Frequency Variator: Lenze EVS9322EP

[2PAC Mafia]

Hello to everybody,

I´ve been on a stone quarry where there is a big machine to make sandbags and other things. On the electrical box there are two frequency variators of this Lenze EVS9322EP.

First time people from the stone quarry contacted me to repair one of the modules. I saw at different components damaged at power board and the main IGBT module (BSM10GD120DN). As there wasn´t so much different in price between IGBT + components + time and the complete power board I decided to replace the board.

People from the stone quarry told me they had repaired the motor which was burnt.

When we installed the repaired frequency variator again it was damaged, exactly same problem at IGBT and I saw same phototransistor to IGBT signal damaged. We saw the other one for controlling another different motor also was damaged at IGBT board.

Now I have 2 of them damaged, I have to go and check the electrical installation, motors and so on.

I would like to know if you have tricks to verify and discard any problem on the control board because I want to be sure that when I replace again the power board on the frequency variator there isn´t any failure inside. I would say problems are external to the units. As I have to take spare board from China I would like to check as deep as possible the function of the modules without installing them. Sure, I know it´s difficult, they are 400V three phase input and also three phase output, connected to a main unit for command the modules...

As always, I don´t have any schematic but I think usually power board is isolated from control board so when it´s damaged is not damaging driver board.

I´ll pass you some pictures when I have more time. Sorry for the long history but they need to use the big machine and they contacted me to troubleshooting and repair all.

 

[kubeek]

Did you test the VFDs before reinstalling?

 

[2PAC Mafia]

Hi Kubeek,

that´s the thing, I can´t do real test because it works only installed on the machine, I don´t know how to test them at workshop, I think I can do only partially... This is my main question, if you know a way to test these types of units.
I´m thinking about installing a current protection at output just if I check the electrical installation and I don´t find anything wrong to be sure power board is not damaged again.

 

[rumpfy]

I think Lenze is a german? company and makes a good range of variable speed drives for both AC and DC motors and also servo type equipment. I have a Lenze catalog for DC commutator motors and they produce DC motors up to 100 kWatt. This is fancy stuff, so why you are unable to get proper support in Europe for such equipment puzzles me.

 

[KeepItSimpleStupid]

What if some of the parameters are wrong? manual: https://www.google.com/url?sa=t&rct...=txbvbve6bS_2f2QDG1I89Q&bvm=bv.83829542,d.eXY

 

[2PAC Mafia]

Hi,

I think Lenze is a german? company and makes a good range of variable speed drives for both AC and DC motors and also servo type equipment. I have a Lenze catalog for DC commutator motors and they produce DC motors up to 100 kWatt. This is fancy stuff, so why you are unable to get proper support in Europe for such equipment puzzles me.

I´m not official service, I touch all kind of electronics and when you go inside the equipment forget about support, they always tell you are not prepared to touch such a thing, you should send us the unit to repair, you only can buy a new unit, bla, bla, that is waste of time, I know by self experience...

What if some of the parameters are wrong? manual: https://www.google.com/url?sa=t&rct=...=txbvbve6bS_2f2QDG1I89Q&bvm=bv.83829542,d.eXY

Manual I have already, but the units were working before, nobody changed parameter there.

Tomorrow I´ll go probably there to check electrical installation and try to get more information about machine, past troubleshooting... I´ve thinking also in connecting bulbs at it´s output or current protection to avoid equipment damaged again before doing last test, I have to be sure what is causing the problem.

Thanks for your help.

 

[2PAC Mafia]

I´ve been on the Masterpal 1200 machine checking electrical installation and I found some electrical derivation L1, L2, L3 to earth. On same machine, but working, I measured 1,5Mohm and on the machine with problems I measured 600-700Kohm so I found a place with the problem, nothing visible but for sure with problems. I guess it has sense this derivation could be the cause of the problem as it´s the supply of L1, L2, L3 to frequency variators and I didn´t find any protection for derivations.
On motors I didn´t find anything wrong. What is your opinion?