110 Charging Question

Discussion in 'Clarity' started by Aaron, Oct 23, 2018.

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  1. Aaron

    Aaron Active Member

    Sorry if this has been asked 1000 times. I have looked but apparently my looking skills are poor.
    I have heard that we should NOT be plugging our 110 charger into an outlet that has something else plugged in.
    Does this mean we should not be sharing the actual outlet (like....don't use an octopus or a surge protector) or does this mean if you have an outlet with two available plugs but your freezer is plugged into one of them you can't use the other one?

    Does that question make any sense?
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  3. Mark W

    Mark W Active Member

    I think the point of not sharing the charging with other items drawing on the same circuit is trying to maximize the speed of the charging. Charging can take the maximum amperage load available in the circuit, so if other things are running off of it, it can really slow down the already slow charging rate.
  4. Aaron

    Aaron Active Member

    I'm thinking of sharing it with my garage door opener which wouldn't be opened or closed at night anyway. There's no risk of damage? That's my main concern.
  5. Sandroad

    Sandroad Well-Known Member

    What Mark W said.....and it's especially true if you have something with large current draw (like and old inefficient freezer) plugged in. In that case, the circuit breaker may trip. Give the car the benefit of the full circuit capacity if you can.

    Should be no problem with your door opener.
  6. petteyg359

    petteyg359 Well-Known Member

    The car will draw up to 12A from a 120V source. Most 120V circuits are nominally 15A, but often garages that were built with space for a small work area will have a 20A circuit (the socket with the little horizontal notch added to one of the vertical slots). A freezer is typically 5A according to Google, so could easily share the same circuit.

    Also, every circuit is actually wired to safely carry 125% of nominal (assuming your house isn't over 30 years old), so you shouldn't have any problem actually pulling a bit more than 15A on a 15A circuit.
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  8. ryd994

    ryd994 Active Member

    My personal rule :
    Yes if it's high(>500w) and continuous consumption (>3hrs)
    The reason behind: ev charging is continuous use. Your charger is rated for 12A but usually only draw 10-11A.
    Assuming 14awg wire and 15A breaker, you shall not have more continuous load per electrician's code.(80% continuous use rule)
    You can still use the remaining capacity for short term use, which is ~5A*110V.

    And in reality, slight overclocking might be just okay.

    Not professional suggestion, don't cite on me.
    Remarksman likes this.
  9. Aaron

    Aaron Active Member

    Your all the best! So it sounds like I could reasonably use either the one with the freezer or the garage door one.
    Is there a way to know the amperage on the circuit that my freezer is plugged into?
  10. ryd994

    ryd994 Active Member

    Some smart plug can monitor power consumption, too
  11. Hi.Ho.Silver

    Hi.Ho.Silver Active Member

    I think you would be safer using the one shared with the door opener since you can control when the added load is applied.
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  13. ryd994

    ryd994 Active Member

    By the way, share with garage opener makes more sense.

    You don't know when does the freezer want to turn on itself. Likely, during that 12hr charging, the freezer would work for some time.

    On contrast, the car should have completed charging when you open the garage. That sounds like perfect time sharing.

    Well, i'lI say both are fine. The difference is marginal.
  14. qtpie

    qtpie Active Member

    Also, if you are going to have anything between the charger and wall outlet, such as extension cord, octopus or surge protector, make sure it is rated for 12amp or more.
  15. DucRider

    DucRider Well-Known Member

    An EVSE is one of the few devices in a home that is considered a "continuous load". As such, it requires additional capacity on the circuit (125% to be exact). That means using the EVSE at 12 A on a 15 A circuit uses the entire capacity and anything else plugged in on that same circuit would be considered an overload. The circuit breaker may or may not trip, but the danger of heat buildup and fire is the concern. With rare exceptions, 120V circuits in a garage will be 15 A.

    Some EV's default to 8 A and a setting must be changed in the car to draw more for that very reason.

    Electrical codes such as this are put in place for a reason and not pulled out of thin air. It is true they are fairly conservative and fudging a little will work - right up until the time that it doesn't (with sometimes very serious consequences). Anything built in the last several decades likely has receptacles that use the push in type wire connectors that have a very small contact point with the wire. These weak spots can result in increased resistance/heat and a circuit with multiple outlets will have many of these connections as the outlets are daisy chained.

    Many people routinely violate electrical (and other) codes with no dire consequences. The most likely outcome of using your EVSE on an overloaded circuit (anything else on it) is the circuit breaker tripping during your charge session (when you open the garage door, the freezer compressor kicks in, etc.). Worst case scenario is a fire.
    Remarksman likes this.
  16. petteyg359

    petteyg359 Well-Known Member

    Everything I've seen done by a real electrician uses the screw terminals. My house (2001), my parents house (1994), my grandparents' and their neighbours' houses (pre-1960 with fuses, rewired with breakers and a few circuits replaced in 2015), etc. Anecdotal, sure, but goes against your "anything".

    If a circuit is nominally 15 A, that's continuous. That means if you have a 15 A circuit with open sockets on it, it should be on a 20 A breaker with wire gauge appropriate to handle 20 A.
    Last edited: Oct 23, 2018
  17. DucRider

    DucRider Well-Known Member

    My experience has been just the opposite - every house I've owned (or helped someone with electrical) built from 1979 on has used the push in connectors. We had a home custom built in 2005 and I had to insist the electricians (licensed and the GC's usual sub) use screw terminals. Part of the reason I decided to spring for the extra buck or so an outlet for "commercial grade" since they wouldn't have a choice. Our current home (built in 1994) had the push in type in use (I've replaced ~80% of them over time).
    Clarity_Newbie likes this.
  18. akcoffee

    akcoffee New Member

    I have a first gen plug in Prius on a shared 15 amp 110v outlet ... the circuit breaker only trips when my wife or daughter tries to blow dry their hair.
  19. V8Power

    V8Power Active Member

    The 120V L1 charger has lower current draw than other appliances in a house, so no worries as long as your house is wired to code:
    I worry more about the high-power salon-grade super-sonic hair-dryer that I bought my wife than the L1 charger... it blows the L1 charger away when it comes to power & current draw and has yet to trip our 15A circuit breaker!
    Clarity_Newbie likes this.
  20. ozy

    ozy Active Member

    You need to have a good understanding regarding what circuits in the garage are connected to which breakers. For example, my garage opener is directly connected to a 15 amp breaker and there's nothing else on that circuit. In fact, the plug is in the ceiling and apart from the garage opener there's nothing else there. The garage outlets, on the other hand, are on a seperate 20 amp circuit but there are 3 of them. A 12 amp charger needs at least 15 amps available to be in the "safe zone". This means that even if you have the evse on one of those outlets, you still have the ability to plug something else into one of the others (unless it takes up too many amps). On the other hand, if you use a 16 amp evse on that 20 amp circuit you have basically maxed yourself out since you need to leave a 20% safety net ie:16 amp evse needs 20 amps to itself. Therefore, nothing else can be plugged into a 20amp circuit which is running a 16 amp evse.

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