Did 120V/30A service exist in California/Bay Area?

E

exp

Member
Location
SF Bay Area
Occupation
Electrical Engineer
Hoping to find some people with historic knowledge here.

Today I found what I think is the original main service panel hidden in a wall cavity of my 1929 house in the Bay Area.

People have pointed out this was a larger appliance disconnect and can’t be service because it’s just 120V.

However, the box was found in an abandoned external wall cavity right next to the service entrance. It’s clear that it was a wooden enclosure with an exterior door and that door has been removed, replaced with plywood and out stucco over.

In this cabinet it not much room for more than this one panel. On the panel side is a thick iron conduit which goes outside. It is exactly where the service enters now. From the top, abandoned K&T exists that has been capped a bit farther downstream.

The location of the cabinet is the corner of the living room where definitely no appliances were.



All of this makes me very strongly believe that this was the original fused main service disconnect and from there, a K&T run went to another sub panel.

Were there 120V/30A services in the Bay Area which would make this a plausible explanation?


PS: in the pictures I enter the cabinet from the back. I found it while installing new ductwork and removing the piece of wood which used to be the backside of the cabinet.
 

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I can't speak for SF, but that sure looks like an original 120v service to me, when all that was powered was a pendant ceiling light in each room.

In fact, that SqD switch is more advanced than what we usually see in homes that were built both before and after electrification became common.

The cut lock tang and the padlock suggest someone had to cut it open at some point before it was eventually abandoned.
 
I actually ran into a live 120 volt service a couple years back. An old church on a country road had a historic marker out front so I stopped to look. The door was open so went in. Just pews and bare bulbs hanging from the ceiling that all went back to a single pole fused disconnect in the corner. The meter outside had two wires coming from the transformer.
 
California and specifically the Bay Area was absolutely the cradle of electrification. Of all the places that had electricity it was there the very first. So anything that could have been done, was done, in the Bay Area.

By 1929, things would have been much more standardized. They were running 110 kilovolt long distance power on steel towers that look the same as modern structures from generation in the northern mountains direct to the Bay Area in the 19-teens. And 220 kilovolt in the early 1920s. So a 1929 house would be fairly modern.

SF had all sorts of strange things like DC power in the early days, and they were still providing it at least into the 2000s for old services, I think.

I know one house still running straight 120 volt service here in town. I used to rent a house of a similar era from yours that had several generations of electrical service evident, and some stored in the garage attic such as antique meters that had been on the house. Sadly the garage burnt down a few years back or I would have asked the landlord for that stuff.
 
PG&E had 30A, 120V services, & Pacific Graft & Extortion, is the PoCo for SF, they once had their HQ in SF also until they went to Oakland.
 
Here in Oregon there are still 120V services, we upgraded a farm pole service last summer to 120/240.
It had 60A 120V feeder to the old house, and a 40A 120V feeder to a barn.
There is a well on the property that has a boost boost transformer to 240V.
As it was just a service upgrade they did not want anything changed to the buildings (yet) so I had to order a 1-pole 60A breaker.
 
tortuga said:
Here in Oregon there are still 120V services, we upgraded a farm pole service last summer to 120/240.
It had 60A 120V feeder to the old house, and a 40A 120V feeder to a barn.
There is a well on the property that has a boost boost transformer to 240V.
As it was just a service upgrade they did not want anything changed to the buildings (yet) so I had to order a 1-pole 60A breaker.
Click to expand...
That's awesome the supply house must have had some fun ordering that. Idk if I would've bothered I probably would just have used a 2 pole and only used one leg of it.
 
tortuga said:
Here in Oregon there are still 120V services, we upgraded a farm pole service last summer to 120/240.
It had 60A 120V feeder to the old house, and a 40A 120V feeder to a barn.
There is a well on the property that has a boost boost transformer to 240V.
As it was just a service upgrade they did not want anything changed to the buildings (yet) so I had to order a 1-pole 60A breaker.
Click to expand...
You could have use a 2P60 and just connected 1 load wire.
 
I was doing service upgrades in Morro Bay/Cayucas/Cambria in the mid to late 60's and definitely upgraded more than one 30A 120V service.
 
@exp

Never actually seen one in original condition but as others have said I'm sure the answer is yes.

I actually installed a solar system on a 240V 30A service once. The original disconnect was feeding a 125A breaker panel so there was no trouble meeting the 120% rule. 🤗

I knew of a pair of houses near my old place in SF that had 120V services until about 10 years ago. I could see the weatherheads, but I never saw the amps inside.

I've also seen a couple where the original service disconnect had been replaced by something else in a bad way. That is, they replaced the disconnect but not the service conductors. One of these I bet was 30A like what you're showing.
 
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