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[Auriga]

Really tough to say. The next step for you I think is to build an MBB serial cable and issue the charging command. You should be able to see the pilot signal and which chargers are active and what the bike thinks the limit should be.

[NervEasy]

I have such a cable. What command should I use to see this data?

[peterwarm]

Not quite following why you need MBB. Whats wrong with the displayed amps into the battery? It measures into the battery, so doesnt care about which charger it comes from.

I agree with Auriga, what you did by joining L1 and L2 in the cable is fine, as long as you have the supply current. The phasing is lost in the chargers anyway.

But what you ask about the control sequence I can only add my findings: 

The PP line gives the bike and charging point information about the current limit for the cable, by using a particular value of resistor at either end of the cable, connecting that connectors PP pin to earth.  This is used at both ends to limit the  current, at both ends. Typical values are 16A and 32A cable rating and this is per phase, so 3 phase cable has this same limit but on each of three phases.

The CP line is a signal sent using a 1 kHz voltage signal ranging between 12 and -12v (cant remember). Different voltages indicate various states of readiness fro charging, and the value is used to control the current, eg as the current slows as you top off.

I have some of the  simple circuits from the ISO standard for EV charging if you're interested.

I have a SRF with the rapid charger, so I have 3kW, 3kW, and 6kW chargers.  I have made a cable to fit under my seat with two ends: a single phase Uk plug, and a three phase Type 2 connector, all permanently connected to the Type2 socket on the bike with a low profile socket head designed as a 3d printable item by Remmie. (wish I knew how to do references on this forum)

I have often thought, whilst rolling up to a 7kW charge point, that if I could swap the pins in the plug around, I could probably get 6kW out of these charge points, rather than 3kW, as the standard type2 plug seems to default to L1 on single phase.  Not found a simple way to do it yet.

There's a lot on this forum, but nut under Zero, under Hacks,  under "PP and CP control" mentioned earlier. I put my cable design in there.

Let us know how you get on. pete

*mod edit* assist with reference:
+ PP and CP control on a type 2 charger cable
+ SRF charging in EU/UK - how many phases?
+ SRF SRS 3 kW chargers how controlled?

[Auriga]

I believe the command is either charging or chargers

[remmie]

Zero configured the chargers to each be on a separate phase. So if the MBB receives an 8A command from the EVSE, it will send "you can charge at 8A (input)power" to EACH charger.
Because you connected both chargers to L1 (which zero didn't anticipate) they will both receive power and draw 8A, so together they will draw 16A and the EVSE trips because of the excessive current.

There are only 2 ways this is going to work.

1) If your supply AND EVSE can handle at least 26A (preferably 32A) on that single phase. Then both chargers will top out at 13A and the bike will charge at 5.8 kW. but then there is no way of setting the charge level. It will always be flat out at 5.8 kW.
2) Set the EVSE at a specific current, pick up the PWM signal and send a different PWM signal, effectively halving the advertised current. So if you only want to draw 12 amps from the socket you have to pick up the (12A) PWM signal and send a 6A signal. Then both chargers will receive a 6A signal from the EVSE/MBB and charge at that 6A (EACH). You can't go lower than 12A because the standard doesn't allow for an advertised current lower than 6A.
So an 8A draw from the socket from 2 chargers is not possible (by advertising only 4A) unless Zero allows lower amps from the EVSE than 6A (I have not tried that....yet)

[NervEasy]

Hi Remmie thanks for the clarification.

The second option should be possible with an 8A or 10A max. As my goals was 16-20A charging current at the socket (it is capable of that).

I guess I will have to check the OpenEVSE source code to see if I can halve the PWM duty cycle easily and flash a custom firmware to the Open EVSE hardware.

[NervEasy]

Or a dirty hack to check if this works would be to open my EVSE hardware see where the current sensing coil output is fed to the microcontroller ADC pin and place a voltage divider (50%)??