A friend is having a heated pool installed. He has a breaker panel outside
near the pool. He was told that per NYS code, the wires that go run through
his basement from the exterior panel to the main panel must be run inside
rigid conduit. He said that they didn't use individual wires, they used
some type of jacketed cable that contains 4(?) wires and they ran that
inside grey plastic conduit. I haven't seen it, but I assume it's Schedule
40 PVC.

Another friend had a heated pool installed last year (also in NYS) and he
said that they didn't use conduit through his basement. They just stabled a
large cable to the joists.

So what's the story? Is the conduit required? If it is, is it specifically
related to the pool or is it because there's another panel involved?

Thanks.