Microwave Overloading my 3000W inverter

[WTrippe]

Hi,

So my generator quit working on me the other day. Until I can find some help to pull it out of my RV and change the starter I've been using my inverter.

I've got a 3000W GoPower pure sine wave inverter. 8x 6v AGM batteries wired as a 12V bank with around 1k AH. Everything is wired with 4/0 gauge wires.

It connects to a transfer switch along with the shore power cord. It also has a relay in there that shuts off the converter when the inverter is on.

It should surely be enough to run my microwave. It's only 800W or 1200W at most. I run the engine to compensate for the voltage drop.

When I try running the microwave the OUTPUT on my remote display maxes out and the inverter shuts off with the overload protection.

Any input is greatly appreciated.


Thanks,

William

[pianotuna]

Hi,

Are the batteries wired in a balanced manner?

[ktmrfs]

WTrippe wrote:

GordonThree wrote:
X2 on 2oldman's suggestions.

My humble opinion, 2-0 isn't enough for that size inverter, but I'm a pessimist and wire for worst case and then some.

Manual suggested 4/0 so I stepped it up to 2/0.

sorry 4/0 is much higher capacity than 2/0. 4/0 wire is larger cross section than 2/0.

BTW I use 4/0 with my 1000W sine wave inverter to run my panasonic true inverter microwave. draws about 800VA at 50% power.

and a 1200W microwave refers to the output power of the magnetron. with a 1200W microwave, actual VA draw is likely close to 1600 or even 1800VA. you have the power supply efficiency and the fact it is not a resistive load but an inductive load.

But, with proper wiring and 4 or more 6V batteries, I would expect you should be able to run the microwave.

[BFL13]

SidecarFlip wrote:
I don't believe your wiring is heavy enough. I use welding cable myself.

I have no problem with my MW pulling 120 amps with four feet of #1 AWG (8 ft round trip) staying above the 11 volt alarm with the batts down near 50% SOC. (0.6v drop) He has way fatter wiring than that (don't know how long though).

His readings with the coffee maker are very good, so can't see the inverter-battery wiring as an issue. Something about the complicated installation set -up as to what is wired to what is my guess.

[SidecarFlip]

I don't believe your wiring is heavy enough. I use welding cable myself.

[BFL13]

How is the inverter 120v side wired up for what appliances are on what? IE is the MW on a different sub-panel from the other things that work ok? Try plugging in the MW to a receptacle that runs the kettle ok and see if the MW runs ok there.(will need an extension cord )

What is the 3a on standby compared with the 6a water heater? 3a 120v??? Makes no sense. Inverter on standby, no load, would have maybe 1/2 an amp DC although inverter/chargers seem to have more what with their extra "features".

What is the "output" all about? Not following. 😞

Like the others, I have no problem running the MW with a 2000w inverter. But I don't have a remote display and transfer switch and relay etc. I plug the shore power cable into the Inverter and shut off the converter etc manually.

[WTrippe]

GordonThree wrote:
4/0 is a lot heavier than 2/0

my mistake, I checked my amazon orders.

This is the wire I used.

https://www.amazon.com/gp/product/B00LIB60WW/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

TEMCo WC0342 - 50' (25' Blk, 25' Red) 4/0 Gauge AWG Welding Lead & Car Battery Cable Copper Wire BLACK + RED | MADE IN USA

[GordonThree]

4/0 is a lot heavier than 2/0

[WTrippe]

time2roll wrote:
Yes very odd. You are certain there are no other loads on before you hit go on the MW?

My GP 2000 SW runs my Dometic MW just fine at about 1700 watts. 4x GC2 no assist unless the sun is shining.

I would be checking actual power draw with a clap-on ammeter. Check both the AC out and the DC in. Also verify DC voltage on the actual inverter terminals.

Has it run the MW previously?

Yes it has run the MW before. I remember making popcorn with it when I only had 4 batteries and it would drop the voltage down to below 12V but the output would be around 50% at most. After I got 8 batteries I tried it again and the voltage stayed above 12V with a 50% draw. I didn't use it for a long time I've been using the generator to make coffee and cook with until now.

[WTrippe]

GordonThree wrote:
X2 on 2oldman's suggestions.

My humble opinion, 2-0 isn't enough for that size inverter, but I'm a pessimist and wire for worst case and then some.

Manual suggested 4/0 so I stepped it up to 2/0.

[time2roll]

Yes very odd. You are certain there are no other loads on before you hit go on the MW?

My GP 2000 SW runs my Dometic MW just fine at about 1700 watts. 4x GC2 no assist unless the sun is shining.

I would be checking actual power draw with a clap-on ammeter. Check both the AC out and the DC in. Also verify DC voltage on the actual inverter terminals.

Has it run the MW previously?

[Mandalay_Parr]

My 2000 watt MSW inverter runs my big microwave just fine.
I agree with all suggestions above.

[WTrippe]

MrWizard wrote:
fridge ?
wiring ?
inverter failure ?
MW is on its way out ?

is that 3000 peak watts? or continuous watts

try (2) electric heaters on different circuits
heater and foreman grill
any combo over 2000w and see 'how' it functions

Fridge runs off the propane.
I started up the coffee maker without the engine running so I could see the draw.
I'm using about 900W, 75A with it running and batteries holding at 12.4 V
remote display on the inverter is showing a 50% output which is too high.

http://gpelectric.com/products/3000-watt-pure-sine-wave-inverter

3000W continuous, 6000W surge.

[Lwiddis]

“I run the engine to compensate for the voltage drop.”

So when you...need...to microwave...a real need...you are running your generator AND your TV or MH engine? How about your toad? Kick that engine too. Should be enough.

[MrWizard]

fridge ?
wiring ?
inverter failure ?
MW is on its way out ?

is that 3000 peak watts? or continuous watts

try (2) electric heaters on different circuits
heater and foreman grill
any combo over 2000w and see 'how' it functions

[2oldman]

WTrippe wrote:
Foreman grill, coffee maker, rice cooker all work fine .

Those are also high draw items, the only difference being MW's have a startup surge. It is possible the 2/0 won't take that.

Try running the air conditioner.