No, connecting the AT power connectors (P8,P9) on the ZIV is enough. If you plug the Z4 into an Infinitiv tower with the special power connector then you also should connect to that small power connector which gives the +5V and +12V. The missing -12V come from the motherboard to the ZIV. This is an extract from a mounting guideline I got together with the ZIV.
Regards
A1200freak