FR-V520 3.7Kw VFD no braking.

[jets]

Hi.


I have a FR-V520 3.7Kw VFD that seems to have lost it braking.


I used to run the machine it is driving and when the motor stopped the rotating stopped dead.



Now I am getting error E0v3 described as "regenerative over-voltage shut-off during deceleration or stop".


I am now trying an external brake resistor but I get the same result. I have set parameter 30=1 and 70=10(%) like the manual describes but no braking.


Is it possible the internal brake transistor has failed.


I seem also to have not DC injection brake.Any thoughts?

jets

 

[jraef]

A blown braking chopper would be my first thought. Taht drive looks to be old enough that it would have had a separate brake transistor, not one integrated into an IPM with the other transistors, so it could be damaged without affecting the entire drive.

 

[goghie]

The error is Deceleration overvoltage.
Look at chapter 3.4.1 DC injection brake operation, off manual below.
https://dl.mitsubishielectric.com/dl/fa/document/manual/inv/ib0600131e/ib0600131ec.pdf

 

[JesperMP]

I seem also to have not DC injection brake.

If the drive had DC braking before, and none now, and it otherwise works OK, then it sounds to me that the configuration has changed. Maybe that can also explain the lack of brake resistor braking.

Disclaimer: I dont know the FR-V520 VFD.

 

[jets]

Goghie,


First thing I checked as that is what error E0v3 describes.


At the end of the day I did an "All Clear" of parameters and re-entered them from record. Now it's working again. I have also slightly reduced both acceleration and deceleration time and added an external brake resistor and program P30 and P70 as described in manual.



I will put it down to a microprocessor glitch? If it does act up again I will either take the drive apart and repair it or replace it.


Back to another project involving a servo with a resolver.



Thanks, Jets

 

[goghie]

I don't believe it is "microprocessor" glitch, knowing the reliability of components inside, but there are the components that have much more limited life (mostly capacitors and fans). You have very capable, but very old VFD. Replacement model is A800 and has almost same parameter list and PLC inside.

 

[JesperMP]

Are the parameters stored on an EPROM, or in battery-backed or capacitor-backed RAM ?

 

[goghie]

As Jesper wrote, you should check it. It is parameter 342. If parameter 342 is 0 and 804 is 1‚ there is big probability that E2PROM is at end of life.

 

[jets]

Hum that is a good one to check. I don't think I have it back up to e2prom. I'm not at work, do I need to set 342 = 1 to store to e2prom? I have never done it's so for sure it only backed up by power or cap.



Will look Monday. Thanks all.

 

[GaryS]

If you are getting regenerative over voltage then you are not using DC injection braking
Dc injection braking would not increase the buss voltage all the baking energy in dissipated in the motor not the vfd

so their has to be a braking resister someplace sometimes they are built into the vfd
it may have finely just opened of the buss loader (Chopper) burned out