How to waterproof metalic electrical conduit entrance in concrete wall?
I have had need to seal up a few places like that in basements where the conduits came in and had a potential leak risk. On occasion I would use a Sika product, 2c-sl is the name Sika give it. A 2 part, self leveling, pourable material that can be painted on. I even made a form and poured it into that to ensure it saturated the crevices, since it was well below grade. This is good stuff. WR Grace also makes a 2 part liquid applied membrane that comes in 2 consistencies, trowel or knife grade. One is thick, the other thinner. I think either one will work for you. It is called Bituthene Liquid applied membrane. If you can get to Tremco products, they make a one part waterproofing solution, Tuff and Dri is all that I can find on that. They make another product that works really well, to bad I cannot find not more info on, other than I used it, sorry.

All these products are super flexible, and if you clean the wall real good you can paint that and the end of the conduit that the wire goes in to wrap it all in waterproofing.

Disclaimer: I do not work for or represent any of the above mentioned companies, I only know how to recommend products that do the job, and do it well.