2.2.5 Brake resistor
When the motor decelerates, braking resistance converts energy into heat.
There are two different brake resistors for the L50 power supply:
DR2020
MAR2-E-191
20
2.2.6. Line inductors
For normal operation, inductors do not have to be used at the power supply input.
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However, if using a low-inductance network (below 100 uH, it is advisable to t a line inductor to the network in order to protect
the power supply.
Systems with a very low line inductance produce dV/dt values above 1000 V/uS of the three-phase input voltage applied to
the drive. This is a limit value for thyristors, which IN THESE PARTICULAR CONDITIONS may become conductive, even without
controlled triggering by the internal circuit.
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Speci cally, if switched on early, they may cause the fuses in the soft-start circuit to break (the soft-start circuit is designed to
limit starting current caused by the DC BUS capacitors preventing uncontrolled currents).
To de
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ne an approximate value for line inductance, the cable length between the three-phase input of the drive and MV/LV
transformer cabin must be considered, using 0.6 uH/m as a typical inductance value per metre of wiring, and summing the
inductance of the transformer cabin.
To limit possible dV/dt, the effect of limiting the value induced by the input EMC
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lter should also be considered, checking the
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lter inductance value.
INFORMATION
The inductor must b
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tted between the transformer of the cab and the drive
TOTAL LINE INDUCTANCE 100 uH
DM2020_D_005
Fig 2.10 Diagram of a three-phase input inductor connection
Power supply size
Inductance value
Current
Frequency
Type L50
0.1 mH
Inom. 60 A
50/60 Hz
Type L150
0.1 mH
Inom. 130 A
50/60 Hz
Tab 2.6 Example of external three-phase inductor dimensioning
Code
Power (W)
Ohm
Notes
Standard
370
15
Supplied
AR5974
500
16
Available as an option to be ordered separately
The braking resistor is not provided for the L150 power supply. The recommended resistor is 4.7 ohms/1000 watts (to be ordered
separately using code AR5988).
INFORMATION
If the dissipated power exceeds 1000 W, contact the Applications Service at Moog-Casella for component sizing
CAUTION
For the L50 model, the braking resistor must always be connected as it also features a soft-start function. In the
absence of this, the system will not start up; moreover, it will not be possible to stop the rotating motors in a controlled
manner.
ATTENTION
Pour le modèle L50, la résistance de freinage doit toujours être raccordée car il dispose également d'une fonction
de démarrage progressif. A défaut de cela, le système ne démarrera pas; en outre, il ne sera pas possible d'arrêter
les moteurs rotatifs d'une manière contrôlée.
