MM440 IT Y CAP = necessary ?

Is it necessary to remove the Y CAP for an IT supply ?

If yes, why is it important ?

Combo, do you mean the Y capacitor placed over the mains supply contacts? If that's the cap you're referring to I would say: don't ever remove it unless you're replacing it with an X cap. That type of Y capacitors are intended for noise reduction. The Y class is somewhat less robust than the X class.

If you mean something else: please clarify.

Kind regards,

Hi

The Y Capacitor, in the manual they say that u have to remove it.

Brugje wegknippen om MM440 op IT net te laten werken. In the manual they say to remove it ?

Combo,

it seems Siemens uses their own definition of a Y capacitor. I had to search the manuals to see what you were talking about.

The capacitor mentioned is a capacitor assembly (consisting of three capacitors): one X2 class capacitor connected between the line and neutral and two Y class capacitors, one connected between line and earth and one between neutral and earth. Earth is here mentioned to be the earth connection of the drive.

If you don't remove the connection between these Y capacitors and the earth terminal and you are not connecting the earth terminal to an earth connection, it will result in a very dangerous situation if you touch the earth terminal.

Remember: capacitors DO tend to let AC current pass.

Kind regards,