Question about panel bonding

I’m looking at a panel in a condo. The outside disconnect is 125amps. At the time this condo was built there was no main disconnect directly at the panel in the condo. I’m not sure why, but there are a total of four ground and neutral bus bars in this panel. I’m not sure if they cut the original grounds too short and needed to add more. On top of the (3) 2/0 aluminum service wires coming in, there is what looks like stranded aluminum wiring coming in and to one of the ground bars. I’m thinking it is bonded from the disconnect outside to the panel, and of course the ground rod outside then? My main question is are the grounds and neutrals completely bonded together? I see the two main bars have a solid copper between the two bonding them, but there is no sure evidence from the other two bars being bonded together. Is this complete bonding?

Regarding your specific questions it looks fine. There should be no connection between the EGC bus and the neutral bus because this is downstream of the service disconnect and is a sub-panel. The #2/0 conductors are feeder conductors not service conductors. The feeder should contain 4 conductors and it does so that is correct. Since the service disconnect is located upstream from this panel there is no requirement for a disconnect or main in this panel. The “two main bars” are the neutral bus.

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Thanks Robert. I’m taking the prerequisite courses right now from internachi. This is the first panel from the outside disconnect. There is just the disconnect, and then this panel far away from the condo outside. Doesn’t modern code specify that a main breaker would also be placed in this panel with modern construction?

Welcome to our forum, Andrew!..Enjoy! :smile:

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No, a single main is not required in this panel. The panel is fed with a feeder and the overcurrent protective device for a feeder is typically at the origin of the feeder so nothing is required at the other end which is the panel. Here is the relevant NEC code section:

408.36 Overcurrent Protection. In addition to the requirement of 408.30, a panelboard shall be protected by an overcurrent protective device having a rating not greater than that of
the panelboard. This overcurrent protective device shall be located within or at any point on the supply side of the panelboard.


Thanks Robert. I appreciate the quick responses.