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EVSE on 20A circuit

scanchain

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I am thinking of getting a 240V EVSE to charge my car. The unit is rated at max of 20A continuous current and requires a 25A circuit:

http://www.metroplugin.com/shop/clippercreek-lcs-25/

I believe theoretically and by code, I should be using 10/2 wiring with a 25A or 30A breaker.

The problem is that I am already currently wired with a 12/2 120V dedicated circuit to charge the car.

I am thinking of simply rewiring this to get 240V (the 240V EVSE does not require a neutral) by labeling the white wire with red tape and connecting it to another HOT leg. I know the car I have only draws 16A at 240V. No other car will use this EVSE. I will put a 20A breaker on this circuit.

Would there be safety concerns? I understand usually there are significant margins built into the numbers.

Thanks.
 
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pattenp

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You are okay by the numbers. A 20 amp breaker on #12 wire is okay and 16 amp continuous draw on a 20 amp circuit is okay. It will be safe. If you do exceed the circuit's current limit the breaker will trip and if tripping becomes a constant issue then you know you need to up size the circuit.
 

aandpdan

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Margins and numbers or not, you have to wire it in accordance with the manufacturers instructions.

Rewire the circuit using #10. It'll then be safe and to code.
 

pattenp

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Margins and numbers or not, you have to wire it in accordance with the manufacturers instructions.

Rewire the circuit using #10. It'll then be safe and to code.

It's best that he wires it in accordance with the manufactures specs, but he doesn't have to if he doesn't want to. :dunno: Now, if he was to stick a 30A breaker on the #12 then it would be unsafe.
 
OP
S

scanchain

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Thanks for the replies.

On hindsight, I should have bought new 10/2 wires instead of just using the leftover 12/2 wires from a previous project when I ran the line.

Now I am just trying to avoid having to climb into the attic again...
 

aandpdan

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It's best that he wires it in accordance with the manufactures specs, but he doesn't have to if he doesn't want to.

He does if he wants it to be up to Code.

NEC 110.3(B) Installation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.
 

pattenp

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He does if he wants it to be up to Code.

NEC 110.3(B) Installation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.

You're citing code to me? I'm very well aware of what code requires. I wasn't stating what was or not to code. All I said was a 20A breaker on #12 wire with a load of 16A was okay and safe.
 

aandpdan

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You're citing code to me? I'm very well aware of what code requires. I wasn't stating what was or not to code. All I said was a 20A breaker on #12 wire with a load of 16A was okay and safe.

I am, and I'm not trying to be a smart*ss.

It could be interpreted by you saying "it will be safe" and "he doesn't have to" that using #12 wire when the manufacturer requires a higher ampacity circuit is acceptable.

The OP should be be give advice that complies with applicable Codes or not be given any advice at all.
 

pattenp

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Excuse me scanchain, but using the charging device you posted on a 20 amp circuit does not meet NEC requirements. I'm sorry for misleading you and ask for your forgiveness.
 

wyliesdiesels

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Margins and numbers or not, you have to wire it in accordance with the manufacturers instructions.

Rewire the circuit using #10. It'll then be safe and to code.

But if the manufacturer also allows the device to be run on 240v then youre wrong! A 16a contious load is fine on a #12/20a circuit and thats what pattenp was trying to convey!
 

aandpdan

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But if the manufacturer also allows the device to be run on 240v then youre wrong! A 16a contious load is fine on a #12/20a circuit and thats what pattenp was trying to convey!

The specs on the charging station says 25 amp circuit. The only Code compliant way to install it is to wire it according to the manufacturers instructions.

It doesn't matter what his car will draw, the charger is rated for more and the wiring would be undersized.
 
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wyliesdiesels

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Ok, so I followed the link and read the specs on the unit. It turns out that the unit draws 20a continous @ 240V NOT 20a continous @ 120v NOR 16a continous @ 240V. The way the original post read implied that the unit drew 20-25a @ 120v or 16a continous @ 240V. At least the way i was understanding what the OP wrote. I think this may have confused pattenp as well. So, disregard my previous comments. The OP needs 10/2 NM and a 30a breaker!
 
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scanchain

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Ok, so I followed the link and read the specs on the unit. It turns out that the unit draws 20a continous @ 240V NOT 20a continous @ 120v NOR 16a continous @ 240V. The way the original post read implied that the unit drew 20-25a @ 120v or 16a continous @ 240V. At least the way i was understanding what the OP wrote. I think this may have confused pattenp as well. So, disregard my previous comments. The OP needs 10/2 NM and a 30a breaker!
Let me clarify.

This Clipper unit is capable up to 20A @240V BUT it does not mean that every EV will draw this.

As it is, the Prius Plug-In draws a max of 12A @240V and the Leaf (without the upgraded charger option) draws 16A @240V. The EV will never draw more than the capability of the internal charger (which converts AC to DC) built into the car.

As for Patrick's comment, I already have the Blink unit which delivers up to 30A @240V. I am considering the Clipper as a second unit. But, in any case, I have decided not to buy this Clipper unit with the hassle of running new wires.

Thanks for everyone's posts.
 

Speedy Petey

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Maybe crazy to you but I'm sold. But then again if every one was like you we would be riding horses and Mr ford would be broke
Great preconceived notion there. :rolleyes2
On the contrary, I love technology, innovation and new ideas. It's just bad ideas that I am not fond of.

IMO "all electric" vehicles are an incredibly bad idea and foolish.
I'm not too fond of hybrids either.

If I may ask, what "sold" you on them?
 

outdoorspace

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Great preconceived notion there. :rolleyes2
On the contrary, I love technology, innovation and new ideas. It's just bad ideas that I am not fond of.

IMO "all electric" vehicles are an incredibly bad idea and foolish.
I'm not too fond of hybrids either.

If I may ask, what "sold" you on them?

Speedy Petey, what preconceived notions do you have against EVs?
 

Charles (in GA)

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I work in an airline maintenance facility with a bunch of $mart guys. Turns out a whole lot of them did the math and went out and leased Nissan Leafs. (the parking lot is starting to look "green") With the discount the company had arranged thru participating dealers, and the Federal and state tax incentives, it works out to about $50 per month cost on these. One of the guys bought a Kill-A-Watt and kept track of the current used on his for a months worth of charging, and it works out to about three cents per mile for "fuel". My Pontiac Vibe, 31-32 mpg is running in the ten cent per mile range with todays gas prices.

For these guys, it was simple math and a business decision.

Their next move is to ask the company to be a good corporate citizen (and take advantage of Federal and State tax incentives to the company) and install charging stations, even if the guys have to pay to use them.

One Mitsubishi dealer here sold exactly two of the i-MiEV they make (one of the worst selling cars ever) and both sales were to employees. I noticed that the employees seem to take turns parking their car at the charging station in front of the showroom, so the customers can see them....... and get free charging........ they ain't no dummies....... The i-MiEV can handle real high rates of charge. At higher levels, it turns on the vehicles A/C and ducts it to the battery compartment to cool the batteries during the charge, pretty clever actually.

Charles
 
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Norcal

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And what would happen when you take away the tax incentives???? Let em sink or swim on their own.
 

outdoorspace

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And what would happen when you take away the tax incentives???? Let em sink or swim on their own.

While we're at it let's take away all of the oil subsidies...

The fact that Teslas can't legally be sold in Texas and now New Jersey -- I guess now we really are picking winners and losers.

I'm not a greenie; I'm just a gearhead that's been blown away by the speed + fun + economy of my Ford Focus Electric. Maybe y'all should give electric cars a chance. (Especially in a year or two after the Model E has been released) -- Battery tech is improving very rapidly and will soon overtake ICE vehicles in every regard. Range of 1000+ miles per charge won't be an issue in a few years.

Cheers,
<Anon-
 
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