Like I mentioned before the only exception is for 'existing'.Any feeder on the supply side of the branch circuit panelboard serving a pool where the feeder is on the load side of the service or the load side of the separately derived system must be installed using one of these wiring methods:
Rigid metal conduit (RMC),
Intermediate metal conduit (IMC),
Rigid nonmetalic conduit (RNC), or
Electrical metal tubing(EMT)