Electrical line noise while charging at 240V

[Ingineer]

This might be an interaction between the car and some equipment/appliance in the house. That's one explanation of how it could move with him to another house.

It could also be a poorly designed power supply in the audio system. There are plenty of these out there!

-P

 

[Christopher]

This might be an interaction between the car and some equipment/appliance in the house. That's one explanation of how it could move with him to another house.

It could also be a poorly designed power supply in the audio system. There are plenty of these out there!
-P

For what it's worth, it's not just a single piece of gear that exhibits the noise. I think I inventoried the equipment earlier in this thread but it's a set of Harman/Kardon Soundsticks, an Apple 24" LED Cinema Display (it has built-in speakers), and a Sony ES receiver/amplifier -- basically any speakers powered from AC. It's readily apparent with the Soundsticks and the display's built-in speakers but only noticeable from the Sony amplifier if I go right up to the speakers and listen for it. Anyway, I stopped looking for more sources once I saw it was happening with various gear.

[Update: It's worse at the new home. It's louder at my computer speakers but I also just discovered this evening (as the car started charging on an after-midnight timer) that I can hear it from my home theater speakers without going up close to the speakers now *and* I now hear the buzzing from my projector, a JVC RS-1.]

You may recall that the noise also emanated from the electrical panel itself at my old condo -- it does also at the subpanel in my new home. Speaking of which, my new home is only five years old.

Note that a number of things have to be true for this issue to be heard by Nissan:
1) The vehicle must be one of the older LEAFs as supposedly the updated EMI filter was already shipping in newer vehicles in June.
2) The owner has to own and make use of certain powered speakers *while* the vehicle is being charged. In other words, they don't primarily charge overnight while they're sleeping. Also, it's unlikely I would have ever noticed the problem with my Sony receiver/amp if I had not gone looking to see what other gear was affected.
4) The vehicle has to be charged at 240V, not merely 120V.
5) The owner has to be the type of person to notice such low-level noise. (Good hearing and in a quiet environment.)
6) The owner has to care enough about this noise and be motivated enough to actually report the issue to Nissan -- not just mention it on a web forum. This is the kind of issue that I can imagine plenty of people just opting to ignore. Now if the car broke down or if this damaged devices... then there'd be some noise! ;-)

So my frustration lies with Nissan withholding the updated part that I already know solves the problem -- at least for my equipment. Just give me the part please! (Well, and install it too, please. ;-))

 

[tps]

I'd be looking for some sort of grounding problem... In a former life, I spent 15 years as a radio broadcast engineer and PA sound engineer. If you think the LEAF's 3.3kW charger can create problems, imagine what kind of problems one might run into next to a 50kW broadcast transmitter. Grounding topology at transmitter sites is particularly important, not only because of noise problems in the audio, but because most transmitters are sitting under one or more multi-hundred foot towers, which take many direct lightning hits per year. A good grounding topology keeps the equipment at the transmitter site from blowing up when the tower takes a hit. Usually the transmitter just gets a momentary overload, and in half a second or so it has automatically recycled and is back on the air.

Usually, for grounding problems to induce noise into signal paths, a ground path and a signal path have to have a common wire. In consumer electronics, this is almost always the case, because most consumer gear uses unbalanced internal circuitry and unbalanced interconnect cables. But the other element that is necessary is to have noise currents flowing through the same ground wires as signal currents. When this happens, the resistance of the wire causes the noise current to impress a small noise voltage on the signal.

The best way to reduce the possibility of noise currents is to use star grounding, which prevents power current from flowing in the signal grounds. One usual "sneak path" is the TV cable, so one can disconnect it temporarily to see if the problem goes away. If so, a cable isolation transformer is in order. The coax(s) to satellite dishes may present a similar problem because of lightning grounds at the dish.

Star grounding does not eliminate leakage currents. These typically flow because of the capacitance between the windings of the power transformers in various equipment. The best solution is for the equipment to have faraday shields on the power transformers so the leakage current can be directed away from the signal ground paths. Sometimes I've dug into the offending piece of equipment and separated the power grounds from the signal grounds with a 4.7 ohm resistor so that all the voltage due to these leakage currents builds up across the resistor. Unfortunately, the only external way I found which works consistantly when dealing with equipment with power leakage current and intermixed power/signal grounds is to power the equipment through an external isolation transformer with a faraday shield. (I used to carry 1.2 kVA and 2.4 kVA medical isolation transformers with my PA rig to deal with leaky electric guitar amps; not only to eliminate grounding noise but to keep the players from getting "bit" on the lips when they got too close to the mic.)

Grounding is not a trivial topic, but grounding problems are well known to produce many kinds of noise problems in audio equipment as a result of interactions with various electrical devices.

 

[QueenBee]

I hear the same crackling sound in my Blink, in my panel, and most annoyingly in my APC UPS which is the most apparent. Also it seems like some of my CFLs get louder.

I asked Ecotality about the issue and they sent out the electrician that installed the Blink. He confirmed that the humming I was hearing from the Blink was normal but he had never heard the crackling. SOP is to replace the Blink so he did that and of course like we both thought it had no effect. The Ecolality tech, Nissan live chat, and the electrician were not aware of this issue. Nissan Live chat is doing research and is going to get back to me.

I finally got around to adding an OL for my EVSEUpgrade and verified that it still makes the noise with it as well.

I have a 2000 VIN which I vaguely remember as being a March production.

 

[QueenBee]

Grounding is not a trivial topic, but grounding problems are well known to produce many kinds of noise problems in audio equipment as a result of interactions with various electrical devices.

Certainly, but these sounds can literally be heard in the electrical panel.
One thing I have done since this started is replaced my full and aging electrical panel with a new one as well as update the grounding systems to current code requirements (Two grounding rods and grounding water line within 5' of entrance).

 

[LEAFer]

Grounding is not a trivial topic, but grounding problems are well known to produce many kinds of noise problems in audio equipment as a result of interactions with various electrical devices.

Certainly, but these sounds can literally be heard in the electrical panel.
One thing I have done since this started is replaced my full and aging electrical panel with a new one as well as update the grounding systems to current code requirements (Two grounding rods and grounding water line within 5' of entrance).

Ok ...
And the result is ... ? Still hearing the sounds in the panel ?

 

[QueenBee]

Ok ... And the result is ... ? Still hearing the sounds in the panel ?

Correct. Nissan LEAF CS was supposed to contact me today but did not.

Is there someone I should contact or should I just bring it up with a dealer service dept.?

 

[LEAFer]

Ok ... And the result is ... ? Still hearing the sounds in the panel ?

Correct. Nissan LEAF CS was supposed to contact me today but did not.

Is there someone I should contact or should I just bring it up with a dealer service dept.?

For starters, stick with the dealer, but you might mention Bill Grossi's name as the Nissan Technical Services Manager, who should be notified. (See the following post higher up in this thread: http://www.mynissanleaf.com/viewtopic.php?f=30&t=3988&start=120#p132076" onclick="window.open(this.href);return false

 

[Christopher]

I just updated my previous post to note that I discovered this evening that I can now hear the buzzing from my home theater projector as well as from my speakers -- and now without having to get near the speakers. The issue is definitely worse at my new home. (This was the first night since I moved in that I was using the system when the car started charging on a timer.) And I just verified that I can hear the buzzing from the electrical subpanel here, as I did at my old condo. I also verified of course that unplugging the car eliminates the noise at all points.

 

[hill]

Ever notice how all electric appliances like phones, TV's stereos, PC's, etc ALL have FCC notices that state the device MUST not interfere with other equipment? I hope Nissan doesn't make me get the FCC involved.

When I'm out in the garage, our solar PV inverters' buzzing (while charging) drives me nuts. But heck ... we've only been complaining about this for - what - a HALF YEAR now?

 

[TomT]

The Part 15 FCC certification refers to RF that is radiated by a device over the air. It does not cover interference which is conducted by power lines, but not otherwise radiated...

Ever notice how all electric appliances like phones, TV's stereos, PC's, etc ALL have FCC notices that state the device MUST not interfere with other equipment? I hope Nissan doesn't make me get the FCC involved.

 

[hill]

The Part 15 FCC certification refers to RF that is radiated by a device over the air. It does not cover interference which is conducted by power lines, but not otherwise radiated...

Ever notice how all electric appliances like phones, TV's stereos, PC's, etc ALL have FCC notices that state the device MUST not interfere with other equipment? I hope Nissan doesn't make me get the FCC involved.

I didn't refer to Part 15 in relation to the FCC's jurisdiction over RFI. EMI and RFI are often used interchangeably because they're inextricably linked ... induction versus radiation. I believe in the early 1980's the FCC was given authority over ALL consumer electronic equipment susceptible to EMI/RFI... whether it be a 50K watt transmitter, a bug zapper, a toaster or a 12v transformer. (Public Law 97-259).

but I could be wrong


I'd hate to toss out a perfectly good remedy, if in fact it's there.

.

 

[TomT]

For a good primer on this, read the volumes of information that transpired over the BPL debacle with the ham radio community... The FCC only has jurisdiction over radiated RFI.

I didn't refer to Part 15 in relation to the FCC's jurisdiction over RFI. EMI and RFI are often used interchangeably because they're inextricably linked ... induction versus radiation. I believe in the early 1980's the FCC was given authority over ALL consumer electronic equipment susceptible to EMI/RFI... whether it be a 50K watt transmitter, a bug zapper, a toaster or a 12v transformer. (Public Law 97-259).

 

[hill]

ARRL actually DOES have a case that was granted Fed jurisdiction. ARRL seeks to enjoin BPL noise created on hf. So that issue may still be over turned. But now we're switching back over to RFI if we're talking BPL. Certainly we are in agreement on RFI being within the purview of the FCC. Public Law 97-259 regulates interference standards for both EMI and RFI.

 

[Christopher]

Bzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz...

Hey, Nissan! I'm sitting here once again listening to the buzzing while I work...

...bzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz...

You've examined the problem, tested your new part at my house back in June, asked me to wait...

...bzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz...

I've waited...

...bzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz...

I bring it in to a dealer in September, you ask them to wait...

...bzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz...

I hear back from Bill Grossi of Nissan and he asks me to wait for another visit...

...bzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz...

It's late October now and nothing but buzzing......

...bzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz...

Yeah, I know you've said you've seen our posts on the issue, but could you just please address this issue.... pretty please? You have the updated part, right? It's shipping in other vehicles, right?

...bzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz.........

 

[Christopher]

Yay! Finally! Problem resolved!

As I sit here at my computer, the car is charging in the garage -- and there is no buzz! Yay!

I was finally granted a new charger (and they installed it! ;-) Yeah, I was surprised that it required a whole new charger. I was expecting replacement of some separate line noise filter or something. Probably would have been too much too hope for a 6.6 kW charger, eh?! hehe....

For what it's worth, they are standing by the fact that it's a very rarely reported issue and of course only an annoyance (the car does work), so I wouldn't expect a recall on the part or anything. (They actually came out to my new house this month to check it out again even though they'd tested the issue at my old condo back in June.) If it's bugging you like it was me, you'll probably need to report it to your dealer, possibly multiple times.

Best of luck, meanwhile... ahhh... sweet silence...

 

[hill]

Expect a PM sir !

 

[LEAFer]

Yay! Finally! Problem resolved!

Congrats ! And thanks for being so tenacious with them

 

[Christopher]

Expect a PM sir !

Hey, so to everyone who's started to PM me asking for my paperwork and such... don't bother, it's not useful! It wasn't the dealership that could make the decision. It was really Nissan corporate. I suggest you continue to politely describe your situation and/or frustration publicly in the forum, to your dealership and try contacting Bill Grossi or others at Nissan either directly or through your dealer. And describe it in detail, you need to convince them that it's a problem for you personally.

I can commiserate, but the private messages to me expressing your frustration won't be heard by Nissan! ;-)

 

[TEG]

I switched to charging from 120V when at home... Just barely enough time to get me recharged nightly.
When I charged on the blink at 240V, I would hear buzzing start to come out of my solar panel inverter.
A short while later, the solar inverter failed. I doubt I could get Nissan to pay for that.
(A lot of finger pointing could happen including - "we don't output any noise that the other device should find harmful.")
So, rather than risk possibly causing another inverter failure, I will just use 120V charging at home.

I still use public 208V/240V EVSEs occasionally, and hope I am not damaging any equipment on the other side of the EVSE.
I think I may have heard some buzzing coming from transformer closets at public garages when charging there, but apparently it is not supposed to be harmful, so I am trying not to worry about it.

If Nissan comes forward and says there is a problem that needs to be fixed, and I can get my charger replaced as a routine service, then I will gladly get it done. But if I have to mount a fight to convince them to change it, I am not inclined to put in all the time. I try to workaround the shortcomings of the vehicle, including the limited range, slow charging, and sometimes 'noisy' charging.