protection
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