Capacitor Forming in Siemens Sinamic S120 Drives

Well without going too far out on a limb, I would say 600v is more than 400v...Wouldn't you feel more comfortable asking Siemens tech support this question? I know I would...

http://iadt.siemens.ru/assets/files/infocenter/Documetations/Drives/Sinamics%20G150/sinamics-engineering-manual-v6-0-external-en.pdf

Contacted Siemens tech support UK unfortunaly they were unable to give a direct answer, and having to await further information from Siemens.

OK. Wait, then. Wouldn't that be better than getting random mischevious answers from a global forum?

What kind of a ____ forming circuit are you trying to make? I this a pulse forming circuit? Is this a phase lag forming circuit for starting a motor? Do you have a link to Siemens documentation that we might be able to read? Siemens does do a good job in their designs. If they say you need 400V capacitors for a 690V system, I need more information than what you provide to say otherwise.

No, wait a minute. I'm looking at this the wrong way.

Siemens is a lousy company that is just trying to rip you off by getting you to buy more useless junk. You don't need any specialty capacitors in this. They sold you this S120 thingy to do the bloody job. Well turn it ON. Plug the cables in and wiggle that little knobby thing until the blighter starts doing it, whatever it does.

Oh? What? That hole there where the capacitors are supposed to go? No, you don't need anything there. Look what is a capacitor but two conductors near each other with an insulator between them. You've already have a capacitor here with these terminals near each other. Siemens is just trying to take your money. Its not like Siemens knows how to build these things or that a Siemens is a unit in electricity or anything. Unlike Webber and carburetors.

What do you mean I don't know what I'm talking about. You came to me. As sure as my name is Frank Gallagher, I'm sure that you should do this.

What? Aren't you going to pay my bar tab? I've worked hard for you here and now your not going to pay?

<end rant>

The forming system should be designed to take the caps up to the nominal DC Bus level. Clearly this can not damage the drive and any lower may not condition them sufficiently to survive sudden full bus voltage.

When you say 690 volts - is that the AC 3 phase output? If so the DC Bus is higher. The manual should tell you the nominal voltage.

I agree with others - pester Siemens into replying.

Most likely it will take weeks to find anyone at Siemens who even knows what you are talking about. I used to work there, I tried to educate some of them on capacitor reforming, they were clueless.

But how long are you going to store them? If under a year, I wouldn't worry about it and if over that, just connect your 690V AC to one phase once per year for an hour or so.

Have spoken to good Siemens engineer and there are many ways in which these can be formed. Thanks to all the suggestions which have been made.