Heatworks 1 Manual página 14

Electrical sub-panels, containing circuit breakers, may be
used with appliances such as the Heatworks MODEL 1
water heater in residential and commercial applications.
In new, and in some existing residential construction,
there is generally enough breaker spaces in the main
electrical panel to accommodate several additional circuit
breakers, for the Heatworks MODEL 1 water heater.
However, in some existing homes, the main electrical
panel may be nearly full with circuit breakers serving
existing load. In these cases, one or more sub panels,
each with a single large breaker rated for the entire load
of the water heater, can be installed off the main panel.
The boxes for a 50 or 60 amp subpanel can be purchased
for about $15 each, and the breaker for about $12.
Smaller boxes and breakers are slightly less expensive.
CAUTION: Breaker must remain off until installation is complete.
12
BRANCH CIRCUITS AND BREAKERS:
As a non-continuous heating appliance, the branch
circuit wires and breakers must be sized to at least 100%
of the maximum ampere rating of the appliance. This is
particularly important to avoid over heating of the wires
at the connections to the breakers. Over heating at the
breaker connections may cause nuisance or premature
breaker trips. It is recommended that the wire for the
branch circuits and sub-feeds be rated for at least 75
degrees C. If you use THHN, which is rated for 90C, the
wire gauge is smaller than standard 75C wire, and the
nylon covering makes it much easier to pull. It also costs
about the same.
Current draw Wire gauge
(amps) (75C)
15 14
20 12
30 10
40 8
50 6
ISI Technology March 2015
Wire gauge
(90C – THHN)
14
12
10
8
8
www.myheatworks.com