Using a 30A charger rated for a 40A breaker on a 30A breaker

[caffeinekid]

Is this feasible? I really like the Schneider EVlink, but want to wire it so that I can plug it into an existing 10-30R dryer outlet on a circuit with a 30A breaker. The specs say 40A breaker. Would this be a situation where the unit tells the on-board charger that it is OK to draw the full 30A load and pops the breaker? It doesn't appear that Home Depot carries a charger that runs on a 30A circuit for 20A+ charging. I already have a Turbocord for our 2011 Leaf, but would like to take better advantage of the faster charger on my 2014 Leaf.

http://www.homedepot.com/p/Schneide...ic-Vehicle-Charging-Station-EV230WS/203670265

PS: I want to buy from Home Depot because I have a lot of $$$ in gift cards that I have collected over the last couple of years, otherwise I would just go with a Clipper Creek charger.

 

[greengate]

Is this feasible? I really like the Schneider EVlink, but want to wire it so that I can plug it into an existing 10-30R dryer outlet on a circuit with a 30A breaker. The specs say 40A breaker. Would this be a situation where the unit tells the on-board charger that it is OK to draw the full 30A load and pops the breaker? It doesn't appear that Home Depot carries a charger that runs on a 30A circuit for 20A+ charging. I already have a Turbocord for our 2011 Leaf, but would like to take better advantage of the faster charger on my 2014 Leaf.

http://www.homedepot.com/p/Schneide...ic-Vehicle-Charging-Station-EV230WS/203670265

PS: I want to buy from Home Depot because I have a lot of $$$ in gift cards that I have collected over the last couple of years, otherwise I would just go with a Clipper Creek charger.

Only if the fire department is 24/7 and next door.

 

[smkettner]

I have to recommend against it. Certainly will not meet NEC.
Far better to use the Clipper Creek or pull some #6 wire from HD.

 

[caffeinekid]

Thanks.

 

[kubel]

If the wire is 10GA and the breaker is 30A and you are using it with a LEAF, I wouldn't see a problem. AFAIK, LEAF will not trip a 30A breaker, it doesn't have the guts to pull more than 16A (2011-2012, S base) or 25A (2013+ non-S base), correct?

 

[caffeinekid]

If the wire is 10GA and the breaker is 30A and you are using it with a LEAF, I wouldn't see a problem. AFAIK, LEAF will not trip a 30A breaker, it doesn't have the guts to pull more than 16A (2011-2012, S base) or 25A (2013+ non-S base), correct?

That is what I was thinking. The charger on my 2014 is 6.6KW, and 6.6KW/240V=27.5A max. The only concern that I had was with potential initial surge tripping the breaker. The #7 wire is rated at 30A, the breaker is rated at 30A and the car only pulls 27.5A max. I know nothing about the control circuitry within the charger station itself...whether it made any real difference between 30A and 40A breaker. I figured I would ask considering the GE Watt Station uses the "recommended" 40A breaker terminology on their 30A indoor charger.

 

[jdunmyer]

FWIW: I'm feeding my Schneider EVSE and 2013 Leaf from 30 amp fuses and haven't blown one yet. It's been several weeks now. Although the fuses feed a #6 SO cord to the new garage, I used some #10 wire in the garage itself for a couple of weeks, until I had a warm enough day to install and hardwire the Schneider unit and an old Sangamo KWHR meter. The wire didnt' get hot that I could tell. If you have #7 wire and a 30 amp breaker, you should be OK, but I'd check the connections for tightness, both at the receptacle and the breaker. The only downside I see is that the breaker may fail after a few years of operating near its rating.

The Leaf draws nearly 28 amps, according to my meter, just what you'd expect. Does anyone know what an electric dryer actually draws? A quick search says 22-24 amps.

I'd monitor the temperature of things closely during the first few charge cycles, checking after an hour or so, but before the current begins to taper off.

 

[MikeD]

Keep in mind that the main purpose of the NEC rules regarding a circuit's wire gauge and the circuit breaker for that circuit is to protect that circuit's wiring insulation. If you push the limits of a circuit's allowable current, then my understanding is there is a definite risk that insulation breakdown (such as hardening/cracking) due to higher than expected temperature can occur over a period of time much shorter (sorry I can't be more definite) than one would want.

 

[DaveinOlyWA]

If the wire is 10GA and the breaker is 30A and you are using it with a LEAF, I wouldn't see a problem. AFAIK, LEAF will not trip a 30A breaker, it doesn't have the guts to pull more than 16A (2011-2012, S base) or 25A (2013+ non-S base), correct?

That is what I was thinking. The charger on my 2014 is 6.6KW, and 6.6KW/240V=27.5A max. The only concern that I had was with potential initial surge tripping the breaker. The #7 wire is rated at 30A, the breaker is rated at 30A and the car only pulls 27.5A max. I know nothing about the control circuitry within the charger station itself...whether it made any real difference between 30A and 40A breaker. I figured I would ask considering the GE Watt Station uses the "recommended" 40A breaker terminology on their 30A indoor charger.

unless you can turn it down, you simply need to follow code. insurance companies SPECIFICALLY check these kinds of details. it would really suck if a kitchen fire burned your house down and they denied claims due to wiring not in spec. just because the out of spec circuit did not cause the fire will mean nothing to them... they take anything they can find to use against you

 

[greengate]

If the wire is 10GA and the breaker is 30A and you are using it with a LEAF, I wouldn't see a problem. AFAIK, LEAF will not trip a 30A breaker, it doesn't have the guts to pull more than 16A (2011-2012, S base) or 25A (2013+ non-S base), correct?

That is what I was thinking. The charger on my 2014 is 6.6KW, and 6.6KW/240V=27.5A max. The only concern that I had was with potential initial surge tripping the breaker. The #7 wire is rated at 30A, the breaker is rated at 30A and the car only pulls 27.5A max. I know nothing about the control circuitry within the charger station itself...whether it made any real difference between 30A and 40A breaker. I figured I would ask considering the GE Watt Station uses the "recommended" 40A breaker terminology on their 30A indoor charger.

 

[TonyWilliams]

Continuous loads are 80 % of circuit.

0.80 * 40 = 32 amp continuous max

 

[smkettner]

30a circuit = 24a max continuous load.

Too bad Nissan could not have engineered an optional 24 amp charge setting.
Are there any 24 amp EVSEs? s/b more common IMO but the engineers do not consider the very common 30 amp supply.

 

[GlennD]

The OpenEVSE can be edited to set any current. The default table has 5A steps so you can set 25A. I usually edit the table for 2A steps from 10A to 40A so 24A is settable.

30a circuit = 24a max continuous load.

Too bad Nissan could not have engineered an optional 24 amp charge setting.
Are there any 24 amp EVSEs? s/b more common IMO but the engineers do not consider the very common 30 amp supply.

 

[cwerdna]

To echo the comments here, I wouldn't recommend it. Either get an EVSE that's within the limits of the breaker and wiring or retrofit the breaker and wiring upstream to comply w/NEC for a 30 amp continuous load.

Only if the fire department is 24/7 and next door.

Even that's not necessarily good enough.

The restaurant at http://www.nbcbayarea.com/news/local/Flames-Restaurant-in-San-Jose-Damaged-by-4-Alarm-Fire-241010131.html" onclick="window.open(this.href);return false; was destroyed even though it was virtually next door to the fire department. I went there to take a look, after the fire had been put out.

https://www.google.com/maps?saddr=Flames+Coffee+Shop+of+San+Jose,+1812+Hillsdale+Ave,+San+Jose,+CA+95124&daddr=San+Jose+Fire+Department+Station+9,+3410+Ross+Ave,+San+Jose,+CA+95124&t=m&geocode=FfSWOAIdH7C7-CmNy3FdbzSOgDHK9wgC198esQ%3BFRSYOAIdqrO7-ClL1UJ6bzSOgDFEqPOi7ft9Hg&dirflg=w&z=18" onclick="window.open(this.href);return false; shows you how close they were.

 

[caffeinekid]

:lol: Ha. Quite the contrary actually. This is why I was soliciting advice on the matter. I suspected something along the lines of what Tony Williams posted and MikeD elaborated on. Thanks for the replies. I will go with another option.

 

[kubel]

insurance companies SPECIFICALLY check these kinds of details

I'm a residential insurance inspector, and this is not something underwriters tend to look for, unfortunately. There are just too many houses to insure to do in depth inspections like that. One insurance inspector will usually hit over 30 houses per day in the summer. We're only looking for obvious liability concerns. Unless you're talking about after a claim... if you have an inspector sniffing around then you might be in trouble.

 

[GaslessInSeattle]

you really don't want to push this. I recommend going even beyond code not shorting code when it comes to EV charging, wire and hardware are cheap compared to labor and ultimately your life/home/vehicles. when an electrician feels that it is OK to "overload" a circuit it's when it's unlikely that the total continuous draw at any given time is likely to peak for prolonged periods. EV's are a whole different kettle of fish since they push the limits more by requiring many hours of continuous high AMP draw, leading to more heat from resistance... limiting a 40A circuit to 30A of draw is done to give cushion. The bigger the battery and the higher the amperage of the station, the more you should add padding into the numbers, IMHO. For my charging stations, I go one gauge down (larger wire) from the code requirements, it's peace of mind for me... so far, no issues, fingers crossed. I also have a smoke detector and fire extinguisher in my garage and I believe that to be common sense, not paranoia. the older I get, the more I see happen that shouldn't, the lower I set my risk tolerance.

 

[johnrhansen]

The codes are written with a safety margin for good reason. In a perfect world, you would get away just fine doing what you propose. But the world is not perfect. It only takes one number to screw up the whole equation. Parts age over time, wires get installed in a less than ideal manner, old low temperature tolerant wire is used in older homes, combustible material or dust gets near the wires. When weight is a factor like on aircraft, wiring is loaded to even higher currents, but rigid quality control measures are in place, more expensive higher quality, more consistently manufactured parts are used, etc to make this installation safe. All those measures are expensive, so they relax things a bit in homes. To keep it safe, they derate everything with a healthy safety margin. You won't live long if you operate outside that margin too many times. I have a full sized evse I take on trips. I never plug it into a dryer plug, only 50 amp plugs. If all I have is a dryer plug, I use the 20 amp evse upgrade unit.