New Charge Point Flex Charger not giving full current

[jeffdawgfan]

Just installed a new Charge Point flex Charger. My old Juice Box finally bit the dust after seven faithful years with no problems. So any way, installed the new Charge Point (plug in) on a 240v 50 amp circuit. After entering breaker rating in the charge point app the charger is still only giving about 9.2kw. My ford app says the car is charging at 8.8kw. It seems to me that I should max out at around 12kw on the 50 amp service??? Cable is not hot so should not be temp restricted.

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[johnnycombo]

50 amps x .8 = 40amp max current, 40amps x 220 = 8.8kwh
60 x .8 = 48. 48 x 220=10.56kw
Breaker amps multiplied by .8 gives you the maximum continuous current for the breaker. https://learnmetrics.com/sizing-a-circuit-breaker-breaker-size-calculator/

 

[markboris]

Adding to this, the only way the ChargePoint Homeflex charger will provide the full 48 kWh output is if its hard wired to a 60A breaker. This is in the installation manual.

 

[rreddy3]

My charge point EVSE is on a 60 amp breaker so is capped at 48 amp output. 240v. At the charge point I routinely charge at 11.5 kw or a bit higher. The car is routinely taking in 10.5 +/- a fraction. I would think your evse ought to be delivering in mid 9 kw range with car accepting mid + 8s. I think the rule of thumb is the car loses about 10% of the evse delivered amount to the onboard charger. Looking at your comments again, it looks like the 50A breaker set up is ultimately delivering about the right amount given the code 80% continuous duty rated cap and losses to the onboard charger. My incoming electric service is 200A so I had the capacity in incoming and physically in the breaker box to easily support 60A for the EVSE. With plug in you’re limited to 50A even if your incoming amps and box size will support 60A. Mine is hardwired which along with existing capacity allowed for 60A breaker.

 

[generaltso]

This is why ChargePoint built there system to automatically limit the current when a breaker size is entered instead of relying on the customer to do the math.

 

[tbrumleve]

Same EVSE, same breaker. 50A will give you 40A charging. 9.2kW from the EVSE - heat loss = 8.8kW. This matches what I see daily. The CP will set it self correctly for the breaker you have. If you were previously pulling 50A on a 50A circuit, you are darned lucky your home didn’t burn down.

 

[devmach-e]

Just installed a new Charge Point flex Charger. My old Juice Box finally bit the dust after seven faithful years with no problems. So any way, installed the new Charge Point (plug in) on a 240v 50 amp circuit. After entering breaker rating in the charge point app the charger is still only giving about 9.2kw. My ford app says the car is charging at 8.8kw. It seems to me that I should max out at around 12kw on the 50 amp service??? Cable is not hot so should not be temp restricted.

The Ford app shows what is going into the battery, not what is drawn from the wall. It is always less. If the ChargePoint app is showing 9.2 kW, it is possible that you are seeing some voltage sag. I.e you get 230V instead of the nominal 240V.

 

[RickMachE]

This is why ChargePoint built there system to automatically limit the current when a breaker size is entered instead of relying on the customer to do the math.

Yup. People don't read manuals.

 

[johnnycombo]

After using your 50 amp breaker for seven years on a continuous load, you should replace it with a new 50amp breaker. After that many heat and cool cycles things just get old and worn out.

 

[devmach-e]

After using your 50 amp breaker for seven years on a continuous load, you should replace it with a new 50amp breaker. After that many heat and cool cycles things just get old and worn out.

That’s partially why the breaker and wire are oversized For the load. I’m going on 12 years with a 40A breaker and a 32A EVSE.

 

[jeffdawgfan]

Same EVSE, same breaker. 50A will give you 40A charging. 9.2kW from the EVSE - heat loss = 8.8kW. This matches what I see daily. The CP will set it self correctly for the breaker you have. If you were previously pulling 50A on a 50A circuit, you are darned lucky your home didn’t burn down.

Wasn't pulling 50 amps. It was a 32amp juice box on a 40 amp breaker. I installed a new breaker and ran a 6-3 cable in conduit to the the new charger. My math sucks I guess. I was miscalculating. Thanks everyone for re-calibrating my brain.....

 

[tbrumleve]

Wasn't pulling 50 amps. It was a 32amp juice box on a 40 amp breaker. I installed a new breaker and ran a 6-3 cable in conduit to the the new charger. My math sucks I guess. I was miscalculating. Thanks everyone for re-calibrating my brain.....

Glad all is well.

 

[Mach-Lee]

After entering breaker rating in the charge point app the charger is still only giving about 9.2kw.

That is a normal charge rate. Current will be limited to 40A on a 50A breaker to comply with electrical codes for safety. The amount of voltage drop you have at your house determines the actual rate. You may see as low as 9.0 kW. FordPass reports the power reaching the battery after charging losses, so that reading will be around 8.5 kW. Again this is all normal/expected values, no concern here.

 

[highland58]

I'm pretty sure the only difference between the 60A hardwired and the 50A plug-in is the cord. You should be able to replace the 50A plug-in cord with a 60A hardwire cord and use a 60A breaker. You just open the front of the EVSE, and replace the old plug-in cord with a hard-wire cable. I could be wrong but I seem to remember that is an option.

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