While doing work in my breaker panels I noticed the following:
300A service enters into a large box on the right where it is split to a 200A and a 100A panel. Neutral and ground are bonded in the splitter box (d) AND in each of the main panels. The boxes are joined by conduit (c) and there is also a wire joining the combination neutral/ground bus in each of the two load centers to the splitter box (a). The splitter box is also connected to the cold water (b) and to a ground rod outside.
From the limited understanding I've developed of how grounding should work, it seems to me I have neutral and ground bonded in multiple locations here. Is that ok? This was all done by a licensed electrician.