Evolution of the E-Panel

(AIC) for inverter breakers. 25,000 amp interrupt is an industry standard. AC breakers are not
suitable for DC operation due to interrupt rating and the lack of arc suppression. AC breakers
tend to weld themselves in the closed position when subjected to high DC fault currents.
A little History
The first commercially available circuit breaker boxes made for the RE industry came in around
1989 from Photron. These boxes used paralleled breakers for added current capacity on the
inverter circuit. The boxes were not UL listed but were much better than nothing. Lawrence
Jennings was a real pioneer in those early days. Our industry was called Alternative Energy back
then.
A little later, Ananda Power came on the scene with a fully listed AC / DC box. The breaker
boxes were usually custom built for each installation though. They had standard versions, but
since each installation was different, they advocated custom fitting the features to the
installation. This made it almost impossible for distributors to stock the right product. The
Ananda engineers built flexibility into each power center; such systems were quite complicated.
They did not allow customizing in the field to any degree, so things had to be planned in advance
by the installer and distributor. The retail price of this custom solution ran $1000 or more. The
Ananda Power System quickly became the industry standard due to its UL listing and lack of
competition. Now customers could actually get their renewable energy system inspected to NEC
compliance.
Ananda Power Center with a Trace SW and conduit box
During the early 1990’s when Ananda was gaining in popularity, I was very busy at Trace
Engineering doing the mechanical engineering on the SW and DR inverters. The industry
standard inverter at the time was the Trace U series. I never made the U series able to accept
battery cable conduit because I had little knowledge of the NEC. As it turns out, the industry was
just learning about the NEC. Remember, the inverter industry was fueled by marijuana growers
in Northern California and they didn’t have much use for inspectors. The Trace DR and SW
series inverters were the first in the industry to have this NEC compliance addressed by virtue of
conduit boxes among other mechanical design aspects. Ananda boxes concentrated heavily on