A.O. Smith AOSRE50100 Owner's Manual page 8

OPTIONAL CORD SET WIRING
(120 VOLT AND 240 VOLT)
There may be a cord set supplied with the water heater at the time of manufacture. If not, one can be ordered through the Parts Department, see
"Repair Parts" section. Refer to figure 10 below.
WIRING DIAGRAMS
DANGER
TURN OFF THE HEATER ELECTRICAL SUPPLY BEFORE SERVICING ANY ELECTRICAL COMPONENTS.
240 VOLT WIRING
120 VOLT CORD SET
FIGURE 10
8