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[Doctorbass]

For the case where the charger  are not split in few units to share all the power seperatly  it will require a J plug with single 240v with more than 30A.  ex: new ultra power charger that might come in the future.

I just wonder if someone tried to parallel the AC output of two J plug together for a single charger unit that need more than 6.6kW (30A) ?


As well i know that it might be tricky as some L2 charge station are on 208v witch mean they are on one of the 3 phase.. And sometime two  charge stations at the same area might be on different phase witch mean they can not be paralleled as both are 120 degree out of phase...

But for the case where it only require to know if the two J plug are in phase or out of phase, a simple 240V coil relay could solve the problem and auto arrange phase for making paralleling possible.

Does anyone tried that yet?

Doc

[jnef]

For the case where the charger  are not split in few units to share all the power seperatly  it will require a J plug with single 240v with more than 30A.  ex: new ultra power charger that might come in the future.

I just wonder if someone tried to parallel the AC output of two J plug together for a single charger unit that need more than 6.6kW (30A) ?


As well i know that it might be tricky as some L2 charge station are on 208v witch mean they are on one of the 3 phase.. And sometime two  charge stations at the same area might be on different phase witch mean they can not be paralleled as both are 120 degree out of phase...

But for the case where it only require to know if the two J plug are in phase or out of phase, a simple 240V coil relay could solve the problem and auto arrange phase for making paralleling possible.

Does anyone tried that yet?

Doc

No, it won't work--  you'll almost definitely trip the rcd/gfci built into the evse.  You would have to stay under 30ma of imbalance, which given the uncertainty of the cable/connector resistances would be practically impossible. You would need transformer or similar isolation...


Sent from my iPhone using Tapatalk

[Doctorbass]

For the case where the charger  are not split in few units to share all the power seperatly  it will require a J plug with single 240v with more than 30A.  ex: new ultra power charger that might come in the future.

I just wonder if someone tried to parallel the AC output of two J plug together for a single charger unit that need more than 6.6kW (30A) ?


As well i know that it might be tricky as some L2 charge station are on 208v witch mean they are on one of the 3 phase.. And sometime two  charge stations at the same area might be on different phase witch mean they can not be paralleled as both are 120 degree out of phase...

But for the case where it only require to know if the two J plug are in phase or out of phase, a simple 240V coil relay could solve the problem and auto arrange phase for making paralleling possible.

Does anyone tried that yet?

Doc

No, it won't work--  you'll almost definitely trip the rcd/gfci built into the evse.  You would have to stay under 30ma of imbalance, which given the uncertainty of the cable/connector resistances would be practically impossible. You would need transformer or similar isolation...


Sent from my iPhone using Tapatalk

Yes it make sense the mA imbalance relative to the ground might make these to go into protect...

[jnef]

Yes it make sense the mA imbalance relative to the ground might make these to go into protect...

It's more sensitive than that--  the evse is just measuring the net imbalance between L1/L2 and is assuming the difference is flowing through ground. But in this case there is the other path of the other evse.  It would mean that for each evse, their resistance from where you join them together, all the way back to where L1 and L2 meet in common again upstream, have to be within 30mA.  I wouldn't categorize it as might, but rather almost surely.

[Electric Cowboy]

Electricians often assume it's AC so it does not matter the order you put the wires and so the phases on two identical chargers right next to each other could be reversed and short when you parallel them.

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[Electric Cowboy]

We did testing on this, fireworks ensued.

Do not do this.

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[Electric Terry]

I've tried many times, and it ground faults the stations immediately. I even tried with massive diodes and it doesn't work. Just faults the station.  This is whay chargers over 6.6 kW don't make sense. But it does make sense to have multiple 6.6 chargers that are isolated for use with multiple plugs

[Shadow]

...This is [why] chargers over 6.6 kW don't make sense. But it does make sense to have multiple 6.6 chargers that are isolated for use with multiple plugs

Chargers over 6.6kW can use Tesla Destination Chargers, 15kW J1772 stations (rare, but they do exist I have seen one in person), and say 3-phase power anywhere beyond the USA's terrible electrical grid.

[togo]

Just googled that, there's one at a casino in Boise Idaho

https://www.plugshare.com/?location=85965

[Electric Terry]

So you can run 5 Diginow 3.3's off a 16 kW Tesla station but you couldn't run a 8 kw or higher single charger off 99% of J plugs which are 95% of available charging locations. Again as I said above, it doesn't make any sense to have any single Charger over 6.6 kW.

[Shadow]

Source of data?

[togo]

> For the case where the charger  are not split in few units to share all the power seperatly  it will require a J plug with single 240v with more than 30A.  ex: new ultra power charger that might come in the future.

> I just wonder if someone tried to parallel the AC output of two J plug together for a single charger unit that need more than 6.6kW (30A) ?

Maybe if you run them through big rectifiers first.

EDIT: NO!  Can still have a ground mismatch.  You'd have to run at least one of them through a transformer to isolate and then rectify individually, and even then it could only work if you have chargers that tolerate DC input.  Luckily they generally do (switch mode power supplies start with a rectifier).

[Electric Terry]

You can not parallel 2 J plugs whether its on the same phase or not.  It's current sensing on each leg is so precise a 50 mA differential and the station will fault by EVSE requirement code.  That's what at 240 volts was determined the maximum a 5 year old child touching the hood of a car where the charger wires are chaffed and touching the chassis could not have her muscles freeze so she could not pull away.   I agree it's ridiculously low and that's why the standard Zero gets ground faults from some stations just using the Calex charger.   

But with the superchargers there is no need to parallel J plugs anyway, you just run each plug to its own set of chargers.  No need to try to solve something that isn't broken.  But with this, there isn't any solving it anyway.  You'd have to hack the code of the station to allow small spikes over 50 mA to get this to work without ground faulting

But there's also a 1 in 3 chance that the stations will have their frequency 1/180th of a second out of sync. or 120 degrees out.