Thank you for the welcome. That is what I suspected, my problem is that EMT body goes inside a wood panel before entering the breaker panel. Should I use an EMT ground bushing that is bonded via another ground wire or something else?
Metal raceways in general needs to be electrically continuous with the equipment grounding conductor. As is metal anything in general, that doesn't intentionally carry current, and has a likely chance of becoming energized.
A bonding bushing is one of the ways to do this, but it is not necessarily the only way to do it. It is very common that the standard locknuts that you use for mechanically terminating the EMT connectors on metal enclosure walls, can also accomplish the bonding. The locknut teeth bite in to the enclosure wall, through the coating, making the raceway electrically continuous with the enclosure wall. The enclosure itself would of course need to be bonded.
Some circumstances specifically require bonding bushings:
1. Service raceways
2. Ferrous raceways containing GEC's
3. Missing continuity, when you terminate on a plastic enclosure.
4. Impaired continuity, when you terminate on ring knockouts remaining, and the box isn't listed otherwise for over 250V to ground. Some boxes have heavy-duty knockouts that are listed for the higher voltage, and they are tougher to remove than standard knockouts.
