19 April, 2014


I have two Powerflex 4 VFDs rated for 3 phase 240 AC. They are running conveyors and keep faulting out for over voltage fault. I named the company and they said to try some line reactors on the incoming lines. What type of line reactor would be best for this application, its for my company so money is no problem I just need to fix it. And If you know anything about Powerflex 4 Iv all ready tried turning up the decel time and no reason to use dynamic braking because the fault occurs at random times not when the motor is being stopped. I think I found an answer. The problem that line reactors are likely to cure is line voltage transients of the type that are caused by the utility switching power factor correction capacitors. That can cause relatively small over-voltage transients that have a frequency that is only about 5 or 10 times the line frequency and last for perhaps 3 to 5 cycles of the transient waveform. There is enough energy in the transient to charge the DC bus capacitors to the trip voltage, but not enough voltage or energy to damage the drive. Here are a couple of line reactor manufacturers: You may be able to find a local supplier. PS1 Dynamic braking might help if the design is such that the DB resistor is connected when the DC bus rises a certain amount. I have heard of that recommended by at least one drive maker, but I think a lot of drives use a DB control strategy that wouldn't work for that purpose. The idea in using the DB for transients is that adding that load would slow the charging of the bus caps enough to prevent tripping.

Gilad viberPeopleGKB Video Fire Detection System (VFDS) – Fire Test2011-08-12T16:12:37. 000Z2013-12-17T20:23:48. 000ZBoosting Pump Efficiency with VFDsIn today's economy, everyone is trying to find more efficient and cost-effective ways to operate their facility. A Variable Frequency Drive (VFD) is an easy . . .

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