TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker or making a Paypal contribution here: paypal.me/SupportTMC

HPWC kapoooooooot!

Discussion in 'Model S: Battery & Charging' started by bhuwan, Jul 6, 2013.

  1. bhuwan

    bhuwan Active Member

    Joined:
    Mar 30, 2013
    Messages:
    1,256
    Location:
    Boston, MA
    I was charging my nearly dead battery this evening, and noticed, a few hours into charging I checked the app and it said not charging. I checked the HPWC and there's no power, and it was EXTREMELY warm. Checked the breaker and it did not trip.

    I'm thinking that perhaps the internal fuse is blown, though i thought my HPWC was the newer version without the fuse problem.

    Anyone have suggestions ?
     
  2. Doug_G

    Doug_G Lead Moderator

    Joined:
    Apr 2, 2010
    Messages:
    15,851
    Location:
    Ottawa, Canada
    Cycle the breaker. Failing that, call Tesla.
     
  3. ShortArc

    ShortArc Member

    Joined:
    Aug 20, 2012
    Messages:
    92
    Location:
    Massachusetts
    #3 ShortArc, Jul 6, 2013
    Last edited: Jul 6, 2013
    I would still think one of the internal fuses is "blown". Are you sure you have the new JJN-200 fuses?

    Turn the breaker off. Open the HPWC and see which ones you have. If they are the old TJN-100 fuses, then more than likely that is the problem. Remove the fuses and measure the resistance. Of hand I forgot the values but can tell you tomorrow. Now if you have the JJN-200 fuses with the bus bar design, than all bets are off....
     
  4. AmpedRealtor

    AmpedRealtor Active Member

    Joined:
    Jun 30, 2013
    Messages:
    4,698
    Location:
    Buckeye, AZ
    Why does the HPWC even have its own fuses? Seems silly to me, especially since the HPWC will be on a 100 AMP breaker. If you find this to be an internal fuse issue, I would probably look into bypassing the internal fuses. What purpose do they serve if the HPWC connection is already on a 100A breaker? I'm not an electrician, but it seems like adding a redundant set of fuses leads to unnecessary problems.
     
  5. stopcrazypp

    stopcrazypp Well-Known Member

    Joined:
    Dec 8, 2007
    Messages:
    7,041
    #5 stopcrazypp, Jul 7, 2013
    Last edited: Jul 7, 2013
    A fuse acts faster than a breaker. It's better to replace a fuse than the whole HPWC when something happens. That's probably why most higher power EVSEs have internal fuses.

    Also, Tesla can't really control what you connect your EVSE to. Even though NEC 625 is designed to make this illegal (assuming your local code adopts it), it's still possible for a person to connect the EVSE to a shared circuit or one with a different rating. The fuses will prevent something bad from happening in that case.
     
  6. bhuwan

    bhuwan Active Member

    Joined:
    Mar 30, 2013
    Messages:
    1,256
    Location:
    Boston, MA
    Called Fremont service; hopefully tomorrow they'll come by and check it ojt
     
  7. cinergi

    cinergi Active Member

    Joined:
    Sep 17, 2010
    Messages:
    2,169
    Location:
    MA
    You mean Watertown?
    I got my upgraded fuses from Matt -- if indeed that's what your problem is -- so hopefully that's all it is and he still has some in stock.
     
  8. bhuwan

    bhuwan Active Member

    Joined:
    Mar 30, 2013
    Messages:
    1,256
    Location:
    Boston, MA
    Watertown closed so it bounced me to Fremont :D I'll talk to them Monday hopefully.
     
  9. TurboFroggy

    TurboFroggy Member

    Joined:
    Dec 5, 2012
    Messages:
    287
    Location:
    Everett, WA
    If you were charging at greater than 60 amps and you have vertical fuses in your HPWC (old style) you have blown your fuses. This is exactly what the pop-up warns you of when you go over 60 amps without having the updated horizontal fuses.

    Call your nearest service center and have them send a Ranger out with a set of fuses. Ask them if they have a upgraded horizontal fuse retrofit kit in stock, if not have them bring out a direct replacement set of the old style vertical fuses. If you get the vertical old fuses, limit your charging current to 60 amps or less until you can get the updated fuses.
     
  10. Borgie

    Borgie Member

    Joined:
    Jan 13, 2013
    Messages:
    33
    Location:
    Connecticut
    Uhhhh.....it's not necessarily the fuses. My HPWC stopped working today (no lights on; nobody home). I opened it up and checked for voltage from the breaker. All OK. Then, assuming it was probably the fuses, I checked for voltage downstream of the fuses. Also, all OK. Then checked for voltage on the other side of what appears to be a relay (at top of HPWC). No power there. So, for some reason the relay has decided not to close. It's NOT the fuses.

    Called Tesla. They indicated that the local service center would contact me and send out a ranger to evaluate the problem. Sure hope it doesn't take long. Charging on a 110VAC circuit is SOOOO slow.
     
  11. ShortArc

    ShortArc Member

    Joined:
    Aug 20, 2012
    Messages:
    92
    Location:
    Massachusetts
    A blown fuse in the HPWC can/will show proper voltage. Only a resistance measurement will tell you if it is really blown. I am not saying that it could not be the relay but statistically the fuse has a higher probability.
     
  12. FlasherZ

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

    Joined:
    Jun 21, 2012
    Messages:
    7,019
    Depends on where you measure it to/from. A bad fuse in the HPWC will show zero voltage when measured from the top of one fuse to the top of the other fuse.

    The contactor only closes when the car modifies the voltage on the J1772 pilot pin; so measuring across the NO contactor contacts only shows voltage if everything else is working. If the HPWC's circuit board, or the pilot signal line to the car has a failure somewhere, the contactor will never get the voltage required to close and you'll never see voltage north of those contacts.

    If you have voltage between the two north ends of both fuses, but no lights, then you likely have an HPWC circuit board failure of some type.
     
  13. ShortArc

    ShortArc Member

    Joined:
    Aug 20, 2012
    Messages:
    92
    Location:
    Massachusetts
    Good point. That would be the proper way to diagnose the circuit.
     
  14. Borgie

    Borgie Member

    Joined:
    Jan 13, 2013
    Messages:
    33
    Location:
    Connecticut
    Well, color my face red! Tesla Ranger came to look at HPWC the other day. Told me he would try replacing the fuses as a first step. I confidently informed him the "fuses are not the problem." Of course, he had to replace them anyway, as that's the protocol. And, of course, that solved the problem! Talk about feeling like an idiot. Other than that, a very positive first experience with Tesla service.
     
  15. brianman

    brianman Burrito Founder

    Joined:
    Nov 10, 2011
    Messages:
    15,487
    What led to this initial conclusion?
     
  16. bob_p

    bob_p Member

    Joined:
    Apr 5, 2012
    Messages:
    939
    My house has two breaker panels. The main panel gets the 200A circuit into the house - and there's a 125A breaker/line to the second panel.

    When my HPWC was first installed - the breaker for the HPWC was installed opposite the 125A breaker to the second breaker panel.

    After a few months, the 100A HPWC breaker melted and the HPWC lost power. The breaker shouldn't have melted - so it's possible the breaker was defective (and could have caused a fire).

    However, it's also possible there was too much power going through the breaker panel at the same place - and the heat of transferring that much power - at about the same place in the breaker pane, might have caused the breaker failure.

    So word of caution - when installing the HPWC 100A breaker - look at the breakers that are adjacent in the panel - and don't install it near another high amp breaker - just to be safe...
     
  17. Cottonwood

    Cottonwood Roadster#433, Model S#S37

    Joined:
    Feb 27, 2009
    Messages:
    5,062
    Location:
    Colorado

    When I saw this, I sent the link to this post to my electrician with the question, "Have you ever seen anything like this?"

    His response:

    Bolt down breakers could be good insurance.
     
  18. FlasherZ

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

    Joined:
    Jun 21, 2012
    Messages:
    7,019
    If your breaker melts, it's not due to adjacent breakers and "heat build-up", it's almost certainly due to a bad connection that is causing a higher resistance. It could be (as Cottonwood's electrician friend mentions) the lack of a tight grip (especially if used breakers were snapped in place) on the busbar, it could be the panel's bus bars were corroded or pitted or previously damaged due to overloads. More often than not, though, it's an improper placement of the wire and torque on the screws in the breaker. When the wire is placed into the breaker and the bolt tightened, it should cause the strands of the wire to fan out and create a broad, flat connection. If you don't tighten the screws with enough torque, the wire will still remain round and the surface area will be reduced. This, in turn, creates a higher resistance, and some serious heat, enough to melt breakers.

    As for bolt-down breakers, they provide extra insurance, but a bolt is adding suspenders to the belt. If the breaker doesn't securely snap onto the bus in the first place, a bolt won't eliminate heat. Both are likely to fail in that case. I see this frequently on older panels, where the panel is simply plum worn-out.
     
  19. wycolo

    wycolo Active Member

    Joined:
    May 16, 2012
    Messages:
    2,423
    Location:
    WY
    > I checked for voltage downstream of the fuses. Also, all OK. [Borgie]

    Are you sure you were 'downstream'? Fuses only have one failure mode = blown. If they just melt a tad, then they still conduct and thus are still fuses. I prefer to draw actual current using a pair of 60 watt light bulbs in series as a 'tester'. No false positive readings.
    --
     

Share This Page