L8 Hardware Protection - YASKAWA E7U Programming Manual

L8 Hardware Protection

L8-01 Internal Dynamic Braking Resistor Protection Selection
Setting
0 Not Provided (factory default)
1 Provided
This parameter is not applicable for Drive operation.
L8-02 Overheat Pre-Alarm Level
Setting Range: 50 to 130
o
Factory Default: 95 C
L8-03 Overheat Pre-Alarm Operation Selection
Setting
0 Ramp to Stop (Decel Time C1-02)
1 Coast to Stop
2 Fast-Stop (Decel Time C1-09)
3 Alarm Only
4 OH Alarm and Reduce (factory default)
The Drive is capable of warning the operator of an impending heatsink over-temperature fault via an OH pre-alarm. The level
at which the pre-alarm will activate is determined by the setting of parameter L8-02. Measurement of the heatsink temperature
is done with several strategically mounted thermistors. If any of the heatsink thermistors measure a temperature in excess of
the setting of L8-02, the Drive will fault (OH2) and either: ramp to stop using the C1-02 deceleration rate (L8-03= "0: Ramp
to Stop"), coast to stop (L8-03= "1: Coast to Stop"), ramp to stop using the C1-09 fast stop deceleration rate (L8-03=
"2: Fast-Stop"), alarm (OH) and continue running (L8-03 = "3: Alarm Only"), alarm (OH) and continue running but at a
reduced speed (L8-03= "4: Alarm & Reduce"). If L8-03= 4: Alarm and Reduce, the Drive will continue to run but will reduce
the speed to the level determined by parameter L8-19. Refer to the description for parameter L8-19.
If a digital output is configured for OH Prealarm (H2-01= "20: OH PreAlarm"), it will close whenever the heatsink temperature
is greater than the L8-02 level no matter what the setting is of L8-03.
L8-06 Input Phase Loss Detection Level
Setting Range: 0.0 to 25.0% of Drives OV Trip point
Factory Default: KVA Dependent
The Drive checks for a lost input phase by monitoring the DC Bus voltage ripple. After an initial delay of approximately 12
seconds, the Drive will sample the DC BUS voltage every 1.28 seconds to determine the minimum and maximum voltage
readings. The difference between the minimum and maximum voltage is averaged over ten consecutive scans. If this
"averaged" value is greater than the trip level as determined by L8-06 (L8-06 x 400 for 200 volt class Drives; L8-06 x 800 for
400 volt class Drives) the Drive shuts down and displays "PF", an input phase loss fault.
Description
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C
Description
Programming 113