Inverter receptacle phase question ???

[veggie]

Hi All,

I have a 12V, 3000 watt (6000 peak) inverter with four X 120 VAC receptacles in the end plate.
Does anyone know if all 4 receptacles are typically on the same circuit and phase?

My assumption is that they are all on a single phase modified sine wave and that all of them are in sync.
Meaning... (just for the sake of discussion) ... all of the L1 wires could be externally connected together, all of the neutrals could be connected, as well as the grounds.
Thereby creating a single 3000 watt (3000/120 = 25A) outlet . ?
There is only one overload breaker on the unit.
Anyone every investigated this ?

What say ye...

Veggie

[veggie]

Well !!

Being that there are no replies I proceeded to open up the case of the inverter to see if there were any clues.
I found that all four receptacles are wired together and are on the same circuit.
They SHARE the full capacity but each individual 15 amp receptacle would not be able to carry the full load capability due to the wire size (16 Gauge).
All of the L1 spades are connected together internally. Same with the neutrals and grounds.

I assume that if the 4 receptacles were externally joined into one heavy gauge cable (Junction box) the resulting cable would be able to carry load up to the full load of the inverter (3000W or 25A).

Why do this ?
The loads applied to this inverter may be over 50 ft away.
Rather than run 4 extension cords in order to utilize the full capacity, I think it would be useful to run one heavy gauge conductor and terminate at a distribution box with a breaker and some receptacles.

If anyone has any caveats or suggestions please pipe in.

Veggie

[BruceM]

You've handled it just right, I think.
Best Wishes,
Bruce

[LowGear]

I'm pretty sure that NEC doesn't apply but in their book I remember 16 gauge wire isn't rated for 15 Amps at 120 volts.

Casey

[veggie]

I'm pretty sure that NEC doesn't apply but in their book I remember 16 gauge wire isn't rated for 15 Amps at 120 volts.

Casey

Thanks LowGear, my error, I double checked and it is in fact 14 gauge.

veggie

[LowGear]

Sounds like two of the receptacles would be sufficient and would leave two available for easy access at the generator.

Casey

[mike90045]

before you get too excited about hooking up a beefy load to those 4 outlets, consider your 12vdc feed line to the inverter (and the 12V internal inverter wiring)
3Kw @ 90% eff is 3,300watts consumed, at
12V  275A
13V  253A
14V  235A
  It's a pretty stiff drain on a battery bank, and even the resistance on OO gauge cable can still give you some voltage droop.  At some point the low voltage protection will kick in and shut things down.
The origin of the fireball is usually the connection terminals at the inverter, and the internal inverter wires.  They can't fit much OO wire into there.

[LowGear]

Sounds like two of the receptacles would be sufficient and would leave two available for easy access at the generator.

Generator?  I've just got to learn to read.  Inverter, Inverter, Inverter.  The "current" reality is why I thought my SMA string inverter was designed to like the 400 volt area.  So a measly 1500 watt inverter would need 125 Amps from my truck batteries?  Shorter, fatter leads with better connectors might be a plan for Izzy.

Casey

[glort]

For 12V inverters I always calculate by 10 the amp draw on the batteries.  IE 2000W = 200A on the batteries.

This takes into account the 80-90% efficiency of the battery, the varying voltage, voltage drop etc.
If you calculate over and go under, not problems. If you do it the other way around.... Yeah, that might spoil your day.

I was given one of my favorite inverters yesterday.... a UPS. 24V so easy to gang to a couple of car batteries.  Very clean power and come with battery charger and gauge for remaining power as well.
I'll give it a fire up tomorrow and see how it goes.

[LowGear]

I dream of a 36 Volt inverter for my golf cart.  Unusual stuff often costs more than it can deliver.  Going back to the teaching of this thread; Input is really important on low voltage applications.

Casey

[buickanddeere]

Simpler to install 48V of batteries and charger into the golf cart. Had a ride on such a conversion. When the motor controller sensed foot on the floor. The 36V motor received 48V. It would squeal tires on concrete .