Nissan finally gets it with new 240V portable EVSE

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SageBrush said:
Aren't there 20 Amp (continuous rating) circuits in the wild ? Certainly 24 Amp continuous are common.
That's what I have my EVSEUpgrade plugged into. It is one of the second-generation of upgrades that drew 16A from 240VAC (the first ones drew 12A). It has a 20A twist-lock connector on it, so that is what I installed in my garage. I used a 20A breaker for that branch circuit, but I ran 10 AWG wires to allow for a possible change to a 30A connector. That allows me to move up to an EVSE which draws 24A in the future, but that's it. That's about 5.5 kW into the battery, so it should suffice for most home charging.

Unfortunately, this new Nissan EVSE goes beyond the capability of my exisiting wiring. I would likely be in the market for one of the 24A EVSEUpgrades from the MY2013 and later LEAF 1s which go up to 24A and use a 30A twist-lock connector.
 
webeleafowners said:
One of the advantages of the 14-50 plug is that many homes have a stove plug . Even if it doesn't reach, an RV 50 amp extension cord can solve the problem. I would rather adapt down than up.


A sotve is a 10-50 not a 14-50. A 14-50 is an RV plug .
 
EVDRIVER said:
A stove is a 10-50 not a 14-50.
Only on older installations. The 10-50 is an ungrounded 120/240V receptacle with 2 hots and a neutral. The neutral may used to ground the stove by special allowance in the NEC for existing installations meeting certain conditions. Any new stove receptacle installed in the past twenty years (or more?) should be a 14-50. And if you are replacing a stove that was using a 10-50, then if a ground wire is available in the stove receptacle box, the receptacle should be changed to a 14-50 at that time.

Cheers, Wayne
 
cwerdna said:
scottf200 said:
Re: 120v/240v -- Hardware-wise if you use the Tesla_Model_S/X/3 Gen 2 NEMA Adapters then they have circuitry in them that talk to the S/X/3 to tell it to automatically set the amps. That way users can't try to draw too many amps.
As for Tesla, I'm aware of what you're talking about, where the mobile connector, depending on the adapter attached will limit the amount drawn (presumably via the J1772 pilot signal, to which the car's OBC must comply). However, this isn't part of the car's UI. And, it assumes that if for example, a 14-30 adapter is attached, that the circuit itself is a 30 amp circuit, able to sustain a 24 amp continuous load. The driver doesn't need to screw with any UI. They select the adapter that fits and the car will not draw more than what's safe for a continuous load on that circuit.
In regards to the underlined, the Tesla UI still gives you the flexibility to lower the amps in the UI. Many of us do that to limit the total amps drawn for something like a garage subpanel. As an example, I lower my Tesla 14-50 plugged charging within the UI from 40a to 32a so that if the two Volts are charging we don't draw too much (subpanel). We do all 3 do schedule charging but you have to make sure you handle worse case scenarios (Volts doing charge 'immediates' instead of schedule).
ceB05j8.jpg
 
EVDRIVER said:
webeleafowners said:
One of the advantages of the 14-50 plug is that many homes have a stove plug . Even if it doesn't reach, an RV 50 amp extension cord can solve the problem. I would rather adapt down than up.


A sotve is a 10-50 not a 14-50. A 14-50 is an RV plug .

Yep. Any new stove will plug into a 50 amp 240 volt campground outlet. I guess that is another good reason for the 14-50 plug on the new EVSE. You can plug into any 50 amp 240 volt campground service. Done it twice. Our motorhome tow vehicle is an EV soooo... kinda handy.
 
scottf200 said:
cwerdna said:
scottf200 said:
Re: 120v/240v -- Hardware-wise if you use the Tesla_Model_S/X/3 Gen 2 NEMA Adapters then they have circuitry in them that talk to the S/X/3 to tell it to automatically set the amps. That way users can't try to draw too many amps.
As for Tesla, I'm aware of what you're talking about, where the mobile connector, depending on the adapter attached will limit the amount drawn (presumably via the J1772 pilot signal, to which the car's OBC must comply). However, this isn't part of the car's UI. And, it assumes that if for example, a 14-30 adapter is attached, that the circuit itself is a 30 amp circuit, able to sustain a 24 amp continuous load. The driver doesn't need to screw with any UI. They select the adapter that fits and the car will not draw more than what's safe for a continuous load on that circuit.
In regards to the underlined, the Tesla UI still gives you the flexibility to lower the amps in the UI. Many of us do that to limit the total amps drawn for something like a garage subpanel. As an example, I lower my Tesla 14-50 plugged charging within the UI from 40a to 32a so that if the two Volts are charging we don't draw too much (subpanel). We do all 3 do schedule charging but you have to make sure you handle worse case scenarios (Volts doing charge 'immediates' instead of schedule).
ceB05j8.jpg
I'm not electrician and don't claim to know NEC, but it sounds like your installation and others that need to do that have a set up that isn't to code.

Back to the i3 case, I found a post that directly relates to what I was talking about. Some guy posted in the i3 Facebook group:
Any issues with an EV charger that has this warning? Note: Due to wiring limitations, this station should only be used at 25 amps continuous, although the EVSE is configured for 30 amps. I want to make sure that isn't something the i3 can't automatically handle.
and a reply that came back was
1. That's a code violation installing a device that knowingly draws 30A on a 25A circuit.
2. You can set the i3 to reduced charging but there's no way for it (or any EV) to know that it shouldn't pull what the EV is rated to provide. (The entire point of an EVSE [the J1772 protocol] is to report to the EV what it can provide. The EV subsequently draws up to that reported limit. If this EVSE cannot be set internally to only draw 25A, there's no way for the car to know that limit.)
 
Aside:
cwerdna said:
I'm not electrician and don't claim to know NEC, but it sounds like your installation and others that need to do that have a set up that isn't to code.
I think this is the basic thing that you (and many) misunderstand. A given main-panel or sub-panel can have a sum total circuit breakers amperage that is > the main amperage coming into it. All homes have this.

Example:
200 amps coming into home,

150 amps = 10 circuits at 15 amp each,
100 amps = 5 circuits at 20 amp each,
080 amps = 2 circuits at (20*2) amps each for A/C and oven

330 amps max total ! The home owners just never max out each circuit so they always stay under 200 amps!!!

i.e. https://www.do-it-yourself-help.com/images/wattage-chart.gif
 
^^^
While some of the values in the table are right/within the ballpark, some are WAY off.

Clock radio having an average load of 100 watts is insane. My over 25 year old clock radio when I plug it into my Kill-A-Watt doesn't even register as 1 watt, to my pleasant surprise. I have 5 other newer clock radios in the house to make the place sound occupied when I'm away and they have tiny AC adapters. I plugged in my power strip that has those 5 clock radios on it into my Kill-A-Watt and it registered as a 1 watt, in total.

The computer values are way off unless one is building a very power hungry gaming machine w/multiple high end video cards. My not very efficient ancient i7-860 machine w/1 SSD + 3 rotating hard drives all running, idles at under 70 watts. I don't recall power consumption reaching more than double if i max out the CPU and GPU by running benchmarks. If I turn on my 2 not very efficient LCDs (20" IPS and a 24" IPS), my total draw w/the LCDs is about 164 watts.

I have an LCD for use w/my security camera system that is way more efficient.

I used to use a 21" CRT monitor long ago and I posted this elsewhere:
Sony GDM-500PS 21" CRT monitor:
- 2 W in standby
- 93 W when in WinXP at desktop w/default background
- ~115 W when displaying an all white screen

I put together an i5-2500 machine for my dad, and IIRC, it idles at under 30 watts.

TV at 300 watts? Way of, as well. My former 27" CRT wasn't that high with an all white screen. I have an old Samsung HL61A750 DLP RPTV w/3 LED lights (no color wheel) and the figures at http://www.avsforum.com/forum/63-rear-projection-units/1029686-2008-samsung-hl61a750-led-dlp-owners-thread-faq.html sound about right. I run mine in low or min.
User chuckolson made these measurements with his Kill A Watt P4400 Tester to show how power usage depends on LED control setting:
Auto 170 - 190 W.
Max 170 W.
High 140 W.
Medium 119 W.
Low 99 W.
Min 84 W.
 
cwerdna said:
^^^
While some of the values in the table are right/within the ballpark, some are WAY off.

Clock radio having an average load of 100 watts is insane. My over 25 year old clock radio when I plug it into my Kill-A-Watt doesn't even register as 1 watt, to my pleasant surprise. I have 5 other newer clock radios in the house to make the place sound occupied when I'm away and they have tiny AC adapters. I plugged in my power strip that has those 5 clock radios on it into my Kill-A-Watt and it registered as a 1 watt, in total.

The computer values are way off unless one is building a very power hungry gaming machine w/multiple high end video cards. My not very efficient ancient i7-860 machine w/1 SSD + 3 rotating hard drives all running, idles at under 70 watts. I don't recall power consumption reaching more than double if i max out the CPU and GPU by running benchmarks. If I turn on my 2 not very efficient LCDs (20" IPS and a 24" IPS), my total draw w/the LCDs is about 164 watts.
[/quote]

This belongs in a forum about saving electricity...
Who cares about any of that chart? We are talking about the EVSE circuit....
 
powersurge said:
This belongs in a forum about saving electricity... Who cares about any of that chart? We are talking about the EVSE circuit....
Sorry about that. I was just trying to explain the very basics of an electrical panel and circuit board to him since he didn't understand how circuit max vs max input to the panels worked. For people with multiple electric cars in their garage that may be on a subpanel it is an important concept especially as EVs are able to pull larger kW now a days with the larger batteries. i.e. multiple 6.6 kw or 7.2 or Tesla (TM3 9.6kW|240v|40a?) cars. We charge 3 cars in our garage at once on our subpanel and I could easily see 2 as being common for the enthusiast.
 
scottf200 said:
powersurge said:
This belongs in a forum about saving electricity... Who cares about any of that chart? We are talking about the EVSE circuit....
Sorry about that. I was just trying to explain the very basics of an electrical panel and circuit board to him since he didn't understand how circuit max vs max input to the panels worked. For people with multiple electric cars in their garage that may be on a subpanel it is an important concept especially as EVs are able to pull larger kW now a days with the larger batteries. i.e. multiple 6.6 kw or 7.2 or Tesla (TM3 9.6kW|240v|40a?) cars. We charge 3 cars in our garage at once on our subpanel and I could easily see 2 as being common for the enthusiast.
That doesn't past the smell test to me: having a permanent installation that depends on having a vehicle having a means of turning down current drawn at 208/240 volts (vs. what the EVSE's pilot signal advertises) to prevent overload and tripping breakers? As I said, other than the i3 and Teslas, most other EVs don't have any such UI nor should they present such UI.

If the pilot signal from the EVSE advertises, "hey, you can draw 40 amps", the circuit should be able to handle it. It doesn't sound right that there should be caveats. To me, either the EVSE needs be changed to a lower amperage one to prevent overload or turned down (if it provides a means to, which some do (e.g. Tesla's wall connectors)).

Can any electricians or those familiar w/NEC chime in?
 
If a Tesla UMC defaults to a 40 amp pilot signal when a 14-50 or 6-50 plug is connected to the UMC, and there is no way to configure the UMC to use a 32 amp pilot signal with that plug, then that Tesla UMC should not be plugged into a 40 amp circuit that uses a 14-50 or 6-50 receptacle. This lack of configurability I would consider a design flaw in the Tesla UMC.

However, as a practical matter, the worst that will happen is that the 40 amp circuit breaker will trip. Absent bad installation or other problems, the wiring and receptacle are all capable of 40 amp continuous; the 40 amp circuit breaker is the weak link and may trip on 40 amps continuous. The only real way to do harm in this case would be to continually reset the 40 amp circuit breaker as it trips, since that may weaken the circuit breaker and cause it not to trip when it should.

So for a knowledgeable user to occasionally do this by controlling the maximum current through an EV's interface, rather than through an EVSE with the proper pilot signal, strikes me as a reasonable compromise. If it would be a regular occurence, it would be better to get an EVSE with the proper pilot signal or to use a 50 amp circuit. I'm not a fan of the "nobody is going to use it but me" argument.

Cheers, Wayne
 
wwhitney said:
So for a knowledgeable user to occasionally do this by controlling the maximum current through an EV's interface, rather than through an EVSE with the proper pilot signal, strikes me as a reasonable compromise. If it would be a regular occurence, it would be better to get an EVSE with the proper pilot signal or to use a 50 amp circuit. I'm not a fan of the "nobody is going to use it but me" argument.
Cheers, Wayne
Good point about the circuit breaker being the safety factor in all this.

BTW, in the Tesla whatever you manually change the the amps to at that GPS location it remembers it. i.e. mine stays at 32a in my garage even if I charged at a campground at 40a with the same UMC. ie. If you go to your parents for a long holiday or whatever and they have older home with even 120v receptacles in their garage you can dial it to 9a (or whatever) to be extra safe and it will default to that the next time so you (or spouse) do not have to remember.

I think the Gen II Volts do the same ... remember to stay on 8a if that is what was used at a location before.

On the related threads topic, I wonder if the Gen II LEAFs do GPS/location base remembering for these things.

FYI on warning in the Volt manual:
Volt manual text: Using a charge level that exceeds the electrical circuit or electrical outlet capacity may start a fire or damage the electrical circuit. Use the lowest charge level until a qualified electrician inspects the electrical circuit capacity. Use the lowest charge level if the electrical circuit or electrical outlet capacity is not known.
FYI on Tesla manual on its lowering amperage button AND the builtin safety detection:
Tesla manual text: The current [amperage] automatically sets to the maximum current available from the attached charge cable, unless it was previously reduced to a lower level. If needed, touch the up/down arrows to change the current (for example, you may want to reduce the current if you are concerned about overloading a domestic wiring circuit shared by other equipment).

It is not possible to set the charging current to a level that exceeds the maximum available from the attached charge cable.

When you change the current, Model X remembers the location. So if you subsequently charge at the same location, you do not need to change it again. Note: If Model X automatically reduced a charging location's current because of f-luctuations in input power (see the note in Charging Status on page 143), Tesla recommends charging at the lower current until the underlying problem is resolved and the charging location can provide consistent power.

Note: If Model X is charging and detects unexpected fluctuations in the input power, it automatically reduces the charging current by 25%. For example, a 40 amp current is reduced to 30 amps. This automatic current reduction increases robustness and safety in situations when a problem exists outside of Regular maintenance is the key to ensuring the continued reliability and efficiency of your Model X.
 
scottf200 said:
wwhitney said:
So for a knowledgeable user to occasionally do this by controlling the maximum current through an EV's interface, rather than through an EVSE with the proper pilot signal, strikes me as a reasonable compromise. If it would be a regular occurence, it would be better to get an EVSE with the proper pilot signal or to use a 50 amp circuit. I'm not a fan of the "nobody is going to use it but me" argument.
Cheers, Wayne
Good point about the circuit breaker being the safety factor in all this.

BTW, in the Tesla whatever you manually change the the amps to at that GPS location it remembers it. i.e. mine stays at 32a in my garage even if I charged at a campground at 40a with the same UMC. ie. If you go to your parents for a long holiday or whatever and they have older home with even 120v receptacles in their garage you can dial it to 9a (or whatever) to be extra safe and it will default to that the next time so you (or spouse) do not have to remember.

I think the Gen II Volts do the same ... remember to stay on 8a if that is what was used at a location before.

On the related threads topic, I wonder if the Gen II LEAFs do GPS/location base remembering for these things.

I would be shocked, the LEAF features are pretty basic.
 
wwhitney : Does your just previous post apply as written if the 40a (CB) circuit to the 14-50 receptacle is wired with NM-B 8/3 cable?
 
wwhitney said:
However, as a practical matter, the worst that will happen is that the 40 amp circuit breaker will trip. ...

I'd say the worst that might happen is that the 40 amp circuit breaker doesn't trip.

I'm not sure how load calculations are derived for subpanels but it seems reasonable for a subpanel dedicated to 240V devices, the concurrent load of those devices should not exceed the rating. It's entirely reasonable to suppose that both cars will be charging at the same time and for long periods. This is different than whole house loads where obviously most branch circuits are nowhere near capacity at any given time. Adding the loads is how our electrician handled our garage subpanel which feeds the whole-house AC and the EVSE. The subpanel is 60 amps; the AC breaker is 40 amps and EVSE breaker is 20 amps (I use a 16A EVSE). He advised no further load be put on that subpanel. I.e., a 40A or even a 30A circuit for the EVSE was not allowed.

Circuit breaker is there to protect you but shouldn't be used as a crutch, imho. And a vehicle's optional settings is not a substitute for adequate wiring design. Well that's my theory. Hopefully an actual electrician will come along and correct us :)
 
Nubo said:
I'd say the worst that might happen is that the 40 amp circuit breaker doesn't trip.
No, you're missing my point. The only part of a (properly installed) 40 amp circuit that isn't rated for 40 amps continuous is the circuit breaker itself. The breaker may be "overly protective" in the case of a continuous load. To deal with this requires upsizing the breaker, but then the conductors have to be upsized as well, since the breaker is not "overly protective" for other load profiles.

Nubo said:
Adding the loads is how our electrician handled our garage subpanel which feeds the whole-house AC and the EVSE. The subpanel is 60 amps; the AC breaker is 40 amps and EVSE breaker is 20 amps (I use a 16A EVSE). He advised no further load be put on that subpanel. I.e., a 40A or even a 30A circuit for the EVSE was not allowed.
That's the wrong way to do the calculation. Motors and HVAC equipment can use breakers that are rated higher than the actual steady state current draw, to deal with high startup current. The HVAC system should be marked with a Minimum Circuit Ampacity (MCA) and a Maximum Overcurrent Protection (MOC), where MCA < MOC. You can use the MCA value to size the conductors and I believe for the load calculation on the panel, but install a breaker anywhere up to the MOC. So if the HVAC MCA is under 30A, you could use a 30A EVSE circuit for a 24A pilot signal EVSE, along with a 40A breaker for the HVAC, all in a panel fed by a 60A feeder.

Cheers, Wayne
 
wwhitney said:
No, you're missing my point. The only part of a (properly installed) 40 amp circuit that isn't rated for 40 amps continuous is the circuit breaker itself. The breaker may be "overly protective" in the case of a continuous load. To deal with this requires upsizing the breaker, but then the conductors have to be upsized as well, since the breaker is not "overly protective" for other load profiles.

I see your point. Sorry, I was being lazy and didn't read carefully enough and was responding to the general idea of manually setting a car's amp draw on a regular basis to avoid overloads.

Your HVAC info is interesting. Maybe I can get a cheap upgrade after all. I did have them wire the EVSE run with 10-gauge :)
 
Nubo said:
It's entirely reasonable to suppose that both cars will be charging at the same time and for long periods. This is different than whole house loads where obviously most branch circuits are nowhere near capacity at any given time.
That is a solid point. Nice info by @wwhitney about the EVSE pilot signal draw and different HVAC criteria. Great input and discussion related to EVSEs.

Pilot Signal Interface
The pilot signal interface, which Section 3 covers in further detail, requires a 1-kHz, ±12-V PWM signal to
be transmitted down the length of the charger cable to the vehicle. The duty cycle communicates the
power capability of the EVSE to the vehicle. The EV returns its current state by placing a load on the line,
which causes a voltage drop.
To facilitate this, the design requires an amplifier with a wide dual-rail
voltage input and sufficient drive strength to facilitate the various line impedances. This design has
selected the OPA171 amplifier based on its input range characteristics (up to ±18 V) and ability to handle
various line impedance changes, even non-resistive changes in the event of cable parasitics.
via: http://www.ti.com/lit/ug/tidub87/tidub87.pdf

ARmSNln.jpg

via: https://energy.gov/sites/prod/files/2014/07/f18/vss142_pratt_2014_p.pdf
 
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