Model S - HPWC (High Power Wall Connector)

[Andyw2100]

There are fuses inside the HPWC. I'd check those.

Are those fuses that can be checked visually? I ask because...

Do you have a multimeter to check if there is power coming in or not? Hard to know where the problem is without one. Could be a bad breaker, blown fuse, or bad HPWC. Would be easy to pinpoint where the problem is with a meter.

I do have a multimeter, though it's not at this house and to be honest I don't really know how to use it, though I imagine I could look that up online.

I can go out tomorrow and get a multimeter somewhere, I'm sure. But if I may be able to tell by looking at the fuses in the HPWC that they are the problem, I should probably start there.

Thanks, everyone!

 

[pgiralt]

I do have a multimeter, though it's not at this house and to be honest I don't really know how to use it, though I imagine I could look that up online.

I can go out tomorrow and get a multimeter somewhere, I'm sure. But if I may be able to tell by looking at the fuses in the HPWC that they are the problem, I should probably start there.

Thanks, everyone!

If you do get one, this is something you can easily check yourself. Most meters will have a COM or Ground input to which the black cable connects and one or more connections for the Red wire. You'll want to make sure this is connected to the one marked V or Volts, not any of the ones that might be marked for measuring Amps.

There will likely be various settings for Voltage, one set with a squiggly line and one with a pair of parallel lines (most likely one of the two lines dashed). You'll want to set it to the squiggly line which is to measure AC voltage. If it has numbers, set it to the number that larger than 240.

Once you've done that, touch the black probe to the terminal that has the white wire attached to it (or you can touch the lug near the bottom with the green wire and bare metal wire - either one will work) and touch the red probe to the bottoms of each of the two fuses. You should measure around 120V AC between neutral and each of those terminals. If one or the other does not show 120V, you've found your problem. If that looks okay, do the same with the two terminals at the tops of the fuses. For good measure, you can measure the voltage between the two hot legs as well by putting the black problem on the fuse with the black wire and putting the red on the red (really it doesn't matter, you can reverse these because it's AC). You should measure around 240V across the two hot legs.

You can do the same on the HPWC if everything in this switch box looks okay.

If you don't feel comfortable doing this, don't do it to be safe, but I figured if you were comfortable enough opening up the box, you're probably okay with with using a meter on it.

 

[Andyw2100]

If you do get one, this is something you can easily check yourself. Most meters will have a COM or Ground input to which the black cable connects and one or more connections for the Red wire. You'll want to make sure this is connected to the one marked V or Volts, not any of the ones that might be marked for measuring Amps.

There will likely be various settings for Voltage, one set with a squiggly line and one with a pair of parallel lines (most likely one of the two lines dashed). You'll want to set it to the squiggly line which is to measure AC voltage. If it has numbers, set it to the number that larger than 240.

Once you've done that, touch the black probe to the terminal that has the white wire attached to it (or you can touch the lug near the bottom with the green wire and bare metal wire - either one will work) and touch the red probe to the bottoms of each of the two fuses. You should measure around 120V AC between neutral and each of those terminals. If one or the other does not show 120V, you've found your problem. If that looks okay, do the same with the two terminals at the tops of the fuses. For good measure, you can measure the voltage between the two hot legs as well by putting the black problem on the fuse with the black wire and putting the red on the red (really it doesn't matter, you can reverse these because it's AC). You should measure around 240V across the two hot legs.

You can do the same on the HPWC if everything in this switch box looks okay.

If you don't feel comfortable doing this, don't do it to be safe, but I figured if you were comfortable enough opening up the box, you're probably okay with with using a meter on it.

I'm not sure I'd want to mess around testing anything with power actually going to it.

I'm comfortable killing the power, pulling the fuses, and testing them with the multimeter, assuming that is possible.

I found some images of the fuses in the HPWC and unless I'm mistaken there is no way I could tell if they are good or not by just looking at them, right?

Roughly what should those cost, and are they something I can find easily at, say, a Lowes or Home Depot? If they are inexpensive enough might it make sense to just buy a couple, and assume that there's a very good chance that they are the problem? (If they're not this time, they may be some day anyway.)

Reading up in the last few minutes on the old problems with 80 Amp charging and the original HPWCs, it just seems more probable to me that the problem lies in the HPWC fuses than elsewhere.

 

[pgiralt]

I'm not sure I'd want to mess around testing anything with power actually going to it.

If you don't feel comfortable with the power on, then don't do it. That said, it's pretty safe if you do it correctly.

I'm comfortable killing the power, pulling the fuses, and testing them with the multimeter, assuming that is possible.

If you want to go down this route just to test the fuses, once you've pulled power, you'll have to pull out those fuses and test each one with the multimeter. There should be an Ohm setting on there. The fuse should basically read close to 0 ohms if you put the two probes on either side of the fuse. Technically you can do it without removing the fuse, but I'd remove the fuse to test.

I found some images of the fuses in the HPWC and unless I'm mistaken there is no way I could tell if they are good or not by just looking at them, right?

Right - there is no way to tell on fuses like this where you can't see the wire inside.

Roughly what should those cost, and are they something I can find easily at, say, a Lowes or Home Depot? If they are inexpensive enough might it make sense to just buy a couple, and assume that there's a very good chance that they are the problem? (If they're not this time, they may be some day anyway.)

Doesn't look like the carry these at HD or Lowes. They'll be about $15 a piece. FRNR80 Bussmann Fusetron Fuse 80 Amp 250 Volt Dual-Element Time Delay Current Limiting UL Class RK5 Fuse

One thing that stands out to me is it looks like you have 80 Amp fuses in there. Is your HPWC set to charge at 80A or 64A? I would think with 80A fuses, your HPWC should be set to 64A. If you're constantly drawing 80A, that would explain why one of the fuses might have blown.

Reading up in the last few minutes on the old problems with 80 Amp charging and the original HPWCs, it just seems more probable to me that the problem lies in the HPWC fuses than elsewhere.

If you have an original HPWC and never had the fuses replaced by Tesla, there's a good chance that's where your issue is.

 

[Andyw2100]

Right - there is no way to tell on fuses like this where you can't see the wire inside.

I was actually asking about the fuses in the HPWC, but it appears you can't see the wire in those either. I'm including pictures below. Wondering what the white paper/carboard near what I believe the fuse is would be. Is that supposed to be there, or did my electrician leave it in by mistake?

Doesn't look like the carry these at HD or Lowes. They'll be about $15 a piece. FRNR80 Bussmann Fusetron Fuse 80 Amp 250 Volt Dual-Element Time Delay Current Limiting UL Class RK5 Fuse

One thing that stands out to me is it looks like you have 80 Amp fuses in there. Is your HPWC set to charge at 80A or 64A? I would think with 80A fuses, your HPWC should be set to 64A. If you're constantly drawing 80A, that would explain why one of the fuses might have blown.

I almost never charge at 80 amps, but want to be able to, and was tonight.

I had paid to have a 100 amp service installed, and the breaker at the panel is 100 amp. The electrician knew that the HPWC would be capable of 80 amps, and that I'd want to charge at 80 amps occasionally. Should the electrician in this case have included 100 amp fuses there instead of 80 amp fuses? If that's the issue, I should be able to get the electrician back here to rectify that at no charge.

If you have an original HPWC and never had the fuses replaced by Tesla, there's a good chance that's where your issue is.

I checked and the fuse problem is supposed to affect A and B versions of the HPWC. I purchased my HPWC in October 2014, and it appears to be a D version, so I wouldn't expect that to be the problem.

Below are a couple of pictures of the inside of it. I'm really wondering about that paper / cardboard.

Again, thanks for all the help!

 

[pgiralt]

Your HPWC fuse is the new type, so that's not likely the issue. The old ones were a double fuse and the new ones are a larger single one. You can see the difference here:

New HPWC is out (soon?) - Page 4

Hopefully FlasherZ will chime in here, but I'm pretty sure those fuses should be 100A, not 80A if you're running 3 AWG cable to the HPWC which it looks to be, but hard to tell from the photos.

 

[DMC-Orangeville]

If you don't feel comfortable with the power on, then don't do it. That said, it's pretty safe if you do it correctly.




If you want to go down this route just to test the fuses, once you've pulled power, you'll have to pull out those fuses and test each one with the multimeter. There should be an Ohm setting on there. The fuse should basically read close to 0 ohms if you put the two probes on either side of the fuse. Technically you can do it without removing the fuse, but I'd remove the fuse to test.

If it has a very low number (continuity) - the fuses are still intact. 0= blown

One thing that stands out to me is it looks like you have 80 Amp fuses in there. Is your HPWC set to charge at 80A or 64A? I would think with 80A fuses, your HPWC should be set to 64A. If you're constantly drawing 80A, that would explain why one of the fuses might have blown.

Correct. You should use 100 amp time delay fuses for an 80 amp setting on the HPWC

If you have an original HPWC and never had the fuses replaced by Tesla, there's a good chance that's where your issue is.

I'm not sure about that.....
In any case, the fuses in the HPWC are class T fuses, and you won't find them at a Home center. You can source them at an electrical wholesaler....but they may need to order them in, as they are uncommonly used.

 

[pgiralt]

If it has a very low number (continuity) - the fuses are still intact. 0= blown

The last part is incorrect. 0 is a very, very low number. 0 or very close to 0 means the fuse is good. A very high (infinite) number = blown.

 

[Andyw2100]

Again, many thanks.

It sounds like my electrician should just come out and replace the 80 amp fuses, at least one of which is probably blown and the cause of the problem, with 100 amp fuses.

I never charge at 80 amps. But over the weekend I had moved my charge setting to 50%, from 90%, so that the car would not charge to 90% early Saturday morning, and sit at 90% SOC until the car was needed Monday morning. I wanted to be able to benefit from the heat generated during charging at 72 amps when my wife left for work Monday morning by charging just before she left, not days before.

On Sunday I figured out when I wanted charging to start at 72 amps, based on when she was going to leave, but apparently forgot to set the charge percentage back to 90%. I checked the car this morning about 20 minutes before she was to leave, and realized what I had done.

At that point I figured if I got the car to 150 rated miles, she should be fine, as her round trip would ordinarily use only about 125-130. Since time was tight, though I started the charge from the app, I did go out to the garage and kick the amps up from 72 to 80.

When my wife returned home this evening with about 30 rated miles I wanted to charge up a bit immediately, rather than leave the car at such a low state of charge until the full overnight charge. I forgot to set the amps back to 72, so the car was again charging at 80 amps. It charged that way for perhaps 30 or 40 minutes before whatever stopped it stopped it.

Is it likely that charging at 80 amps with those 80 amps fuses (instead of 100 amp fuses) for such a short time would have caused one of them to blow? I'm really hoping that is it.

Also what's with that paper in my HPWC? Should I remove it, or is it supposed to be there?

Thanks!

 

[Peter_M]

Also what's with that paper in my HPWC? Should I remove it, or is it supposed to be there?

Leave the paper there. It's to prevent arcing or accidental shorts.

 

[DMC-Orangeville]

The last part is incorrect. 0 is a very, very low number. 0 or very close to 0 means the fuse is good. A very high (infinite) number = blown.

You are indeed correct, as 0 would be no impedance........I guess I should have qualified. Some inexpensive meters will read "0" when turned on and remain so until they read a value. Also, some old analog meters start and end at 0. In any case.....if you get a small value, there is continuity. Of note, if the HPWC is set at 80 amps, you may have blown one of the legs, but replace both fuses, as the element of the "good" fuse may still be damaged.....

 

[pgiralt]

Is it likely that charging at 80 amps with those 80 amps fuses (instead of 100 amp fuses) for such a short time would have caused one of them to blow? I'm really hoping that is it.

Very likely.

Also what's with that paper in my HPWC? Should I remove it, or is it supposed to be there?

Yes, it's supposed to be there. Don't mess with it

 

[Andyw2100]

Again, many thanks for the quick and solid help!

I had considered calling Tesla, but thought I'd probably be better off coming here first, and now I'm sure I made the right call on that one.

I will call my electrician in the morning, and I expect he won't give me much of a hard time about sending someone out to replace the 80 amp fuses with 100s. The job was definitely spec'd for a 100 amp circuit. (With #2 copper, by the way. It's a long run.)

In fact, I just dug out the original quote, (screen shot below) and it specifically says "2-pole, 100 amp breaker for charger" and "100 amp disconnect."

Do I now need to be concerned that the hardware itself may not be rated properly, or is it just a question of swapping out those two fuses?

 

[AWDtsla]

Again, many thanks for the quick and solid help!

I had considered calling Tesla, but thought I'd probably be better off coming here first, and now I'm sure I made the right call on that one.

I will call my electrician in the morning, and I expect he won't give me much of a hard time about sending someone out to replace the 80 amp fuses with 100s. The job was definitely spec'd for a 100 amp circuit. (With #2 copper, by the way. It's a long run.)

In fact, I just dug out the original quote, (screen shot below) and it specifically says "2-pole, 100 amp breaker for charger."

Do I now need to be concerned that the hardware itself may not be rated properly, or is it just a question of swapping out those two fuses?

View attachment 114179

Why did he put in fuses in the first place? There are fuses in the HPWC but they are not meant to be user serviceable. Something really terrible has happened if those pop. But fuses in your house??? I would get it swapped for a 100A breaker.

 

[Andyw2100]

Why did he put in fuses in the first place? There are fuses in the HPWC but they are not meant to be user serviceable. Something really terrible has happened if those pop. But fuses in your house??? I would get it swapped for a 100A breaker.

I'm not sure. He was adding the 100 amp disconnect. It looks like the fuses are needed for the 100 amp disconnect, aren't they?

 

[Lloyd]

You can have a non-fused disconnect which may have been more appropriate if the wire is as quoted.

 

[AWDtsla]

I think this is your main problem: http://www.cooperindustries.com/content/dam/public/bussmann/Electrical/Resources/product-datasheets-b/Bus_Ele_DS_1020_FRN-R(70-600A).pdf

You have to imagine the curves up high enough for 80A, but it seems like average time to melt is somewhere just past 1000 seconds @ 80A.

 

[Andyw2100]

I think this is your main problem: http://www.cooperindustries.com/con...tasheets-b/Bus_Ele_DS_1020_FRN-R(70-600A).pdf

You have to imagine the curves up high enough for 80A, but it seems like average time to melt is somewhere just past 1000 seconds @ 80A.

I just checked logs, and it looks like the car was really charging at 79 amps for about 29 minutes or so before something blew. So this is pretty much in line with that, assuming more time with the slightly lower amps. This morning when I charged it was five or ten minutes at 72 before another five or ten at 80 (or probably really 79), so I never got close to 1000 seconds at 80.

 

[Andyw2100]

I just heard from the electrician. I had emailed, with photos, late last night.

One of the guys who did the installation is on the way here, and will be bringing 100 amp fuses, "in case he can use them." When I asked about that, and why 80 amp fuses were installed in the first place, the answer I received was that the guy thought he remembered that the wire from the charger was only rated for 80 amps.

Now of course that makes no sense to me, if the charger needs a 100 amp circuit to charge at 80 amps. I'm about to go see what I can dig up in the HPWC manual, but if someone sees this in the next few minutes and could respond with, "The cable from the HPWC is x and is rated for y" that would be helpful, as I could then repeat that when the electrician shows up.

Thanks!

Edit: I found this in the manual--

--
NOTE: For most branch circuits of 100A, use 3 AWG (26.7 mm2), 75°C(167°F) copper wire. For installations less than 100A, use conductors thatare sized according to local electrical codes.
--

So it appears what wire to use to connect to the HPWC was up to the electrician.

Also I believe I recall reading that it was possible to connect #2 copper, but that it was tight, and took some skill. In fact I think the electrician who installed my other HPWC (about 60 miles away) commented on it. Looking at the pictures of this installation can someone tell me if these guys did connect #2 copper to the HPWC or not? (They were supposed to.)

Thanks!


Edit 2--

I think I answered my own question. See picture below. It appears to me that the cable running to the disconnect is quite a bit thicker than the cable running from the disconnect to the HPWC. I'm guessing they used #2 copper as stated to the disconnect, but then decided to use smaller cable to the HPWC. Is this something I should complain about, and ask them to rewire?

Edit 3:

This is what FlasherZ had to say about #2 copper and making the connection to the HPWC--

You can fit #2 into the terminals carefully, but it's tight - you have to make sure you get all the strands in there. I believe Tesla's installation specifies CU-only. If you use AL, they recommend taking it to a disconnect or junction box just before the HPWC and using proper connectors with the final length of copper.

I'm wondering if this means that the smaller gauge wire from the disconnect to the HPWC is really no big deal, assuming it is at least #3 copper.

Still wondering if I should push for the #2 copper that I asked for, and that the other electrician did install.

 

[pgiralt]

#3 should be fine, however the concern I have is that the wire from the disconnect to the HPWC is not in conduit. I'm not familiar enough with what that wire is, but it might not be rated for 100 Amps. I know NM-B would not be rated for 100 Amps, but this looks like something else. Are there any words printed on the side of that black wire going between the disconnect and the HPWC?