[KonaKaiKen]

I've seen a couple posts where a JuiceBox 40 was connected to a 30 amp circuit. The JuiceBox would need to be set at 24 amps to be safe. I have an existing 30 amp circuit that I want to use. I've been on the fence about doing this so I submitted a question on Amazon and received this answer from Enel X:

"Hello, TheCeladon! Yes, it is safe. The JuiceBox is an infinitely current adjustable device, meaning you can set a limit for any value according to any supply circuit capacity you might have available.
If you do plug in to a 30A circuit, you can adjust the JuiceBox to draw no more than 24 Amps, which is the maximum continuous current draw allowed.
You can set this limit through the dashboard or through the app:
Go into the menu settings and look for the "Maximum Rate (A) and select the appropriate limit.
Make sure to save or hit the check mark in the upper corner.
On the dashboard you would go to 2 places.
My JuiceNet devices, more details, status--set Allowed Current (A) to the appropriate amperage.
Next, switch to the settings tab and set the Wire Rating to correct (A). The wire rating is used for offline amperage, so both should be set. (This is automatically done thru the app's one setting.)"

Thank you for the interest!

Enel X

I found this answer to be enough to motivate me to try this setup.

 

[redpoint5]

Yup, that's the correct way to do it. 80% of rated circuit is code.

 

[ZoomZoom]

The Tesla charger is based on this premise. You buy that charger and you set it's output according to your wiring.

 

[masters]

I believe I set our Juicebox to 25a or 26a, the Bolt shouldn't pull more than 24, but I give it that wiggle room and still be safe.

Car will get the max power without ever feeling the cap.

 

[KonaKaiKen]

I believe I set our Juicebox to 25a or 26a, the Bolt shouldn't pull more than 24, but I give it that wiggle room and still be safe.

Car will get the max power without ever feeling the cap.

Makes sense. I think I'll do this

 

[The Other Tom]

I believe I set our Juicebox to 25a or 26a, the Bolt shouldn't pull more than 24, but I give it that wiggle room and still be safe.

Car will get the max power without ever feeling the cap.

The Bolt will pull up to 32 amps on 240V A/C.

 

[GregBrew]

I believe I set our Juicebox to 25a or 26a, the Bolt shouldn't pull more than 24, but I give it that wiggle room and still be safe.

Car will get the max power without ever feeling the cap.

Just remember that the NEC is based on solid science and research. That "80% rule" is there for a reason.

I'm sure your homeowners insurance company would be pleased to know you're violating the electrical code if your house goes up in smoke from burnt wiring in the wall. They could refuse to cover the loss, due to homeowner negligence.

Just food for thought.

 

[ZoomZoom]

Just remember that the NEC is based on solid science and research. That "80% rule" is there for a reason.
I'm sure your homeowners insurance company would be pleased to know you're violating the electrical code if your house goes up in smoke from burnt wiring in the wall. They could refuse to cover the loss, due to homeowner negligence.
Just food for thought.

Do you call your insurance company every time you speed? Or have you notified them of any code violations in your house? That's not how the real world works. The insurance companies lose in battles, that's why it never gets to court. Anyway, we all have insurance for exactly that; negligence. It always ends up being negligence. They pay out, because that's what we have it for. Now, intent is a different beast. But here's the funny thing about intent. You have to prove it exists. Knowing it exists isn't the same as proving it. In cases of intent, it's possible they will fight it but Allstate learned the hard way not to fight for intent. One example was a guy driving down I-94. He saw deer off the highway, opposite side. Pulled to the median, pulled out a rifle, shot towards the deer but killed a driver who's car was crossing his line of fire, opposite side of traffic. The widow filed suit, Allstate allowed it to go to court, lost. Appealed it, lost, but this time they lost 3x's as much due to state law allowing triple damages. Allstate had a great argument, but they couldn't prove intent.

 

[kman]

ZoomZoom, having worked in insurance law for over 20 years, I can assure you that should there be a fire, your insurance company would investigate, subpoena the records from JuiceBox, find out that you set your system out of spec for electrical code, and nullify your policy. That's 100% the way it works. I've personally watched literally 1000s of homeowner lawsuits go down that way over the course of my career. Any little action or inaction by the insurer becomes a reason for the insurer to play the "get out of paying benefits free" card, and they WILL use it.

If you never have a fire, you'll probably be fine. But if you do, you're leaving very traceable electronic records evidencing your risky behaviour, and it'll likely bite you, HARD.

I'm all for grownups making their own risk assessments, but knowing this should be part of your decision-making, whichever way you decide to go. I wish you luck either way!

 

[ZoomZoom]

ZoomZoom, having worked in insurance law for over 20 years, I can assure you that should there be a fire, your insurance company would investigate, subpoena the records from JuiceBox, find out that you set your system out of spec for electrical code, and nullify your policy. That's 100% the way it works. I've personally watched literally 1000s of homeowner lawsuits go down that way over the course of my career. Any little action or inaction by the insurer becomes a reason for the insurer to play the "get out of paying benefits free" card, and they WILL use it.

If you never have a fire, you'll probably be fine. But if you do, you're leaving very traceable electronic records evidencing your risky behaviour, and it'll likely bite you, HARD.

I'm all for grownups making their own risk assessments, but knowing this should be part of your decision-making, whichever way you decide to go. I wish you luck either way!

I totally disagree. I've been in a house fire and the insurance company did nothing. It was American Family. They took the state marshals report which didn't pinpoint the cause beyond wiring. I work in LE, have been to many fires and have fire investigators in my department. By the time the insurance company shows up, the chain of evidence is destroyed or trampled by hose draggers. I'd quite frankly like to see them do subpoena's for MV accidents which they don't do. They don't look at the black boxes, or the computers in 99.99999% of the cases. If the state troopers pull it, if, they pull it is when the insurance company gets involved. As for sending a subpoena to the EVSE company, that will only show, at best, I have one. I have seen thousands of lawsuits, that never get to court because of settlements. The PI industry is the largest legal entity in that profession. Why is that? Because of the profit and greed. The payouts are huge. Liability insurance and costs are why we are paying what we pay for commodities. If you want to trade stories and specifics send me a private message. I'd be interested to know of 1000's of cases where a policy is negated. I've seen them fight to decline some elements of a payout but that's about it. But just so we are on the same page, let me be crystal clear; If I wired up my EVSE with the wrong gauge wire and I burned down my house as a result I'm getting paid out. Anyone who works in the industry will tell you that the insurance company will pay out for a covered peril regardless of the cause. I have never seen a policy that excludes coverage because the cause of the damage arose from faulty workmanship, work done without a permit, or improperly performed work by a homeowner.

 

[kman]

Good luck with that.

 

[JD4JC]

Here's what a JuiceBox 40 looks like on a 50 Amp circuit feeding a 2019 Bolt

 

[KonaKaiKen]

If I set charging at 24 amps on a 30 amp circuit which was found to be safe according several users, am I not protected by the 30 amp circuit breakers in the unlikely event that 30 amps is exceeded?

 

[p7wang]

If I set charging at 24 amps on a 30 amp circuit which was found to be safe according several users, am I not protected by the 30 amp circuit breakers in the unlikely event that 30 amps is exceeded?

Theoretically. The breaker could also fail to trip, the wiring melts, and a fire starts.

 

[ZoomZoom]

If I set charging at 24 amps on a 30 amp circuit which was found to be safe according several users, am I not protected by the 30 amp circuit breakers in the unlikely event that 30 amps is exceeded?

Yes, the breaker is there to protect the wiring from overload.

 

[neutrondrip]

I thought the 80% rule was for continuous loads. While a continuous load of, say, 29 amps would never trip a 30 amp breaker, it's been found that 29 amps on a continuous load at that wiring could lead to a hazard, no?

 

[ZoomZoom]

I thought the 80% rule was for continuous loads. While a continuous load of, say, 29 amps would never trip a 30 amp breaker, it's been found that 29 amps on a continuous load at that wiring could lead to a hazard, no?

Correct, it is for continuous loads which EVSE's have been designated as such. As for answering the question about hazard, that is really tough and too subjective, most just keep it to the basics which is the breaker is designed for the aggregate of the expected load on the circuit. So, technically running a 30 amp breaker at 29 amps is considered overloaded from a 'design' aspect when you use the NEC/NFPA circuit load chart but it is not wrong nor a technical violation. No one is expected to add up the amps in a residence, and the NEC/NFPA takes that into account. It just technically is not wrong as long as the design of the circuit wasn't 29 amps from day 1. There is a fancy and super complicated circuit capacity formula that electrician's should follow. So, basically, if you have 29 amps running on a 30 amp circuit continuously that is not wrong. Even if it's 24/7. However, any component like an EVSE that is expected to run over 2 hours non stop is a continuous load and for that, the wiring must follow the 80% rule. Wiring running to outlets is treated completely differently than your breaker box that is a service entrance. When I put in a whole house generator recently, doing it myself with an electrician and the building inspector over my shoulder, I learned a lot about the rules and how they differ by what and where something is. I had to use the 75 degree C wiring limit, not the 90 degree Home Depot puts on the wire for amp capacity charts. All the breakers are rated at the 75 degree level, so you have to use that for the wiring.

 

[GregBrew]

<snip> Or have you notified them of any code violations in your house? <snip>

I have no code violations in my house.

 

[ZoomZoom]

I have no code violations in my house.

I have enough for both of us and I didn't pull permits for 'all' the work I've done.

 

[steveskolnik]

I thought the 80% rule was for continuous loads. While a continuous load of, say, 29 amps would never trip a 30 amp breaker, it's been found that 29 amps on a continuous load at that wiring could lead to a hazard, no?

A continuous load is defined in the National Electric Code (NEC) as one that draws current for greater than 3 hours. Modern circuit breakers that we have in our homes have TWO methods of protecting circuit wiring: instantaneous overload, e.g., when you plug in an appliance (or whatever) that has a short circuit, AND thermal overload, e.g., you plug in something that draws 35 amps on a 30-amp circuit. The thermal overload takes time to operate, as it depends on heating inside the circuit breaker itself -- but it does work to protect the circuit wiring.

Incidentally, the current restrictions on wire sizes given in the NEC are very conservative, particularly for the smaller wire sizes like 14-, 12- and 10-AWG (American Wire Gage) used for branch circuits. The 80% rule for continuous loads is, in my humble opinion, a belt added to the suspenders -- not saying it's a bad idea, of course, and as others have said, the last thing we want is a house fire and the REALLY last thing we want is voided insurance after the fire ... Way better to be safe than sorry!