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Capacitor inrush

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#1 Carl



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Posted 08 October 2005 - 10:42 AM


I’m looking at limiting the inrush current for the dc bus in a bank of capacitors on an inverter.
The methods that I’m aware of are resistor and contactor
Solid state control of the bridge rectifier.
There is another one and that is using a ntc this method I find interesting it looks cheap to and it seems simple….does it work on the principle of having a high resistance on inrush and a low resistance on running current……seems to good to be true.
If it’s that simple why bother with all the other methods??

#2 marke


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Posted 08 October 2005 - 08:11 PM

Hello Carl

The standard way is to use a limiting resistor and shorting relay or contactor.
The NTC option can be used, but it will remain in circuit unless it is shorted out and contribute to losses in the drive. For very small currents, it can be used but the resistance only stays low if it is hot, this is heat and power dissipated.

Best regards,

#3 Carl



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Posted 09 October 2005 - 09:14 AM

Thanks Mark

I'll have a closer look at this device.


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