White Paper

Appleton’s PowerPlex Panelboard redefines NEC-style panelboard enclosures
by transferring the protection from the cast enclosure to the component level.
circuit breakers can then be placed within enclosures that
do not require explosionproof construction. When circuit
breakers need to be replaced, the individually sealed flameproof
component is simply removed and swapped with another.
By protecting the individual breakers, IEC panelboard
enclosures do not require the traditional North American cast
enclosure. The enclosures are lighter and are opened easily,
resulting in substantially less downtime with lower installation
and maintenance costs. Factory-sealed IEC circuit breaker
panelboard enclosures do have some disadvantages. The
expensive pre-sealed flameproof circuit breakers create higher
ongoing maintenance costs and may not be readily available.
Also, because they are sealed, the unvented enclosures retain
heat, potentially requiring amperage derating.
Creating North American
Component-Level Protection
Appleton’s PowerPlex Panelboard redefines North American
hazardous-location panelboard design by transferring the
flamepath protection from the enclosure to the component
level through individual circuit-breaker housings. This allows
for the functional advantages of IEC designs while meeting
NEC/CEC hazardous-location equipment requirements.
The circuit breaker housings offer quick, onsite maintenance
without the disadvantages of higher costs and reduced breaker
performance. The result is a superior hazardous location
panelboard that offers optimum protection, greater application
flexibility and lower maintenance costs.
Circuit Breaker Housing
Each North American circuit breaker is placed within a
housing that features a labyrinth flamepath joint located
between the cover and body (Figure 1). The top cover has a
ridge that encircles the entire opening. This ridge fits into the
lower housing’s channel to form the flamepath. Individual
circuit breaker housings are easily bolted and unbolted for
fast breaker replacements while retaining hazardous-location
integrity. The bottom half of the housing is designed to utilize
standard, off-the-shelf North American circuit breakers for
easier, more efficient maintenance.
Vents are located in the housings to allow for pressure and heat
to dissipate (Figure 2). This minimizes nuisance tripping and
the need for additional circuit-breaker derating. The result is
optimized breaker performance and increased lifespan.
ADVANCING PANELBOARD TECHNOLOGY
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FIGURE 1:
The top and bottom
housing include a
labyrinth channel to
form a flamepath.
FIGURE 2:
Each housing is vented
to safely dissipate heat.