I am far from an electrician and would only ever hire a licensed electrician to do any major electrical work on my home. But I am reasonably comfortable measuring AC voltages.

In 2013 we had a 240V electric car charging station installed in our garage.. 50 amp breaker, 6 gauge wire. The actual unit is convenient, because it has a plug and is designed to plug in to a 240V outlet. For reference, it is Leviton EVB40-SPT Level 2 surface mount charging station. So we had our electrician install and wire a 240V receptacle on a dedicated 50A circuit, mounted the unit on the wall above the receptacle and plugged it in. All appeared to work just fine for about two years.

Then, a couple of years in, it started having this issue where the unit would rapidly click (on/of) when charging (though it did always charge the car - Nissan Leaf). When trying to troubleshoot this, I noticed that turning the garage light on (different circuit) or turning on another light in the adjacent room on (other different circuit) would cause the clicking to stop.. It's hard to say how long this problem existed prior to discovery, since normally the car would charge at night when we were asleep (taking advantage of our dual rate electric). But since we would occasionally plug it in during the day for a recharge, we eventually noticed this issue.

Recently (since we are between electric cars) I have sent the unit back to the company to be tested.

For further troubleshooting, I recently measured the voltage at the receptacle. The first time I did this, I measured the voltage at around 238V (over the course of a few minutes I measured the voltage at values between 238V and 238.8V) - with garage lights on. I measured the next day and the voltage was closer to 242V (slowly fluctuating between 241V and 242V). Both times, during the few minutes I was measuring, the voltage would slowly fluctuate within about half a volt of the avg. value. I also measured the voltage between the neutral and hot terminals and found that those values were each about half of the total (as expected), but importantly, that they were the same value - though when I was measuring the first time around, I thought that one side was consistently about 0.2V higher than the other side. I didn't see that 0.2V variation the second time I measured. On my second test, I remembered to turn the lights on and off to check for differences. I found no discernible difference in voltage with the lights on or off.

I know that household voltage fluctuates, but I can't seem to find a definitive answer about how much fluctuation is normal or acceptable. Furthermore, when talking to the tech on the phone earlier, he made the claim that the voltage had to be *above* 240. That just sounded completely wrong to me. I was pretty sure that any appliance was supposed to work between a range of voltages. If anything, I might be worried about voltages above 240, since 220-240V is often a range I hear.

Can someone on here with electrical wiring knowledge let me know if it sounds like the voltage I measured at this outlet is within the normal range for household service, and if the fluctuation that I measured seems normal?

Thanks.

-J

On Tue, 23 Aug 2016 11:46:36 -0700 (PDT), J wrote:

snips

I know that household voltage fluctuates, but I can't seem to find a definitive answer
about how much fluctuation is normal or acceptable. Furthermore, when talking to the tech
on the phone earlier, he made the claim that the voltage had to be *above* 240.
That just sounded completely wrong to me. I was pretty sure that any appliance was supposed
to work between a range of voltages. If anything, I might be worried about voltages above 240,
since 220-240V is often a range I hear.
Can someone on here with electrical wiring knowledge let me know if it sounds like the voltage
I measured at this outlet is within the normal range for household service,
and if the fluctuation that I measured seems normal?
Thanks.
-J


see page 49 - 50 of this document for normal voltage range.

http://www.hydroone.com/MyHome/MyAcc...15_ENGLISH.pdf

Momentary fluctuations or transients would not be detectable without
specialized equipment. These can be caused by many things - internal
and external to your service.
John T.

On 8/23/2016 2:46 PM, J wrote:

I am far from an electrician and would only ever hire a licensed electrician to do any major electrical work on my home. But I am reasonably comfortable measuring AC voltages.

In 2013 we had a 240V electric car charging station installed in our garage. 50 amp breaker, 6 gauge wire. The actual unit is convenient, because it has a plug and is designed to plug in to a 240V outlet. For reference, it is Leviton EVB40-SPT Level 2 surface mount charging station. So we had our electrician install and wire a 240V receptacle on a dedicated 50A circuit, mounted the unit on the wall above the receptacle and plugged it in. All appeared to work just fine for about two years.

Then, a couple of years in, it started having this issue where the unit would rapidly click (on/of) when charging (though it did always charge the car - Nissan Leaf). When trying to troubleshoot this, I noticed that turning the garage light on (different circuit) or turning on another light in the adjacent room on (other different circuit) would cause the clicking to stop. It's hard to say how long this problem existed prior to discovery, since normally the car would charge at night when we were asleep (taking advantage of our dual rate electric). But since we would occasionally plug it in during the day for a recharge, we eventually noticed this issue.

Recently (since we are between electric cars) I have sent the unit back to the company to be tested.

For further troubleshooting, I recently measured the voltage at the receptacle. The first time I did this, I measured the voltage at around 238V (over the course of a few minutes I measured the voltage at values between 238V and 238.8V) - with garage lights on. I measured the next day and the voltage was closer to 242V (slowly fluctuating between 241V and 242V). Both times, during the few minutes I was measuring, the voltage would slowly fluctuate within about half a volt of the avg. value. I also measured the voltage between the neutral and hot terminals and found that those values were each about half of the total (as expected), but importantly, that they were the same value - though when I was measuring the first time around, I thought that one side was consistently about 0.2V higher than the other side. I didn't see that 0.2V variation the second time I measured. On my second test, I remembered to turn the lights on and off to check for differences. I found no discernible difference in voltage with the lights on or off.

I know that household voltage fluctuates, but I can't seem to find a definitive answer about how much fluctuation is normal or acceptable. Furthermore, when talking to the tech on the phone earlier, he made the claim that the voltage had to be *above* 240. That just sounded completely wrong to me. I was pretty sure that any appliance was supposed to work between a range of voltages. If anything, I might be worried about voltages above 240, since 220-240V is often a range I hear.

Can someone on here with electrical wiring knowledge let me know if it sounds like the voltage I measured at this outlet is within the normal range for household service, and if the fluctuation that I measured seems normal?

Thanks.

-J


Well within normal limits.

You may want to check at other times of day though. I was burning out
bulbs in the bathroom and it ws only in the morning. I checked and
found that at 6;45 AM to voltage was 134 instead of 120. The rest of
the day was good.

Turns out at a local substation they increased the voltage in the
morning to cover the extra draw as industry came on line. They over
compensated though. Once adjusted it was back to a low tolerance.

J writes:
snip


Can someone on here with electrical wiring knowledge let me know if it soun=
ds like the voltage I measured at this outlet is within the normal range fo=
r household service, and if the fluctuation that I measured seems normal?

In the USA, voltage can vary by 5% (RMS) +/-. Each side of
the 240VAC circuit may vary independently depending on how the load
is distributed in the rest of the house. Fluctuations will
occur as load is introduced and removed both within your house and
depending on your neighborhood, as load is introduced by your
neighbors.

I am far from an electrician and would only ever hire a licensed electrician to do any major electrical work on my home. But I am reasonably comfortable measuring AC voltages.

In 2013 we had a 240V electric car charging station installed in our garage. 50 amp breaker, 6 gauge wire. The actual unit is convenient, because it has a plug and is designed to plug in to a 240V outlet. For reference, it is Leviton EVB40-SPT Level 2 surface mount charging station. So we had our electrician install and wire a 240V receptacle on a dedicated 50A circuit, mounted the unit on the wall above the receptacle and plugged it in. All appeared to work just fine for about two years.

Then, a couple of years in, it started having this issue where the unit would rapidly click (on/of) when charging (though it did always charge the car - Nissan Leaf). When trying to troubleshoot this, I noticed that turning the garage light on (different circuit) or turning on another light in the adjacent room on (other different circuit) would cause the clicking to stop. It's hard to say how long this problem existed prior to discovery, since normally the car would charge at night when we were asleep (taking advantage of our dual rate electric). But since we would occasionally plug it in during the day for a recharge, we eventually noticed this issue.

Recently (since we are between electric cars) I have sent the unit back to the company to be tested.

For further troubleshooting, I recently measured the voltage at the receptacle. The first time I did this, I measured the voltage at around 238V (over the course of a few minutes I measured the voltage at values between 238V and 238.8V) - with garage lights on. I measured the next day and the voltage was closer to 242V (slowly fluctuating between 241V and 242V). Both times, during the few minutes I was measuring, the voltage would slowly fluctuate within about half a volt of the avg. value. I also measured the voltage between the neutral and hot terminals and found that those values were each about half of the total (as expected), but importantly, that they were the same value - though when I was measuring the first time around, I thought that one side was consistently about 0.2V higher than the other side. I didn't see that 0.2V variation the second time I measured. On my second test, I remembered to turn the lights on and off to check for differences. I found no discernible difference in voltage with the lights on or off.

I know that household voltage fluctuates, but I can't seem to find a definitive answer about how much fluctuation is normal or acceptable. Furthermore, when talking to the tech on the phone earlier, he made the claim that the voltage had to be *above* 240. That just sounded completely wrong to me. I was pretty sure that any appliance was supposed to work between a range of voltages. If anything, I might be worried about voltages above 240, since 220-240V is often a range I hear.

Can someone on here with electrical wiring knowledge let me know if it sounds like the voltage I measured at this outlet is within the normal range for household service, and if the fluctuation that I measured seems normal?

Your voltage readings are not unreasonable however I am troubled by that clicking on and off that you mentioned. You could have a loose connection somewhere on that circuit or on the main service to the house. Have you noticed any lights flickering in the house when the car is not plugged in? Are other 240 volt appliances operating okay such as the stove, water heater, or air conditioning? Any other strange electrical phenomenons going on?

If so I suggest that you have the power company come out and check their lines to your house. Then have an electrician tighten the connections in your electrical panel.

John Grabowski
http://www.MrElectrician.TV

On 08/23/2016 01:53 PM, John G wrote:
If so I suggest that you have the power company come out and check their
lines to your house. Then have an electrician tighten the connections
in your electrical panel.

1+

I have seen this before. If the wires are not tightened
properly at the panel, it could cause a fire.

The symptom I saw was that if you turn the lights
on (not off) in the hall, the lights in the living room
got brighter.

In this instance, the power company had to remove about
six inches of burnt wire and reattach at the panel

On 8/23/2016 2:21 PM, T wrote:

The symptom I saw was that if you turn the lights
on (not off) in the hall, the lights in the living room
got brighter.

I had the same problem. Turned out to be a poor neutral connection at
the power pole.

On 2016-08-23 5:42 PM, AL wrote:
On 8/23/2016 2:21 PM, T wrote:

The symptom I saw was that if you turn the lights
on (not off) in the hall, the lights in the living room
got brighter.

I had the same problem. Turned out to be a poor neutral connection at
the power pole.

Same here, I had noticed something was wrong one day when it was
especially windy it was really bad, local electric company jumped on it.
Guy was here within the hour, inspected my panel, said it was one of
the neatest panels he had ever seen, it must be the company's problem,
called in a crew for that night, they fixed it up. Floating neutral at
the top of our mast from the meter, all fixed up and no problem since,
that was about 12 years ago.

--
Froz....

Thanks for the input. After speaking with a more knowledgeable tech at the company, I found that there was nothing wrong with those voltages that I measured. However, that doesn't help me resolve my problem with the car charger.

According to the knowledgeable tech, the clicking is almost certainly caused by voltage fluctuations, but not the noticeable kind that make your lights dim noticeably (more on that later). Instead, he suggested that there is noise on the line that is causing voltage spikes - very brief voltage fluctuations that might only last milliseconds at a time, and therefore not be measurable on my crude multimeter, but would cause the safety circuitry in the charging station to briefly suspend the flow of electricity to the car - that's what all the clicking is. He suggested that this could be caused by loose ground connection at the panel, or that there could be something on another circuit introducing noise. I thought that it was odd that turning lights on would mitigate the problem, but he said it might be that the extra loads could actually help to dampen the noise (or something like that) so that the voltage fluctuation at the charging station would not be enough to cause the problem.

So, further diagnosis required.

Now, when he brought up these brief voltage fluctuations, I said oh, like how when the compressor for our geothermal heat exchange system kicks in the lights dim for a fraction of a second? No - apparently that's a different but possibly related problem. I can't decide from searching the internet, whether that is normal or a real problem - depends who's talking. Our house, built in '77 has a 200 amp service (I think). but we live in a rural area, and are literally the last house on the power line, so distance from the transformer could be a problem.

So, there could be multiple issues.

I've had a number of CFL and LED bulbs fail prematurely (IMO), but I always chalked this up to new technology not being particularly robust. Now I wonder if these failures are really due to a problem with our electric service or wiring.

Wondering if the next step is to have an electrician come have a look or to ask the power company to test things on their end first - apparently they can hook up some kind of data logger.

-J

Top Post Alert - too long sentences

Trouble-shooting - of a fresh occuring problem - is best.
by a professional with proper instruments

vs : trouble-shooting an old intermittent occasional problem -
after the homeowner and all his expert friends & neighbours
have fiddled around with things ..

Can you shut off the geo-heat-pump and see if that is the problem ?
Any new neighbours on your supply feeder ? Solar / wind / industry ?

... far too many variables for this guessing game ..

Good Luck. John T.




- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Thanks for the input. After speaking with a more knowledgeable tech
at the company, I found that there was nothing wrong with those
voltages that I measured. However, that doesn't help me resolve my
problem with the car charger.

According to the knowledgeable tech, the clicking is almost certainly
caused by voltage fluctuations, but not the noticeable kind that make
your lights dim noticeably (more on that later). Instead, he
suggested that there is noise on the line that is causing voltage
spikes - very brief voltage fluctuations that might only last
milliseconds at a time, and therefore not be measurable on my crude
multimeter, but would cause the safety circuitry in the charging
station to briefly suspend the flow of electricity to the car - that's
what all the clicking is. He suggested that this could be caused by
loose ground connection at the panel, or that there could be something
on another circuit introducing noise. I thought that it was odd that
turning lights on would mitigate the problem, but he said it might be
that the extra loads could actually help to dampen the noise (or
something like that) so that the voltage fluctuation at the charging
station would not be enough to cause the problem.

So, further diagnosis required.

Now, when he brought up these brief voltage fluctuations, I said oh,
like how when the compressor for our geothermal heat exchange system
kicks in the lights dim for a fraction of a second? No - apparently
that's a different but possibly related problem. I can't decide from
searching the internet, whether that is normal or a real problem -
depends who's talking. Our house, built in '77 has a 200 amp service
(I think). but we live in a rural area, and are literally the last
house on the power line, so distance from the transformer could be a
problem.

So, there could be multiple issues.

I've had a number of CFL and LED bulbs fail prematurely (IMO), but I
always chalked this up to new technology not being particularly
robust. Now I wonder if these failures are really due to a problem
with our electric service or wiring.

Wondering if the next step is to have an electrician come have a look
or to ask the power company to test things on their end first -
apparently they can hook up some kind of data logger.

-J
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

On Tuesday, August 23, 2016 at 9:10:57 PM UTC-4, J wrote:
Thanks for the input. After speaking with a more knowledgeable tech at the company, I found that there was nothing wrong with those voltages that I measured. However, that doesn't help me resolve my problem with the car charger.

According to the knowledgeable tech, the clicking is almost certainly caused by voltage fluctuations, but not the noticeable kind that make your lights dim noticeably (more on that later). Instead, he suggested that there is noise on the line that is causing voltage spikes - very brief voltage fluctuations that might only last milliseconds at a time, and therefore not be measurable on my crude multimeter, but would cause the safety circuitry in the charging station to briefly suspend the flow of electricity to the car - that's what all the clicking is. He suggested that this could be caused by loose ground connection at the panel, or that there could be something on another circuit introducing noise. I thought that it was odd that turning lights on would mitigate the problem, but he said it might be that the extra loads could actually help to dampen the noise (or something like that) so that the voltage fluctuation at the charging station would not be enough to cause the problem.

So, further diagnosis required.

Now, when he brought up these brief voltage fluctuations, I said oh, like how when the compressor for our geothermal heat exchange system kicks in the lights dim for a fraction of a second? No - apparently that's a different but possibly related problem. I can't decide from searching the internet, whether that is normal or a real problem - depends who's talking. Our house, built in '77 has a 200 amp service (I think). but we live in a rural area, and are literally the last house on the power line, so distance from the transformer could be a problem.

So, there could be multiple issues.

I've had a number of CFL and LED bulbs fail prematurely (IMO), but I always chalked this up to new technology not being particularly robust. Now I wonder if these failures are really due to a problem with our electric service or wiring.

Wondering if the next step is to have an electrician come have a look or to ask the power company to test things on their end first - apparently they can hook up some kind of data logger.

-J

When you have the problem, I'd start by having someone at the panel
open the breakers for everything else, one at a time, and see if you
can narrow it down. It's possible something on one circuit is the
problem and that somehow having the lights turned on, manages to
shunt enough of it that the car charger no longer objects. If that's
what's going on they must have a charger that is unusually sensitive
to this kind of thing, most power supplies aren't.

On Wednesday, August 24, 2016 at 9:43:54 AM UTC-4, trader_4 wrote:
On Tuesday, August 23, 2016 at 9:10:57 PM UTC-4, J wrote:
Thanks for the input. After speaking with a more knowledgeable tech at the company, I found that there was nothing wrong with those voltages that I measured. However, that doesn't help me resolve my problem with the car charger.

According to the knowledgeable tech, the clicking is almost certainly caused by voltage fluctuations, but not the noticeable kind that make your lights dim noticeably (more on that later). Instead, he suggested that there is noise on the line that is causing voltage spikes - very brief voltage fluctuations that might only last milliseconds at a time, and therefore not be measurable on my crude multimeter, but would cause the safety circuitry in the charging station to briefly suspend the flow of electricity to the car - that's what all the clicking is. He suggested that this could be caused by loose ground connection at the panel, or that there could be something on another circuit introducing noise. I thought that it was odd that turning lights on would mitigate the problem, but he said it might be that the extra loads could actually help to dampen the noise (or something like that) so that the voltage fluctuation at the charging station would not be enough to cause the problem.

So, further diagnosis required.

Now, when he brought up these brief voltage fluctuations, I said oh, like how when the compressor for our geothermal heat exchange system kicks in the lights dim for a fraction of a second? No - apparently that's a different but possibly related problem. I can't decide from searching the internet, whether that is normal or a real problem - depends who's talking. Our house, built in '77 has a 200 amp service (I think). but we live in a rural area, and are literally the last house on the power line, so distance from the transformer could be a problem.

So, there could be multiple issues.

I've had a number of CFL and LED bulbs fail prematurely (IMO), but I always chalked this up to new technology not being particularly robust. Now I wonder if these failures are really due to a problem with our electric service or wiring.

Wondering if the next step is to have an electrician come have a look or to ask the power company to test things on their end first - apparently they can hook up some kind of data logger.

-J

When you have the problem, I'd start by having someone at the panel
open the breakers for everything else, one at a time, and see if you
can narrow it down. It's possible something on one circuit is the
problem and that somehow having the lights turned on, manages to
shunt enough of it that the car charger no longer objects. If that's
what's going on they must have a charger that is unusually sensitive
to this kind of thing, most power supplies aren't.

I think I would attack this from the opposite direction. I would shut off
*everything* except for the charging circuit and see what happens. If there
is no clicking, I would begin to turn on other circuits and add loads until
the problem shows up. That would (to some extent) eliminate the charging
circuit as the root cause.

However, just because the clicking started when the e.g. third circuit
was turned on, I wouldn't immediately blame that circuit. I'd circle back
and turn off the others. It could be a combination of circuits/cumulative
load from multiple circuits that's causing the problem. Maybe even one side
of the panel.

I never worry about electrical issues. My wiring is 80 years old, with
no ground, except the j boxes.
I just plug everything in and enjoy life.

DerbyDad03, excellent strategy! Very well reasoned. I'll give it a go when I have the opportunity.

-J

On Friday, August 26, 2016 at 11:46:20 AM UTC-4, J wrote:
DerbyDad03, excellent strategy! Very well reasoned. I'll give it a go when I have the opportunity.

-J

Glad you liked his so much better than mine, which was essentially the
same thing and suggested first.