how do the cables work technically?

[suxxer]

this interesting since telsa told me no not possible in Switzerland and my engineers whom are designing the epectical system for my new house said no problems I can even have max 80amp single phase!

It IS possible but it is forbidden by swiss-law to pull more than 3500W single phase. You can ask the guys from your local grid-provider. The are not allowed to give you more than 16A single phase.

 

[dpeilow]

Interesting. Can you post a link to something describing that please?

 

[suxxer]

Sure.

It's called the "WERKSVORSCHRIFTEN" (Example of zurich: Regionale Werkvorschriften Zrich - Elektrizitätswerke des Kantons Zürich | PDF: https://www.ekz.ch/internet/ekz/de/geschaeftskunden/netzdienstleistungen/installationskontrolle/werkvorschriften.-EKZSlot1-0018-File.File.FileRef.pdf/WV%20ZH%202009-01_2.pdf)

They only allow <3.6kw (that's 16A@230V) from 230V or <6kW (16A@400V) from 400V....

 

[Alfred]

"Werksvorschriften" are not law. These are regulations issued by the local or regional supplier. You will find that such "regulations" are not the same everywhere and in particular that they are not handled the same everywhere. Regulations can also be interpreted as "guidelines", just perhaps not in Zurich...

 

[TEG]

The problem is the spare cable has conductors (metal wires) sized for 15A or so. Thus your professional would resistor code the cable and when plugged in to a Mennekes-style EVSE capable of 70A, the EVSE would note the 15A coding of the cable and only offer the signal to the car for 15A charging.
Obviously if you started with an MC240 cable you could code that for 30A (probably 32A) and if you took the cable from an HPC you could code it for 70A.

(Tesla, Yazaki J1772, and Mennekes type 2) are all basically using the same communication protocol. A straight through would pass the current availability signal from the EVSE to the car. No UMC signal generator box necessary. There are also some passive components in the cable to indicate how much current it's able to deliver. That means the max current could be 70 Amps or whatever the single phase limit is for Mennekes.

Are these cable "coding" techniques documented somewhere?
Do we know if RFMC, Tesla UMC, and Mennekes all use similar mechanisms for "cable coding"?
I know a bit about the RFMC where a diode can be installed in different orientations to different connectors resulting in something like 4 possible cable types being detected.
Andrew made it sound like the Mennekes cable coding allows for more steps of current control based on the cable type.

 

[felixtb]

yes those must be guidelines and seem to be different in the different cantons and even counties. in our county we can have up to 80A on single phase 230V according to the local utility. so I guess I have to discuss that with tesla Zurich so they sell me an HPC.

 

[AndrewBissell]

Felix - please consider making your HPC public or semi-public (available by arrangement).

 

[AndrewBissell]

TEG - I believe they are documented but don't recall where now.

 

[felixtb]

will defenetly consider that it would be semi public, but as I told you in another note the said house wont be completed for a while yet.

 

[dpeilow]

The Mennekes cable size coding is done with resistor values. It's explained in the 2009 Daimler/BMW presentation that has been posted here a few times. It is supplemental to the EVSE pilot signal that they all have in common (because the others don't have detachable cables).

 

[TEG]

And by the way, with "full handshake" there is a signal back and forth. We have been focusing on the pilot signal that the EVSE sends to the vehicle to tell it what current capability is available, but there is another signal that goes back from the vehicle to the EVSE saying basically "yes, I want that", which then connects the actual power lines. This is a "safety interlock" of sorts such that the cable is not fully energized until the EVSE and the vehicle agree to start a charge cycle.

Contrast that to a household outlet (including 240V from things like NEMA14-50) where the power is always live on the pins.

Something somewhat related I just noticed:
EVDL Archive / Forum Interface - Electric Vehicle Discussion List

Need help retrofitting EVI MCS 100-3 EVSE
I have a EVI MCS 100-3 EVSE that I have retrofitted by replacing the Avcon with a Yazaki. What I have discovered however is that this particular unit was programmed to only allow one charge cycle per charge request. That is to say once a charge request is completed the unit will no longer provide a pilot signal until it is unplugged and plugged back in again. This behavior prevents the EVSE from working properly with my new Leaf.

According to Jason at ClipperCreek this programming was done to get around a bug that was in the original Honda EV Plus. The bug was that after the Honda EV Plus finished a charge cycle it would keep listening to the pilot if it was plugged in and would eventually kill the 12 volt battery as a result. So having the pilot shut down after one cycle prevented this.

I was told by the folks at ClipperCreek that there is currently no practical method to remove this single cycle programming from this unit and I should just consider buying a new unit or continue to work with this unit as is. I was also told that they no longer have the documents or programming equipment for this unit.

What information about the unit I could find on the web http://www.bowzerbird.com/eviweb/products2.html#mcs100

So I am looking for help in removing this single cycle feature. Any help or suggestions will be appreciated. Thanks!
---
Re: Need help retrofitting EVI MCS 100-3 EVSE
So, what you want is a small circuit that listens to the pilot, when the pilot completely disappears it will power up a relay where the relay has a normally closed contact in the feed to the charger, so the charger auto-resets itself as soon as the pilot signal disappears.

This what you want? How experienced are you with designing and building some electronics? This would probably not be more than 2 transistors, a capacitor, three resistors, a diode and a relay.

 

[TEG]

Back to my earlier question - can you use the VDS to make the Roadster pull more current than the signal suggests is available?

 

[donauker]

The original Tesla MC240 had a fixed signal generator that would tell the Roadster that 24A was available.

Actually the MC240 has a fixed signal generator which signals 30 amps available. This was due to the fact that the GFI device used was rated at 30 amps only so even though the unit had a 50 amp NEMA 1450 plug it could only provide 30 amps instead of the normally expected 40 amps from this circuit type.

Question: Can the Roadster VDS be used to pull MORE current even if there is no signal on the charge cable?
I know it can be used to lower the rate (to less than the signal says should be available), but can it work the other way so you could tell the Roadster to grab 40amp from a cable with no max current signal?

When a signal is provided to the Roadster it will allow only charging at the signaled rate or lower. In the case of no signal it will default to 12 amp charge rate and will allow for override up to 15 amps only.

I know a bit about the RFMC where a diode can be installed in different orientations to different connectors resulting in something like 4 possible cable types being detected.

The RFMC allows for three different signal levels. The processor is configured by placing a diode between the unused neutral (white) wire in the adapter and the ground wire. The absence of a diode signals the processor to produce a 16 amp signal. A diode in position in one orientation while signal a 24 amp signal and in the other orientation it will signal the processor to supply a 40 amp signal.

 

[TEG]

Thanks, Don!

Oh, and I just found something "very juicy!":

http://smartgrid.epri.com/UseCases/PEV-S3-PremiseEVSEthatincludesthecharger%28RevD%29.pdf

Check out the steps in section 3.1.1
This includes new features such as VIN communication for billing, TOU controls, and other new "SmartGrid" features.

 

[donauker]

And by the way, with "full handshake" there is a signal back and forth. We have been focusing on the pilot signal that the EVSE sends to the vehicle to tell it what current capability is available, but there is another signal that goes back from the vehicle to the EVSE saying basically "yes, I want that", which then connects the actual power lines. This is a "safety interlock" of sorts such that the cable is not fully energized until the EVSE and the vehicle agree to start a charge cycle.

The full handshake is actually done in a rather unique manner and uses only the pilot signal lines coming from the EVSE. The car signals the EVSE by placing several different levels of resistive loads across the pilot signal thus loading down the pilot signal to different voltage levels. The EVSE detects these different loads on its pilot signal to determine the car's state.

Also it is not a requirement of the car that the EVSE disconnect the power from the charge pins when it is not requesting a charge. The pins are always hot on the RFMC as well as the 120 volt mobile cables when they are plugged in.

 

[dpeilow]

You just beat me to it.

But we also discussed this about 10 days ago in the thread regarding buying a Mennekes plug and making a UMC pigtail.

 

[TEG]

I still consider it a "signal" if it puts a load back to tell the EVSE when it may wish to re-connect main power (for those EVSEs capable of disconnecting it.)
If the RFMC/UMC lacks a relay to disconnect the power when not in "charge mode" then they are missing a safety feature...
(But it makes them smaller, less costly and more reliable.)

 

[Talkredius]

The original Tesla MC240 had a fixed signal generator that would tell the Roadster that 24A was available.

It was a somewhat conservative level since some NEMA15-50 plugs could offer more, but they pre-set it to a level likely to be safely available on any NEMA14-50 you might find.
(I am speaking of the USA version, I am not sure if the UK/Europe version was the same.)

The old EU version can draw 30A (grey plastic box with Tesla black front plate, picture above) the new version 32 A (picture beneath, with the pig tail)

Then there is the RFMC and Tesla Universal Mobile Charger.