Is it possible to add a charger outlet to my condo?

[eprosenx]

Panel is challenger. Here is the sticker. Thanks.

Thanks!

So lots of thoughts here:

How far is it from the service entrance (meter base) to the electrical panel? I wonder how hard it would be to upgrade that line? A 60a feed is pretty limiting (but might be possible given your minimal needs). Can you post some pictures of the meter base and main disconnect?

Is the main 60a breaker in a location accessible to you in the event you were to blow it? (that is the risk if you overload the panel) One thing I was thinking is that if you continue with the 60a main it might be worth replacing the breaker with a new (modern) one just to add a layer of safety.

As others have pointed out, there are concerns with Murray panels. That might drive you to replace that panel (even if you stay with just a 60a feed). There may even be upgrade / retrofit kits for your panel that allows an electrician to replace the panel bus and breakers but without having to replace the breaker pan entirely. What year was your condo built? (how old is that panel)

So in thinking about your situation, I might consider doing a Wall Connector instead of a wall plug and the UMC Gen 2. The reason I call this out is because the Wall Connector has a rotary dial where you can select the max current draw it will allow. This could allow you to say wire it up with 6 AWG wire (even NM cable which is only good to 50a) and put it on a 50a breaker, but then dial it down to say 16a of actual draw (equivalent of a 20a circuit) which then code wise counts as only being 16a of continuous load even though the breaker itself is much higher. Also, spending a few more bucks on the wire upfront might give you an option down the road if you ever did upgrade your main service, and it will also run cooler with less loss and voltage drop (though for these distances that would be extremely negligible).

I also like having my Wall Connector since it allows me to keep my UMC in the car at all times just in case.

What really needs to be done is you need to do a load calculation using the NEC formulas to figure out where you are at now. There are tons of spreadsheets and forms and tools online for doing this. Though please note, some of them differ (may be incorrect, may be wrong version of the code for your locality). I am not an expert in this. This calculation is what is defensible to the inspector that comes out. Note that often times the inspectors are pretty wishy washy on this stuff as well. There is some school of thought that even if you do the wall connector cranked down to 16a and with 6awg you might want to put it on a 20a breaker since that might raise less eyebrows than a 50a breaker (even though the load is the same). You do have to make sure whatever breaker you use will have large enough terminals to accept the wire though.

Oh, and I just discovered recently in 2017 NEC that any receptacle for an electric car is supposed to be GFCI, even if it is 240v and higher amperage. So then this would beg the question if you could even get those for your old panel and how much they would cost. If you do a hard wired wall connector this is not a requirement since it is built into the wall connector and there is no shock hazard upstream of the EVSE.

 

[eprosenx]

I agree, a hardwired solution is probably preferable. However, when you start talking panel upgrades and running new circuits it starts to get pretty pricey. The nice thing about converting existing circuits is that there's no worries about capacity, which is probably the ops biggest problem. There's nothing inherently unsafe about this.

I don't think the comment about "there is no worries about capacity" is true. Those existing circuits were factored into the load calculation as general purpose lighting or garage circuits. They are not calculated as if they are loaded 100% of the time like EV charging circuits are. Just because the circuits exist, does not mean they can be loaded 100% all the time. Also, if you connect in an EV to these circuits then it sucks 100% of their capacity by default leaving nothing for the other random devices that are supposed to use those circuits.

Additionally, per NEC, EV's are supposed to be on dedicated circuits with only a single receptacle, shared with nothing else.

Now in a pinch, I am sure we have all plugged into whatever was available at a friends house, etc... But I would make sure to have a robust solution at my home charging location.

 

[Runt8]

I don't think the comment about "there is no worries about capacity" is true. Those existing circuits were factored into the load calculation as general purpose lighting or garage circuits. They are not calculated as if they are loaded 100% of the time like EV charging circuits are. Just because the circuits exist, does not mean they can be loaded 100% all the time. Also, if you connect in an EV to these circuits then it sucks 100% of their capacity by default leaving nothing for the other random devices that are supposed to use those circuits.

Additionally, per NEC, EV's are supposed to be on dedicated circuits with only a single receptacle, shared with nothing else.

Now in a pinch, I am sure we have all plugged into whatever was available at a friends house, etc... But I would make sure to have a robust solution at my home charging location.

You're right - I should have said "fewer concerns about capacity." Since those circuits are already taken into account in the load calcs you would need less overhead than if you added a new circuit. You would definitely want to cap off any additional outlets to prevent them from being used.

As for NEC, that only applies to permanent wiring. Since this plugs in you would want to look for the UL listing.

I totally agree that a permanently wired solution is preferable. But if you're facing a panel upgrade (or, god forbid, a service upgrade) then you're looking at potentially several thousand dollars.

 

[Dana1]

Hi all,

I want to install a charger outlet, for a Model 3, in the garage of my condo and after checking the cable that supplies power to the panel inside my condo in NEC table 310.15(B)(16) .... It is not looking good at all, I think. I need some help verifying the info I got. I did call an electrician and he was here but he hasn't gotten back to me yet.

The service cable to my condo has the following label, sorry for the caps I was just copying what's on the cable:
"ALCAN S STABILOY(R) TYPE SE CABLE STYLE SER TYPE XHHW CDRS 600 VOLTS 3 CDRS 4 AL 1 CDR 6 AL (UL) 1985"

This is aluminum cable. It is AWG 4 for the three conductor that are insulated (Hot) and AWG 6 for the uninsulated ground, right? That is what I see inside the breaker box if I remove the panel inside my condo.

The main breaker to my condo is 60A. I checked the aluminum cable rating with the NEC table 310.15(B)(16). This table shows 55A (for 60C), 65A (for 75C), 75A (for 90C). It looked like I'm either 65A or 75A with cable type "XHHW". There is a note on that table to go check table 310.104. This table shows the different types. I found "XHHW" and it says that 65A is for wet locations and 75A for dry and damp locations. My cable is on the inside of the building (maybe in the external wall behind the stucco, not sure) and I don't see it going underground so I'm thinking is dry location so 75A is the max amps. The external wall faces the sunset so it gets pretty warm in the summer. I figure 75A with derating for temperature, about 60A? Breaker is maxed out no current available for charger extra breaker?

Please tell me I'm wrong! More info available upon request ... I called another electrician, I'm getting impatient that the first hasn't called back yet, but he wanted to charge me $150 to check what was possible.

Thanks

Maybe call Tesla for their electricians’ opinions. They’ve done tons of installs...mine was fantastic. They may see an alternate solution based on past experience. If you end up petitioning HOA board for a solution: Spend the time to do a nice write up. Photos help, don’t anticipate they know anything about electricity and EVs. Their job is to spend money wisely, not save the planet. Make sure the solution makes sense from that perspective. If your solution includes running new cable it may be worthwhile to mention destination chargers which can promote building to prospective homeowners and their guests.

 

[posity]

One possibility that I have not seen discussed is to add a double throw safety switch onto that A/C circuit. I believe this meets code since I have seen it used in industrial applications and did this in my own house that was inspected. I had calculated too much total load to add a welder circuit in our garage, so by adding this switch, it insured only one of the two loads (my 50A welder outlet in garage or my 50A steam generator) could be on at a time. You can google 'GE 60 Amp 240-Volt Non-Fused Indoor General-Duty Double-Throw Safety Switch' to see the type of switch I am suggesting. This could get you to the point that you suggested of choosing your A/C vs. a 14-50 outlet (the 14-50 would be setup for 40A which is allowed), so you could set the switch to the A/C position to run your A/C, or to the 14-50 position to provide power to your 14-50 outlet in your garage.

The double throw switch is around $200, but would save any messing around trying to add capacity in the panel. So might be a very cost effective approach. And I can't imagine there are any safety concerns since the A/C or the 14-50 would both be protected at 40A when in use. Since you would be adding exactly zero extra load, seems like it would be an easy sell to your condo owner's association. And would not impact any future tenants. Would be interesting to see if your electrician considers this a viable option.

 

[Rodo]

Hi all,
I wanted to get a better idea of how much current the different things in my condo were drawing so I stopped by harbor freight and picked up a cheap clamp meter. Here are the results. See picture pls.

I'm really surprised that the A/C draws about 20A. It has a 40A breaker!!. I think I could replace the electrical panel inside my condo and lower the A/C breaker to 30A. Those challenger/murray breakers are really expensive. $25 for a 15A or 20A and $50 for a 40A. A new panel like the Square D Homeline is about $30 at homedepot and the breakers are $5 to $10 each. I could install a 30A breaker for the charger outlet, that would give me 24A continuous.... provided this is all blessed by the electrician and the city... I'm feeleing iffy though.

The main breaker is about 100ft from my unit. I can see two other service entrance cables on the ceiling of my garage (which is the floor of my unit, BTW unit=condo). I've had to fix leaks in my copper pipes and the cables run next to the pipes in between the floor joists. From what I've seen the designers of the place didn't seem to like drilling the joists to run across them. I assume these cables are for the other units behind mine or they have to cross the joists to reach my panel. I don't know if any of those two are mine. Assuming they are not, it looks like they route to the front of the building (through my garage) to the front wall behind the stucco. If I'm right mine should be about 10 feet from those cables and join once it reaches the front wall. from there is about 100ft to the utility room. That's like a closet with all the meters, cable/FIOs stuff. There is free access to it so if I trip the 60A breaker I can just go reset it. Replacing that breaker panel is not easy. My unit is on a panel with other 4 units and that is HOA property, not the breakers the panel itself because there're multiple units on it. It would be great to replace my service entrance cable but I think I'm ok for now.

Thanks.

 

[eprosenx]

One possibility that I have not seen discussed is to add a double throw safety switch onto that A/C circuit. I believe this meets code since I have seen it used in industrial applications and did this in my own house that was inspected. I had calculated too much total load to add a welder circuit in our garage, so by adding this switch, it insured only one of the two loads (my 50A welder outlet in garage or my 50A steam generator) could be on at a time. You can google 'GE 60 Amp 240-Volt Non-Fused Indoor General-Duty Double-Throw Safety Switch' to see the type of switch I am suggesting. This could get you to the point that you suggested of choosing your A/C vs. a 14-50 outlet (the 14-50 would be setup for 40A which is allowed), so you could set the switch to the A/C position to run your A/C, or to the 14-50 position to provide power to your 14-50 outlet in your garage.

The double throw switch is around $200, but would save any messing around trying to add capacity in the panel. So might be a very cost effective approach. And I can't imagine there are any safety concerns since the A/C or the 14-50 would both be protected at 40A when in use. Since you would be adding exactly zero extra load, seems like it would be an easy sell to your condo owner's association. And would not impact any future tenants. Would be interesting to see if your electrician considers this a viable option.

That a transfer switch would for sure be allowed. There are actually rules in the NEC that allow you to have two devices wired up, but only calculate the loads for one of them as long as they won't ever be running at the same time (you don't even have to interlock them in any way I don't believe). A good example here is backup heat strips in a furnace and an AC unit.

I should call out that just because your AC is on a 40 amp breaker, that does not mean 40 amps is what is used for the load calculation. That 40 amp breaker has a lot of headroom to allow for momentary surges as the motor starts up. This does not result in long term heating of the wire, and so I think the load of a motor like that is calculated at its steady state running current rather than startup current. A UMC Gen 2 on the other hand will draw a solid 32 amps by default.

(though I would find it annoying to have to manually flip a switch - I commonly want to run my AC and my car charging at the same time)

 

[eprosenx]

Hi all,
I wanted to get a better idea of how much current the different things in my condo were drawing so I stopped by harbor freight and picked up a cheap clamp meter. Here are the results. See picture pls.

Nice! I like how you roll. I use mine enough that I splurged for a nice one: https://www.amazon.com/gp/product/B000J19B8W/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

I'm really surprised that the A/C draws about 20A. It has a 40A breaker!!. I think I could replace the electrical panel inside my condo and lower the A/C breaker to 30A. Those challenger/murray breakers are really expensive. $25 for a 15A or 20A and $50 for a 40A. A new panel like the Square D Homeline is about $30 at homedepot and the breakers are $5 to $10 each. I could install a 30A breaker for the charger outlet, that would give me 24A continuous.... provided this is all blessed by the electrician and the city... I'm feeleing iffy though.

So that AC breaker is likely sized properly. Electrical motors need a lot of surge current capacity to start up. The NEC does not calculate the "load" of a circuit based on its breaker rating. The load is calculated based on the nameplate of the connected device irrespective of what ampacity breaker is used. I should also note that the circuit breaker for motors I don't think is the current limiting device. Motors generally have some overheat protection device integrated (I think) so the breaker is only for handling "faults" (short circuits that cause a rapid trip).

I like your idea of panel replacement. For that size panel the cost would be tiny for the parts as you point out. Do note that they may make you bring the panel up to code when replacing it, so that might mean requiring all AFCI/GFCI breakers for most of the circuits which are a lot more expensive (still a really good idea). I am not 100% sure though - they might not require that since they often operate under the "lesser harm" model where they want to encourage folks to at least get rid of old less safe panels without forcing them to bring everything up to latest and greatest.

If you do replace the panel one of the main gotchas is to make sure neutral and ground are bonded together (or not bonded together if this is not the main panel). Actually, in looking at the picture you posted this panel is wired as a sub-panel which is interesting to me. So your main service panel must be at the meter base. Can you please send pictures of your main meter base and main disconnect? I am wondering if you actually have a 100a service or something and if perhaps you could add a direct breaker right off of that and home run some wire to the garage for the car off of there? (bypassing the 60a limit from the panel in your house)

The main breaker is about 100ft from my unit. I can see two other service entrance cables on the ceiling of my garage (which is the floor of my unit, BTW unit=condo). I've had to fix leaks in my copper pipes and the cables run next to the pipes in between the floor joists. From what I've seen the designers of the place didn't seem to like drilling the joists to run across them. I assume these cables are for the other units behind mine or they have to cross the joists to reach my panel. I don't know if any of those two are mine. Assuming they are not, it looks like they route to the front of the building (through my garage) to the front wall behind the stucco. If I'm right mine should be about 10 feet from those cables and join once it reaches the front wall. from there is about 100ft to the utility room. That's like a closet with all the meters, cable/FIOs stuff. There is free access to it so if I trip the 60A breaker I can just go reset it. Replacing that breaker panel is not easy. My unit is on a panel with other 4 units and that is HOA property, not the breakers the panel itself because there're multiple units on it. It would be great to replace my service entrance cable but I think I'm ok for now.

Thanks.

Can you post pictures of those meter bases and main disconnect and the wires across the ceiling? If running exposed wire there is acceptable then maybe there is a game to be played here where you direct wire your Tesla charger back to that main panel. Often times there will be multiple breaker positions in the combo meter/main setups. You may just have a single 60a breaker feeding the sub-panel in your condo, but maybe a second breaker could be installed for the car charger. Up to six "main disconnect" breakers are allowed.

We should also make sure that the HOA owned main panel is not of a hazardous type.

 

[Rodo]

Here are the pictures. There are 4 meters on the sides of the main feed to the building. There are 7 units (condos) per building. The eith meter is for building lights I think. those breakers are 20A. You can see them next to unit "F" breaker. Weird how unit F has a 90A breaker (picture labeled units main breaker 2). Doesn't that exceed the cable rating? I check that cable, it is the same as mine. Mine is on the left side (unit E). It is hard to see the letter. I also have a picture of the small box with the unit's breaker open (units main breaker 1). The main feed has 3 4/0 aluminum wires, you can see them after I removed the cover with the note about the "fire sprinkler at unit D" in picture "building main wires".

After I was measuring the current yesterday I was thinking: Adding all the breakers inside my unit, they add up to 205A (12x20A + 3x15A + 40A= 205A). This is obviously way more than the 60A main breaker. So ... what makes adding ...say a 40A breaker ...not able to pass code? I can easily overload my current setup without tripping any breakers inside my unit but trip the 60A breaker. Adding the 40A breaker for the charger and using it at night when all of the heavy loads are off wouldn't be a problem but that won't pass a code inspection, right? Why?

Nice Fluke combo. Added it to my amazon list for next time . Mines are getting old (Fluke 23 and 29).

Thanks

 

[Runt8]

Here's a nice site to help you estimate your house load. It's not a matter of just adding up the breakers.

Whole House Load Calculator

If you wanted to add an additional circuit you would need an electrician to do a real load calculation.

 

[eprosenx]

Here are the pictures. There are 4 meters on the sides of the main feed to the building. There are 7 units (condos) per building. The eith meter is for building lights I think. those breakers are 20A. You can see them next to unit "F" breaker. Weird how unit F has a 90A breaker (picture labeled units main breaker 2). Doesn't that exceed the cable rating? I check that cable, it is the same as mine. Mine is on the left side (unit E). It is hard to see the letter. I also have a picture of the small box with the unit's breaker open (units main breaker 1). The main feed has 3 4/0 aluminum wires, you can see them after I removed the cover with the note about the "fire sprinkler at unit D" in picture "building main wires".

After I was measuring the current yesterday I was thinking: Adding all the breakers inside my unit, they add up to 205A (12x20A + 3x15A + 40A= 205A). This is obviously way more than the 60A main breaker. So ... what makes adding ...say a 40A breaker ...not able to pass code? I can easily overload my current setup without tripping any breakers inside my unit but trip the 60A breaker. Adding the 40A breaker for the charger and using it at night when all of the heavy loads are off wouldn't be a problem but that won't pass a code inspection, right? Why?

Nice Fluke combo. Added it to my amazon list for next time . Mines are getting old (Fluke 23 and 29).

Thanks

Thanks! So many comments here:

Can you post a picture of the bottom right panel with the cover removed? I am very curious about that 90a breaker. Are you sure it is 4 awg just like yours? Is it copper or aluminum? If copper, that could be legit. Note that if you come up with an ampacity rating that is in between breaker sizes you are often allowed to go to the "next size up". Hence the "next size up" rule. But that in and of itself does not explain how a 90a breaker would be allowed. Copper wire might explain it though - at 4awg and 75c terminals it is rated for 85 amps, and with the next size up rule the 90a breaker might be allowed.

Can you find any documentation on those meter bases or the panels down below them? Is there a sticker on the panel cover at all? I am wondering if those meter bases are rated to 100a and you could possibly upgrade your main without any other modifications to the meter bases.

My code knowledge gets a bit more fuzzy in these many tenant MDU setups. On a standard service you must not have more than six main disconnects. So I wonder if you could install a 240v tandem style breaker that would count as just two disconnects on your one electrical service (even though there are eight electrical services there - the building feed already has two independent 120v breakers installed...). So maybe you could continue feeding your panel at 60a, but then also feed some amount of power separately to a dedicated charger in the garage. Or actually, I am not sure that they make 60a quad tandem breakers, but I know Eaton at least makes a 50/50 breaker (two 240v 50a breakers). So if you could find a compatible breaker with that panel, maybe you could downgrade the main feed to your unit to a 50a breaker, and then have a second 50a breaker for a dedicated car charger (wall connector or NEMA 14-50). I know actually Eaton cross rates a lot of their breakers for installation in other manufacturers panels (including Murray). Not sure if the quad tandem is rated that way though and for this specific main panel.

Eaton BR 2-50 Amp 2 Pole BQC (Common Trip) Quad Breaker-BQC250250 - The Home Depot

I am also concerned about how the neutral lines from each unit are attached back to the neutral from the power company. It looks like the four neutral lines in the bottom left box (from the units) are terminated to a lug that is attached to the housing. But I don't see any connection from that lug back to the neutral line from the power company (the neutral does extend up from the large middle box into the meter bases, but I have no idea where it terminates behind the meter bases). That is concerning to me as I don't think neutral current should be conducted by the electrical box itself.

Additionally, if that main service panel for the building is Murray as well I wonder if it is considered a hazard as well? If so, that should be communicated to the board. HOA's (at least like in Washington) are required to keep a capital reserve for replacing things like electrical panels. It might eventually be time to replace that entire meter base setup if it is a safety hazard (though the pictures you sent look quite clean install wise). Maybe upgrade everyone at that time to be able to support 100a or higher services at the same time if they wanted to run new cable.

Another option could be to replace the 60a breaker with say a 100a breaker but then run new higher ampacity wire (copper probably) to a new subpanel right in the main meter room next to the electrical panel. Then in that subpanel have a 60a breaker with wire spliced back through the existing feed to your unit. That gives you at leas 40a to play with (if not more depending on load calculations) for a dedicated car charger.

At the end of the day, I don't know how exactly to do the NEC load calculations on this entire setup (beyond just for your own unit). This likely needs a professional to weigh in on it (perhaps if you are lucky you could ask your local inspectors office what they would look for load calcs wise).

I should also call out that the power company may need to upgrade their main feeder wire into the building some day. I am not sure how it works in your area, but I think often for existing services, the wire up until the point of demarcation (like the meter base, or the big middle cabinet) is on them to keep it up to the necessary capacity. I doubt it is an issue today, though if multiple tenants start adding AC and car chargers, the original loading calculations they used may not hold true anymore. I am also shocked that the middle panel cover you pulled off was not locked with a power company seal. That is upstream of the meter bases and so you could steal power there. ;-)

 

[tga]

Do note that they may make you bring the panel up to code when replacing it, so that might mean requiring all AFCI/GFCI breakers for most of the circuits which are a lot more expensive (still a really good idea).

I know of a recent house fire that the fire investigators blamed on mice chewing through wires. Luckily, no one was home (early May, lake house in Maine, house not opened for the season yet), but it got me thinking about replacing breakers with AFCI's.

 

[Electric700]

If you really have two 120 outlets in the garage on separate circuits, it's possible to combine them into a 240 circuit.

110-120 and 220-240 Voltage Converters & Accessories

Or just convert one of them to a 240 V, 20 A NEMA 6-20 and use the Tesla Gen 2 Mobile Connector with a 6-20 adapter (or a 6-15 if 6-20 wiring is not supported, and you don't wish to change the wiring).

Here are the Tesla Gen 2 Mobile Connector adapters:
Model S/X/3 Gen 2 NEMA Adapters

 

[eprosenx]

Here are the pictures. There are 4 meters on the sides of the main feed to the building. There are 7 units (condos) per building. The eith meter is for building lights I think. those breakers are 20A. You can see them next to unit "F" breaker. Weird how unit F has a 90A breaker (picture labeled units main breaker 2). Doesn't that exceed the cable rating? I check that cable, it is the same as mine. Mine is on the left side (unit E). It is hard to see the letter. I also have a picture of the small box with the unit's breaker open (units main breaker 1). The main feed has 3 4/0 aluminum wires, you can see them after I removed the cover with the note about the "fire sprinkler at unit D" in picture "building main wires".

After I was measuring the current yesterday I was thinking: Adding all the breakers inside my unit, they add up to 205A (12x20A + 3x15A + 40A= 205A). This is obviously way more than the 60A main breaker. So ... what makes adding ...say a 40A breaker ...not able to pass code? I can easily overload my current setup without tripping any breakers inside my unit but trip the 60A breaker. Adding the 40A breaker for the charger and using it at night when all of the heavy loads are off wouldn't be a problem but that won't pass a code inspection, right? Why?

Nice Fluke combo. Added it to my amazon list for next time . Mines are getting old (Fluke 23 and 29).

Thanks

@Rodo The more I look at this the more concerned I am that you have a major safety issue with those current meter base units for the entire building. It looks like the four neutral lines from the condos are landed on a bus bar that does not appear to be connected back to the neutral from the utility in any way other than via the back shell of the meter base assembly. This means that any unbalanced load between the two phase legs is traveling through the shell of the meter base (some amount of imbalance is totally normal and expected). It almost looks to me like the back of the meter base pan might be slightly discolored, but hard to tell. I am guessing the bus they landed those on was intended to be used for ground wires perhaps, and that the neutral lines were supposed to be brought all the way up to each meter base assembly? (that is all I can think of)

Obviously this has likely been this way for a very long time, but it is extremely concerning to me. Adding a 240v car charging circuit will have no impact on this since the load is fully balanced between the phase legs, but you don't want to be the last person to make a change to the electrical system before the building catches fire.

But also, regardless of if you install any charger for your unit, I would want this checked out ASAP. (maybe I am missing something in the picture and am wrong about this, but I doubt it)

Actually, I should also call out that if you just plug your car into like a 20a 120v circuit you would potentially be putting up to 16 amps of load on that neutral connection (though depending on which way the loads are unbalanced that could either increase the load on the neutral, or decrease it... - and it could change throughout the day as loads change in the building)

 

[Rodo]

@eprosenx The neutral is fine. It is very hard to see in the pictures I posted but it is not on the enclosure. I'm attaching a side view close up so you can see it. It has a bar that goes up (see "neutral bar close up.jpg"). I also included a picture of the box with the 90A breaker ("90A breaker box.jpg"). It has the same cable as mine so I guess that's a code violation? I thought I could add a 90A or 100A breaker when I first started to look into this EV charger thing because that breaker was already upgraded but then I check the cable rating and I was wondering how could that be. I also took a picture of the sticker on the inside of the cover ("90A breaker cover.jpg").

I wish the builders of this place would have placed the breaker panel for my condo in the garage. The switch that posity suggested would have been perfect. But with the panel on the wall next to the bedroom ...it would be an eye sore with the red handle sticking out :-(.

I don't want to do anything that involves talking to the HOA. They are a bunch of dummies that say no to anything without even thinking. I was one of them for years until I got tired of being the odd guy out that would take time to investigate and talk to owners before the meetings. I quit years ago. Now I go there once in a while and I tell them how dumb they're doing things. So they ..ahem .. we don't like each other . Besides the rules are that if something is only for my unit, it is my responsibility and they don't need to know.

Adding a new run of copper cable would be nice. But that would be pricey and I'm not sure where the service entrance cables are 100%. I'm trying to save as much as possible to get the LR Model 3 instead of the SR.

I'm still waiting for the electrician to get back to me. He said this week so we'll see what he says and what options are available.

Before I forget I'd like to thank you eprosenx for all the info you have provided. Also everyone else for all the good suggestions and comments.

 

[posity]

Just put the transfer switch right next to the 14-50 or HPWC in the garage. Super clean setup. Requires a little bit extra wire since the two switched A/C line wires would go all the way back to the existing panel (and then be spliced to the two existing A/C load wires), but your electrician will get the idea. In fact, if you use an HPWC, you are required to have a 'means of disconnect' visible from the HPWC, so the transfer switch (in the middle disconnected position) is actually a safety feature required when permanently wired (using the HPWC).

And the other plus to this approach is when you leave as a tenant, it would be trivial to rewire the A/C wires right back into the original breaker, eliminating all your changes.

 

[eprosenx]

@eprosenx The neutral is fine. It is very hard to see in the pictures I posted but it is not on the enclosure. I'm attaching a side view close up so you can see it. It has a bar that goes up (see "neutral bar close up.jpg"). I also included a picture of the box with the 90A breaker ("90A breaker box.jpg"). It has the same cable as mine so I guess that's a code violation? I thought I could add a 90A or 100A breaker when I first started to look into this EV charger thing because that breaker was already upgraded but then I check the cable rating and I was wondering how could that be. I also took a picture of the sticker on the inside of the cover ("90A breaker cover.jpg").

I wish the builders of this place would have placed the breaker panel for my condo in the garage. The switch that posity suggested would have been perfect. But with the panel on the wall next to the bedroom ...it would be an eye sore with the red handle sticking out :-(.

I don't want to do anything that involves talking to the HOA. They are a bunch of dummies that say no to anything without even thinking. I was one of them for years until I got tired of being the odd guy out that would take time to investigate and talk to owners before the meetings. I quit years ago. Now I go there once in a while and I tell them how dumb they're doing things. So they ..ahem .. we don't like each other . Besides the rules are that if something is only for my unit, it is my responsibility and they don't need to know.

Adding a new run of copper cable would be nice. But that would be pricey and I'm not sure where the service entrance cables are 100%. I'm trying to save as much as possible to get the LR Model 3 instead of the SR.

I'm still waiting for the electrician to get back to me. He said this week so we'll see what he says and what options are available.

Before I forget I'd like to thank you eprosenx for all the info you have provided. Also everyone else for all the good suggestions and comments.

Ok, great, glad to hear that neutral is not a dangerous situation. That bus bar is hiding in there pretty well! Thanks for taking the extra pictures.

FWIW, the fact that there are eight different services without a common disconnect is interesting. I thought you are only allowed up to six, however, maybe older code was different or your local area had/has modified rules. Also, the building electrical meter has two independent 120v breakers and so that counts as two by itself. I additionally question whether terminating both neutral wires under the single screw is legit (probably not) but probably not that big a deal.

It looks like I am guessing each four pack of meters is good for a total of 250 amps (based on the sticker in the most recent pictures), so that is likely one reason they did 60a to each unit so that in aggregate you can't go over the 250 (though the chances that all four units are maxing out at the same time is very very low - I am sure NEC has some formula for calculating load for multiple MDU's on a common feed and allowing for some oversubscription).

I can not come up with any code allowance for that 90 amp breaker. That seems like a horrible idea. Maybe someone was reading the table for #4 *copper* wire? Also, I am curious if that breaker type is rated for use in that panelboard type?

One question just to confirm: The cable from the main meter base up to your condo is SE type as described in your original post. Does it also say it has a 75c or 90c rating on it somewhere? I just wanted to confirm. I am operating under the assumption that it is rated at least at 75c which gives it an ampacity of 65 amps.

My understanding of the code is that you are allowed to use the "next size up" rule which would allow you to replace the main breaker with a 70 amp one instead of a 65a one. Now you would still have to do the load calculations and make sure you fit within the 65a limit, but that would basically "unlock" another 5a of capacity (it does not seem like much, but on a 60a service everything helps!). Please check with a licensed electrician on this though.

At the end of the day, you need to do that load calculation based off the NEC formulas. I need to read more up on that. ;-) I have just used the various ones online, but they seem to differ from each other.

I think you will either end up with:
* A 20a 240v receptacle (12awg), a 30a 240v receptacle (10awg - dryer plug), or a 50a 240v receptacle (6awg in most cases, unless in conduit and then sometimes can do 8 awg - NEMA 14-50 or 6-50 though 14-50 is more common). Each of these solutions would use your UMC.

* Then the other option would be a wall connector, which the nice thing about that would be the ability to crank up or down the allowed amps as long as you wired it with sufficient ampacity wire. You might start it out set to 16a, but once you gained historical data on usage you might find you could charge at higher rates safely. Maybe say wire a Wall Connector up with 6awg and put it on a 50a breaker. (remember the load calculation is based on what the rotary dial is set to - NOT the breaker).

You might want to consider a Sense energy monitor in your main panel so you can keep tabs on your power usage. I personally put my Sense on its own dedicated 240v breaker just to make it as clean an install as possible. This may be easier if you replace your main panel.

Note that the transfer switch is not a bad idea if you are running up against load calculation issues, though I would find it annoying to not be able to charge my car when it was hot out. A 20a 240v plug without having to do the transfer switch might be less annoying than having to manually transfer all the time. Or if you wanted to get really tricky you could do both a 6-20 receptacle on its own circuit (if the load calc allowed), PLUS put the transfer switch on the AC and then wire it to a 14-50, a 6-50, or a HPWC. Then you could have "slowish" charging while running the AC, or "fastish" charging at times of year you did not need the AC. You would do the load calc as the greater of either the AC running plus the car at 16a on that 20a circuit, OR just the car by itself drawing 32a if using the UMC on the 14-50 or 6-50, or if a HPWC then whatever you chose to set that to.

I will call out that a disconnect right next to the HPWC is NOT always required for the HPWC in 2017 NEC. You do need a disconnect that can be "locked off" if the HPWC is fed from a circuit *over* 60a (or greater than 150v to ground - which is never the case in standard US residential service). My understanding is that you can buy a little metal clip for the breaker panel to allow it to be locked off which then counts as the disconnect. As far as I know the code calls for "readily accessible" disconnect, but it does NOT say it has to be within a certain number of feet or be "visible". Now some jurisdictions may modify this rule to be more stringent, or they may interpret "readily accessible" differently.

My take on it is that HPWC's don't have anything in them that really needs servicing. Local disconnects make all the sense in the world for HVAC units where techs are in and out of them all the time and they may not have access inside or to the electrical panel. If you are coming to work on a HPWC you are probably an electrician and have access to the panel...

Let us know what you end up doing! You have a rather unique challenge. ;-)

 

[eprosenx]

@eprosenx The neutral is fine. It is very hard to see in the pictures I posted but it is not on the enclosure. I'm attaching a side view close up so you can see it. It has a bar that goes up (see "neutral bar close up.jpg"). I also included a picture of the box with the 90A breaker ("90A breaker box.jpg"). It has the same cable as mine so I guess that's a code violation? I thought I could add a 90A or 100A breaker when I first started to look into this EV charger thing because that breaker was already upgraded but then I check the cable rating and I was wondering how could that be. I also took a picture of the sticker on the inside of the cover ("90A breaker cover.jpg").

I wish the builders of this place would have placed the breaker panel for my condo in the garage. The switch that posity suggested would have been perfect. But with the panel on the wall next to the bedroom ...it would be an eye sore with the red handle sticking out :-(.

I don't want to do anything that involves talking to the HOA. They are a bunch of dummies that say no to anything without even thinking. I was one of them for years until I got tired of being the odd guy out that would take time to investigate and talk to owners before the meetings. I quit years ago. Now I go there once in a while and I tell them how dumb they're doing things. So they ..ahem .. we don't like each other . Besides the rules are that if something is only for my unit, it is my responsibility and they don't need to know.

Adding a new run of copper cable would be nice. But that would be pricey and I'm not sure where the service entrance cables are 100%. I'm trying to save as much as possible to get the LR Model 3 instead of the SR.

I'm still waiting for the electrician to get back to me. He said this week so we'll see what he says and what options are available.

Before I forget I'd like to thank you eprosenx for all the info you have provided. Also everyone else for all the good suggestions and comments.

Oh, and can you post pictures of all the nameplate data from your AC and air handler (furnace) units? This will be necessary to do a load calculation.

 

[rdlink]

...You might want to consider a Sense energy monitor in your main panel so you can keep tabs on your power usage. I personally put my Sense on its own dedicated 240v breaker just to make it as clean an install as possible. This may be easier if you replace your main panel...

Question about your Sense. Does it give you accurate readings on your HPWC?

The reason why I ask is because I have had a Sense for about a year. Overall I have been pretty underwhelmed by it. Between the fact that every other device it finds in my home is a "heating" device of some sort, the fact that it is inconsistent in seeing things turn off and on, and other issues I find it to be a fairly "beta" device. Especially for $300.

When I installed my Sense I had one spot available on my 150 amp panel that could accommodate a two pole 240v breaker, and I followed Sense's recommendation to put it on its own breaker. Fast forward to a week and a half ago, and it was time to install my HPWC. Since I needed the spot where the Sense breaker was for my 60 amp, I shut down the Sense and removed it.

I have tried to determine if I can safely piggyback the Sense on a currently used two pole 240, since it draws so little voltage, in the hope that it would allow me to at least get an accurate metric on how much juice the Model 3 was putting on my bill. I reached out to Sense, and they told me it's possible from their perspective, but that I should consult with an electrician to make sure it's compatible with code, and safe. However, given that most electricians are not going to want to come out for such a trivial call, and my fear that the Sense might not do a great job of tracking the HPWC anyway I haven't done that.

But if the Sense has a decent chance of giving me accurate readings on the HPWC I would reconsider. Your thoughts/experience?

 

[eprosenx]

Question about your Sense. Does it give you accurate readings on your HPWC?

The reason why I ask is because I have had a Sense for about a year. Overall I have been pretty underwhelmed by it. Between the fact that every other device it finds in my home is a "heating" device of some sort, the fact that it is inconsistent in seeing things turn off and on, and other issues I find it to be a fairly "beta" device. Especially for $300.

When I installed my Sense I had one spot available on my 150 amp panel that could accommodate a two pole 240v breaker, and I followed Sense's recommendation to put it on its own breaker. Fast forward to a week and a half ago, and it was time to install my HPWC. Since I needed the spot where the Sense breaker was for my 60 amp, I shut down the Sense and removed it.

I have tried to determine if I can safely piggyback the Sense on a currently used two pole 240, since it draws so little voltage, in the hope that it would allow me to at least get an accurate metric on how much juice the Model 3 was putting on my bill. I reached out to Sense, and they told me it's possible from their perspective, but that I should consult with an electrician to make sure it's compatible with code, and safe. However, given that most electricians are not going to want to come out for such a trivial call, and my fear that the Sense might not do a great job of tracking the HPWC anyway I haven't done that.

But if the Sense has a decent chance of giving me accurate readings on the HPWC I would reconsider. Your thoughts/experience?

So I *love* my Sense. But I think that is only possible if you just totally don't care about the machine learning based device identification. Basically I am really not sure that it is possible to accurately identify devices based solely on a single set of current CT's on the mains. Too many devices would look similar, and many things these days (especially EV's) ramp up relatively slowly and without any obvious spikes at startup and so they are difficult to match a signature for.

With that being said: No, it does not detect my Tesla Model 3 as a device, but that is not what I use it for. My use case is graphing the power draw, and my solar generation, and looking at the mains voltage. I guess $300 for that is quite expensive, but there is nothing else really that does this and the app is very good about providing that data in real time. I keep encouraging them to add more non machine learning features - like I want a graph of voltage over time (in addition to the year long graph of current), and I want alerts when the power company has issues with voltage or frequency, etc...

I will say the machine learning stuff has gotten better, it detects certain devices flawlessly (basically like all the parts of my refrigerator it does a great job on - I can monitor the compressor and the water dispenser and the ice dispenser and the ice maker and the defrost heater, etc....

The installation instructions of the Sense do say it can go on another 240v circuit with something else. I prefer to have it on its own circuit so I could power cycle it independently if ever needed (others have reported issues of the Sense going offline if there is a slight power bump, but I have had zero stability issues - though my power is really solid). I think the rules are weird since the Sense is inside of your electrical panel and so it may be allowed to have the Sense on some much larger than necessary circuit. The smallest breakers I was able to find for it were 15a ones. The Sense needs as close to zero power as you could imagine. Like a handful of watts, so capacity wise sharing is not an issue at all.

When I installed my Tesla charger I got some quad tandem breakers that helped me save panel space. Depending on your situation, perhaps you could do the same.

P.S. I did use my Sense to discover my M3 was doing something weird with the charger. It was cycling on and off every four minutes or so after completing its charge. My M3 is in for service right now due to this issue.