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Your MODEL 3 is an electrically powered high voltage and high current device. You should NEVER
attempt to install, repair or disassemble this water heater without first disconnecting the power
supply to the unit directly at the fuse or breaker box. Failure to do so could result in property
damage and/or personal injury, and void your warranty.
ELECTRICAL SERVICE
The MODEL 3 only draws power when hot water is used and is considered a non-continuous load
(draw power for periods shorter than three hours).
The MODEL 3 amperage draw to total household amp draw is considered to be 40% of its
maximum nameplate rating of 100 amps, or 40 amps (see NEC sections 220-82 (new buildings)
or 220-83 (existing buildings). 40% of the nameplate rating for a conventional 4.5 kW electric
tank water heater is 7.5 A. One MODEL 3 will add 32.5 A (40 A minus 7.5 A) additional amps to the
service. This relatively small increase in design service entrance amp draw can sometimes be
accommodated by modifying sizes of other loads on the system, such that no service entrance
wiring upgrade is necessary.
The installer should determine what the existing design amperage load is on the house as there
may already be excess current carrying capacity at the service entrance. If not, one option would be
to set the MODEL 3 to a lower maximum current draw capability so no increase in service entrance
amp draw would exist.
DISCONNECTS AND SUBPANELS
Electrical disconnect devices do not contain circuit breakers and are not required by the NEC for
residential appliances such as the MODEL 3 or any appliance rated less than 300 volts. Electrical
subpanels or parallel panels, containing circuit breakers, may be used with appliances such as the
MODEL 3 in residential applications. A load analysis by a licensed professional is recommended to
determine if a subpanel, with a single breaker rated for the entire load of the water heater, can be
installed off the main panel.
BREAKERS
Each MODEL 3 should be wired to its own, dedicated breaker. The dedicated branch circuit breaker
must be rated to the same current value selected on the MODEL 3 and marked on the maximum
current setting label.
NEVER wire a single MODEL 3 to multiple breakers.
WIRE SIZING
To prevent serious injury, death and property damage:
•
NEVER set the maximum current setting on the MODEL 3 to a value higher than the maximum
amperage rating of the wiring supplying the unit.
•
ONLY use a breaker with the appropriate voltage rating and a maximum amperage rating no
higher than the wire’s maximum amperage rating to protect the power supply wiring.
Unlike other water heaters, the MODEL 3 can be adjusted from 30 to 100 amps and 208-240 volts
upon installation, depending on your hot water needs and the existing wiring. The following charts
highlight temperature rises you can expect at the different voltages, amperages, and flow rates. The
higher the amperage/power setting, the more hot water the unit can provide.
