Inverter does not power up microwave

[paulga]

I have a 1,000w Sharp Carousel Microwave in the galley and a 2,000w Xantrex Inverter. I have not figured out why the inverter does not turn on the microwave's status light. So when underway or at anchor, I have to crank up the Genset to use the microwave.

Is the inverter supposed to power up the microwave?

I have attached the breaker panel setting, is there some switch I have missed?

There are two inverters, the left one is 1000w dedicated to the refrigerator. The right one is the 2000w Xantrex.

 

[lwarden]

It's possible your Xantrex inverter is a modified sine wave. If your micro is an inverter style, which I believe a Sharp is then it might not play well with that inverter style.

Or, it could be that the micro circuit is only wired to the leg going to the genset and not the inverter. But as I said, that might be intentional since the micro may not run from the Xantrex inverter.

 

[tiltrider1]

You didn’t mention the inverter model number. It is very likely a modified sign wave instead of a pure sign wave. Microwaves do not like modified sign wave inverters.

I would take a multimeter meter to the microwave’s outlet while on the inverter just be sure that the socket is wired to the inverter.

 

[SteveK]

Also possible the inverter search watt is set above the micro demand watt.
If there is something else on the 2000 watt inverter less than say 500 watt turn that on and then see if inverter will show status light on. Then if it does run micro.
Lower or turn off search watt.

 

[SeaDogAK]

Is the microwave plugged into an outlet? Can you try plugging something else into it to see if it works?

 

[O C Diver]

If the microwave works on shore power or generator, my guess is that it's the breaker on the smaller panel, in the last picture, labeled "## ### AC outlets" or one labeled "Spare". Based on the fact that the panel has "Air Conditioning" circuits, it’s not likely connected to the inverter.

Ted

 

[Max1]

I have a 1,000w Sharp Carousel Microwave in the galley and a 2,000w Xantrex Inverter. I have not figured out why the inverter does not turn on the microwave's status light. So when underway or at anchor, I have to crank up the Genset to use the microwave.

Is the inverter supposed to power up the microwave?

I have attached the breaker panel setting, is there some switch I have missed?

There are two inverters, the left one is 1000w dedicated to the refrigerator. The right one is the 2000w Xantrex.

I had this same problem.
I had purchased my inverter and microwave over the winter.
When I tested the system at home it worked great.

When installed in the boat, it would only power the microwave for 60s before it quit.

My problem was 2 fold. the gage of wire was too small and the length was too long.

I relocated my inverter to be closer to the battery bank and went with 1 gage wire.

Not sure what you can do about your current inverter location but you might want to check the condition of the cables and connectors- make sure they are not cracked or damaged at the terminals. Also make sure they are clean and give them a polish with 220 sandpaper if needed. same for the battery terminals. Some dielectric grease on the connectors might help and make sure the terminals are tight.

 

[twistedtree]

First, figure out which breaker feeds the microwave. It's probably a breaker that isn't powered by the inverter. If the breaker is powered by the inverter, then start looking at the inverter installation, wire gauges, etc.


What are the two toggle switches? Does the "12V" position run things off the respective inverter, and "110" run it directly off shore or gen? I would check the current rating on those toggle switches to be sure they are rated the same or higher than the breaker that powers them. Toggle switches like that typically don't have very high ratings.

 

[Don L]

My boat came with a Freedom 2500 modified sine wave inverter. It powered my microwave just fine for 14 years and then one day is just didn't. Other things still worked on the on the inverter, like the wet/dry vac etc, but not the microwave. I replaced the inverter with a new pure sine wave unit 5 years ago and the microwave has run off it just fine since.

So it is apparent to me that even though all the manuals say modified sine is ok for a microwave, and mine was for a long time, something in the wave can change.

 

[twistedtree]

Basic first test is whether the light and controls are working on the microwave. Don't worry about the inverters capabilities until you have confirmed that it's even getting power.

 

[Don L]

Basic first test is whether the light and controls are working on the microwave. Don't worry about the inverters capabilities until you have confirmed that it's even getting power.

When my inverter stopped running the microwave the lights on it worked. Even the turntable and fan worked. But it didn't heat anything up.

I still have that microwave and it works just fine with a new inverter.

 

[rwidman]

Your "1,000 watt" microwave is 1,000 wats "cooking power". Read the label near where the power cord exits to find the actual power consumed by the microwave.

My Panasonic microwave works fine on an Xantrex "modified sine wave" inverter. It's a bit noisier than on shore power and possibly 10% slower (I did tests), but it works.

Either the microwave is not getting the proper voltage from the inverter (because it doesn't have enough power or it's drawing down the voltage from the batteries) or it is incompatible with the modified sine wave inverter.

Take your trusty multi meter and stick the probes into the receptacle the microwave is plugged into and turn on the inverter. You should read somewhere around 120 volts AC. Now turn on the microwave. Check the voltage reading. It should not drop below 110 volts or so.

If the voltage drops, the problem is with the inverter or the wiring. If the voltage does not drop, I would guess your microwave will not run on your inverter.

I have only found one electrical appliance that would not run from my inverter and that was a simple heating pad that's used for muscle pains, etc. We returned it as defective and got another. It wouldn't work either. We got a different brand and it works fine. Apparently, a heating pad is no longer just a resistance element in a pad.

 

[paulga]

Xantrex 1800, its manual says it provides 1800w continuous modified sine wave, designed to handle loads such as 1000w microwave, etc. However the sharp carousal microwave does not work. I'll test when I get a multimeter.

the 6kw westbeke generator can power the microwave, but not convenient.

 

[tiltrider1]

So we know the microwave works on shore or generator. What we don’t know is whether the inverter is connected to the socket that the microwave is plugged into. Easy enough, plug something else in to the socket and see if it works.

 

[Delta Riverat]

Agree. One test is worth a thousand expert opinions -

 

[Darlin]

Could be battery issue. If you are using a lithium battery the BMS may cut off at 100 amp draw. 2000 watt inverter requires almost 2x that load.

 

[mickand]

I installed a 2000watt full sine wave inverter and it wouldn't start my 1100watt microwave.
Upped the inverter to a 3000watt and it has run the microwave for many years.

 

[greatpapabear]

As has been said before, it's very likely to be either the modified sine wave, or frequency. Modern electronics in cooking kit (microwave, induction hob, etc) will not work if the tolerance is more than a gnat's whisker off perfection.

 

[rwidman]

Is the microwave plugged into an outlet? Can you try plugging something else into it to see if it works?

There you go!

Try this before doing any additional troubleshooting. The outlet your microwave is plugged into may not have been connected to the inverter. Or it may be on a GFCI protected circuit that has tripped.

 

[tiltrider1]

There you go!

Try this before doing any additional troubleshooting. The outlet your microwave is plugged into may not have been connected to the inverter. Or it may be on a GFCI protected circuit that has tripped.

The microwave worked on shore or generator. OP was asked to verify if the socket was connected to the inverter by plugging in a different device. If it had been a GFCI issue it would not have worked on shore power.

 

[YukonRon]

Xantrex 1800, its manual says it provides 1800w continuous modified sine wave

There's your problem right there, modified sine wave. We also had a Xantrex modified sine wave inverter that ran the microwave, sometimes, until suddenly it didn't anymore. We swapped it out for a Victron full sine wave inverter; no more problems. Electronic devices don't run well on modified sine waves.

 

[paulga]

I installed a 2000watt full sine wave inverter and it wouldn't start my 1100watt microwave.
Upped the inverter to a 3000watt and it has run the microwave for many years.

i also read somewhere it takes 3x certified watt of a device to power the device. the inverter manual specifies it can power a 1000w microwave, that's only in theory.

be it modified sine wave, or wattage, I decided to keep the current configuration.

 

[SteveK]

I have a 2000 watt pure sine inverter and it runs 1800 watt induction stovetop. Not sure what wattage the micro is, but it works, as does toaster, griddle, coffee maker. Not at the same time as max load continuous is 2000w. Soon it will be 4000.