Portable charger question

[Glueslug]

Hi Everyone -
My question is about these portable chargers that are both Level 1 and 2, such as the Ford Mobile charger, Webasto Go, or the soon-to-be-released Lectron portable charger. I see that they support 40 amps on a Nema 14-50 plug backed by a 50 amp circuit. But what happens if you plug them into a 14-50 that is backed by a 40 amp circuit? There doesn't seem to be any switch or setting on them to configure. Does anyone know with certainty that they automatically control the amps they will pull?

Much thanks!

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[Mach-Lee]

At least the Ford/webasto charger is 32A, which is safe to use on either a 40A or 50A breaker. So they set the amps low enough to work on both types of circuits.

 

[Glueslug]

Thats interesting about the Ford/Webasto charger, since the instructions for it call out for a 50 amp circuit. I must have assumed that it be 40 amps. Thanks!

 

[HuntingPudel]

Even the Tesla Mobile Connector runs at 32A with its 14-50P pigtail. ??

 

[Gyrfalcon08]

The ford mobile doesn’t regulate and isn’t configurable so if you plug in to something protected by 32A or less while on lvl 2 it’ll blow the breaker. Ie trying to use adapter to old 30a dryer outlet etc.

 

[zvez]

Thats interesting about the Ford/Webasto charger, since the instructions for it call out for a 50 amp circuit. I must have assumed that it be 40 amps. Thanks!

but by definition and I guess electrical codes guidelines, a nema 14-50 plug is supposed to be on a 50 amp breaker. I can't imagine an electrician wiring that configuration plug to something different from specs.

 

[Pedro Diaz]

I can asure you by personal experience that in all my trips to Florida, and I stayed at a RV park, I've plug in to their shore power stand (parallel to my 30A RV) on the 50A 14-50 outlet. It has never tripped. And the FordPass reported charging at 12 kWh. I don't have evidence of this but it is true. I use the standard portable charger every day as my main charger at home on a 110v outlet. But plan to install a 14-50 outlet soon. I've recently drained my battery to 1% and it's took 69.5 hrs to charge to 87% (236 mi @ 1 kWh). If I was on 14-50 it would be 100% 9-10 hr.

 

[Adventureboy]

I can asure you by personal experience that in all my trips to Florida, and I stayed at a RV park, I've plug in to their shore power stand (parallel to my 30A RV) on the 50A 14-50 outlet. It has never tripped. And the FordPass reported charging at 12 kWh. I don't have evidence of this but it is true. I use the standard portable charger every day as my main charger at home on a 110v outlet. But plan to install a 14-50 outlet soon. I've recently drained my battery to 1% and it's took 69.5 hrs to charge to 87% (236 mi @ 1 kWh). If I was on 14-50 it would be 100% 9-10 hr.

What EVSE are you using for this? No UL-certified 14-50 pluggable EVSE will allow more than 40 amps. If you are seeing 12kw in Fordpass, I expect there is something wrong with the monitoring mechanism, since this would require 53-55amps at the plug.

 

[RickMachE]

I can asure you by personal experience that in all my trips to Florida, and I stayed at a RV park, I've plug in to their shore power stand (parallel to my 30A RV) on the 50A 14-50 outlet. It has never tripped. And the FordPass reported charging at 12 kWh. I don't have evidence of this but it is true. I use the standard portable charger every day as my main charger at home on a 110v outlet. But plan to install a 14-50 outlet soon. I've recently drained my battery to 1% and it's took 69.5 hrs to charge to 87% (236 mi @ 1 kWh). If I was on 14-50 it would be 100% 9-10 hr.

Ford Mobile Charger is 32amps. 32 x 240 = 7.7kW BEFORE loss to vehicle.

Max charging rate for the Mach-E is 48amps. 48 x 240 = 11.5kW BEFORE loss to vehicle.

So, 12kWh isn't possible.

 

[ChasingCoral]

Hi Everyone -
My question is about these portable chargers that are both Level 1 and 2, such as the Ford Mobile charger, Webasto Go, or the soon-to-be-released Lectron portable charger. I see that they support 40 amps on a Nema 14-50 plug backed by a 50 amp circuit. But what happens if you plug them into a 14-50 that is backed by a 40 amp circuit? There doesn't seem to be any switch or setting on them to configure. Does anyone know with certainty that they automatically control the amps they will pull?

Much thanks!

1. A 14-50 outlet should NEVER be installed on a 40A circuit.
2. The Ford Mobile Charge Cord has no way of knowing the circuit capacity. If you plug it into a NEMA 14-50 outlet supplying 240v it will pull at its full rated capacity. If the circuit can't supply that draw safely it is up to the circuit breaker to shut off the power before the circuit fries. There is no "automatic control".

At least the Ford/webasto charger is 32A, which is safe to use on either a 40A or 50A breaker. So they set the amps low enough to work on both types of circuits.

The Ford Mobile Charge Cord sold for the Lightning is limited to 30A rather than the 32A draw on the one sold for the Mach E and eTransit.

 

[Glueslug]

1. A 14-50 outlet should NEVER be installed on a 40A circuit.

I am little confused though. If the mobile charger pulls at a max of 32 amps, wouldn't a 40 amp circuit be fine? It's within the 80% rule.

 

[dtbaker61]

Thats interesting about the Ford/Webasto charger, since the instructions for it call out for a 50 amp circuit. I must have assumed that it be 40 amps. Thanks!

Breaker required by code for NEMA 14-50 is 50a, with 6awg wiring on conductors.

A NEMA 14-50 plug/receptacle is rated for 50a MAX current, but recommended use is 36amps 'continuous' for 3+hrs.... 32amps is a little conservative, but safer and won't heat up.

 

[dtbaker61]

I am little confused though. If the mobile charger pulls at a max of 32 amps, wouldn't a 40 amp circuit be fine? It's within the 80% rule.

a hardwired EVSE could be set to go 'up to' 40amps, but 38a is safer.
introducing the NEMA 14-50 p/r introduces a little resistance, and thus a little heat which becomes a problem with 3+ hour use.... and reduces the recommended load to 32amps for safety.

It is a terrible idea to push the limits for faster charging... the risk of fire goes way up with the slightest error in wire size, wiring torquing, or a loose connection from thermal cycling causing arcing.

 

[ChasingCoral]

I am little confused though. If the mobile charger pulls at a max of 32 amps, wouldn't a 40 amp circuit be fine? It's within the 80% rule.

Your charger isn't the point. A NEMA 14-50 outlet should never be installed on a 40A circuit due to the National Electrical Code requirements. When someone sees a NEMA 14-50 outlet, they will assume it is installed on a circuit capable of delivering 50A. That person may then plug in a 40A charger, thinking the circuit is appropriate.

If they are lucky, the circuit breaker will trip.
If they are unlucky the fire will consume the garage, the car, then spread to the house with the family sleeping inside.

 

[ChasingCoral]

I am little confused though. If the mobile charger pulls at a max of 32 amps, wouldn't a 40 amp circuit be fine? It's within the 80% rule.

If you do find a 40A circuit and use the proper adapters to go from your NEMA 14-50 plug into the receptacle on that 40A circuit, yes, you may charge on that circuit using your 32A charger.

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