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Charging fire hazard?

Discussion in 'Prime Plug-in Charging' started by Nick Lai, Mar 3, 2023.

  1. Nick Lai

    Nick Lai New Member

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    I've got a 2017 Prius Prime and I'm thinking of purchasing a plug-in 120v wall-charger and plugging it in.

    My landlord is concerned that it might be a fire hazard because it's an old house with dubious wires, and charging a car might pose a risk with heating the wires and whatnot, and frankly I don't know whether our concerns are valid or just paranoia. Can somebody inform me a little bit better about whether it should be a concern or not, and what things I may need to watch out for?

    Thanks!
     
  2. Tideland Prius

    Tideland Prius Moderator of the North
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    The car will draw 12A continuous (which is the max on a 15A circuit) until nearly full (80ish percent) before slowly dropping as the battery gets full.

    If you’re concerned (or to ease his concerns), the Prime can also be set to charge at 8A only. This will increase the charge time of course but can help alleviate any concerns about fires.
     
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  3. ChapmanF

    ChapmanF Senior Member

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    A tool like the one in this post might help decide just how dubious the wiring on that particular circuit might be.
     
  4. bisco

    bisco cookie crumbler

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    you're supposed to have a dedicated circuit. if the wiring is that old, (does it have fuses?) it would be worth having an electrician take a look.
     
  5. Marine Ray

    Marine Ray Senior Member

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    All that matters is that your landlord is satisfied. Little we say will influence that satisfaction. For me, the only voice of authority for your landlord is a licensed electrician's written decision.
     
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  6. BiomedO1

    BiomedO1 Senior Member

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    The old wire and bulb setup was very robust stuff. They can usually easily handle twice the fused current load, but they are only two wire systems. No valid safety ground. Their main problem was the thin asbestos wrap around the wires. Anything that penetrated the wrap would be energized, and if the other end touched ground - it would short/burn. Just because you have a 3-prong outlet, doesn't mean that you have a valid ground.Use one of these to test proper wiring:

    You can find them in any hardware store, and they won't break the bank. If you have some newer, upgraded wiring - look for GFCI outlets. I'm assuming they weren't installed for "show" and was properly wired in. That tester would tell you this also.

    Hope this helps.
     
  7. ChapmanF

    ChapmanF Senior Member

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    It's allowed (unless it changed after the 2017 NEC, latest I looked in) to put a GFCI in to replace an old receptacle on a circuit that has no equipment ground. It works, because all the GFCI needs to trip is to see unequal current flowing on the two circuit conductors. It doesn't have to see the ground. If the circuit conductor currents are unequal, it knows the difference is going somewhere.

    If a GFCI is installed that way, it's supposed to be marked NO EQUIPMENT GROUND.

    it seems, pre-2017, the rule said the "receptacles" were what had to be marked, and 2017 changed the language to the receptacles "or their cover plates" where you could, like, actually see the marking. Heh. I had always just assumed that was what they meant anyway.

    Not everybody, ahmm, 'remembers' to put that marking on, so there's still a reason to use one of those ground testers to see if there's really an equipment ground there.
     
    #7 ChapmanF, Mar 4, 2023
    Last edited: Mar 4, 2023
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  8. BiomedO1

    BiomedO1 Senior Member

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    Thanks Chapman, next time I'm in an old home for sale; I'll look for that. It just may be I'm old, but I don't ever recall seeing that on any GFCI outlet; even though my outlet tester states open ground.
     
  9. ChapmanF

    ChapmanF Senior Member

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    Yeah, I edited #7. Those labeling rules are not always the most consistently followed in the NEC.

    There can also be ordinary receptacles 'downstream' of a GFCI, if their wiring comes from the GFCI's protected LOAD terminals. Those receptacles (or, ahem, their cover plates) are supposed to be marked GFCI PROTECTED OUTLET. Often a GFCI that you buy will come with a few sticky labels that say that. Sometimes they just get thrown out.

    Naturally, if there are plain receptacles downstream of a GFCI that replaced an old receptacle with no equipment ground, they're supposed to be marked both GFCI PROTECTED OUTLET and NO EQUIPMENT GROUND.

    I'd like to see somebody fit all of that on the receptacle itself. :)
     
  10. BiomedO1

    BiomedO1 Senior Member

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    LoL; all too common.
    One time I asked a hospital electrician, why wasn't the emergency/generator backed outlets marked? Come to think about it, doesn't NFPA- 99 require outlet checks? Since nothing is marked, how do you know what's been checked or not, per state and federal standards/regulations?
    I was persona non grata for 5 years; for that simple question; excuse me two questions.:(:oops: I was just doing my job.:whistle::cool:

    My house was built in the early 90's. The electrician saved money by daisy-chaining kitchen and bathroom GFCI outlets. None of them are marked. I had to trip them to see where the primary GFCI outlet was located; then mark them accordingly. That way, family members knows where to go to reset things. I've already replaced two that trigger prematurely. The extra outlets on the circuit probably doesn't help either.
     
    #10 BiomedO1, Mar 4, 2023
    Last edited: Mar 4, 2023