Installation Guide

Heatworks MODEL 1 Electrical installation reference

guide

Electrical Service:

The Heatworks MODEL 1 tankless water heater is considered a non-

continuous heating appliance according to the Definitions in the

National Electric Code. An appliance load that is not continuous for 3

hours or more is considered non-continuous. Therefore, the MODEL 1

heater, when used for standard domestic hot water applications, is

considered a non-continuous heating appliance. Due to the diversity of

water heating in a home, the load (amps) contribution of the MODEL 1

heater to the overall service load of the home or building can be

calculated using the optional methods of National Electrical Code,

sections NEC 220-82 or 220-83.

For new dwellings, the service load should be calculated using NEC

220-82. For existing dwellings, the service load should be calculated

using NEC 220-83. By both calculation methods, the Heatworks

MODEL 1 load is generally added to the service load at 40% of it’s

maximum nameplate rating. For instance, the maximum current (amp)

rating of the Heatworks MODEL 1 is 48 amps and 40% of this rating is

about 20 amps. The 20 amps is typically the load added to the overall

service load of the dwelling when using the optional calculation

methods as described in NEC 220-82 and 220-83, not the maximum

current rating, 48 amps. (Note that a conventional electric water

heater rated at 30 amps load will be rated at 30 amps as is it

considered a continuous device.) So, two Heatworks MODEL 1s will

actually only add 10 amps to the service load. As a result, one or

more Heatworks MODEL 1s will fit in most homes that have a 150 or

200 amp whole-house electrical service, or can be installed using one

or more sub-panels with a breaker that is sized accordingly.

Power/Voltage Modulation:

During operation, the Heatworks MODEL 1 is designed to use only the

power necessary to heat the water for various combinations of

temperature rise and flow rate.

Disconnects and Sub-panels:

Electrical disconnect devices do not contain circuit breakers and are

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Heatworks MODEL 1 Electrical installation reference guide Electrical Service: The Heatworks MODEL 1 tankless water heater is considered a noncontinuous heating appliance according to the Definitions in the National Electric Code. An appliance load that is not continuous for 3 hours or more is considered non-continuous. Therefore, the MODEL 1 heater, when used for standard domestic hot water applications, is considered a non-continuous heating appliance.
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not required by the National Electrical Code (NEC) for residential appliances such as the Heatworks MODEL 1 water heater or any appliance rated less than 300 volts. However, disconnects may be required by the NEC for motor loads and for appliances with multiple circuits in commercial applications. Electrical sub-panels, containing circuit breakers, may be used with appliances such as the Heatworks MODEL 1 water heater in residential and commercial applications.