I am installing a standby generator on a concrete slab and there is about 4.5 ft from the grounding rod to the connection on the generator. I am using bare 4AWG copper wire and a copper rod. I am going to bury the rod and clamp and just leave the 4.5ft length exposed. Is this OK? I have no way to bury the length. Should I use plastic conduit to cover this length?

The wire does not need conduit if you bury it.

Tkrussel. I can not bury it because the slab is already in place. So for the 4.5ft that is exposed I should use conduit?

OK, I misread your question.

The #4 wire does not need conduit if it would not be subjected to physical damage.

Use conduit to protect it, it it can be damaged.

Thank you. All installed. Passed inspection.