I had an electrician move my service panel in my basement. To connect the 20 circuits from the old location to the new location of the service panel, he used ten 3-wire (blue, red, white) cables. He connected the black wire of each circuit to either a blue or red of the 3-wire. He connected the two white wires and the two grounds of the circuits that were connected to blue wire and a red wire in the cable to the one white wire in the cable. The blue and red wires are connected to the breakers on the hot bus bar. The white wires in the 3-wire cable are connected to the neutral bus bar in the service panel. The service panel has no ground bar. I am concerned that the electrician has not connected the grounds properly -- shouldn’t they have gone directly to the panel rather than through the white wire?

Did the electrician wire correctly (the work was permitted and approved although I do not think the inspector inspected the wire connections at the old location)?

If so, could some one explain what is the point of having separate black, white, and ground wires in cable if the white can act as a ground in a circuit?

 

Only at the main service panel (disconnect) is the ground and neutral connected to the same bar.

He used a multiwire configuration to go from the old panel location, to the new by combining the neutrals. This will only work if the blue and red at the new panel are connected to different phases (usually adjacent breakers one on top of the other).
The bare wire in the new three wire cable should have connected to the bar in the new panel, and the bare or grounds in the old location.
Again, ground and neutral are the same only at the main disconnect/panel.