Re: [EVDL] Will this gizmo let my EV conversion talk to a J-1772
The interesting thing about a GFI is that it doesn't actually need a ground to do its thing. It senses an imbalance in current between hot and neutral, or for a 240v GFI, between the hot legs and/or neutral. If any portion of the current drawn from a hot leg isn't balanced by a return via the other hot or neutral, it assumes that the errant current is going to ground. Since this could be happening via a person, with the possibility of shock or electrocution, it trips. Apart from tripping a GFI, the hazard in using equipment ground for a neutral is that if the equipment ground bonding at the main panel should be loose or damaged, the entire building's equipment ground wiring is energized - and so is the frame of any appliance connected to that ground. That's not good. So don't use ground as a neutral substitute, even without a GFI present. Couldn't you solve your RV problem with an isolation transformer? You could also potentially use the same transformer to derive 120v for conversion EV charging. David Roden, EVDL moderator & general lackey To reach me, don't reply to this message; I won't get it. Use my offlist address here : http://evdl.org/help/index.html#supt = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = If you made a column of things you're pretty sure you know, and then made another column of how you know those things, most of that column is like: "Some guy told me." It's just clickbait and hearsay. Goes into the head, locks onto a feeling, you're like: "That sounds good. I'm gonna tell other people that." And that's how brand marketing works, and also fascism, we're finding. -- Marc Maron = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ___ Address messages to ev@lists.evdl.org No other addresses in TO and CC fields UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/ LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org
[EVDL] Ground versus Neutral (was: Will this gizmo let my EV conversion talk to a J-1772)
This is, unfortunately, a "common" misconception. (So to speak :-) ) Yes indeed, the ground and neutral conductors are at the same potential. The two conductors serve very different purposes, however. If you connect the neutral conductor of an appliance to the ground conductor by mistake, the appliance will seem to function normally, (if it is not on a GFI protected circuit.) If sometime later, the ground wire becomes disconnected somewhere in your house, maybe at the ground rod or the electrical panel, then very bad things will happen. The appliance will stop working, even though it is "on", because the current has found a dead end at the ground circuit break. The metal parts of EVERY electrical device and appliance in your house will go to 120 volts, and become live. Everything will seem normal, but it isn't. Someone is very likely to be injured or killed. Your house is waiting for you, personally, to complete the circuit. If someone were to touch, say, the toaster with one hand and the water faucet with the other, they would get a shock, perhaps lethal. Even if the toaster is off, but simply plugged in. If someone was in the bath, and touched a light fixture, or a switch plate, they would get a shock. The ground conductor can have _no_ current flowing through it under normal circumstances. It is there for safety purposes only. If you are thinking "What are the odds that this will happen?". I was an electrician in a former life and this happens all the time. The ground rod conductor gets loose or damaged by gardening equipment, and the bonding wire to the plumbing is left dangling because it was disconnected during a DIY remodel. Then, all it takes is a cheapo surge suppressor to fail, (and connect the hot to the ground) and your entire house becomes live, waiting for _you_ to complete the circuit to a pipe, or a masonry floor, etc. Bill D. On 9/5/2021 8:55 AM, Lawrence Rhodes via EV wrote: I thought you could mix ground with neutral? Not sure I know what I am talking about. Two of my 3 AVCON EVSE use neutral. Lawrence Rhodes ___ Address messages to ev@lists.evdl.org No other addresses in TO and CC fields UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/ LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org ___ Address messages to ev@lists.evdl.org No other addresses in TO and CC fields UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/ LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org
Re: [EVDL] Will this gizmo let my EV conversion talk to a J-1772
Yes.but RV's can have a weird problem. When operating in stand alone mode (i.e. self supported and not connected to the grid) they often act like a house in that the inverter/generator makes its own 120|240 and therefore the ground and neutral are often bonded together (at one place...in the RV)...and connected to the frame. This means neutral and ground are connected together.at one placeprobably the frame So it's just like a house. It makes sense in. stand-alone mode (i.e. NOT connected to external power) and works just like a house in that if RV internal GFI (in the RV) senses current going to "ground" (i.e. frame) it trips the internal GFI or breaker So if your RV dryer connects the neutral or hot to the RV dryer metal box which is "grounded" , then internal RV GFI trips. and you kept from being electrocuted. The ground effectively acts like a neutral to provide a path to sink the current and blow a breaker (or GFI). Keep in mind that normal NON GFI breakers also expect a big enough ground wire even though in theory no current should pass through groundBUT if it does,then the ground wire must be big enough to handle enough current to blow the breaker... If you use a 1 Mohm resistor for ground, then the breaker will never get 20 amps and it'll never blow, but the case can still be 120v The problem is when you connect the RV to external power because NOW the RV neutral-ground bonding creates a path to ground. So if you power the RV via an external GFI, some of the current may come back through the external ground because now you effectively have 2 paths back to the bonding point of the house. It's as if you had a huge appliance where neutral and ground were connected together. Not good. it's bad. In fact I think most RV's will pop an external GFI. (at least the ones I've seen). Not good. I suppose the right answer is to have something inside the RV that switches between bonding and not-bonding depending whether you are stand alone or not stand alone. A similar problem can happen if you try to give temporary emergency power to your neighbor via an extension cord. I'm not condoning it, but unfortunately it's pretty common situation that most people seem blissfully unaware. On Saturday, September 4, 2021, 3:03:13 PM PDT, EVDL Administrator via EV wrote: > I thought you could mix ground with neutral? Ground and neutral are bonded together at only one point in your house. Usually that's at the main panel or main disconnect. From that point on, ground and neutral are kept totally separate. You can't use the equipment ground as a substitute for neutral. It creates a potentially hazardous situation and will trip a GFI, including the one in an EVSE. To charge at 120v, you'll need an appropriately sized transformer. David Roden, EVDL moderator & general lackey To reach me, don't reply to this message; I won't get it. Use my offlist address here : http://evdl.org/help/index.html#supt = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = People don't sleep enough, and they all seem to be hunting something that can't be caught. You think you're the dominant species just because you go to the bathroom in a bowl instead of a box. But who's cleaning up after whom? -- Souseme, "Felines of New York" = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ___ Address messages to ev@lists.evdl.org No other addresses in TO and CC fields UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/ LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org ___ Address messages to ev@lists.evdl.org No other addresses in TO and CC fields UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/ LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org
Re: [EVDL] Will this gizmo let my EV conversion talk to a J-1772
On 4 Sep 2021 at 20:55, Lawrence Rhodes via EV wrote: > I thought you could mix ground with neutral? Ground and neutral are bonded together at only one point in your house. Usually that's at the main panel or main disconnect. From that point on, ground and neutral are kept totally separate. You can't use the equipment ground as a substitute for neutral. It creates a potentially hazardous situation and will trip a GFI, including the one in an EVSE. To charge at 120v, you'll need an appropriately sized transformer. David Roden, EVDL moderator & general lackey To reach me, don't reply to this message; I won't get it. Use my offlist address here : http://evdl.org/help/index.html#supt = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = People don't sleep enough, and they all seem to be hunting something that can't be caught. You think you're the dominant species just because you go to the bathroom in a bowl instead of a box. But who's cleaning up after whom? -- Souseme, "Felines of New York" = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ___ Address messages to ev@lists.evdl.org No other addresses in TO and CC fields UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/ LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org
Re: [EVDL] Will this gizmo let my EV conversion talk to a J-1772
>RVs need a neutral for 120vac. I thought you could mix ground with neutral? Not sure I know what I am talking about. Two of my 3 AVCON EVSE use neutral. Lawrence Rhodes ___ Address messages to ev@lists.evdl.org No other addresses in TO and CC fields UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/ LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org
Re: [EVDL] 250V high line effects on solar EVs
On 9/4/21 9:34 AM, Mark Hanson via EV wrote: Thanks Lee My extension cord power company said they won’t do anything unless it hits 7% over 240V and since I’m near the substation , I see it 250-252V so the folks at the end of the line miles away aren’t too low. Most local pole peg transformers don’t have taps anymore to save $$ so it’s up to the customer to put bucking transformers in on sensitive equipment. Most appliances are power loads with the wattage the same as they draw less current (no change in meter billing) at a high line condition but solar inverters must run higher than the line to push back current. They use the switching power supply universal 85-264V operational range so always operating near the high end. I told Enphase to bump up their voltage to be mid range operational but they won’t do it due to increased cost for higher voltage components. I can copy the club. I don’t have a problem with gmail although sometimes the settings block Outlook email and have to reset to allow secondary devices. Here are some musings that some may find relevant. Or, maybe not. When I started putting in PV, I noticed my line voltage wast about 245. I had a 15kva transformer which, in this rural area, is normal for not all electric house. All electric houses tend to get 25kwa. I've never seen a 50kva for a "normal" residence. As I install more and more PV, I noted my voltage climbing. Sometimes, some of my micro inverters would shut down presumably when they saw 265v. Some of this high voltage was due to marginal branch circuits which I worked to alleviate. I found when my meter voltage reached about 255, I had inverters shutting down somewhere. Consulting my utility: they put a voltage monitor in my meter for a few days and found it, indeed, high. I suggested to them that I would be happy with more like 230v which would have given me more "head room" at inverters. They claimed to no longer installing multi-tap transformers which could have, at least temporarily, alleviated the problem. I ended up having them replacing, at my cost, the 15kva with a 37.5kva. I was walking on thin ice because my PV agreement called for me to produce no more that 10kw. I eventually accepted an agreement that allowed me to produce 50kw. I am now pushing the capacity of the 37.5kva; I see delivered power as high as 30kw. In case it is not obvious, producing power raises voltage just a using power reduces. My understanding of that and transformer capacities developed only as my PV projects proceeded. ___ Address messages to ev@lists.evdl.org No other addresses in TO and CC fields UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/ LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org
Re: [EVDL] 250V high line effects on solar EVs
Thanks Lee My extension cord power company said they won’t do anything unless it hits 7% over 240V and since I’m near the substation , I see it 250-252V so the folks at the end of the line miles away aren’t too low. Most local pole peg transformers don’t have taps anymore to save $$ so it’s up to the customer to put bucking transformers in on sensitive equipment. Most appliances are power loads with the wattage the same as they draw less current (no change in meter billing) at a high line condition but solar inverters must run higher than the line to push back current. They use the switching power supply universal 85-264V operational range so always operating near the high end. I told Enphase to bump up their voltage to be mid range operational but they won’t do it due to increased cost for higher voltage components. I can copy the club. I don’t have a problem with gmail although sometimes the settings block Outlook email and have to reset to allow secondary devices. Best regards Mark Sent from my iPhone On Sep 4, 2021, at 1:16 AM, Lee Hart wrote: Mark Hanson via EV wrote: > Hi Cor etc > I have the same issue, our pole pigs are set to 250V split phase no taps > (taps only at local sub station) due to rural feed on an extension cord > company (rural coop) so the folks far away get 240ish. This causes the solar > Enphase 64 inverters to hit 264V at 2pm and then pop. Since Enphase didn’t > do a FMEA , I found out from the recorded data, dying on high line after > about half of them died. The fix (since the power company refused to change > the sun station tap, said they did but didn’t ) is to get two 6.3V toroid > core 120V transformers (can not be EI core for idle losses) and put the > secondaries out of phase in buck mode in series with each 120V hot side thus > reducing the 250V to 237.4V and the inverters no longer drop out at 264V and > pop. My 3 EV charging stations for the Leaf, Bolt and Tesla don’t care since > they have wider range switching power supply/chargers in the cars and don’t > see over 250V since they’re a load and not a source. Hi Mark, I can't post to the EVDL; Earthlink started using Vadesecure last month, and the EVDL listserver (and others) won't accept email from it. (grump grump...) But I wanted to mention I've had exactly the same problem. My line voltage tends to be a bit high, and PV pushes it even higher. My Enphase hasn't died yet (thankfully), but my Trace Microsine trips off at 126 vac. That prompted me to do exactly as you did; I installed a buck/boost transformer to drop the AC line voltage a bit so the inverter doesn't trip off. It's no doubt protecting the Enphase (which I got from you) as well! Best wishes, and hope you and your family are well. Lee Hart -- We aren't devoting nearly enough scientific research to find a cure for the most recent pandemic; contagious stupidity. -- paraphrased from Bill Watterson (creator of "Calvin and Hobbes") -- Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ___ Address messages to ev@lists.evdl.org No other addresses in TO and CC fields UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/ LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org
