American Water Heater 52 Series Instruction Manual page 19

CONVERSION TO SINGLE PHASE
When the heater is shipped for connection to a three-phase
electrical service, it may be connected to a single-phase electrical
service of the same voltage by:
1. Disconnect blue wires from terminal L2.
2. Connect all blue wires to terminal L1 (with black wires).
3. Disconnect all red wires from terminal L3.
4. Connect all red wires to terminal L2 (with yellow wires).
5. Connect incoming power to terminals L1 and L2.
WIRING DIAGRAMS
Figure 12. Nine Elements - Single And Three Phase
19
CONVERSION TO THREE PHASE
When heater is shipped for connection to a single-phase
electrical service, it may be connected to a three-phase electrical
service of the same voltage by:
1. Disconnect blue wires from terminal L1
2. Disconnect red wires from terminal L2.
3. Connect all blue wires to terminal L2 (with yellow wires).
4. Connect red wires to terminal L3.
5. Connect incoming power to terminals L1, L2 and L3.