Electric hot water heaters are major household appliances that use a significant amount of electricity, and, therefore, have specific wiring requirements. Follow a few guidelines to install your hot water heater safely and ensure that it will operate properly. Does this Spark an idea?
Circuit Requirements
Standard electric water heaters use 240 volts, have a 50-gallon capacity and draw 30 amps of current. A double-pole (two switch) 30-amp circuit breaker should be installed at the breaker box to accommodate the water heater.
Cable Requirements
The cable running from the breaker box to the water heater should be 10-2 NM copper cable to ensure the circuit can handle the demands of a heater with a high-wattage heating element. This cable is sheathed, and contains three wires: black (hot), white (normally neutral, but in this case also hot), and bare copper (ground).
Direct Wiring
If the water heater is located within direct sight of the breaker box, it can be wired directly. The cable runs from the box to the splice box at the top of the heater. The cable's black wire is connected to the heater's black wire. The cable's white wire should be taped with a piece of black electrical wire to indicate that it will also be carrying current, then connected to the heater's other wire (usually red). These two connections are both made using twist-on wire connectors. The cable's ground wire should be wrapped around the water heater's grounding screw.
Cutoff Switch
If the water heater is not within direct sight of the breaker box, a cutoff switch must be installed near the heater to provide an easily accessible way to shut off power to the heater. It can be a fused or nonfused disconnect switch, and it must be rated for 30 amps. The cable from the breaker box runs to the cutoff switch box. A second length of 10-2 NM wire encased in conduit is wired to the water heater and run to the cutoff switch. Inside the switch box, the switch links the two black wires and the two white wires (both white wires are taped to indicate they're hot). The ground wires from both cables are connected to the grounding bar of the switch box.
Tags: water heater, black wire, connected heater, cutoff switch, direct sight