Multiplus 2 not shutting down

[boatingmusicman@gmail.]

I am running a Multipluss 2 240v 12v inverter on my boat.
It is not connected to AC shore power, but is connected to onboard gen set.
If we draw too much current (hot water & kettle together) the inverter does not shutting down and eventually blows a 300anp fuse on the 12v feed.
Anyone give me a clue.
I do have a dongle.

 

[Suijkerbuijk]

What model ?
Start with that first .

 

[boatingmusicman@gmail.]

What model ?
Start with that first .

12volt 3000 120amp

 

[boatingmusicman@gmail.]

12volt 3000 120amp

 

[Suijkerbuijk]

12volt 3000 120amp

Not strange the your fuse breaks
3000watt÷ 12 = 250a +10% inverter lost =275
So max that this inverter can do is 6000watts for some sec 550a .

Victron inverter will not shutdown till the heat systeem inside will shutdown.
So you can pull more for longtime .

My own Victron 1200ve do 1000watts on 95A
Still it Run my microwave that pull 1245watts easy for 10min to make my dinner without shut down.
Reason it can do max 2000watts.
And the systeem stay cool so i can pull more.

Best thing is to plug a watt meter between the inverter and your stuff you use to see how much watts you pull.

In the best conditions your inverter can do 130% for 10 min or more. (3900watts 325a )
And with lifepo4 and 25 Celsius with good wire you can pull it .

That is the reason that my microwave run on my 1000watt inverter (130% = 1300watts.)

Edit Manuel explain.
400a for that model.

 

[Rocketman]

In your owners manual it tells what fuse & wires to use.
My 120v Multiplus II 12/3000 2x120v requires 2x 1/0 wire (that’s two hots and two commons of 1/0 wire) and a 400a fuse. I used 4/0 wire and a 400amp fuse - which ends up slightly fewer amps can travel down the wire. (Reused the too long 4/0 OEM MotorHome cable).

With two large items - Microwave & Hairdryer - my voltage will drop below the cutoff and I get several alerts at once - low voltage, overload of watts, and high ripple, and it shuts off due to low voltage after about 1 second.

My guess is you may need to upgrade both the wire & the fuse. Remember the fuse protects the wire - so the fuse CANNOT be larger than the wire can support.

Also what style of fuse do you have? - class T, MBRF, Mega, etc?

 

[HarryN]

Maybe put a breaker on the 120 vac side so it cuts off if your load is too high.

 

[boatingmusicman@gmail.]

Not strange the your fuse breaks
3000watt÷ 12 = 250a +10% inverter lost =275
So max that this inverter can do is 6000watts for some sec 550a .

Victron inverter will not shutdown till the heat systeem inside will shutdown.
So you can pull more for longtime .

My own Victron 1200ve do 1000watts on 95A
Still it Run my microwave that pull 1245watts easy for 10min to make my dinner without shut down.
Reason it can do max 2000watts.
And the systeem stay cool so i can pull more.

Best thing is to plug a watt meter between the inverter and your stuff you use to see how much watts you pull.

In the best conditions your inverter can do 130% for 10 min or more. (3900watts 325a )
And with lifepo4 and 25 Celsius with good wire you can pull it .

That is the reason that my microwave run on my 1000watt inverter (130% = 1300watts.)

Edit Manuel explain.
400a for that model.

Thanks for that info. Seems I may need heavier cables ...batteries to inverter.