Dear sir,

   in sinamic g150 i was facing the problem off2 with h201 orange, i refer the manual it shows the dc voltage was present,, in screen also there was some voltage like80VDC,, kindly help to fix this problem

Vithani

Here is some Basic for you..

DC Link Over Voltage: You will get DC Link OVER VOLTAGE in case where your motor is generating power instead of taking it. During Ramp up and Ramp Down, if Load is sufficiantly high to pull the Motor, then motor will run at More then setpoint speed and will act as a generator and that will fed back to Motor terminals of drive and will convert in to DC which will add orignial DC voltage converted from Supply voltage so your DC Voltage will rise and you need to Protect your Inverter so either you use Breaking Resistor or RRU or otherwise drive will trip on DC OverVolt trip

Example: In case of high inertia load, lets say if Motor is stop by inertia then it will take 3 min to stop and if you set Ramp Down to 30 Sec, then Motor will try to stop and Load will try to PULL so it will creat generating Power in Motor..

DC Link UNDER Voltage: Normally reason for this fault is Either Failure or temp dip in Input Supply.
Some times, because of defective sensing of Power supply board it will detect No DC Volt although you might get voltage at DC terminals. In some cases, if your Load is suddenly rises then also DC link may drop to some level which may trigger this fault but chances for this is Rare..

I Tried to explain you basics..

I hope this will help you to understand it

Regards
Devesh Vithani

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Split from All possible reasons of DC link over voltage and DC link under voltage faults.