[TYPO3] prevent translation of plugin

[Sander van Gelderen]

Hello List,

I have a multilingual site with

mod.web_layout.defLangBinding = 1
config.sys_language_mode = content_fallback
config.sys_language_overlay = 1


I also have a plugin I made in the site, and would like to prevent it 
from being translated, while the records the plugin works on are 
translateable (this is ok)

I have tried adding sys_language_uid to
$TCA['tt_content']['types']['list']['subtypes_excludelist'][$_EXTKEY.'_pi1']

but that is only part of it.

How can I prevent my plugin (wich is tt_content record) from being 
translated while leaving other CE as they are?

TIA,

Sander