This is what my dishwasher installation guide says:
You must have:
■ 120-volt, 60 Hz, AC-only, 15 or 20 amp fused electrical supply.
■ Copper wire only.
■ A time-delay fuse or circuit breaker.
■ A separate circuit.
If direct wiring dishwasher:
■ Use flexible, armored or nonmetallic sheathed, copper wire
with grounding wire that meets the wiring requirements for
your home and local codes and ordinances.
■ Use strain relief method provided with house wiring junction
box or install a UL Listed/CSA Approved clamp connector to
the house wiring junction box. If using conduit, use a
UL Listed/CSA Approved conduit connector.
If connecting dishwasher with a power supply cord:
■ Use Power Supply Cord Kit (Part Number 4317824) marked
for use with dishwashers. Kit contents include:
■ Voltex, Inc., UL Listed 16-gauge 3 wire power supply cord
with 3 prong grounded plug.
■ Neer C-500 ⁷⁄₈" strain relief.
■ 3 wire connectors.
■ Part Number 302797 grommet.
Follow the kit instructions for installing the power supply cord.
■ Power supply cord must plug into a mating three prong,
grounded outlet, located in the cabinet next to the dishwasher
opening. Outlet must meet all local codes and ordinances.
IMPORTANT: If you plan to install a garbage disposer, an
additional separate 120-volt, 60 Hz, AC-only, 15 or 20 amp fused
electrical supply is required.