For EV / EVSE circuit installation in older apartments: Tap connectors you like?

[brycenesbitt]

Ok, this question might take a moment to ask, forgive the buildup.

I'm working on specifications for adding EV circuits to existing apartment buildings.
These have 200-600A main split phase service entrances, 60A to 100A meter bases, and 30A to 100A main breakers per apartment. There may or may not be a subpanel, but if there is it's likely 50A and more than half the buildings use FPE breakers (with the next most common being Zinsco). The main breakers are sometimes FPE as well, but are sometimes singular. There's the occasion 3 phase main, but mostly it's split phase.
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The goal is to place each new EV circuit "behind the tenant meter" for a variety of reasons most notably convenience for the tenant, and access to their tariff.
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The question is what tap or splice connectors would you recommend for the confined and varied spaces? Which ones really work well, don't take too much space, and hold tight? In some cases the tap will be after the tenant main breaker. In as many cases the tap will between the tenant 60A meter base and the 30A or so main breaker thus drawing more power than before through the meter base. I hope that it's possible to upgrade some main breakers to modern specifications, but that's really a separate concern.
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I've attached a few typical photos of such vintage panels. The overall house amperage is not a concern, just the process of stubbing for the EVSE EV circuit:

 

[brycenesbitt]

A key challenge here is if any tenant meter can get an EV connection -- that's a lot of new wire clutter in the existing main panels. Thus the hunt for the right tap connectors or wiring methods. Too many little piggies won't fit on the road to market .

 

[jaggedben]

Yuck.

I don't think you should be trying to do this in equipment like that. Asking for lots of trouble. Don't even know where to start.

 

[brycenesbitt]

Yuck.
I don't think you should be trying to do this in equipment like that. Asking for lots of trouble. Don't even know where to start.

The chance of these older main panels being upgraded is exactly 0%. The installation gives a chance for a modern main tenant breaker to replace the historic main tenant breaker. Should one of the FPE subpanel breakers freeze up and refuse to trip, having a modern new main breaker could save the day.
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The set of apartments described are 50-100 years old, and the electrical systems are generally original or were the first electric systems added, and not going to change no matter who cries "NEC" or "Those beakers are old". Until, and if, the insurance companies have reason to complain that's the way it's going to be.
The choices are tap off the main for EV charging, or tap after the tenant meters. There are no other choices.
You don't like the electrical on these buildings? Well try the plumbing outside the walls as indoor water closets were not a thing at the time....

 

[jaggedben]

None of that changes the fact that if those pictures are representative of the locations available to tap you are going to have an very difficult time doing it safely. The connector you choose doesn't change the lack of capacity in the existing conductors or the lack of wiring space. And as far as changing to different type breakers without replacing equipment, that's just not possible.

You asked for advice. Mine is to walk away. There is no magic tap connector that is going to solve the problems for you.

 

[hillbilly1]

Is

The chance of these older main panels being upgraded is exactly 0%. The installation gives a chance for a modern main tenant breaker to replace the historic main tenant breaker. Should one of the FPE subpanel breakers freeze up and refuse to trip, having a modern new main breaker could save the day.
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The set of apartments described are 50-100 years old, and the electrical systems are generally original or were the first electric systems added, and not going to change no matter who cries "NEC" or "Those beakers are old". Until, and if, the insurance companies have reason to complain that's the way it's going to be.
The choices are tap off the main for EV charging, or tap after the tenant meters. There are no other choices.
You don't like the electrical on these buildings? Well try the plumbing outside the walls as indoor water closets were not a thing at the time....

Is this getting inspected? The building department can change the owners mind on upgrading if they want EV charging.

 

[petersonra]

If you tap off the main are you going to have to add another meter for the EV charging circuit, or are you talking about tapping off between the tenant meter and their breakers.

I suspect if you do a load calculation the installation won't allow the added loads.

 

[brycenesbitt]

If you tap off the main are you going to have to add another meter for the EV charging circuit, or are you talking about tapping off between the tenant meter and their breakers.
I suspect if you do a load calculation the installation won't allow the added loads.

Tapping between the meter socket and the tenant main breaker.
Load calculations are fine : there's an EVEMS involved. And the currents are relatively small for overnight off peak charging.

 

[brycenesbitt]

Is this getting inspected? The building department can change the owners mind on upgrading if they want EV charging.

Yes, everything permitted, inspected. It's no different than adding a circuit to the tenant's apartment. Tennant subpanel upgrades happen with permits all the time same situation in the same era buildings: unless I'm missing something huge, this tap method is just avoiding backfeeding the power from the tenant subpanel to the garage.
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There is a 0% chance of budget to replace the main, the subpanels, feed a new drop or any of that. There's no capacity or wire size issue. So the question is indeed how to get reasonably sized EV charging, code legal, safe, behind the tenant meter, under that situation. The building department can't change the owner's mind on upgrading, and they have no apparent basis or motivation to do so.

 

[hillbilly1]

Yes, everything permitted, inspected. It's no different than adding a circuit to the tenant's apartment. Tennant subpanel upgrades happen with permits all the time same situation in the same era buildings: unless I'm missing something huge, this tap method is just avoiding backfeeding the power from the tenant subpanel to the garage.
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There is a 0% chance of budget to replace the main, the subpanels, feed a new drop or any of that. There's no capacity or wire size issue. So the question is indeed how to get reasonably sized EV charging, code legal, safe, behind the tenant meter, under that situation. The building department can't change the owner's mind on upgrading, and they have no apparent basis or motivation to do so.

Several jurisdictions around Atlanta want engineered drawings if any major loads are being done, and will reject issuing permits. Pulling the meter would trigger that. From the looks of it, adding EV charging would be almost doubling the loads. But if the inspection department is just a revenue stream, they don’t care, it’s just passed on to the tax accessor to raise assessment’s.

 

[don_resqcapt19]

Tapping between the meter socket and the tenant main breaker.
Load calculations are fine : there's an EVEMS involved. And the currents are relatively small for overnight off peak charging.

I don't see any way that you could accomplish that in a way that would not cause me to hang a violation notice when I inspect.

 

[jaggedben]

Yes, everything permitted, inspected. It's no different than adding a circuit to the tenant's apartment. Tennant subpanel upgrades happen with permits all the time same situation in the same era buildings: unless I'm missing something huge, this tap method is just avoiding backfeeding the power from the tenant subpanel to the garage.
.
There is a 0% chance of budget to replace the main, the subpanels, feed a new drop or any of that. There's no capacity or wire size issue. So the question is indeed how to get reasonably sized EV charging, code legal, safe, behind the tenant meter, under that situation. The building department can't change the owner's mind on upgrading, and they have no apparent basis or motivation to do so.

We get it. You want to do something on the cheap and you're willing to overlook a few minor code violations to do it. Maybe the inspector won't call them, or maybe they will, but you have no Plan B. Maybe some lugs on the old equipment and breakers will strip out while you're doing the work and ruin your day, or maybe not. Probably you won't torque all the terminations properly because labels are missing or you (reasonably) are afraid of breaking old stuff, so maybe something will fail in a few years, perhaps catastrophically, or maybe not.

Good luck.

 

[Todd0x1]

If tapping between the meter and main breaker what are you doing for OCP? Do those tap conductors go to a new box full of 2P breakers for the charger circuits?

How big are the lugs on the breakers in the first pic? I might look at using twin conductor ferrules to add a 2nd wire on either side of the breaker.

Not sure on the code/UL acceptability of doing so, that compartment looks pretty tight already before 50% more wires are added.

I wonder if AHJ would let you replace all the breakers with new ones on din rail (ex: sqd QOU), add in the extra breakers needed where there's room and in an external enclosure where there's not, and get new covers fabricated.

Where the zinsco is, that looks like theres room to get two QOU2x0 in there.

The breaker space in the first pic, I wonder if those could be replaced with new higher amperage breakers then have each one feed a new little 4 space subpanel (or unit mount breakers in a big box) with a breaker for apartment and breaker for EV behind each new main.

 

[brycenesbitt]

If tapping between the meter and main breaker what are you doing for OCP? Do those tap conductors go to a new box full of 2P breakers for the charger circuits?

Tapping between the meter and the tenant main breaker would be a desperation move. If done it would have to go to a new box of modern breakers and be current limited.

How big are the lugs on the breakers in the first pic? I might look at using twin conductor ferrules to add a 2nd wire on either side of the breaker.

Existing wires are #6 or #4 generally. The lugs themselves are ample.

Not sure on the code/UL acceptability of doing so, that compartment looks pretty tight already before 50% more wires are added.

I wonder if AHJ would let you replace all the breakers with new ones on din rail (ex: sqd QOU), add in the extra breakers needed where there's room and in an external enclosure where there's not, and get new covers fabricated.

Where the zinsco is, that looks like theres room to get two QOU2x0 in there.

The breaker space in the first pic, I wonder if those could be replaced with new higher amperage breakers then have each one feed a new little 4 space subpanel (or unit mount breakers in a big box) with a breaker for apartment and breaker for EV behind each new main.

That's really the core issue. We have old crappy breakers. Putting a new QOU style din rail breaker in would certainly make everything a lot more comfortable, yet fall well short of replacing the entire service panel.
If we knew that for a 20 unit apartment 20 units will want EV charging, well, it's time to bite the bullet and upgrade the service to the street.
But when it's 1 or 2 then the search for a way to make it fit the old panel.
Despite the shade above, there is no intent to avoid code in any way shape or form.