2400 watt outlets on 2024 TRD Off Road, branch wiring undersized?

[BillA]

I dismounted the screws securing the 120 volt / 2400 watt (20 amp) bed outlet to see if it would be possible to tap it for a pigtail installation so the power would be more readily accessible under the ‘Decked’ drawer system.
I was dismayed to discover that the wiring harness connecting the outlet is manufactured using what looked like #18 AWG copper wire.
While granting that motor vehicles are not covered under the National Electric Code, even under the most generous (90*C) installation column 18 gauge wire is only rated for 14 amps (1680 watts) on table 310-16 of that Code.
I abandoned any plan involving altering the wiring harness connection to the outlet and left it as-is from the factory . I plugged in a short store bought 20 amp pigtail and used it to make the power more accessible ‘below Deck’ and will commence looking for a compatible ‘in use’ cover for the outlet since the pigtail will be there all the time.
I praise Toyota for the innovative provision of a more powerful outlet, sourcing it from the Traction battery, and enabling the automatic start of the truck as needed to provide power. I recognize their wisdom and experience in the manufacturing of great vehicles, but I’m an electrician, and plan on replacing the fuse on that branch circuit with one sized more appropriately.
In my opinion the proper thing for Toyota to do would be to replace the wiring harness with one featuring conductors robust enough to carry the potential ampacity without overheating.

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[MT-Taco]

I’m sure Toyota’s Electrical Engineers did their homework…

 

[Sagebrush]

securing the 120 volt / 2400 watt

Isn't it 400 watts? 3 amps?

 

[TacoWill]

Isn't it 400 watts? 3 amps?

Sounds like OP has a hybrid. They have a 2400 watt outlet in the bed.

 

[Sagebrush]

They have a 2400 watt outlet in the bed.

Gotcha.

 

[BillA]

Yes, 2400 watts, 20 amps at 120 volts. Sourced from the 1.87 kWh Traction battery, engine will restart as needed to supply more power as needed.
planned use is for backup to solar on travel trailer.

 

[Forest Moon]

The wiring may have more strands than a standard thhn type conductor? If so, that would increase the max ampacity rating without increasing the diameter. Just guessing here as I haven' t seen this wiring myself.
Or it could be Toyota is just assuming that nobody's going to be running a continuous load on the bed outlet. It would take more than 20a here and there to actually start to break down an 18g conductor.

 

[trailhunger]

I’m charging a power station and M18 batteries all the time, from both cab outlet and bed outlet, near peak inverter threshold often, only complaint I have is the noise it gives off in the cab. Haven’t fried anything yet. My power station can simultaneously pull DC through through its solar port and 120v, truck throws buckets of energy super impressive. Blink and your gear is ready to be put back to work

EDIT: Also noticed something interesting about the inverter. If you’re driving around town doing errands in ECO mode and sitting in a parking lot with the engine off, trying to squeeze every last watt into your power station before the engine cycles back on, the inverter will voluntarily shut itself off the next trip you take; the NiMH gets depleted and between directing driving HP & inverter power, it chooses HP.... I’ve noticed this a couple of times. Basically you can't borrow from Peter to pay Paul. After a few minutes of driving tho, you press the 120V button and stays on the duration of your trip. [in ECO mode, that is. Obviously sport mode throws an assload of power at the expense of MPGs / normal mode seems to use the turbo less in town, with higher RPMs, so I think normal might be the right balance of short distance driving & the intention to charge batteries & power equipment].

 

[hemlockz]

Yes, 2400 watts, 20 amps at 120 volts. Sourced from the 1.87 kWh Traction battery, engine will restart as needed to supply more power as needed.
planned use is for backup to solar on travel trailer.

Does the 2400 have a 5-20R receptacle in the bed? Or 15A kind?

 

[wire4money]

The wiring may have more strands than a standard thhn type conductor? If so, that would increase the max ampacity rating without increasing the diameter. Just guessing here as I haven' t seen this wiring myself.
Or it could be Toyota is just assuming that nobody's going to be running a continuous load on the bed outlet. It would take more than 20a here and there to actually start to break down an 18g conductor.

That’s not how it works

 

[wire4money]

Ampacity of wire is determined by the insulation. If you look at the National Electric Code, 16 gauge wire with a 90 degree Celsius rated insulation is good for 18a.

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