EVSE wiring and/or GFI Breaker

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koolkev

Active member
Joined
Jan 21, 2016
Messages
25
Any comments on installing a GFI breaker for the EVSE circuit? I know the EVSE should have gfi built in but would like a plug in unit so, something to protect the outlet if the unit isn't plugged in.
The panel is an Eaton BR load center.
I think I want a GFI if I can get a breaker for a reasonable price. I would like a 40 or 50 amp circuit. Has anyone installed an Eaton GFI
 
koolkev said:
Any comments on installing a GFI breaker for the EVSE circuit? I know the EVSE should have gfi built in but would like a plug in unit so, something to protect the outlet if the unit isn't plugged in.
The panel is an Eaton BR load center.
I think I want a GFI if I can get a breaker for a reasonable price. I would like a 40 or 50 amp circuit. Has anyone installed an Eaton GFI

Check if your city/town needs it per code. The cost difference is usually $10 v/s. $100.
 
I am thinking of installing a 240v 50A circuit. A calculator shows this requires #6. So 6-3?
The panel is at the side of the house next to a driveway that is shared so the power either has to go to the front or back of the house. It would be easy to get through the crawl space but is the crawl space a damp area? It does get wet on the ground side but does wire running below the floor joists above the ground have to be rated for damp spaces? Does it have to be run in conduit/flex?
 
I would be happy to go $100 even if it isn't required. I picked one out and was quoted $300 but the counter man inferred that I choose a rare over specked part.
 
Keep in mind, that this is for a DEDICATED EVSE circuit, which NEC considers a continuous load.
Your load is a 40A continuous load, which requires a 50A branch circuit, appliance, and receptacle rating.

8 AWG wire is good for 40 amps for 60 degC systems, 50 amps for 75 degC systems, and 55 amps for 90 degC systems. To qualify for the 90 degC rating, *every* point in the system must be 90 degC rated -- and that can be tough. Typically, for ampacity purposes, you look at 60 degC for Romex (NM-B) and 75 degC for wire-in-conduit.

If you're using Romex (type NM cable), it's only good for 45 amps because by code it must be de-rated to the 60 degC rating (NEC 334). AWG 8 is good for 50 amps only if all connection points, breakers, conductors, termination boxes, etc., are all rated for 75 degC or higher. If you're running through an attic that has a high ambient temperature in the summer, you have to de-rate / correct for that per NEC tables 310.15(B)(2).

This is why many electricians will just forego #8 for 50A and install #6, which gives plenty of headroom for all de-rating needs.

So, Yes, go #6
You want 6-2 with a ground.
It has to be dedicated to meet code, and for gods sake, do not put an outlet in the system.
Hard wired!
NO GFI. (saw your other post)
 
Merged the two threads, please keep it here and don't make more threads about your EVSE, wiring, breakers, outlets, etcetera. Just put it all in one thread.
 
6/2 is all you need, but if it doesn't cost that much more I might get 6/3 and install a 14-50 (RV outlet, and also the default outlet Tesla uses). Who knows, some day you or a future owner might want to use the outlet to plug in an RV or some appliance that needs the neutral; if you forego the neutral and use 6/2 then EV charging is pretty much all the circuit's good for.

I'm pretty sure romex in a crawl space is fine, but you'd have to consult the code to be sure. Individual wires in conduit is probably preferred, however. You don't really need a GFI breaker, but if the price isn't exorbitant and you want that extra protection then go for it.
 
If the EVSE is not going to be moved every now and then, a hardwired EVSE is DEFINITELY safer than a cord-and-plug wired EVSE (but if necessary consider using a receptacle with a locking cover).

If you use a GFCI circuit breaker for a cord-and-plug EVSE, I think you can be assured of 5 ma protection for the entire circuit from the breaker box to the J1772 plug -- even if the internal EVSE GFI has only 20 ma protection (which most EVSE brands have now). The problem is that you may have significant trouble with nuisance GF tripping at the breaker! I can't say one way or the other from personal experience, but I noticed that the Siemens VersiCharge originally recommended a GFCI breaker in its manual for cord-and-plug installation -- but it no longer does. I'm guessing that they found some installations were nuisance tripping -- but I don't know for sure.
 
If you have an extra $100 I'd recommend donating it to Plug In America instead of buying a GFI breaker for your EVSE.
 
MikeD said:
The problem is that you may have significant trouble with nuisance GF tripping at the breaker! I can't say one way or the other from personal experience, but I noticed that the Siemens VersiCharge originally recommended a GFCI breaker in its manual for cord-and-plug installation -- but it no longer does. I'm guessing that they found some installations were nuisance tripping -- but I don't know for sure.

+1
 
GFCI nuisance tripping can be a problem. I have a 2nd refrigerator in the garage that's plugged into a GFCI. Here garage outlets by code require they be GFCI. I ended up putting a line voltage monitor on that circuit connected to our home burglar alarm system, so I get notification if the GFCI trips.

I hard wired our EVSE.

If I had installed a 40/50a 240 volt receptacle in the garage I would seriously consider a disconnect nearby for it if the breaker panel was not within reach. I'd leave that receptacle dead when not in use.
 
Can someone explain/point to an explanation of what a "damp location" is? If a crawl space under the house with exposed earth as the floor can be considered a damp location I will use 6-3 UF-B $3.99 a foot. If it can be considered inside I will use 6-3 $2.79 foot. And/or take suggestions

Thanks
 
koolkev said:
Can someone explain/point to an explanation of what a "damp location" is?
Here's the 2012 NEC definition:

Location, Damp. Locations protected from weather and not subject to saturation with water or other liquids but subject to moderate degrees of moisture. Examples of such locations include partially protected locations under canopies, marquees, roofed open porches, and like locations, and interior locations subject to moderate degrees of moisture, such as some basements, some barns, and some coldstorage warehouses.

koolkev said:
If a crawl space under the house with exposed earth as the floor can be considered a damp location
It certainly can be a damp location, but it really shouldn't be. I.e. if your crawl space sees enough water to be considered damp, that is definitely worth fixing. Most crawl spaces aren't damp.

Cheers, Wayne
 
Thanks Wayne, Flyct,
Working on fixing the crawl space moisture but will consider it damp. I'm in California so it's not damp very often but....
 
koolkev said:
Working on fixing the crawl space moisture but will consider it damp.
Using UF is certainly a conservative choice. I thought you might find the definition of dry location from the 2012 NEC enlightening:

Location, Dry. A location not normally subject to dampness or wetness. A location classified as dry may be temporarily subject to dampness or wetness, as in the case of a building under construction.

Most crawl spaces are dry locations.

Cheers, Wayne
 
koolkev said:
Thanks Wayne, Flyct,
Working on fixing the crawl space moisture but will consider it damp. I'm in California so it's not damp very often but....

Really dont do that unless you plan on running the wire in contact with the dirt. It's just throwing money away that you could donate to a good cause. If your crawl space is wet enough that the wiring is wet I would not worry about the wiring as wood it's attached to is going to rot first so you could just plan on rewiring when you rebuild your house.

But seriously if moisture is condesating on things in your crawl space that is a serious problem. If that isn't happening then no need worry about the wiring being wet so then just use normal nm-b.
 
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