3 cars with stock evses on 20 amp curcuits?

[TimLee]

It's an office building with hundreds of employees and hundreds of parking spaces. There are no garage doors though it could have been a janitor or lawn care worker plugging into the same circuit.

I don't have access to the breaker or any sort of wiring schematic. The cable is running the length of the building (several hundred feet, unknown if it is in conduit underground or inside the building) then definitely in a conduit underground to the curb.

I was told verbally that it was a 20 amp breaker but for all I know its a 50 amp breaker and the guy can't read.

Your situation highlights the complex difficulty of using 120V outlets in parking lots.

98% of the time they were not installed as dedicated outlet single breaker.

They were put in with multiple outlets for infrequent use like what would be appropriate for outlets in a home only used for a bit of lighting.

Just not the right approach anymore with electric vehicles. (or even in the home where high current devices can end up with an overloaded circuit)

And in many cases it is difficult to find out details of the installation as the building is often leased by the employer from a landlord. So people end up guessing.
Not a good situation.

Part of why many landlords have taken the lower risk for them approach of banning use of parking lot outlets for electric vehicle charging.
Actual the more legally prudent approach for them if they don't know it is installed with single dedicated outlet for each breaker.

 

[dhanson865]

dhanson865: If GFCI outlets, and a long cable run, doesn't that bring in the possibility that the trip was due to a ground fault? Do you know if the breaker is GFCI?

Perhaps some useful info about current draw could be gleaned by investing in a Kill-a-Watt that you could share with the other Leaf owner?

I already have a killawatt meter but they tend to be unreliable/inaccurate for very high draws like this EVSE would pull. In the PC world people don't trust them with readings on high wattage PSUs which often draw less than my car would.

I don't know if the breaker was GFCI or not. I just know the maintenance man reset the breaker for us after we unplugged one car.

 

[dhanson865]

It's an office building with hundreds of employees and hundreds of parking spaces. There are no garage doors though it could have been a janitor or lawn care worker plugging into the same circuit.

I don't have access to the breaker or any sort of wiring schematic. The cable is running the length of the building (several hundred feet, unknown if it is in conduit underground or inside the building) then definitely in a conduit underground to the curb.

I was told verbally that it was a 20 amp breaker but for all I know its a 50 amp breaker and the guy can't read.

Your situation highlights the complex difficulty of using 120V outlets in parking lots.

98% of the time they were not installed as dedicated outlet single breaker.

They were put in with multiple outlets for infrequent use like what would be appropriate for outlets in a home only used for a bit of lighting.

Just not the right approach anymore with electric vehicles. (or even in the home where high current devices can end up with an overloaded circuit)

And in many cases it is difficult to find out details of the installation as the building is often leased by the employer from a landlord. So people end up guessing.
Not a good situation.

Part of why many landlords have taken the lower risk for them approach of banning use of parking lot outlets for electric vehicle charging.
Actual the more legally prudent approach for them if they don't know it is installed with single dedicated outlet for each breaker.

Ironically these outlets were installed when someone high up the food chain bought a Leaf. She charged on them for almost 2 years before we got ours and changed the status quo.

So the electrician that put in the outlet knew it was for an EV, that doesn't mean he understood the load though.

 

[smkettner]

If the conduit is sufficient you may only need to pull one more wire to have split phase service and you both can charge.
Really should be 20amp breaker and at least #12 wire.

 

[MikeD]

dhanson865: Sorry, I wasn't meaning to recommend the Kill-a-Watt brand so much as to suggest an adequate device with Kill-a-Watt functionality (I would think a reasonably accurate/inexpensive in-line ammeter is not difficult to find!).

The next time the breaker trips, consider trying the other three outlets with the EVSE to verify that they are also no longer live, i.e. on the same circuit. If it were possible to loosen the receptacle cover a bit, you might be able to verify there is only a single set of wires powering all four outlets. Even if there were 2 sets, they still may have the hot wires connected to a single 120v breaker.

 

[DaveEV]

No, 2011 and 2012 can do 16 amps at both 120 and 240... And the 2013+ is 6.0Kw output by the way... Nissan changed the rating from charger output power to input power on the 2013+...

Just to be clear: 2011-2012 will not pull more than 12A on 120V. This is why the original EVSEupgrade without adjustable current setting was OK for most people - it always puts out a 16A pilot signal, but the '11-12 LEAF would still only pull 12A on 120V and thus be OK for nearly everyone. The '13+ LEAF then allowed current up to the max of the OBC, either 16 or 27.5A depending on whether it had the 3.3 or 6.0 kW OBC.

I already have a killawatt meter but they tend to be unreliable/inaccurate for very high draws like this EVSE would pull. In the PC world people don't trust them with readings on high wattage PSUs which often draw less than my car would.

The Kill-A-Watt works fine in my experience with the load of a LEAF on 120V. I just don't trust it for very long at that current.

It seems that the best solution here is more capacity. For EV charging, ideally each 120V outlet would be independent. Though for the same amount of copper and $400 you probably could get an inexpensive 16A EVSE going. Then if you're feeling adventurous get a Hydra and split the current.

 

[dhanson865]

The next time the breaker trips, consider trying the other three outlets with the EVSE to verify that they are also no longer live, i.e. on the same circuit.

confirmed the first time it tripped, all 4 outlets were dead with only one EVSE plugged in.

 

[dhanson865]

The next time the breaker trips, consider trying the other three outlets with the EVSE to verify that they are also no longer live, i.e. on the same circuit.

confirmed the first time it tripped, all 4 outlets were dead with only one EVSE plugged in.

correction, got 2 of the outlets to stop working the other day while the other 2 stayed working. Apparently two separate breakers.

 

[MikeD]

dhanson865: So, are you concluding that
1) there are 2 NEMA 5-20R duplex receptacles, each connected to a separate circuit, each protected by a separate (probably 20a) 120v breaker?
2) because the EVSEs were not connected to the same circuit (true?) when a tripping incident occurred, it is likely the tripped circuit is not dedicated to the outside duplex receptacle only?

BTW, a duplex receptacle should not be used for EV charging unless each of its two outlets are on a dedicated circuit -- otherwise much safer to use single outlet receptacles, as one is prevented from using both outlets (on the same receptacle) at the same time and risk overloading.

I've not seen a recent comment about GFCI. GFCI only at the receptacle has the advantage of resetting it w/o having to make a trip to a breaker (if there is only a GF trip).

 

[dhanson865]

dhanson865: So, are you concluding that
1) there are 2 NEMA 5-20R duplex receptacles, each connected to a separate circuit, each protected by a separate (probably 20a) 120v breaker?
2) because the EVSEs were not connected to the same circuit (true?) when a tripping incident occurred, it is likely the tripped circuit is not dedicated to the outside duplex receptacle only?

BTW, a duplex receptacle should not be used for EV charging unless each of its two outlets are on a dedicated circuit -- otherwise much safer to use single outlet receptacles, as one is prevented from using both outlets (on the same receptacle) at the same time and risk overloading.

I've not seen a recent comment about GFCI. GFCI only at the receptacle has the advantage of resetting it w/o having to make a trip to a breaker (if there is only a GF trip).

I've tripped a breaker twice now when I was the only car there. The last time it happened as I was plugging in or unplugging my EVSE. So I'm not sure that it is over current protection that is tripping or not.

there are 2 NEMA 5-20R duplex in play but I can't verify what circuit(s) they are on or what kind of breakers are on those circuits.

forgive me but the continuance of people saying things in the tone of

"a duplex receptacle should not be used for EV charging unless each of its two outlets are on a dedicated circuit -- otherwise much safer to use single outlet receptacles, as one is prevented from using both outlets (on the same receptacle) at the same time and risk overloading."

seems to imply I'm at fault for the situation. I have no control over the type of outlet, the type of breaker, the type of wiring, or any other aspect of this situation other than what I plug into it. I'm not sure why people feel the need to say "you shouldn't do that" when I didn't do it.

I'd love to open the box and look at the circuit, put a tester on an outlet and check all the other outlets in the building to see which if any are on the same circuit but I don't have access to the entire building. There are way too many locked doors.

For that matter there are way too many people involved for me to just ask. I've involved people from two separate companies as is and everyone I talk to knows less about electricity than I do.

 

[MikeD]

dhanson865: 1) So I gather you and the other Leaf owner who charge haven't yet conferred about trying to use outlets on apparently separate circuits to try to help your breaker tripping problem?

2) You wrote: "So I'm not sure that it is over current protection that is tripping or not.", which I take to confirm (?) that they are not "GFCI receptacles" and since you wrote previously "it is 4 GFCI outlets..." you must have information that the circuits have GFCI protection, which could be at GFCI breakers and/or at a second "upstream" receptacle somewhere in the circuit that is GFCI. It would be helpful to find out what kind of trip is occurring, if possible.

FYI: Be aware that at least some GFCI breakers allow the re-setter to distinguish between a GF trip and an overcurrent trip (or even a AF trip, for some of the newest breakers) .

BTW: I am not trying to beat you over the head about unsafe practices (and this may very well the case for other posters). Those comments were mainly intended to engage other interested thread readers about issues of safety. I (we?) are not trying to just solve your particular problem.

 

[dhanson865]

dhanson865: 1) So I gather you and the other Leaf owner who charge haven't yet conferred about trying to use outlets on apparently separate circuits to try to help your breaker tripping problem?

2) You wrote: "So I'm not sure that it is over current protection that is tripping or not."

FYI: Be aware that at least some GFCI breakers allow the re-setter to distinguish between a GF trip and an overcurrent trip (or even a AF trip, for some of the newest breakers) .

BTW: I am not trying to beat you over the head about unsafe practices (and this may very well the case for other posters). Those comments were mainly intended to engage other interested thread readers about issues of safety. I (we?) are not trying to just solve your particular problem.

1. The other leaf owner and I haven't been charging at the same time since the first breaker trip. Even if it is two separate circuits something is killing the outlets if we both charge at the same time.

2. They ARE GFCI outlets. There is a test and reset button for each pair of outlets. I know what is physically present outside the building I don't know what is physically present inside the building. I'm not sure why what I wrote confused you on the presence of GFCI outlets.

As to GFCI at the outlet my coworker said he was able to reset the right plugs one day with the GFCI reset on the outlet. In my case I've never had the reset button help if I tripped whatever I'm tripping.

Currently the left 2 outlets are off and have been off for several days as I caused them to trip last week and haven't bothered to get someone to reset it at the breaker. I was hoping someone would reset it because it was a shared circuit but so far no action, maybe it is dedicated or maybe I haven't waited long enough for someone to try the other outlet on that circuit?

My working theories are:

a. there are two circuits (it is possible to trip the left pair and keep the right pair hot)
b. the breakers are either 15a dedicated or 20a non dedicated
c. the outlets or breakers are unreliable enough that I can trip them without going over the rated current
d. the outlets and breakers are reliable but there is another load on the circuits I'm unaware of.

My intended next step is to try charging on lower amperage with an OpenEVSE or EVSEupgrade but I still have to buy one. I don't have anything but the stock EVSE to work with right now.

I'm thinking I will try charging at 6a on one circuit while my coworker charges at 12a on the other. If I don't trip the breaker in a week of doing that I'll try 8a on mine with 12a on his. Either way I'd be going out to change mine back to a higher amperage when he unplugs.

 

[MikeD]

dhanson865: 1) No licensed electrician should make the most elementary of mistakes of using a 15a breaker for a 5-20R receptacle (and risk losing his/her job) since that outlet allows plugging in a single device that uses up to 20a.
2) It is unlikely that the breakers involved are GFCI since that involves duplication of functionality (they might be AFCI, however).
3) IMHO you would be wasting your money buying another EVSE if the circuits are not dedicated (which seems likely to me based on your previous posts).
4) See to it that the circuits ARE dedicated, and don't come around here suggesting that it is OK to otherwise use them with some half-assed scheme -- because IT IS NOT OK!!!
5) I know you mean well, but...
6) All the best to you, in all sincerity!

 

[dhanson865]

dhanson865: 1) No licensed electrician should make the most elementary of mistakes of using a 15a breaker for a 5-20R receptacle (and risk losing his/her job) since that outlet allows plugging in a single device that uses up to 20a.
2) It is unlikely that the breakers involved are GFCI since that involves duplication of functionality (they might be AFCI, however).
3) IMHO you would be wasting your money buying another EVSE if the circuits are not dedicated (which seems likely to me based on your previous posts).
4) See to it that the circuits ARE dedicated, and don't come around here suggesting that it is OK to otherwise use them with some half-assed scheme -- because IT IS NOT OK!!!
5) I know you mean well, but...
6) All the best to you, in all sincerity!

1. I have no faith in the average human to do competent work. If I can't verify it I'll assume it is possible someone did what they shouldn't. It's the same reason I look both ways on a one way street. It's why I'd never point an "unloaded" weapon at my head and pull the trigger. It's called being aware of ones surroundings and you aren't aware if all you do is assume that a 20amp socket means a 20amp breaker.

3. I need 240v usage for home anyway. The ability to step down to lower amps on 120v may be useful or may be a moot point but I still need the EVSE to plug into my 14-50 at home.

4. How do you propose I see to it that they are dedicated? I don't own the property. I'm not in management for any of the companies that have control of the situation. My only choice is to plug in or not plug in. The spots are marked as EV vehicle charging so I'd assume the onus is on them to provide a safe situation and it's their fault if something goes wrong

5. But hey, I do troubleshooting for a living and I can't help but try and figure out how to make the situation more livable for myself until they do something long term.

 

[dhanson865]

So we've been happily keeping to the schedule of

Leaf 2 charging from 6am to 2pm
Leaf 3 charging from 2p to 6:30pm

for the last few weeks.

Today Leaf 1 came back and is using the plug. So now we are up to 3 Leafs and only one presumably 20 amp circuit usable. The left 2 plugs have been dead since the breaker tripped two weeks ago or so.

Good thing I have enough range to do the round trip without charging at work if I have to. Not quite sure how winter will play out.

We don't know the driver of the 3rd leaf and will have to leave a note for her to see if we can work out a charging schedule.

 

[TimLee]

...
We don't know the driver of the 3rd leaf and will have to leave a note for her to see if we can work out a charging schedule.

If she had the pull to get the building owner to install the outlets originally, she should have them send the electrician back to do it correctly with each receptacle being on a dedicated 20 amp breaker :?

 

[Ingineer]

Our upgrades for the Nissan EVSE allow the amperage to be programmed down to 6A in 1A increments. This would safely allow multiple LEAFs to be plugged into one 20A circuit without tripping the breaker.

-Phil

 

[dhanson865]

Our upgrades for the Nissan EVSE allow the amperage to be programmed down to 6A in 1A increments. This would safely allow multiple LEAFs to be plugged into one 20A circuit without tripping the breaker.

-Phil

Yeah, when we had 4 plugs and presumably 2 circuits my thought was to try stepping down the amps to prevent the plug going dead (thermal trip, overvoltage trip, bad outlet, don't know why it goes dead).

I was hoping to get a multimeter on that plug after they reset it, but now they've left the left sockets dead since the last time they tripped weeks ago. Told us to just charge one car at a time.

The thing is I don't think I'll be able to get the other two Leaf owners to upgrade and just one at 6a plus one at 12a is possibly enough to trip the breaker.

For now it's a game of musical EVSEs and Thursday I was left without a plug.

I'm hoping they'll change the electrical situation but I'm prepared to just not charge at work if it comes to that. I can charge at home and hit an L2 a couple of miles from work if I'm concerned about range for the return trip.

I just won't have the luxury of preheating the car on the coldest winter days if range becomes an issue. I'm still on 11 bars so hopefully they'll add more circuits in the parking lot before it becomes an issue.