Sound right? Electrician recommended 40A with UF 8/3 outdoor wire to be buried under my concrete

[bewbie]

My electrician recommended 40A with UF 8/3 outdoor wire to be buried under my concrete. Does that sound right?

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[jerock]

It would depend on the charger you plan on using. It's not adequate for the Pro Charger. It's not even adequate for the mobile charger.

 

[jerock]

Ford recommends for the mobile charger a 14-50 outlet which requires a 50 amp circuit. 50 amp circuit which requires 6 gauge wire.

 

[Stlww18]

It would depend on the charger you plan on using. It's not adequate for the Pro Charger. It's not even adequate for the mobile charger.

Mobile charger only pulls 32 amps max, which I’ve found curious given the 14-50 plug. I guess 14-50 is just a more common plug

 

[Amps]

That would work with a 40 Amp breaker and the 32 Amp Ford Mobile. That would be the maximum you could charge on that circuit with any EVSE.

 

[PV2EV]

For a 32amp EVSE, yes. 14h hours for a full charge on an SR battery.

 

[jerock]

Yes you are right about the 32 amp charger & a 40 amp circuit. If I was burying cables under concrete I would future proof it with more than a 40 amp circuit.

Here's the installation recommendations for the 80 amp Pro charger. I'd give this to your electrician. He should know the wiring required for each amperage of charger

https://www.ford.com/cmslibs/conten...ightning/pdf/Lightning_FCSP_Install_Specs.pdf

Here's the installation for Ford's Connected Charge Station & Mobile charger.
https://www.ford.com/ntzlibs/conten...-sheet/Home_Install_Spec_Sheet_0831_FINAL.pdf

 

[krusshall]

Recommended 40A what? The circuit? I would do a 50A rated circuit so that you can have an EVSE rated up to 40A. 8 gauge copper wire ampacity is sufficient and three conductors are needed - two hots and a ground for 240 V.

 

[Stlww18]

That would work with a 40 Amp breaker and the 32 Amp Ford Mobile. That would be the maximum you could charge on that circuit with any EVSE.

Only issue I see is you can either get a 14-30 or a 14-50 receptacle. No such thing as a 14-40. Even with a 40 amp breaker and a 40 am (32 actual) evse, by code you couldn’t put a 14-50 plug on it

 

[PV2EV]

You would be better served/future proofed by going 6-3 UF-B for a 48amp EVSE. That is 10 hours for an SR.

 

[VTbuckeye]

The 14-50 outlet with 8x3 wiring will work for a 30 amp evse, but not for a 40 amp evse. The 14-50 outlet is supposed to be a 50 amp capable outlet and it would be unsafe to only wire it to be 40 amp capable. 14-50 needs to be wired with 6 guage wire to be safe and proper.

 

[bewbie]

it would just be for an ev in general not the f150

 

[Amps]

The 14-50 outlet with 8x3 wiring will work for a 30 amp evse, but not for a 40 amp evse. The 14-50 outlet is supposed to be a 50 amp capable outlet and it would be unsafe to only wire it to be 40 amp capable. 14-50 needs to be wired with 6 guage wire to be safe and proper.

I'm not sure why you think that would be unsafe. I agree that it's not ideal.

You can protect a 14-50R with a 40 Amp breaker. Table 210.24:

https://up.codes/s/branch-circuit-requirements-summary

 

[Amps]

it would just be for an ev in general not the f150

Your electrician is trying to save you money on the cable costs. Others have suggested that you spend a bit more money to future proof it. The electrician has limited you to 32 Amp charging maximum.

 

[besch2410]

I'm going to make the mistake of assuming that this sub-concrete run involves conduit. I'd actually tell you to consider oversizing the conduit, that way of you decide to upgrade to a larger charger (or add a second), the conduit is large enough to meet code. The 40A breaker and 8-gauge is fine. Putting a 50A plug on a 40A circuit is not a problem. The problem would be a hypothetical 40A plug on a 50A circuit (due to excess resistance and heat in the plug if fully loaded).

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