A properly hardwired dishwasher is actually a good thing. That generally means either non-metallic cable (a.k.a., Romex) or a wire whip from the dishwasher to a junction box nearby. Note that in most areas now a dishwasher requires GFCI in most jurisdictions, based on (from a quick search) a [change in the NEC in 2014. That gives you a few possibilities:
- GFCI breaker, cable straight to dishwasher
- GFCI breaker, cable to junction box, wire whip or cable to dishwasher
- Regular breaker, cable to junction box, deadfront GFCI like this one from Leviton @ Home Depot:
cable or wire whip to dishwasher
- Regular breaker, cable to junction box, GFCI/receptacle, dishwasher hardwired to load terminals on GFCI/receptacle, cable or wire whip to dishwasher. Note that you can only do this if the dishwasher uses < 1/2 the capacity of the circuit (10A on a 20A) circuit.
- Regular breaker, cable to junction box, GFCI/receptacle, plug/cord to dishwasher. I do not recommend this.
Why don't I recommend plug/cord connection? The real question is why would you want plug/cord connection when a dishwasher is never unplugged?
Whatever you do, use a metal box.
Update based on model # Samsung DW80R9950QN. There is a small installation manual (one page) which doesn't say much and indicates plug/cord connection. However, the full manual has a lot more details, including on page 14:
For cable direct connections.
- Use flexible, armored or non-metallic sheathed, copper wire with a grounding wire that meets the wiring requirements for your local codes and ordinances.
- Use the strain relief method provided with the wiring junction box or install a U.L.-listed/CSA-certified clamp connector to the wiring junction box. If using conduit, use a U.L.-listed/CSA-certified conduit connector.
so a hardwired connection is definitely allowed.