# [EVDL] ChargePoint - Odd Behavior



## EVDL List (Jul 27, 2007)

There are a few unknowns I hope you can clarify, but what you describe
is not unknown to me with my long history of level-1 charging at public
locations.

-First what is the gauge of the 50' and the 20' cords? (are they 12-3
cable?)

-Have you used that level-1 port at that Chargepoint EVSE before. If so
did it operate at the normal ~1.5kW rate?

-Did your 50' extension cord get hot when it was charging off the
Chargepoint EVSE?

The level-2 and level-1 wiring with a dual level chargepoint EVSE are
on separate sources/breakers/wiring.


My thoughts (without the data needed above):

-If the level-1 port always worked fine before using the 50' extension
cord, and now you are only getting half power, something on the EVSE
power side has changed. While there has been lots of newswire talk of
V2G and other utility tools to reduce EVSE power demand remotely, one
can only guess that there is a circuit inside the EVSE that might be
reducing the current. I doubt any electrician went out of their way to
now change the wiring so that 50% of the power is now wasted on long run
of smaller gauge wiring.

-If this your first time using that EVSE's level-1 port, it also might
be the electrician wired it with a very long run with a smaller gauge
wire.
A good example of that is when trying to plug into an available 5-20
outlet at a parking structure. Drivers can expect to have a hard time
drawing any serious power off of one of those.

-If the level-1 port is working OK but you are using a 50' that a skinny
16-3 extension cable and trying to draw 16A through it, there is going
to be a large resistive loss in the cord. Hence why I asked if your 50'
cord got hot.

Example: When I was on the top floor of a parking structure near Almaden
Park in San Jose, CA. The best I could get even with a MM pfc-20 charger
was 5A at 100VAC. And that was plugged in using a 25' 10-3 extension
cable.

An outlet is an outlet right? Not so. The electrician even following
code could have used 14 gauge, and the run from the breaker panel could
be over 100'. Electricians are not usually taught that whatever plugs
into the outlet they are installing will by itself really draw 16A.


EVSE install history (circa ~1996)
Years ago when I placed the request for a 5-20 outlet installed outside
at a designated EV parking spot at my hp work site, I worked with the
site electrician that had my job ticket. 

I asked him how long the wiring run was from the breaker panel. He said
it was over 50'. When I asked him to bump up the wiring gauge to 10 he
was put off on that idea as it seemed quite unusual (he was going to
install 14 gauge). I explained that even 12 gauge on that long a wiring
run would cut my power. He looked at me like I was from outer-space :-/

When I asked if installing 10 gauge was illegal by code, he said no. And
how much more would it cost to use 10 gauge, he said the difference was
nil as they got a large quantity price break. 

After I knew that, I worked on explaining that when I plugged the EV in,
it was not like the 3A printer or plotter, or a 2A PC or 1A monitor. The
EV was really going to draw 16A by itself, and that there was to be no
other outlets on that breaker. I used the analogy of trying to put out a
fire with a garden hose when a hire hose is needed. He finally got the
concept when I told him that to use small gauge wiring was wasting the
company money in the form of heat, that a large gauge wire would save
money with less power wasted (everyone had hp stock so that idea hit
home with him).

After he began to understand, he went ahead and installed 10 gauge
wiring. He also favored me with my other request to bump up the size of
the conduit encase other wiring had to be run later (for more outlets -
that move would also save the company money in the long term, pulling
wire is much cheaper than having to run another conduit & wire).

The final installation worked out well as those 1990's generation
chargers were quite inefficient (some of power wasted as heat - those
were pre- MM PFC charger days, days of K&W BC-20 or my Bycan half-wave
rectified transformer type chargers).


{brucedp.150m.com}



-


> Tom Keenan wrote:
> > While at a local ChargePoint station today, I plugged in using a cord
> > that I keep in the car for opportunity charging. The charging amp meter
> > in the Electricar indicated just over 5 amps - unusually low. Voltage
> ...


----------



## EVDL List (Jul 27, 2007)

Bruce -

Here is the data I have -

The 50' cord is 14-3. It does get slightly warm (perhaps 80f) when plugged
in to other outlets, but not hot. The 20' cord is 12-3. The 50' 14-3 cord
was at roughly ambient temp after a 30 minute / 800 watt charge.

I've used that level-1 port with my previous EV (Citicar), using the
Citicar's ~1.4 kW charger, and was able to charge at about 1.2 kW using a
different 25' 14-3 cable.

The 25' 14-3 cord for the old Citicar did not get hot when using that
particular ChargePoint EVSE (perhaps 100F).

I do not know if the level-1 and level-2 are on different breakers - the
conduit goes into a wall, and the breaker panel is apparently behind the
wall in a closed maintenance room.

The next time I use that EVSE, I'll measure the voltage sag on the line when
the Electricar is charging - there may simply be a loose connection
somewhere inside the EVSE or other wiring. I'll also try it out with a
shorter, heavier cord to see if that makes a difference.

Tom Keenan

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of Bruce EVangel Parmenter
Sent: Sunday, September 09, 2012 8:35 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] ChargePoint - Odd Behavior

There are a few unknowns I hope you can clarify, but what you describe is
not unknown to me with my long history of level-1 charging at public
locations.

-First what is the gauge of the 50' and the 20' cords? (are they 12-3
cable?)

-Have you used that level-1 port at that Chargepoint EVSE before. If so did
it operate at the normal ~1.5kW rate?

-Did your 50' extension cord get hot when it was charging off the
Chargepoint EVSE?

The level-2 and level-1 wiring with a dual level chargepoint EVSE are on
separate sources/breakers/wiring.


My thoughts (without the data needed above):

-If the level-1 port always worked fine before using the 50' extension cord,
and now you are only getting half power, something on the EVSE power side
has changed. While there has been lots of newswire talk of V2G and other
utility tools to reduce EVSE power demand remotely, one can only guess that
there is a circuit inside the EVSE that might be reducing the current. I
doubt any electrician went out of their way to now change the wiring so that
50% of the power is now wasted on long run of smaller gauge wiring.

-If this your first time using that EVSE's level-1 port, it also might be
the electrician wired it with a very long run with a smaller gauge wire.
A good example of that is when trying to plug into an available 5-20 outlet
at a parking structure. Drivers can expect to have a hard time drawing any
serious power off of one of those.

-If the level-1 port is working OK but you are using a 50' that a skinny
16-3 extension cable and trying to draw 16A through it, there is going to be
a large resistive loss in the cord. Hence why I asked if your 50'
cord got hot.

Example: When I was on the top floor of a parking structure near Almaden
Park in San Jose, CA. The best I could get even with a MM pfc-20 charger was
5A at 100VAC. And that was plugged in using a 25' 10-3 extension cable.

An outlet is an outlet right? Not so. The electrician even following code
could have used 14 gauge, and the run from the breaker panel could be over
100'. Electricians are not usually taught that whatever plugs into the
outlet they are installing will by itself really draw 16A.


EVSE install history (circa ~1996)
Years ago when I placed the request for a 5-20 outlet installed outside at a
designated EV parking spot at my hp work site, I worked with the site
electrician that had my job ticket. 

I asked him how long the wiring run was from the breaker panel. He said it
was over 50'. When I asked him to bump up the wiring gauge to 10 he was put
off on that idea as it seemed quite unusual (he was going to install 14
gauge). I explained that even 12 gauge on that long a wiring run would cut
my power. He looked at me like I was from outer-space :-/

When I asked if installing 10 gauge was illegal by code, he said no. And how
much more would it cost to use 10 gauge, he said the difference was nil as
they got a large quantity price break. 

After I knew that, I worked on explaining that when I plugged the EV in, it
was not like the 3A printer or plotter, or a 2A PC or 1A monitor. The EV was
really going to draw 16A by itself, and that there was to be no other
outlets on that breaker. I used the analogy of trying to put out a fire with
a garden hose when a hire hose is needed. He finally got the concept when I
told him that to use small gauge wiring was wasting the company money in the
form of heat, that a large gauge wire would save money with less power
wasted (everyone had hp stock so that idea hit home with him).

After he began to understand, he went ahead and installed 10 gauge wiring.
He also favored me with my other request to bump up the size of the conduit
encase other wiring had to be run later (for more outlets - that move would
also save the company money in the long term, pulling wire is much cheaper
than having to run another conduit & wire).

The final installation worked out well as those 1990's generation chargers
were quite inefficient (some of power wasted as heat - those were pre- MM
PFC charger days, days of K&W BC-20 or my Bycan half-wave rectified
transformer type chargers).


{brucedp.150m.com}



-


> Tom Keenan wrote:
> > While at a local ChargePoint station today, I plugged in using a cord
> > that I keep in the car for opportunity charging. The charging amp
> > meter in the Electricar indicated just over 5 amps - unusually low.
> ...


----------



## EVDL List (Jul 27, 2007)

I'd check the 50' 14-3 cord's connectors. If the prongs are discolored,
that usually means overheating. Just cleaning them usually is not enough
as the cord wires are likely also tarnished. So, even if you cut back
from the plug by a foot, the cord's wires may still be tarnished (NG).

I will assume the extension cords you have originally had plastic molded
plugs and receptacles on them. In my experience, those types do not
dissipate heat as well as the more expensive connectors (link is an
example only):
http://www.cesco.com/b2c/product/254570?gclid=CMTH-dXlqrICFeaDQgoddAwAiw
When I by these cords for use at their 15A rating, I lop off 1 ft of
cord w/ connector from each end (for other uses), and put better
connectors on the ends of the cord that will dissipate heat better (the
cord lasts longer that way).

I suggest you bring the 50' 14-3 cord as well as a heavier known-good
cord, to test them when plugging in your Citicar at that level-1 EVSE.


...
{For those that did not know ... I hope others who have more expertise
will weigh in here}

Looking at
http://www.pinsandsockets.nl/awg%20info/awg%20info.html
AWG American Wire Gauge info

It says two conductors carrying current (1 hot, 1 neutral), a:
14 gauge carries 15A
12 gauge carries 20A

But it also says that both a 14 and a 12 gauge 50 ft extension cord may
carry 15A (huh?). We all know more copper means more current carrying
capability. But I think that limitation to not bump up the 12 gauge
current is more plug rating related.

Looking at two cheap-e 50' cords one can pick up at their local hardware
store (example links only):
http://www.harborfreight.com/50-ft-x-14-gauge-outdoor-extension-cord-41447.html

http://www.harborfreight.com/50-ft-x-12-gauge-outdoor-extension-cord-41444.html

Both are also rated at 15A. But by experience I know to spend a few
buck$ more and go for the 12 gauge. It will be less lossy, heat up less,
thus last longer (= better bang for the buck in the long term). 
And this is coming from a guy who has used the many-many extension cords
I carried with me in the back seat (I have gone through my share of
cords having had 6 chargers on-board)
http://brucedp.150m.com/blazer/index2.html


The following image links are not exact, but give an idea of what I am
talking about.
When I said 'half-wave rectified transformer type charger', I was
referring to what is called a full-wave circuit where the charger uses a
center tapped secondary transformer winding, and each half of the
winding is half-wave rectified (its a cheaper way to make a charger):
http://www.bristolwatch.com/ele/img/diode18.gif
Where 'R' would be the battery.

Most older chargers are of this type. But what has to be known, is
measurements you make are average readings. If you were to read the AC
current being drawn, it might read as 10A. When really it is a short
duration large current spike in the center part of the AC wave:
http://www.idea2ic.com/Rectifierless%20AC%3C-%3EDC/FullRect.jpg
See the green colored DC wave forms to know how little of the wave is
passing current. The AC current being used by your charger also has
short duration current 'spikes' like that.

So, if the majority of the current spike is only using 10% of the wave,
that means during that time, the current is actually 10 times larger
than the average reading (a 10A average reading comes from a 100A 10%
duration current spike).

100A through a cheap-o cord is a lot to ask. No wonder they heat up and
age so fast. Remember using those older chargers, we are not running a
power factor corrected load, similar to what a leaf blower or electric
lawn mower would draw (drawing AC current throughout most of the AC
wave). Those loads are what that cheap-o cord was really designed for.
We are using it in a much more demanding way, and should understand the
limitations and ramifications (old low pfc chargers wear them out faster
than normal).


{brucedp.150m.com}



-


> Tom Keenan wrote:
> > Bruce -
> >
> > Here is the data I have -
> ...


----------



## EVDL List (Jul 27, 2007)

> Tom Keenan wrote:
> 
> > While at a local ChargePoint station today, I plugged in using a cord that
> > I keep in the car for opportunity charging. The charging amp meter in the
> ...


----------



## EVDL List (Jul 27, 2007)

I tested the charging station with a 20' 12-3 cord today. The initial AC
line voltage (no load) was 122.4 volts. Once the charger was turned on (low
setting - normally about 1.5kW at my house) the voltage sagged to 117.2
volts. The charging station indicated 902 watts charge rate. The amp meter
in the Electricar indicated about 8 amps of charging.

When the charger was set to the 'high' setting (normally about 1.7kW or so
at my house with the same 20' cord) the AC line voltage sagged to 114.9
volts, and indicated about 1.2 kW. (just over 10 amps on the DC amp meter).

I tested another charging station (two spaces over) and the charging rate
was about two amps better on both settings. The charging station at space
119 (lower level 1 rate) is fed via a 3/4" conduit that goes to the left a
few parking spaces, turns up to the second level ramp, turns right for about
80 feet and disappears into a maintenance room - probably where the breakers
are. The very long run of probably undersized wire is the likely cause of
the 7.5 volt (~6%) drop at the rated current of the level 1 plug. If anyone
has the NEC article number, (I believe the max is supposed to be 3% drop)
perhaps the installer can be made to run new wire.

The higher rate charging station (space 117) has a 3/4" conduit that goes
left one space, then connects into a largish electric-looking sub panel (no
external switches or breakers). Feeder conduit into the sub-panel is about
2" in diameter. I did not measure voltage drop on this station, but it
appears to be somewhat better.

I no longer have the Citicar, but it did use an ElCon 2500 charger for the
last month I had it. Probably much less sensitive to voltage changes as you
note, and I only used it at level 1 once or twice, and if memory serves it
would charge at about 1.4 to 1.6kW using these level 1 outlets. I generally
used it with a Level 2 /J1772 plug at these particular charging stations,
and it charged at about 2.5kW just fine. When I had a ferroresonant charger
(Lester) in the Citicar, it was very sensitive to input voltage. At 123
volts input, it would charge at 25 amps (48v nominal). At 115v, it would
hardly charge at all - 10 amps or so.

For reference, the Level 1 plugs in the ChargePoint stations are 5-20, so
they should be able to provide 16 amp service.

Still getting used to the way the Electricar works, but enjoying the ride!

Tom Keenan

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of Roger Stockton
Sent: Monday, September 10, 2012 10:04 AM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] ChargePoint - Odd Behavior



> Tom Keenan wrote:
> 
> > While at a local ChargePoint station today, I plugged in using a cord
> > that I keep in the car for opportunity charging. The charging amp
> ...


----------



## EVDL List (Jul 27, 2007)

Hmm ...you used your known good cable, yet it still provides an
abnormally low amount of power (900W vs 1500W) off that 20A circuit. And
a neighboring/adjacent EVSE's level-1 is different yet still too low an
output.

IMO: There is something seriously wrong with the level-1 AC power being
fed to the EVSE at that site. It reminds me of the lousy wiring on an
level-1 outlet at the top floor of a parking structure I already posted
about.

While in my youth in a trouble-shooting profession, I would desire to
'resolve' this issue to a fix, today I would just note it on recargo's
listing of the EVSE, and find another charging point. I say that because
sadly, level-1 is just not as important to some of those that will
needed to be enlisted/involved to resolve the issue (i.e. a trouble
ticket to Coulomb, onsite electricians, the installer, etc.). Its fix
may not happen in my lifetime. If you have the time to kill/waste, a
good Samaritan would call it in to Coulomb (use their toll-free# on the
EVSE). 

I would be curious to know if the issue persists at other public EVSE.
If the issue follows with the vehicle, there is an incompatibility of
being able to charge through a Chargepoint/Coulomb level-1 20A port with
your EV. (As Spock might say ... interesting )


{brucedp.150m.com}



-


> Tom Keenan wrote:
> > I tested the charging station with a 20' 12-3 cord today. The initial AC
> > line voltage (no load) was 122.4 volts. Once the charger was turned on
> > (low
> ...


----------



## EVDL List (Jul 27, 2007)

Although not directly related, the following in ON TOPIC ("*ChargePoint -
Odd Behavior*").

Some may remember the "OverCurrent" issue I reported with a downtown
SanFrancisco Level 1 Chargepoint (its L2 was in use). I sought out another
CP unit with both level 1 and 2 and ran a quick test yesterday in
Sacramento. Same problem using L1 while L2 was NOT in use. Using RFMC
(which defaults to 16A pilot signal), after a couple minutes or so the
charging stopped and I received the following message

"*The station at which your vehicle is charging, COURTYARD EXPO /
MARRIOTTCALEXPO, has detected that your Vehicle is drawing more current
than the station's rating, and has suspended charging to prevent the
circuit breaker from tripping. This typically indicates an issue with
configuration of the vehicle or an issue with the battery management system
on the vehicle. Please contact the manufacturer of the vehicle if you
receive this notification again. *"

The CP stations include current measurement/over-current detection. I
don't know how sensitive they are. There's the possibility of power-factor
variation that pushes the current slightly above 16A. I did not have time
to do additional tests yet. I doubt I got anywhere close to "*the circuit
breaker from tripping*" rating (20A).

(Sorry I can't help with the OP problem ...)

On Tue, Sep 11, 2012 at 10:26 PM, Bruce EVangel Parmenter <
[email protected]> wrote:

> Hmm ...you used your known good cable, yet it still provides an
> abnormally low amount of power (900W vs 1500W) off that 20A circuit. And
> a neighboring/adjacent EVSE's level-1 is different yet still too low an
> output.
>
> IMO: There is something seriously wrong with the level-1 AC power being
> fed to the EVSE at that site. It reminds me of the lousy wiring on an
> level-1 outlet at the top floor of a parking structure I already posted
> about.
>
> While in my youth in a trouble-shooting profession, I would desire to
> 'resolve' this issue to a fix, today I would just note it on recargo's
> listing of the EVSE, and find another charging point. I say that because
> sadly, level-1 is just not as important to some of those that will
> needed to be enlisted/involved to resolve the issue (i.e. a trouble
> ticket to Coulomb, onsite electricians, the installer, etc.). Its fix
> may not happen in my lifetime. If you have the time to kill/waste, a
> good Samaritan would call it in to Coulomb (use their toll-free# on the
> EVSE).
>
> I would be curious to know if the issue persists at other public EVSE.
> If the issue follows with the vehicle, there is an incompatibility of
> being able to charge through a Chargepoint/Coulomb level-1 20A port with
> your EV. (As Spock might say ... interesting )
>
>
> {brucedp.150m.com}
>
>
>
> -
>


> Tom Keenan wrote:
> > > I tested the charging station with a 20' 12-3 cord today. The initial AC
> > > line voltage (no load) was 122.4 volts. Once the charger was turned on
> > > (low
> ...


----------

