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Surge Protector

Discussion in 'Model S: Battery & Charging' started by rogbmw, Feb 17, 2013.

  1. rogbmw

    rogbmw Member

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    Anyone here concerned with possible electric surges? Here in Florida they happen all the time - actually happened last night. What effect would this have on the Tesla batery pack when charging. The utility company here had a hole house surge protector they can install, and am thinking of getting one. Anyone else concerned about possible surges?
     
  2. rogbmw

    rogbmw Member

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    #2 rogbmw, Feb 17, 2013
    Last edited: Feb 17, 2013
    Anyone here concerned with possible electric surges? Here in Florida they happen all the time - actually happened last night. What effect would this have on the Tesla batery pack when charging. The utility company here had a hole house surge protector they can install, and am thinking of getting one. Anyone else concerned about possible surges?

    -----sorry for the double post
     
  3. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    I've had one at my house for several years. They won't protect against everything, but they will protect against the run of the mill surges.
     
  4. westom

    westom Member

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    Either a surge is connected harmlessly to earth without entering a building. Or that surge will hunt for earth destructively inside via appliances or a Tesla. Even power strip protectors need protection provided by earthing one 'whole house' protector. The only solution always found in a facility that cannot have damage.

    Details (including what is more important than that protector) were provided in Whole house surge suppressor.
     
  5. Robert.Boston

    Robert.Boston Model S VIN P01536

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  6. childressmd

    childressmd Member

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    That topic right there spins out to 'unreadable' very quickly. The last two pages are filled with esoteric argument about the various classes of 'grounds' and earthing. They lost this audience about halfway in, at the first white paper reference. :p

    I am in the process of putting in a 170' run to my garage. My addition with include a 200A disconnect from the existing meter base, buried cable, secondary meter base (for EV rate billing here), and a 200A subpanel in the garage for my charger(s).

    Q1: that previous thread includes a link to Shop Square D Load Center Hardwired Surge Protection Device at Lowes.com but would that not work? It's 175 VAC max. Is something else recommended?

    I will note that we already have the same devices installed on our existing house panel and subpanel.

    Q2: Will it, or will it NOT be beneficial to install another ground spike at the location where the supply will enter the garage?

    TIA
    Scott
     
  7. FlasherZ

    FlasherZ Sig Model S + Sig Model X + Model 3 Resv

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    Your 200A disconnect coming off the meter base will be your "service equipment" and requires your neutral to be bonded to ground there. You then need a 4-wire feeder (2 hot, neutral, and ground) to your detached garage. At the garage, you have a subpanel, so you must keep your grounds and neutrals separate. Because it appears to be a detached building, you will need 2 grounding electrodes at least 6' feet apart, connected to the ground bus on the panel with a continuous length of #6 wire. So basically, you run a ground wire in the feeder from house to detached garage, then also connect that to local grounding electrodes. This is required by NEC.
     
  8. westom

    westom Member

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    Your garage would have numerous and distinct grounds as described by FlasherZ. Even if interconnected, those grounds would be unique. That is required for human safety and described by code.

    Your Q1 is about something completely different - transistor (or Tesla) safety. If four AC wires enter a garage, then all four wires must connect to earth where entering (ie at the sub-panel). Obviously you cannot connect all wires directly to earth ground. So something must connect a wire, as short as possible (ie 'less than ten feet'), to earth ground (ie those 6' separated ground rods).

    175 volts is an irrelevant number for that Square D (and other recommended) 'whole house' protectors. (In reality it is a 330 volt device as listed on the box.) For surges, an important number is current. How many amps can the protector connect to earth and still remains functional? 50,000 amps is a typical minimum number. All protectors are only connecting devices to earth ground. You cannot connect those four incoming wires directly to earth. So a protector must connect as much as 50,000 amps to those earth ground rods.

    Can a 200 amp service carry a 50,000 amps surge? Of course. And even higher currents. 200 amps describes AC power. 50,000 amps describes a completely different current - surge current. Your service must be rated for 200 amps AC current. Your 'whole house' protector must connect up to 50,000 amps from those wires to earth ground.

    If less than 50,000 amps is not connected to earth where it enters a detached building, then current will find earth destructively via items inside. In all surge protection, a surge is either harmlessly earthed outside the building (where it would enter the building). Or that surge finds earth destructively inside. So that a surge need not pass through a Tesla, the surge must be earthed where it would enter the garage. That is what protectors do. Connect a surge harmlessly to earth.

    Every foot shorter to earth means increased protection.

    That Square D is not a 'whole house' protector. Square D makes a 'whole house' protector that would connect three of four incoming wires to earth (the fourth is connected directly; therefore needs no protector). Other manufacturers were listed in that previous discussion.
     
  9. wycolo

    wycolo Active Member

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    > Anyone here concerned with possible electric surges? [rogbmw]

    Two types of surges:

    1. Spikes on top of your 240v ac. These can be handled by fist-sized surge protectors that attach to main service panel. Also by UPSs at each computer station.

    2. Lightning strikes. Less of a problem if house is in a community with completely underground service, ie long way between house and power poles. If you are directly served by power poles then indeed this IS an issue. First get suggestions from local power company who have pertinent database. Keep in mind lightning is radio frequency energy, not 60 cycles per second, and exhibits unpredictable behavior such as traveling on outer skin of conductors and jumping across spaces. Think of the Tesla Coil shenanigans you've seen in photos.
    --
     
  10. rogbmw

    rogbmw Member

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    My main concern is lightning. Living in central Florida, we are in the lightning strike capitol of North America - YES - that is correct. We have more lightning strikes than anywhere else!! We do have underground utilities here in our development, but as an example, our neighbor had lightning strike a tree in his yard, and he lost all his TVs, some computers, stereo equipment and other electronic items. I wonder what would happen to the Tesla if something like that happened?
     
  11. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    Lightning is not electronics friendly. I'd unplug during an electrical storm. Won't help if the lightning actually hits the car but it it will isolate the car from the rest of the house.
     
  12. westom

    westom Member

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    Urban myths get promoted often by salesmen, advertising, or hearsay. Wires (overhead or underground) may carry a destructive surge into a building. Every wire inside an overhead or underground cable must connect to single point earth ground before entering. Otherwise a surge will hunt for earth destructively inside.

    A professional's app note demonstrates how surge protection must be implemented. "The Need for Coordinated Protection" shows all wires (ie underground phone line) earthed before entering:
    http://www.erico.com/public/library/fep/technotes/tncr002.pdf

    App note demonstrates the only solution found in any facility that cannot have lightning damage.

    Ground must be a single point earth ground. An AC utility demonstrates good earthing, defective earthing, and how to kludge a solution should utilities be routed wrong:
    Tech Tip 08 - Indiana Business-Duke Energy

    Another reason for a neighbor's damage (via a tree) might be earthing that the utility describes as "bad". Multiple earth grounds can make interior damage easier. Current incoming on any incoming utility wire must connect short to single point earth ground as demonstrated by the utility.
     

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