Electrical Options for EVSE Install

[jlatl]

Mine is a question as much as it is a suggestion, but does it meet code to terminate the dryer circuit at a sub-panel and then run two 30a circuits off of the sub-panel to the dryer and garage? Leaving the 30a breaker in the main panel to feed the sub would protect the line and as long as he didn't try to run both at the same time he would never trip the breaker. Depending on how the dryer circuit is currently run it may wind up costing more than running the new line if you are not comfortable doing it yourself.

Also, have you checked the dryer circuit, what gauge wire was used to the dryer. If it is not either 8 or 6ga I would suggest just running the new line and forget any other options.

I was mostly just wondering for future reference.

EDIT: After further thought, any attempted work around is going to cost a close to $200 and still have to worry about the circuit. Like smkettner said, pay the $500/600 and get it done right and be done with it or just use the 120v EVSE and live with it until you can afford or justify the expense.

Just a comment on the gauge of the wire. According to code if you have a circuit that has a constant draw over a long term like a heater, stove, dryer, or EVSE you need to de-rate the current capacity of the wire to 80% of what is normal.
This means that while a 10ga. wire will typically run 30a, if you are using it in this category it is only really good for 24a. So for a 30A breaker you need to go to 8ga. or better (8ga. - typically 40A de-rated to 32A).

Also, if you are buying the wire yourself you will find it pretty expensive when going to your local Home Depot or hardware store. However, if you go to an electrical supply house you will probably find it cheaper. (Odd note - local supply house would not sell it cut to length in the gauge I needed, but by going one size larger they would cut it for me and it came out cheaper. Saved about $30.

 

[wwhitney]

Just a comment on the gauge of the wire. According to code if you have a circuit that has a constant draw over a long term like a heater, stove, dryer, or EVSE you need to de-rate the current capacity of the wire to 80% of what is normal.
This means that while a 10ga. wire will typically run 30a, if you are using it in this category it is only really good for 24a. So for a 30A breaker you need to go to 8ga. or better (8ga. - typically 40A de-rated to 32A).

In the situation you describe of using wire with a capacity of 40A for a continuous load of 30A, you need to use a 40A breaker. The breaker will heat up over time with the continuous load, so its thermal trip mechanism may trip below its rating with a continuous load. In practice, that is not too likely to happen, as breaker are calibrated based on an ambient temperature of 40C, which is on the high side.

Cheers, Wayne

 

[jlatl]

Just a comment on the gauge of the wire. According to code if you have a circuit that has a constant draw over a long term like a heater, stove, dryer, or EVSE you need to de-rate the current capacity of the wire to 80% of what is normal.
This means that while a 10ga. wire will typically run 30a, if you are using it in this category it is only really good for 24a. So for a 30A breaker you need to go to 8ga. or better (8ga. - typically 40A de-rated to 32A).

In the situation you describe of using wire with a capacity of 40A for a continuous load of 30A, you need to use a 40A breaker. The breaker will heat up over time with the continuous load, so its thermal trip mechanism may trip below its rating with a continuous load. In practice, that is not too likely to happen, as breaker are calibrated based on an ambient temperature of 40C, which is on the high side.

Cheers, Wayne

No, you can use any gauge wire with a breaker as long as the gauge will support the current rating of the breaker. So with a 30A breaker you could use 8ga, or 6ga, or 4ga, etc. as long as you can get the wire under the connecting lugs.

As for heating of the breaker putting a 40A breaker in (as long as you are using 6ga. or better) it would be less likely to heat. Of course, you do not want a breaker over what the EVSE is rated to handle. For example, the Clipper Creek LC-20 asks for a 25A breaker. However, they manufacture a version with a 50A plug which I am thinking means it can be powered by a circuit that has a 50A breaker without danger. My wiring has a 30A breaker.

Are there any registered electricians out there who can comment?

 

[planet4ever]

Just a comment on the gauge of the wire. According to code if you have a circuit that has a constant draw over a long term like a heater, stove, dryer, or EVSE you need to de-rate the current capacity of the wire to 80% of what is normal.
This means that while a 10ga. wire will typically run 30a, if you are using it in this category it is only really good for 24a. So for a 30A breaker you need to go to 8ga. or better (8ga. - typically 40A de-rated to 32A).

I'm no expert, but along with jlatl I doubt that. As wwhitney says, the breaker must also be de-rated to 80%, so matching the wire capacity to the breaker capacity automatically de-rates the wire capacity as well.

Ray

 

[RonDawg]

One thing that bothers me here - why nobody even blinks an eye if you put several outlets on one 110V 15A line, yet everybody say you need dedicated line for EVSE?

If the OP has one 30A 240V line and plugs both dryer and car to it it's up to him to remember not to run them at the same time, because when he does it will blow the fuse. Exactly the same as if he plugs two 15A space heaters to the same 15A line in his living room. WHy so much fuzz about it?

Mostly because that's what the eggheads who wrote the national electrical code decided. Over the years I've learned it's very well worth respecting what is written in there. It came out of a lot of research by a lot of very smart people.

I'd speculate that large 240 volt outlets are dedicated is because most appliances plugged in to those outlets are capable of drawing near the maximum allowed by the circuit, whereas small 115 volt appliances very rarely draw the full capacity of the circuit, and when they do, typically those oulets are called out to be dedicated as well, think washing machine, garbage disposal, 120 volt evse, etc.

In addition, I can't think of any home appliance that will draw that kind of wattage, for hours at a time continuously, like an EVSE will. Your A/C, fridge, electric stove, oven, heaters, and hair dryers will all cycle on/off as needed.

Plus I suspect the NEC is as just as much learning from previous mistakes as it is a bunch of smart people thinking about what is and isn't a good idea.

 

[wwhitney]

No, you can use any gauge wire with a breaker as long as the gauge will support the current rating of the breaker. So with a 30A breaker you could use 8ga, or 6ga, or 4ga, etc. as long as you can get the wire under the connecting lugs.

Yes, of course, I guess my previous comment wasn't clear. When dealing with continuous loads, just multiply the current draw by 125%, and size the wire AND breaker to that. If you put your 30 amp EVSE on #8 copper and a 30 amp breaker, you may get nuisance trips. You do not need to use #6 copper to put your 30 amp EVSE on a 40 amp breaker, #8 copper is fine.

As for the Clipper Creek with a 50A plug, it may only be rated for a 40A maximum circuit breaker. There are no 40A plugs, so 40A appliances use 50A cord caps.

Cheers, Wayne

 

[jlatl]

No, you can use any gauge wire with a breaker as long as the gauge will support the current rating of the breaker. So with a 30A breaker you could use 8ga, or 6ga, or 4ga, etc. as long as you can get the wire under the connecting lugs.

Yes, of course, I guess my previous comment wasn't clear. When dealing with continuous loads, just multiply the current draw by 125%, and size the wire AND breaker to that. If you put your 30 amp EVSE on #8 copper and a 30 amp breaker, you may get nuisance trips. You do not need to use #6 copper to put your 30 amp EVSE on a 40 amp breaker, #8 copper is fine.

As for the Clipper Creek with a 50A plug, it may only be rated for a 40A maximum circuit breaker. There are no 40A plugs, so 40A appliances use 50A cord caps.

Cheers, Wayne

We agree on the need to de-rate to 80% which equals multiply by 125%, and 8Ga. is fine, no need for bigger wire. But I believe you need to keep it at 30A for the breaker. If you go to 40A breaker I think you need to go to a wire that would support 125% of the breakers rating, or 50A.

 

[wwhitney]

We agree on the need to de-rate to 80% which equals multiply by 125%, and 8Ga. is fine, no need for bigger wire. But I believe you need to keep it at 30A for the breaker. If you go to 40A breaker I think you need to go to a wire that would support 125% of the breakers rating, or 50A.

From the 2011 NEC:

625.21 Overcurrent Protection. Overcurrent protection for feeders and branch circuits supplying electric vehicle supply equipment shall be sized for continuous duty and shall have a rating of not less than 125 percent of the maximum load of the electric vehicle supply equipment.

So, in fact, you are required to use a 40A breaker on a 30A EVSE. There is no language in the NEC that would require the wiring to support 125% of the breaker rating.

Cheers, Wayne

 

[jlatl]

We agree on the need to de-rate to 80% which equals multiply by 125%, and 8Ga. is fine, no need for bigger wire. But I believe you need to keep it at 30A for the breaker. If you go to 40A breaker I think you need to go to a wire that would support 125% of the breakers rating, or 50A.

From the 2011 NEC:

625.21 Overcurrent Protection. Overcurrent protection for feeders and branch circuits supplying electric vehicle supply equipment shall be sized for continuous duty and shall have a rating of not less than 125 percent of the maximum load of the electric vehicle supply equipment.

So, in fact, you are required to use a 40A breaker on a 30A EVSE. There is no language in the NEC that would require the wiring to support 125% of the breaker rating.

Cheers, Wayne

Wayne,
You are right. I had been reading your posts and interpreting them as he needed a 40A breaker because the wire could support 40A.

I went back to the original posts and see that he is looking at the Clipper Creek HCS-40 which has a 30A draw, rather than the LCS-20 that I have (20A draw). In that case he does need the 40A breaker.

Question - what does the NEC say about the wire? I would assume that if the equipment only draws 30A then the 8ga. is fine, but I have found you need to read the NEC standards very carefully, and even then it can be confusing.

 

[wwhitney]

Question - what does the NEC say about the wire?

240.4 Protection of Conductors. Conductors, other than flexible cords, flexible cables, and fixture wires, shall be protected against overcurrent in accordance with their ampacities specified in 310.15, unless otherwise permitted or required in 240.4(A) through (G).

Nothing in 240.4(A) through (G) applies to an EVSE install, so this general rule applies. Since the 30A EVSE requires a 40A breaker, the conductors have to be good for at least 40A. I.e. #8 copper or better.

Cheers, Wayne

 

[smkettner]

So, in fact, you are required to use a 40A breaker on a 30A EVSE. There is no language in the NEC that would require the wiring to support 125% of the breaker rating.

Cheers, Wayne

Yes and the larger breaker rating requires larger #8 wire.

 

[planet4ever]

I went back to the original posts and see that he is looking at the Clipper Creek HCS-40 which has a 30A draw, rather than the LCS-20 that I have (20A draw).

Actually, the LCS-20 has a 16A draw. It is the LCS-25 which has a 20A draw. Clipper Creek, unlike most if not all other EVSE manufacturers, assigns their model numbers based on the breaker size required, not the current they draw.

Ray

 

[jlatl]

I went back to the original posts and see that he is looking at the Clipper Creek HCS-40 which has a 30A draw, rather than the LCS-20 that I have (20A draw).

Actually, the LCS-20 has a 16A draw. It is the LCS-25 which has a 20A draw. Clipper Creek, unlike most if not all other EVSE manufacturers, assigns their model numbers based on the breaker size required, not the current they draw.

Ray

My error. I was thinking 20A draw in my head and typed LCS-20. I have the LCS-25 which is the 20A draw. Good catch

 

[Graycenphil]

Yes and the larger breaker rating requires larger #8 wire.

Can you run 8/2 romex? Is there any need for a neutral?

 

[smkettner]

8/2 romex on a 40a breaker and evse rated 32a or less? Yes.
240v evse needs 2 hot + gound only.

 

[Graycenphil]

Thank you.

 

[LeftieBiker]

I've had a Clipper Creek 20 LCS-25 amp charging station sitting in the box for a whole year now. I may get around to installing it soon, and I was thinking about making it semi-portable. I'd wire a RV/Range type 50 amp plug to the station. Then, since I'll be installing a shutoff switch where the cable enters the garage, I'd install a matching 50 amp outlet after the shutoff. A removable (from the inside only) wooden plate would allow me to get the plug through the wall after unplugging it, and a padlock (probably inside, to make it less obviously removable) would secure the mounting plate for the charging station. I'm not entirely sure I'll be hitting any RV parks to charge though, so the whole thing is hypothetical at this point. Is anyone else using a similar setup? Do all RV parks really use the same 50 amp 240 volt outlet configuration?

 

[jlatl]

I've had a Clipper Creek 20 LCS-25 amp charging station sitting in the box for a whole year now. I may get around to installing it soon, and I was thinking about making it semi-portable. I'd wire a RV/Range type 50 amp plug to the station. Then, since I'll be installing a shutoff switch where the cable enters the garage, I'd install a matching 50 amp outlet after the shutoff. A removable (from the inside only) wooden plate would allow me to get the plug through the wall after unplugging it, and a padlock (probably inside, to make it less obviously removable) would secure the mounting plate for the charging station. I'm not entirely sure I'll be hitting any RV parks to charge though, so the whole thing is hypothetical at this point. Is anyone else using a similar setup? Do all RV parks really use the same 50 amp 240 volt outlet configuration?

What I did was to mount my LCS-25 on a wooden plate just inside the garage door and run the charging cable through a cutout/slot at the bottom of the door. This gives me plenty of cable to reach the car. Since the LCS-25 mounts by slipping over 4 screws so it is easy to just lift it and take it off the wall.

A quick internet search says the most common RV outlet is a NEMA 14-50.

You might want to consider a single box that contains the outlet, breaker, and room for a 120V outlet. ( http://www.homedepot.com/p/GE-70-Amp-Power-Outlet-Box-with-Duplex-20-Amp-GFCI-Outlet-and-Single-30-Amp-Outlet-U041GP/100137294" onclick="window.open(this.href);return false; )

 

[Phatcat73]

Fortunately for my AZ Leaf, our dryer location had both an unused 220V 30 amp outlet as we had a gas dryer. The outlet was about 4 feet away on the opposite side of the wall from the garage, making the self-install a snap. After drilling a 1" hole, I hardwired the Bosch with dryer cord. There are available options for using a 30amp circuit.

1) EVSE upgrade - 5kW/hr max output
2) Siemens Versicharge (7.2kW/hr, 40 amp, but can be set to 25, 50, 75% load); 75% would do the trick
3) 3.8kW EVSE

We chose #3 as the Leaf had the slower onboard charger and found a good deal on the Bosch unit.

If folks have an electric dryer with an available gas hookup, I suggest performing a value analysis. Perhaps it's time for a new dryer rather than a new circuit.

 

[LeftieBiker]

No existing 240 outlet in the garage. It will be a 30 amp circuit with #10 wiring. I need the full reach of the charging cable outside, so I have to mount it outside. 14-50 is the connection I was going to use.