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Cake day: June 15th, 2023

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  • #1 is a terrible idea if you ever need to hire an electrician in the future, plan on selling your house, etc. The National Electric Code prohibits using white, green, or grey wire for a hot/load connection. The 120V cable will contain a black wire for the hot connection, white for neutral, and green for ground. To properly convert it to 240V you would need a cable that consists of black & red wires for the two 120V legs.

    I’ll be the first to admit I’m no certified Sparky, but wire relabeling is used in a number of situations fully in accordance with NEC. My understanding is that some of this is in NEC 200.7. It requires relabeling both ends, but I don’t think there’s any code violation with it. If what you’re saying was true, wouldn’t that mean any -2 NM (Romex) would be code incompatible with 240v loads? I don’t think that’s true.

    Edit: here’s a Sparky doing exactly that



  • Good video. Accurate information.

    Two notes:

    1. For North American homes: I agree with the overlooked value of a downrated circuit for EV charging, but I don’t think he talked about a possibly better option for downrating: Using an existing 120v circuit (at whatever current rating) already wired in the garage . Remove the outlet, install EVSE (charger), and swap the breaker for a 240v one (at a current rating matching the original. So if you have a 120v 15A circuit (white romex) you can use the exact same wire for a 240v at 15A. If you have a 20A (yellow romex) you would end up with a 240v 20A. You get more than double the speed of charging with zero new wires added, only changing the breaker and removing the old outlets. Note: If you have multiple outlets in your garage all fed from this same circuit, this would mean all of your outlets in the garage are now 240v and not usable for regular 120v items.

    2. He didn’t like Smart chargers. Thats a valid opinion, but smart chargers can do some nice things that I like. Some will also talk to each other if you have two chargers, such as if you have two EVs. They can be configured to share the same wire to the breaker box, so you can plug both cars in at night, one car will charge, then when that is complete, the other will charge automatically without having to unplug one car and then plug in the other. It will charge the least charged car first ensuring the best balance of charge to both cars assuming both cars can’t be charged to full in one night. If you have solar panels, some smart chargers can talk to the solar system and be instructed to only charge when there is excess power that would otherwise go to waste. It can do this automatically so if clouds go overhead and not enough juice is available from the sun, the charging stops. As soon as the clouds clear and there is an excess again, charging resumes automatically. For outdoor charging, you can also configure most Smart chargers to only charge you authorized cars. So you don’t need to worry about someone rolling into your driveway when you’re not home (or a bad neighbor) and running up your electricity bill.