Elecrta multisplut

[iv4o777]

Hi,
I have problem with this multisplit:
Outdoor unit electra duo dci delta with 2 indoor units iu 9 and iu12
The problem is:
When 1st indoor starts everything is nornal- outdoor unit starts and increasing compressor speed
Problem appears when starts second indoor unit. Immediately compressor decrease speed to min and keep it till one of the indoor units stops. Selfdiagnostycs dont read any problem.
I suggest some noncomformity between iu and ou
photos oh units and models
Thank you!13973
1397413975

[The Viking]

Assuming it have run in the past....
Refrigerant charge?

:cool:

[iv4o777]

I have checked refrigerant quantity. Its ok