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Re: Simple question with complex answers on level 2 charging

Posted: Thu Apr 25, 2019 9:01 am
by HerdingElectrons
LeftieBiker wrote:
LeftieBiker wrote:

SageBrush wrote:
replacement of the existing cable with 240 volt cable.


Why is that ? I thought 240v is just 120v * 2. Or did you mean a 4 wire run ?


240 volt cable has three wires (two Hots, one neutral) plus the bare ground wire. Devices that don't use Neutral are uncommon enough that you generally either cap the Neutral in a hardwired EVSE installation, or install a 4 wire outlet that can be used by other devices, with the Neutral unused by the EVSE plug. That way the whole cable doesn't have to be replaced if the EVSE is replaced with something that needs a Neutral. If you know that only an EVSE will ever occupy that circuit, then you can use two wire (plus ground) cable of the correct gauge.



Almost ALL 208-230V home wiring that's 20+ years old is only three conductor(wire) configuration. Pure 208-230V loads don't utilize a neutral at all.

The vast majority of current 4 wire 208-230V wiring adds a neutral wire because a portion of the attached load has a 120V component thereby necessitating a separate neutral wire.

Re: Simple question with complex answers on level 2 charging

Posted: Thu Apr 25, 2019 12:01 pm
by LeftieBiker
Almost ALL 208-230V home wiring that's 20+ years old is only three conductor(wire) configuration. Pure 208-230V loads don't utilize a neutral at all.

The vast majority of current 4 wire 208-230V wiring adds a neutral wire because a portion of the attached load has a 120V component thereby necessitating a separate neutral wire.


Maybe it's because 208 volt services are rare here, but I've only seen a couple of 2 conductor cables, for ranges. Well, that's why I'm not an electrician, I guess!

Re: Simple question with complex answers on level 2 charging

Posted: Fri Apr 26, 2019 11:43 am
by GlennD
LeftieBiker wrote:
GlennD wrote:Because the Leaf follows the J1772 spec you could safely set the EVSE to 16A on a 20A circuit. Most outlets are only rated at 15A but they have a lot of wiggle room. A 20A outlet is the same but with an extra slot.

Our member uses a 30A circuit like at a truck stop.


The issue, IIRC, was the Nissan dual voltage EVSE being rated at 30 amps, requiring a 40 amp circuit that is higher amperage than almost all dryer circuits.


Obviously to charge at 16A( 80% of 20A) you need a EVSE that is settable. Like the OpenEVSE or the GE durastation if it is dual voltage. Many EVSEs are L2 only.

For the full 27.5A it needs to be on a 40A circuit to satisfy the NEC. If you need to pull a circuit then pull a 240V circuit. instead.

Re: Simple question with complex answers on level 2 charging

Posted: Fri Apr 26, 2019 11:57 am
by GlennD
LeftieBiker wrote:
Almost ALL 208-230V home wiring that's 20+ years old is only three conductor(wire) configuration. Pure 208-230V loads don't utilize a neutral at all.

The vast majority of current 4 wire 208-230V wiring adds a neutral wire because a portion of the attached load has a 120V component thereby necessitating a separate neutral wire.


Maybe it's because 208 volt services are rare here, but I've only seen a couple of 2 conductor cables, for ranges. Well, that's why I'm not an electrician, I guess!


A ground vs the neutral certainly exists even on a 208V circuit.

Re: Simple question with complex answers on level 2 charging

Posted: Fri Apr 26, 2019 7:44 pm
by Oilpan4
The ground wire is only supposed to flow current during a fault.
That way your body doesn't flow the current to ground.

Find some electricians and tell them you want a full powered 50 amp RV receptacle put in your garage to get some quotes.
They are going to want to check out what they have to work with because there are about a dozen things that can make the job very cheap and easy or very expensive and difficult.

For example,
Is your breaker box full?
Is the breaker box in the garage or on the same wall as the garage or on the other end of the house?
Those are the 2 main ones that can effect a charging circuit install price by a few thousand dollars.

Re: Simple question with complex answers on level 2 charging

Posted: Fri Apr 26, 2019 10:07 pm
by LeftieBiker
A garage panel can also have only 120 volts available.

Re: Simple question with complex answers on level 2 charging

Posted: Fri Apr 26, 2019 10:20 pm
by alozzy
Belskinator is getting some great value from all this time spent by others on his behalf :roll:

Re: Simple question with complex answers on level 2 charging

Posted: Sat Apr 27, 2019 11:49 am
by GlennD
Oilpan4 wrote:The ground wire is only supposed to flow current during a fault.
That way your body doesn't flow the current to ground.

Find some electricians and tell them you want a full powered 50 amp RV receptacle put in your garage to get some quotes.
They are going to want to check out what they have to work with because there are about a dozen things that can make the job very cheap and easy or very expensive and difficult.

For example,
Is your breaker box full?
Is the breaker box in the garage or on the same wall as the garage or on the other end of the house?
Those are the 2 main ones that can effect a charging circuit install price by a few thousand dollars.



I am in Southern California and my breaker box is outside the garage wall The whole run is around six feet. Sometimes you luck out.

Re: Simple question with complex answers on level 2 charging

Posted: Sat Apr 27, 2019 12:54 pm
by Oilpan4
Yeah if you ever have a 240v circuit ran for car charging the electrician will want to know that.
The next biggest thing, are all the breaker box spots full?