How Long Does Google Plus Shadow Ban You?

I experiment a bit with Google Plus, but unfortunately I got all of my accounts shadow banned, because I configured the wrong settings on my Social Media Management Tool and posted dozen of posts per group per account on one day....

Does anyone know how long a shadow ban from G+ lasts? Should I make new accounts with new IPs?

Anyone experience?

Can anyone help?

how do you find out that g+ shadow banned you ?

I can still post in communities, but when I change the account and look into the community my posts are missing.