smkettner
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Location: Orange County, CA

Re: Best EVSE/charging solution for my situation?

Fri Dec 22, 2017 10:06 pm

I would go #6 minimum if pulling wire. #8 puts you just over 3% voltage drop at 30 amps.
1 bar lost at 21,451 miles, 16 months.
2 bar lost at 35,339 miles, 25 months.
LEAF traded at 45,400 miles for a RAV4-EV

LeftieBiker
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Re: Best EVSE/charging solution for my situation?

Fri Dec 22, 2017 11:31 pm

The cable is indoor rated, but as long as it stays inside the house and is in conduit where it's exposed below shoulder level or so, it should be fine. I'm no expert, though.
2013 "Brilliant Silver" SV with Premium and no QC, a 2009 Vectrix VX-1 W/18 Leaf modules, and 3 EZIP E-bicycles.
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

jake14mw
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Location: Connecticut, USA

Re: Best EVSE/charging solution for my situation?

Sat Dec 23, 2017 8:37 am

LeftieBiker wrote:The breaker should be sized for the EVSE, not just the cable. You can always swap in a 50 amp breaker if/when you get a 40 amp EVSE. Assuming a 30 amp EVSE you want a 40 amp breaker now. The link to the cable wouldn't load.


Can you help me understand this? Don't the rest of the breakers in my house work the same way? I have 20 and 15 amp breakers, but rarely is there anything on the circuit pulling that amperage, right? As you said, it should be easy to swap out later, so I will do a 40 amp now if that makes more sense.

wwhitney
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Location: Berkeley, CA

Re: Best EVSE/charging solution for my situation?

Sat Dec 23, 2017 10:27 am

jake14mw wrote:Can you help me understand this?

This is a little bit of a grey area. The breaker's #1 job is to protect the fixed installation, i.e. the building wire and the receptacle. With 6/2 NM (btw, not allowed outdoors) and a 6-50 receptacle, a 50A breaker does that fine.

Some equipment manufacturers will also ask for a particular breaker size to protect their equipment. In the case of the EVSE you posted, its manual calls for a 40A breaker. Whether the NEC requires that instruction to be followed is open to interpretation (110.3(B)).

Cheers, Wayne

LeftieBiker
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Location: Upstate New York, US

Re: Best EVSE/charging solution for my situation?

Sat Dec 23, 2017 10:44 am

This is a little bit of a grey area. The breaker's #1 job is to protect the fixed installation, i.e. the building wire and the receptacle. With 6/2 NM (btw, not allowed outdoors) and a 6-50 receptacle, a 50A breaker does that fine.


Wayne, wouldn't a 40A breaker provide more protection for the cable and outlet, rather than less?
2013 "Brilliant Silver" SV with Premium and no QC, a 2009 Vectrix VX-1 W/18 Leaf modules, and 3 EZIP E-bicycles.
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

wwhitney
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Delivery Date: 01 Apr 2011
Location: Berkeley, CA

Re: Best EVSE/charging solution for my situation?

Sat Dec 23, 2017 10:50 am

LeftieBiker wrote:Wayne, wouldn't a 40A breaker provide more protection for the cable and outlet, rather than less?

Yes, of course. My point was that with 6/2 NM and a 6-50 receptacle, a 50A breaker is sufficient protection for the cable and receptacle. So the only question is whether the EVSE itself requires protection by a 40A breaker, rather than a 50A breaker.

Cheers, Wayne

smkettner
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Location: Orange County, CA

Re: Best EVSE/charging solution for my situation?

Sat Dec 23, 2017 10:51 am

40 or 50 is about the same with #6 wire and a 6-50 connector.

Dead short will instantly trip either. Bad connection could overheat with either one. Exceedingly low probability of having a 48 amp fault that would only trip the 40 amp breaker. I would go 50 amp on the breaker.
1 bar lost at 21,451 miles, 16 months.
2 bar lost at 35,339 miles, 25 months.
LEAF traded at 45,400 miles for a RAV4-EV

jake14mw
Posts: 88
Joined: Sun Nov 12, 2017 9:53 pm
Delivery Date: 13 Nov 2017
Location: Connecticut, USA

Re: Best EVSE/charging solution for my situation?

Sat Dec 23, 2017 1:42 pm

wwhitney wrote:
jake14mw wrote:Can you help me understand this?

This is a little bit of a grey area. The breaker's #1 job is to protect the fixed installation, i.e. the building wire and the receptacle. With 6/2 NM (btw, not allowed outdoors) and a 6-50 receptacle, a 50A breaker does that fine.

Some equipment manufacturers will also ask for a particular breaker size to protect their equipment. In the case of the EVSE you posted, its manual calls for a 40A breaker. Whether the NEC requires that instruction to be followed is open to interpretation (110.3(B)).

Cheers, Wayne


OK, you guys are confusing me now! :) Thanks for looking that up for me. I'm thinking that if the manufacturer calls for a 40A breaker, that's what I should do?

jjeff
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Leaf Number: 422121
Location: MSP MN

Re: Best EVSE/charging solution for my situation?

Sat Dec 23, 2017 1:49 pm

jake14mw wrote:
wwhitney wrote:
jake14mw wrote:Can you help me understand this?

This is a little bit of a grey area. The breaker's #1 job is to protect the fixed installation, i.e. the building wire and the receptacle. With 6/2 NM (btw, not allowed outdoors) and a 6-50 receptacle, a 50A breaker does that fine.

Some equipment manufacturers will also ask for a particular breaker size to protect their equipment. In the case of the EVSE you posted, its manual calls for a 40A breaker. Whether the NEC requires that instruction to be followed is open to interpretation (110.3(B)).

Cheers, Wayne


OK, you guys are confusing me now! :) Thanks for looking that up for me. I'm thinking that if the manufacturer calls for a 40A breaker, that's what I should do?

It sure wouldn't hurt :)
More than likely you'd probably never need 50 amps anyway but I'd also agree with running 6 gauge wire, so you'd never probably have to replace it. 6 gauge may also be a bit more efficient in that running 40a it should never get warm(loss in efficiency) of course breakers also get warm when running near their max rating but as the Leaf only draws 27.5a and the EVSE only outputs a maximum of 30a, even a 40a breaker will probably never get warm.
Breakers are somewhat cheap and easy to replace, a 40a breaker will help protect your 30a EVSE a bit more than a 50a breaker, no real advantage to going with lighter gauge wire, well other than cost :)
2012 SL purchased used 2/'16
2013 S w/QC purchased new
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'12 EVSEupgrade'd 20a L1/L2 EVSE, '13 EVSEupgrade'd adjustable 6-20a L2, 6-13a L1 EVSE
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Nubo
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Location: Vallejo, CA

Re: Best EVSE/charging solution for my situation?

Sat Dec 23, 2017 5:29 pm

jake14mw wrote:
LeftieBiker wrote:The breaker should be sized for the EVSE, not just the cable. You can always swap in a 50 amp breaker if/when you get a 40 amp EVSE. Assuming a 30 amp EVSE you want a 40 amp breaker now. The link to the cable wouldn't load.


Can you help me understand this? Don't the rest of the breakers in my house work the same way? I have 20 and 15 amp breakers, but rarely is there anything on the circuit pulling that amperage, right? As you said, it should be easy to swap out later, so I will do a 40 amp now if that makes more sense.


A 120v circuit has multiple oulets and devices. The current demand is unpredictable and so the breaker is sized to the ampacity of the wiring. 240v circuits are dedicated to a single device, which affords the opportunity to size the breaker to the specific device.
I noticed you're still working with polymers.

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