Electrical Options for EVSE Install

[davewill]

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.

That won't pass inspection. You would have to use a 14-30 for a 30a circuit. You can remove the neutral pin from your 14-50 plug (which the EVSE doesn't use) and be able to plug it into a 14-30, a 14-50, or a 14-60. That way you can still easily take the EVSE with you.

 

[jlatl]

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.

You need to reconsider using 10 gauge wiring. While 10 gauge is rated for 30 amp under typical use, when you have a high amperage constant load (e.g. - heater, EVSE) electrical code requires that you de-rate current capacity. That means the 30 amp rated 10 gauge is only good for 24 amps.

For a 30 amp circuit you need to use 8 gauge. (40 amp de-rated to 32 amp)

 

[wwhitney]

That won't pass inspection. You would have to use a 14-30 for a 30a circuit.

Actually, for a branch circuit with only one receptacle on it, the NEC only requires that the receptacle be at least as big as the circuit rating. So you can put a 50 amp receptacle on a 30 amp circuit. May not be wise or useful, but it is allowed.

Cheers, Wayne

 

[rexki]

Since the EVSE is going to be beyond human reach, you should put a disconnect on the circuit. Just like an AC unit. #6 wire is totally over the top and thus #8 wire is the bullseye!! The disconnect from Hope Depot is not that expensive, red handle throw - GE - $38

Mine is 45 feet long from the 40 amp dual circuit breaker on 100 amp service. 6.6 KW AV-EVSE from the free program of Nissan. I had #10 already pulled for my parent RV connection and used these wires to pull through the #8 - very difficult to to do in thin wall - 1/2" - Chicago Code. The wire chafes and looses its plastic covering in a heart beat when its pulled!!

I also recommend water tight connections if you have exterior installation subject to rain intrusion. Rain will always win!!! Allot of people starting drilling mega holes and many and then try a Romex and start the calk gun up - pure cheap and stupid rationale - Commercial installations will not attempt with a ten foot pole. Please sleep well!! Remember Rain and ice always wins!!

 

[LeftieBiker]

I see people are skimming, as usual. There will be an A/C type disconnect right before the 240 volt outlet. I had originally planned on using a 30 amp plug and receptacle, but that means using a plug adapter at campgrounds for no good reason at all. Can't I just clearly label the outlet and shutoff as 30 amp? (And 30 amps is fine, since the LCS-25 is a 20 amp EVSE.) If it's safer to use the 30 amp plug/socket and a 30 to 50 amp plug adapter, that's what I'll do, but if it's just about a code inspection that won't happen here, I'm not so sure.

 

[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.

That won't pass inspection. You would have to use a 14-30 for a 30a circuit. You can remove the neutral pin from your 14-50 plug (which the EVSE doesn't use) and be able to plug it into a 14-30, a 14-50, or a 14-60. That way you can still easily take the EVSE with you.

So you're saying I should use the 30 amp outlet in the garage, but remove the unused neutral pin from the 14-50 plug when I install it on the EVSE? That I can do - if the pin comes out easily and with no plug damage.

 

[wwhitney]

Since the EVSE is going to be beyond human reach, you should put a disconnect on the circuit. Just like an AC unit.

While that may be a good idea, the NEC only requires a readily accessible disconnect for EVSEs over 60 amps or over 150V to ground.

Cheers, Wayne

 

[LeftieBiker]

The disconnect will be there mainly because I have to use two fuses to get 240 volts in the garage box, and want to shut off both at once. It's in excellent shape, it's just a late install for a fusebox. Yes, I know it would be better to put in a new box, new supply wiring, etc. My health and wallet won't permit that, so I'm going with 'safe but obsolete.'

 

[LeftieBiker]

I'm going with Davewill's excellent suggestion, and will be using a universal 30/50 amp plug with the Neutral pin left off (and the hole sealed) and a 14-30 outlet by the shutoff. Thanks, all.

 

[CharlesinGA]

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.

I realize the post I am quoting is rather old, but after reading thru the entire thread, I see that no one ever addressed this issue.

The National Electric Code (NEC) DOES NOT restrict circuits over 20 amp to a single device or outlet......... HOWEVER, the International Residential Code (IRC, which is the basic building codes for residential construction in most of the US) DOES restrict circuits over 20 amp to a single receptacle, outlet or device. This is why the electrician will not tap into the dryer circuit.

Also. be very wary of punching a hole thru a garage wall to the residence interior to connect to an existing dryer or other circuit, as the garage walls are most likely fire rated and penetrations of them have to be properly sealed with fire sealer and cannot pass fully thru to the inside, nor pass into a stud bay that has a receptacle facing "the other direction" into the residence.

Charles

 

[wwhitney]

HOWEVER, the International Residential Code (IRC, which is the basic building codes for residential construction in most of the US) DOES restrict circuits over 20 amp to a single receptacle, outlet or device. This is why the electrician will not tap into the dryer circuit.

Interesting. What section number is that?

Cheers, Wayne

 

[CharlesinGA]

HOWEVER, the International Residential Code (IRC, which is the basic building codes for residential construction in most of the US) DOES restrict circuits over 20 amp to a single receptacle, outlet or device. This is why the electrician will not tap into the dryer circuit.

Interesting. What section number is that?

Cheers, Wayne

From the 2012 version of the IRC

E3702.5 Branch circuits serving multiple loads or outlets.
General-purpose branch circuits shall supply lighting outlets, appliances, equipment or receptacle outlets, and combinations of such. Multi-outlet branch circuits serving lighting or receptacles shall be limited to a maximum branch-circuit rating of 20 amperes.

But then again, in this section it appears to allow multiple receptacles on larger circuits.......... (this section mimics a table in the NEC)

E3902.1.2 Two or more receptacles.

Where connected to a branch circuit supplying two or more receptacles or outlets, receptacles shall conform to the values listed in Table E3902.1.2.

TABLE E3902.1.2 RECEPTACLE RATINGS FOR VARIOUS SIZE MULTIOUTLET CIRCUITS

CIRCUIT RATING (amperes) RECEPTACLE RATING (amperes)
15....................................15
20....................................15 or 20
30....................................30
40....................................40 or 50
50....................................50

Charles