Today I look at my electrical panel and I realized it doesn't have a main breaker, but the ground bar and neutral bar are connected by a metal on the top (As I remember the ground bar and neutral bar need to be separated if it's a sub panel). I'm wondering if this electrical panel is a main panel or sub panel. I live in a townhouse and look like the main breaker is out side of building. Another question, if I want to install a new breaker, can I wire my ground to the bar on the left side (I'm not sure the left side bar is ground or neutral bar or it doesn't matter, please see attached picture)? Sorry if those questions are stupid, I try to learn more for my new townhouse : )
Panels have 4 parts (not counting the wires going into them):
- cover, which you have removed
- "box" which is the box-shaped thing colored Sandalwood
- accessory ground bars if installed directly onto the box
- "Interior" which is everything else i.e. that huge black plastic thing.
The bars attached to the interior (and obviously insulated from the box) are neutral bars. From the height of them, they look like they are "Plug-On-Neutral" bars, indicating a very modern CH panel. That clearly explains why they are on both sides and run the full height of the panel - neutral bars for sure.
You are thinking the neutral and ground bars are bonded together, but they're not - they are both neutral bars and that bonding is essential.
Your panel appears to have accessory ground bars, hidden underneath the black and white wires on the left and right.
I don't see a bonding strap between neutral and the box, so I think your panel IS ACTUALLY isolated neutral to ground.
So now your question is "how the heck is my panel getting ground from the main? There is literally no ground wire in the conduit." And the answer is that non-flex metal conduit is itself a valid grounding path, and a ground WIRE would be redundant.
But feel free to retrofit it, if you're in a "belt and suspenders" mood.
I think you're confusing the two neutral bars for something else. From the photo, it looks like there are 2 neutral bars near the breakers and 2 totally separate ground bars near the sides. I looked for a main ground wire, but it's really hard to determine from that picture, possibly a stranded aluminum wire with black insulation and a green stripe looping from the right side over to the top left side.