LeftieBiker
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Re: Using the Leaf for power in a Blackout: MY "Leaf to Home"

Sat Jun 29, 2019 7:18 pm

I use an interlock instead of a transfer setup. It's cheap and simple. There is a sliding steel plate on my main panel that alternately covers either the main breaker, locking it in the OFF position, or the generator feed breaker, locking it in the OFF position. The result is that it's physically impossible to feed the grid with your generator, because it can't feed anything if the main breaker is on. I'll have to look to see if they are still sold...

... I don't see mine, but I do see several others:

https://www.google.com/search?client=fi ... +interlock
Scarlet Ember 2018 Leaf SL W/ Pro Pilot
2009 Vectrix VX-1 W/18 Leaf modules, & 3 EZIP E-bicycles.
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goldbrick
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Re: Using the Leaf for power in a Blackout: MY "Leaf to Home"

Mon Jul 01, 2019 9:23 am

^ah, that makes perfect sense now. Thanks for both the question and the answer. And welcome back Leftie.

LeftieBiker
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Re: Using the Leaf for power in a Blackout: MY "Leaf to Home"

Mon Jul 01, 2019 12:22 pm

Thanks. I will add one more thing for those wondering why an interlock is needed: if you back-feed the local grid while the power is out, you can kill a line repair person working nearby to restore power. That's reason enough to spend a bit on a simple interlock.
Scarlet Ember 2018 Leaf SL W/ Pro Pilot
2009 Vectrix VX-1 W/18 Leaf modules, & 3 EZIP E-bicycles.
BAFX OBDII Dongle
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

RustyShackleford
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Re: Using the Leaf for power in a Blackout: MY "Leaf to Home"

Mon Jul 01, 2019 12:39 pm

LeftieBiker wrote:Thanks. I will add one more thing for those wondering why an interlock is needed: if you back-feed the local grid while the power is out, you can kill a line repair person working nearby to restore power. That's reason enough to spend a bit on a simple interlock.
Yeah, I kinda thought that was THE reason for it. I was just curious if shutting off the main breakers would accomplish the same thing, with the huge caveat that you could forget to do that so it's therefore not an acceptable solution. I guess the answer is yes, since the interlock does just that (but in a foolproof way). The issue: does the neutral line need to be disconnected as well ? I'd think not, since it should be grounded at your service entrance, and very likely it is at the transformer as well.
2018 Nissan Leaf SV
2006 Subaru Outback 2.5i Ltd

LeftieBiker
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Re: Using the Leaf for power in a Blackout: MY "Leaf to Home"

Mon Jul 01, 2019 12:46 pm

Most grids don't include a Neutral line, just a ground, so disconnecting the two Hot feeds is enough. My very first attempt at powering my house (partially) with a small generator included a homemade double-ended extension cord that I plugged into the generator and into a 120 volt outdoor outlet on the porch. It worked, powering whatever outlets were on the same "leg" as the outlet, but it required that we remember to turn off the main breaker. We replaced that with a generator connection port feeding a 240 volt 30A Generator circuit that, along with the main breaker, are covered by the interlock plate. Interlock systems are great, and cheap, but you do have to remember to turn most or all of the breakers off before switching over, then turning on the ones you really need the generator to power.
Scarlet Ember 2018 Leaf SL W/ Pro Pilot
2009 Vectrix VX-1 W/18 Leaf modules, & 3 EZIP E-bicycles.
BAFX OBDII Dongle
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

RustyShackleford
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Re: Using the Leaf for power in a Blackout: MY "Leaf to Home"

Mon Jul 01, 2019 1:47 pm

LeftieBiker wrote: Interlock systems are great, and cheap, but you do have to remember to turn most or all of the breakers off before switching over, then turning on the ones you really need the generator to power.
Actually, I was thinking of putting in an "essential loads" subpanel (connected to the main panel with an ordinary 2-pole breaker); this panel would be permanently connected to the well pump, the fridge output, and 1 or 2 lighting circuits. The main breaker of the subpanel would be the interlock; this unit is expensive, but could be the subpanel plus interlock all in one (https://www.norwall.com/products/Cummin ... -A051C991/). Then my backup AC is connected to the subpanel via an ordinary 2-pole breaker.

As discussed above, the Leaf can't directly supply an inverter big enough to supply my backup power needs (thanks largely to the surge current of my well pump). So I'm actually thinking of a big 3000+ watt inverter/charger (https://invertersrus.com/product/sp-ic3312/) but unfortunately it needs AC input power to charge the connected battery bank. So I'm thinking of adding a second inverter (much lower power) that is driven off the Leaf's 12v and supplies the AC input to the big inverter. Seems a little screwy, but I can't think of another way to drive the well pump from the Leaf, unless somebody makes an inverter/charger that takes a 12vdc input to the charger.
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Nubo
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Re: Using the Leaf for power in a Blackout: MY "Leaf to Home"

Mon Jul 01, 2019 4:25 pm

RustyShackleford wrote:
LeftieBiker wrote: Interlock systems are great, and cheap, but you do have to remember to turn most or all of the breakers off before switching over, then turning on the ones you really need the generator to power.
Actually, I was thinking of putting in an "essential loads" subpanel (connected to the main panel with an ordinary 2-pole breaker); this panel would be permanently connected to the well pump, the fridge output, and 1 or 2 lighting circuits. The main breaker of the subpanel would be the interlock; this unit is expensive, but could be the subpanel plus interlock all in one (https://www.norwall.com/products/Cummin ... -A051C991/). Then my backup AC is connected to the subpanel via an ordinary 2-pole breaker.

As discussed above, the Leaf can't directly supply an inverter big enough to supply my backup power needs (thanks largely to the surge current of my well pump). So I'm actually thinking of a big 3000+ watt inverter/charger (https://invertersrus.com/product/sp-ic3312/) but unfortunately it needs AC input power to charge the connected battery bank. So I'm thinking of adding a second inverter (much lower power) that is driven off the Leaf's 12v and supplies the AC input to the big inverter. Seems a little screwy, but I can't think of another way to drive the well pump from the Leaf, unless somebody makes an inverter/charger that takes a 12vdc input to the charger.
The 12V battery can supply a lot of amps on its own and could serve as a startup buffer. If the startup surge is brief and the pump's running consumption is still well below the DC-DC converter output, then driving a larger inverter directly from the 12V might work. Depends on the magnitude of the surge and what the voltage sag on the 12V would be. Or I could be talking out my ass :lol:
I noticed you're still working with polymers.

LeftieBiker
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Re: Using the Leaf for power in a Blackout: MY "Leaf to Home"

Mon Jul 01, 2019 4:29 pm

The 12V battery can supply a lot of amps on its own and could serve as a startup buffer. If the startup surge is brief and the pump's running consumption is still well below the DC-DC converter output, then driving a larger inverter directly from the 12V might work. Depends on the magnitude of the surge and what the voltage sag on the 12V would be. Or I could be talking out my ass :lol:
It would be safer to get a big marine/starting battery to use as the startup buffer, and then charge that from the Leaf's 12 volt system. The OEM Leaf battery is not large or rated for high surge loads. It was designed to crank over little 4 cylinder engines with modest compression.
Scarlet Ember 2018 Leaf SL W/ Pro Pilot
2009 Vectrix VX-1 W/18 Leaf modules, & 3 EZIP E-bicycles.
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PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

RustyShackleford
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Re: Using the Leaf for power in a Blackout: MY "Leaf to Home"

Mon Jul 01, 2019 4:37 pm

LeftieBiker wrote:
The 12V battery can supply a lot of amps on its own and could serve as a startup buffer. If the startup surge is brief and the pump's running consumption is still well below the DC-DC converter output, then driving a larger inverter directly from the 12V might work. Depends on the magnitude of the surge and what the voltage sag on the 12V would be. Or I could be talking out my ass :lol:
It would be safer to get a big marine/starting battery to use as the startup buffer, and then charge that from the Leaf's 12 volt system. The OEM Leaf battery is not large or rated for high surge loads. It was designed to crank over little 4 cylinder engines with modest compression.
Yeah, that's kinda what I was proposing (three posts back); except I forgot to mention there'd be another big battery feeding the big inverter, and then Leaf would keep that one charged. ("Big" in the sense of being able to provide a big surge, but the "big" storage would be the Leaf's traction battery).

I'd hate to screw up the Leaf by trying to suck too much current out of it. Better that it just sees a fairly low (below 1kw) and uniform load to keep the big battery charged.

I dunno if that Spartan inverter I linked is the best way to handle charging the big battery; seems kinda spastic to have a second inverter off the Leaf to go into the AC input of the Spartan. Maybe something like the inverter for an off-grid solar system ? Has one connection to the battery and can either charge it or draw from it to generate AC.
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LeftieBiker
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Re: Using the Leaf for power in a Blackout: MY "Leaf to Home"

Mon Jul 01, 2019 4:46 pm

You can limit the current flowing from the Leaf with a 15 amp DC circuit breaker. That protects the charging system. You should be able to charge the marine battery directly from the Leaf's battery, as that is how virtually all of the improvised Leaf Power systems work. I have the guts of such a system sitting around, with a cheap 2kw inverter, but that would be the last line of "power defense" after the dual fuel generator.
Scarlet Ember 2018 Leaf SL W/ Pro Pilot
2009 Vectrix VX-1 W/18 Leaf modules, & 3 EZIP E-bicycles.
BAFX OBDII Dongle
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

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