ECN Forum
Posted By: Albert GE radial wiring system from 1930s - 09/24/08 12:26 AM
In the 1936 General Electric Supply Corp. wiring materials catalog, more than a dozen pages at the front of the book are devoted to promoting the "radial wiring system" for residences.

Essentially, the system was an extreme version of the concept of feeders and subpanels, with the important difference that the feeders are not fused and therefore had to follow the NEC tap rules. I'm not an electrician and am not familiar with the current code, but at the time the rules were that taps may be no longer than 25 feet, must terminate at a single set of fuses/breakers, and must have a capacity of at least one third of the main fuse/breaker.

The branch circuit breakers at the end of the feeders were installed like toggle switches in standard single or multi-gang outlet boxes with raised covers.

The service-entrance panel was dubbed the "totalizing unit". It consisted merely of a main pull-out fuse block, plus fuse blocks for the range and other special loads. All of the feeders were connected directly to busbars on the load side of the main fuses.

Albert LaFrance

Posted By: EV607797 Re: GE radial wiring system from 1930s - 09/24/08 12:30 AM
I sure would love to see those pages, Albert. Any chance that you might be able to scan them or post a link?
Posted By: electure Re: GE radial wiring system from 1930s - 09/24/08 01:12 AM
It's not a whole heck of a lot different from 1935 until now.

From (2008) NEC 240.21(B)


(2) Taps Not over 7.5 m (25 ft) Long. Where the length of
the tap conductors does not exceed 7.5 m (25 ft) and the tap
conductors comply with all the following:
(1) The ampacity of the tap conductors is not less than
one-third of the rating of the overcurrent device protecting
the feeder conductors.
(2) The tap conductors terminate in a single circuit breaker
or a single set of fuses that limit the load to the ampacity
of the tap conductors. This device shall be permitted
to supply any number of additional overcurrent devices
on its load side.
(3) The tap conductors are protected from physical damage
by being enclosed in an approved raceway or by other
approved means.
Posted By: Albert Re: GE radial wiring system from 1930s - 09/24/08 01:58 AM
Originally Posted by EV607797
I sure would love to see those pages, Albert. Any chance that you might be able to scan them or post a link?


Sure, I'd be glad to scan them - I'll be pretty busy for the next few days, but should be able to get to it by next week. Feel free to remind me if I forget!
Posted By: EV607797 Re: GE radial wiring system from 1930s - 09/24/08 02:38 AM
I'm not interested in the code comparison to today's standards. I am simply interested in old "technology" advertising, that's all.

I did a Google search of "GE Radial Wiring" and enjoyed the old advertising. Unfortunately, being able to read the full text required purchasing a membership. I'm interested, but not that interested.
© ECN Electrical Forums