Add SITIPE private section to IED

[Sander3003]

When adding SIPITE bay templates to the SCD file, we need to also add a Private element to the imported IED like so:

E01_BCU

the content of the Private element is the name of the IED in the bay template here e.g. E01_BCU

Example IED with the correct private time:

It relates to:
#239