Will 110V precondition ok?

[willowma]

Getting a Homeflex installed (new hardwired circuit) on June 3 prior to my Mach-E arriving. Have a 200 amp supply but still not sure whether remaining capacity will support 40 amp charging on a 50 amp breaker during the day, or whether would be safer to limit it to 32 amp charging. Wondering if a possible strategy would be to charge between 11 pm and 7am at 40 amp rate using the Homeflex (when there will only be home 240v AC competing in the summer). The other 240 circuits (range, dryer) would not be in use then.
Thinking that the only time I would need to charge during the day would be to precondition/preheat in winter before leaving. Wondering if connecting the Mobile charger at 110 volt would be enough just for this preconditioning. Does this seem reasonable to avoid having to limit the Homeflex circuit to a 40 amp breaker and 32 amp draw?

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[DocOfClocks]

Getting a Homeflex installed (new hardwired circuit) on June 3 prior to my Mach-E arriving. Have a 200 amp supply but still not sure whether remaining capacity will support 40 amp charging on a 50 amp breaker during the day, or whether would be safer to limit it to 32 amp charging. Wondering if a possible strategy would be to charge between 11 pm and 7am at 40 amp rate using the Homeflex (when there will only be home 240v AC competing in the summer). The other 240 circuits (range, dryer) would not be in use then.
Thinking that the only time I would need to charge during the day would be to precondition/preheat in winter before leaving. Wondering if connecting the Mobile charger at 110 volt would be enough just for this preconditioning. Does this seem reasonable to avoid having to limit the Homeflex circuit to a 40 amp breaker and 32 amp draw?

You are probably overthinking it. With a 200 amp supply it is hard to imagine this is a problem.

 

[willowma]

No, it's a real issue. We have a complex setup (solar, battery backup feeding 40 amp main breaker for critical circuits on subpanel, lots of other 110 circuits on main panel including dehumidifier, sump pump, elevator, high volume forced air, .........). Nothing tripping today but very difficult to estimate actual peak amps ahead of time with the new circuit.

 

[Chudsaviet]

No, it's a real issue. We have a complex setup (solar, battery backup feeding 40 amp main breaker for critical circuits on subpanel, lots of other 110 circuits on main panel including dehumidifier, sump pump, elevator, high volume forced air, .........). Nothing tripping today but very difficult to estimate actual peak amps ahead of time with the new circuit.

I think electrical code shall not allow installing anything that exceeds capacity of your panel.
But in case you get this - yes, 110v will allow precondition, but on a somewhat lower speed.
I’m actually thinking that there shall be an EVSE that varies its peak current based on schedule. J1772 protocol allows this.

 

[Chudsaviet]

Actually, just set charging schedule to night. It does not affect precondition, and precondition does not use full 40 amps.

 

[willowma]

Yes, one of the reasons I bought the Homeflex is the ability to set amps via the mobile app rather than dip switches. Without being able to set this automatically via a schedule, I can't imagine I would want to change this manually each day though.

 

[willowma]

Actually, just set charging schedule to night. It does not affect precondition, and precondition does not use full 40 amps.

Ok, that's what I was missing. This would be much simpler than connecting the mobile charger each day before preconditioning in winter.

 

[generaltso]

A 120V outlet does not supply enough power for preconditioning, particularly in the winter. The car will still precondition if you tell it to, but it will use battery power to supplement the lack of power coming from the wall. That may not be what you want.

 

[willowma]

A 120V outlet does not supply enough power for preconditioning, particularly in the winter. The car will still precondition if you tell it to, but it will use battery power to supplement the lack of power coming from the wall. That may not be what you want.

Any idea what the amp draw would be for Massachusetts winter preconditioning in the day if I use the Homeflex for 40 amp charging at night only?

 

[generaltso]

Any idea what the amp draw would be for Massachusetts winter preconditioning in the day if I use the Homeflex for 40 amp charging at night only?

Don't quote me, but I seem to remember reading that the heater can draw around 5kW. At 240V, that's around 21A. It would take twice the amperage on 120V, which clearly can't happen.

 

[willowma]

Don't quote me, but I seem to remember reading that the heater can draw around 5kW. At 240V, that's around 21A. It would take twice the amperage on 120V, which clearly can't happen.

Thanks, that's helpful.

 

[OttawaGuy]

No, it's a real issue. We have a complex setup (solar, battery backup feeding 40 amp main breaker for critical circuits on subpanel, lots of other 110 circuits on main panel including dehumidifier, sump pump, elevator, high volume forced air, .........). Nothing tripping today but very difficult to estimate actual peak amps ahead of time with the new circuit.

I'm in a similar situation

Had a DCC-12 installed... it's manages the current use and stops sending current to the EV if you exceed 80% of panel capacity


You can get 48A charger with this (60A circuit)

 

[OttawaGuy]

No, it's a real issue. We have a complex setup (solar, battery backup feeding 40 amp main breaker for critical circuits on subpanel, lots of other 110 circuits on main panel including dehumidifier, sump pump, elevator, high volume forced air, .........). Nothing tripping today but very difficult to estimate actual peak amps ahead of time with the new circuit.

See my setup now. 2 bottom right boxes are for EV charging setup

Message me if you need info on dcc-12

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