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Discussion Starter · #3 ·
I think so, though it may not take advantage of all that extra power for example ac charging power would still be limited to 7.4kW compared to 1 phase:

Thank you for info! I was just wondering, because I have installed EASEE charging box at home (3 phase, 32 amps, 11 kw), but only get constant 4.2 kwh charging speed. So was wondering what is the problem. Could it be the included original Mercedes cable weirdly ranked at 20 amps? Something else?
 

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I am no expert on this but some people seem to be having a similar problem even with 1 phase-


Possible ideas to try-

Check other installs, like if you can charge 7.4kw at public ac chargers, especially with your own cable.

Check the ac charging cable, that you are using to connect the wall box to the car. Might be a 16amp/(20amp?!) cable instead of a 32amp triphase one which should be available from Mercedes.

Check other cars, like if you have access to another electric car, check it can make use of the extra power in your new installation, or perhaps the electrical installer can verify the install.

Check car settings, like Mercedes recommends check the maximum charging current settings in the multimedia systrm menu. Check set to maximum, not 8 amp or less.

Check the charging equipment, such as wall box and ancillary load balance devices, as they could be regulating the power to protect the circuit such as if they are setup for or detect there is a low capacity fuse.

The more info the better, to give to Mercedes Me support or dealer might have an ac charger to verify too. Be interesting to know what Mercedes find.
 

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I have installed EASEE charging box at home (3 phase, 32 amps, 11 kw),
3 phase 32A is 22kW. Are yous sure it's not 3 phase 16A, as that would be 11kW? Post a photo of the circuit breaker and we might be able to tell.

Another possibility: others here have reported low AC charging rates on early EQCs that were fixed by a firmware update to the car.
 

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Discussion Starter · #6 · (Edited)
3 phase 32A is 22kW. Are yous sure it's not 3 phase 16A, as that would be 11kW? Post a photo of the circuit breaker and we might be able to tell.

Another possibility: others here have reported low AC charging rates on early EQCs that were fixed by a firmware update to the car.
Yes it is 3 phase 32A 22kW - you are right. Double circuit braker 2X 16A

Original Mercedes cable is 20A - I have no idea why.
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Discussion Starter · #7 ·
I am no expert on this but some people seem to be having a similar problem even with 1 phase-


Possible ideas to try-

Check other installs, like if you can charge 7.4kw at public ac chargers, especially with your own cable.

Check the ac charging cable, that you are using to connect the wall box to the car. Might be a 16amp/(20amp?!) cable instead of a 32amp triphase one which should be available from Mercedes.

Check other cars, like if you have access to another electric car, check it can make use of the extra power in your new installation, or perhaps the electrical installer can verify the install.

Check car settings, like Mercedes recommends check the maximum charging current settings in the multimedia systrm menu. Check set to maximum, not 8 amp or less.

Check the charging equipment, such as wall box and ancillary load balance devices, as they could be regulating the power to protect the circuit such as if they are setup for or detect there is a low capacity fuse.

The more info the better, to give to Mercedes Me support or dealer might have an ac charger to verify too. Be interesting to know what Mercedes find.
Thanks a bunch! I have ordered another cable from Easee 32A - will see how that goes.

And I will see what speed is charging at some public chargers or dealership - all good ideas!
 

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Yes it is something interesting to try though I'd be surprised if cable supplied with car isn't powerful enough, though the 32amp triphase one is more future proof and designed specifically for the power now installed and may help charge faster other cars that use the charger and will mean you can leave one cable at home while having another spare in the car and you have the option of choosing a different length too. I have 2 cables though only use a 32 amp replacement one, though for a different reason which is because it was 8m instead of the too-short 4m that was ridiculously curly and came with car. I see newer cars come with 5m cable that is not curly, and which would have been just about perfect length for me. Interesting to hear what eventually solves the issue
 

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Discussion Starter · #9 ·
Yes it is something interesting to try though I'd be surprised if cable supplied with car isn't powerful enough, though the 32amp triphase one is more future proof and designed specifically for the power now installed and may help charge faster other cars that use the charger and will mean you can leave one cable at home while having another spare in the car and you have the option of choosing a different length too. I have 2 cables though only use a 32 amp replacement one, though for a different reason which is because it was 8m instead of the too-short 4m that was ridiculously curly and came with car. I see newer cars come with 5m cable that is not curly, and which would have been just about perfect length for me. Interesting to hear what eventually solves the issue
So did try at Mercedes dealer with original Mercedes box - 7.4 kw immediately. Public charger with Mercedes included cable - 5.4 kw - never more. Haven't yet got the replacement cable - will see how that works.
 

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So did try at Mercedes dealer with original Mercedes box - 7.4 kw immediately. Public charger with Mercedes included cable - 5.4 kw - never more. Haven't yet got the replacement cable - will see how that works.
I reckon the 32A cable will almost certainly get you back up to 7.4kW.

There are two current limits, and the car will use whichever is lower. The EVSE (aka wall-box) tells the car how much current it can draw via a PWM signal. That value is set by dipswitches inside the EVSE by your installer. Yours is most likely set to 32A since you've got a 3x32A ganged circuit breaker upstream. In addition, the cable that runs between the EVSE and the car also reports to the car how much current it can carry, via a resistor on the Proximity contact. Yours will be reporting 20A, so the car will choose the lesser of 32A and 20A.

My home EVSE has a hardwired cable and its rated for 32A, so I get the full 7.4kW charging. You inspired me to check the cable that came with the car, and like yours it's only rated for 20A. I rarely use that cable, and only when out and about where it's connected to 22kW 3-phase AC chargers. My 2021 EQC can do 3-phase charging but only at 11kW which is 230V * 16A, so the 20A cable is a good match for that, but it's restrictive when you're trying to charge via a single phase. You are effectively single phase, even though your house and EVSE are all 3-phase, your early EQC can only use one.
 

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Discussion Starter · #11 ·
I reckon the 32A cable will almost certainly get you back up to 7.4kW.

There are two current limits, and the car will use whichever is lower. The EVSE (aka wall-box) tells the car how much current it can draw via a PWM signal. That value is set by dipswitches inside the EVSE by your installer. Yours is most likely set to 32A since you've got a 3x32A ganged circuit breaker upstream. In addition, the cable that runs between the EVSE and the car also reports to the car how much current it can carry, via a resistor on the Proximity contact. Yours will be reporting 20A, so the car will choose the lesser of 32A and 20A.

My home EVSE has a hardwired cable and its rated for 32A, so I get the full 7.4kW charging. You inspired me to check the cable that came with the car, and like yours it's only rated for 20A. I rarely use that cable, and only when out and about where it's connected to 22kW 3-phase AC chargers. My 2021 EQC can do 3-phase charging but only at 11kW which is 230V * 16A, so the 20A cable is a good match for that, but it's restrictive when you're trying to charge via a single phase. You are effectively single phase, even though your house and EVSE are all 3-phase, your early EQC can only use one.
Thank you so much! That is is the answer!
 

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That may actually be the cause of several other slow AC charging reports here. AFAIK you're the first to actually read the label on the supplied cable and see that it's only good for 20A, so well done on tracking it down.
 

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Discussion Starter · #13 ·
So got the 32A cable and problem solved - steady 7.4 kW! I am mesmerised why would Mercedes include cable they know doesn't work and also how uneducated dealerships are about things like charging and electrical setups. Thanks god, we have forums like this and people who take time to help the others! Cheers!
 
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