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If my Google searches are correct, your Challenger panel is in the same boat as Zinsco, and really should be replaced for safety reasons if nothing else. Hard to tell from the pictures, but it looks like there are already signs of issues... That top breaker (A/C?) doesn't look too good, for example.
One of the many search results:
Is Your Challenger Brand Electric Panel Safe? - Brubaker Inc.
I'd really get the electrician to take a close look at things, ASAP. As in, now.
One of the many search results:
Is Your Challenger Brand Electric Panel Safe? - Brubaker Inc.
I'd really get the electrician to take a close look at things, ASAP. As in, now.
OP - what's the 50A breaker at the bottom of the main? The sub panel?
Do you have a gas range? 100A is pretty tight if you have an all-electric house - you'd have a hard time adding headroom for charging.
My house has a 100A main. If I turned on the range, dryer, and charged the car I'd pop it. I'm upgrading in the spring, probably to 400A (not much more than 200A, since the bulk of the labor is already factored in). Probably put a 200A main in the house, and a second 200A panel in the garage.
Plus 400A service will mean the poco will supply a heavier gauge feeder (I hope), and maybe even move me to my own transformer (I currently share with 3 other houses)
Do you have a gas range? 100A is pretty tight if you have an all-electric house - you'd have a hard time adding headroom for charging.
My house has a 100A main. If I turned on the range, dryer, and charged the car I'd pop it. I'm upgrading in the spring, probably to 400A (not much more than 200A, since the bulk of the labor is already factored in). Probably put a 200A main in the house, and a second 200A panel in the garage.
Plus 400A service will mean the poco will supply a heavier gauge feeder (I hope), and maybe even move me to my own transformer (I currently share with 3 other houses)
There are some unused knock-outs in the cover plate and spare bus bar connections in the picture on page 2, so barring a posted limit on # of circuits in the subpanel, you could add another breaker. But the subpanel is fed with #6, so you're limited to 60A total load there (assuming 75 degree wire/connections), so a new 14-50 is tough.
Actually, SOOW is total number of conductors (the ground is insulated) - romex would be 10/2 or 10/3 (the bare ground isn't included in the count), but equiv SOOW would be labelled 10/3 or 10/4.
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BTW, what is it about CA and their exterior-mounted breaker panels? I've never seen a main panel on the outside of the house, except in CA...
The solar usually feeds through the main panel. They will not use that panel.
Replacing that panel and getting your home's wiring fixed is something you need to do, whether you get an EV or not, and whether you get solar or not. It just flat is not safe, even for the loads you are currently running.
Model3: I'll be honest I dont know what the 50 at the bottom is for, BUT I do not have I do have a gas stove and a gas dryer. I will do some testing this weekend to see if that 50 at the bottom is being used. But I'm thinking either that 50 at the bottom is what is feeding the sub panel in the garage or the very top breaker. I do have a trusted electrician coming on Monday, so I will see what he has to say.
BerTX: I'm hoping the solar company would include that upgrade in the cost, is that something you think would happen?
BerTX: I'm hoping the solar company would include that upgrade in the cost, is that something you think would happen?
I honestly don't know. I'm sure they have an electrician that does work for them. Likely they will, but it becomes a little cloudy with what is needed for the solar and what is needed to incorporate what they do to make the solar work into the rest of your system. If they come into the main panel, and want to replace the main panel, that doesn't really involve the garage wiring other than hooking up the sub-panel. Now if they were to put the solar breaker into the garage panel, then they would have to replace both panels...
Or they do a supply-side connection (before the main breaker) and none of the panels are touched.
Actually, the probably won't do that unless your main panel is full (no room to add a backfeed breaker) or there is some reason your installation needs it, since it's kind of a pain - they need to get the power company involved to pull the meter and shut off the power before doing the work.
My installation did, because of how my whole house generator connection was done. The meter was at the street, and panel in the basement. They cut the cable and spliced in the solar feed before the main.
I don't know if they can do a supply side connection with your meter-combined-with-breaker outdoor panel.
A 6-20 would be super easy to install in that subpanel, and offer a decent charging pace using the UMC and the 5-20 adapter with an adapter cable from EVSEadapters.com . It would be the cheapest way to get a decent setup going on this panel, and 3.8kW is nothing to complain about for charging rate unless you need to do back to back long trips with no Supercharging on the route. Even a 6-15 with the stock Tesla adapter would be 2.8kW which is also plenty for most drivers.
I kind of thought that top breaker looked funky too. Not sure if dirty or scorched. I once had an electrical plug that had shorted and the plug kind of looked brownish like that.
I love reading these threads cuz you never know what you'll learn. Great link to provide here on the subject of panels. Actually when we were buying our home from a developer back in early 90s (during that Challenger/GTE-Sylvania/Zensco timeframe), I recall overhearing a very upset buyer come into the sales office complaining that they were installing some brand of panel box in his home and it was a cheaper brand and they had problems and he wanted the Siemens brand that was installed in some of the other homes. This discussion just reminded me of that. Hubby just checked our interior subpanel and it's a Siemens. Now checking the main panel outside, so thanks for this important alert. Great, no visible label on it but it looks like there was one at one time on the panel lid....any way of knowing without the label?
We live in Calif as well and have our main and sub outside. Just a guess but maybe it's located outside so in case of an earthquake and power needs to be shut down quickly it's easily accessible to anyone?
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Determine the max solar size that you want (or budget affords, whichever comes first). You are limited to 20% of the rating of the busing in your electrical panel. For example, the largest breaker for solar backfeed on a 100 A panel is 20 amps (=4.8 kw array). If you are going to get a Tesla, than you really should upgrade your service anyway to kill two birds with one project. If you have a new 200A service you are set already for both projects (solar and EVSE). Also, that Challenger panel should be replaced, and use bolt-on breakers for the best connections for the solar and EVSE circuits. Square D QOB is very common breaker and can be used in Square D NQ panels. Note, you don't have to use bolt on breakers for the other circuits; the panel accepts either type. Lastly, use copper for both the EVSE and the solar circuit, not Aluminum. Good luck!
Oh yeah, that's another reason for a supply-side connection - no 20% limit. Although 20% of 200A gives you 9.6kW, which is still a lot of solar.
AndreSF
Member
My $.02 on the topic. In the ideal world, the advice of upgrading service is a sound one, but in reality, you can probably get by without upgrading your service.
Just discuss with electrician the largest possible circuit he/she can pull (probably from the main, as it seems to have better flexibility) for your charging needs. Get a wall connector, which has the most flexibility in terms of using differently sized circuits.
I don't know what your specific use case is, but I've had EV for over 4 years now with daily commute around 40 -50 miles, and good portion of that time I was charging at 16Amp (now using 24Amp charging after installing 14-30 circuit for Model S ~8mo ago). Even on 16Amps (~9miles/hour) car was always ready for me in the morning with enough charge to support commute and beyond. I always charge between 11PM and 7AM to get the lowest TOU rates.
You can always consider upgrading your service later when/if you decide to make major changes such as getting a PV based system.
Good luck!
Just discuss with electrician the largest possible circuit he/she can pull (probably from the main, as it seems to have better flexibility) for your charging needs. Get a wall connector, which has the most flexibility in terms of using differently sized circuits.
I don't know what your specific use case is, but I've had EV for over 4 years now with daily commute around 40 -50 miles, and good portion of that time I was charging at 16Amp (now using 24Amp charging after installing 14-30 circuit for Model S ~8mo ago). Even on 16Amps (~9miles/hour) car was always ready for me in the morning with enough charge to support commute and beyond. I always charge between 11PM and 7AM to get the lowest TOU rates.
You can always consider upgrading your service later when/if you decide to make major changes such as getting a PV based system.
Good luck!
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