Microwave on Inverter Power-does yours do it?

[twinboat]

I don't recall any 12 volt water heaters as standard equipment. Are you actually running a 120 volt water heater thru your inverter. They draw a lot of energy and will run down any typical battery bank.

The low voltage cut off depends on the inverter and should be listed in the specs. Some are adjustable.

My Xantrex ProWatt 1000 has a low battery alarm at 11 volts and a low battery cutout at 10.5 volts. It is not adjustable.

Originally Posted by Kahoona

I wonder how the Xantrex does it to determine when to cut off. The other night I left it with a fully charged set of 4 NAPA golf cart batteries and I set the water heater to 12v. The inverter had tripped the low battery cutoff. I should have checked the voltage then.

[Kahoona]

Originally Posted by twinboat

I don't recall any 12 volt water heaters as standard equipment. Are you actually running a 120 volt water heater thru your inverter. They draw a lot of energy and will run down any typical battery bank.

The low voltage cut off depends on the inverter and should be listed in the specs. Some are adjustable.

My Xantrex ProWatt 1000 has a low battery alarm at 11 volts and a low battery cutout at 10.5 volts. It is not adjustable.

I have 2 toggles that say 12v and 120v. Probably is the same as yours then. I will probably only run that while the sun is shining on the solar then. 10.5 sounds like a pretty good cutout amount anyway. Thanks.

[Richard S.]

The 12 volt switch is what lights the propane side of the water heater.


DSI ( Direct Spark Ignition )

[riverdancer]

the 12 Volt switch only powers the control circuits for the water heater. In 12V mode the water heater is operated by propane, but still needs the 12vdc to operate the control. Your batteries are really bad if they wont hold that load. the load in this circumstance is negligible.

[Persistent]

If all you want is coffee, get a camping percolator from Cabela's. It takes about 16 minutes using stove top burner, but it is extremely quiet and costs a lot less than a generator, inverter, and new wiring.

[twinboat]

Originally Posted by Persistent

If all you want is coffee, get a camping percolator from Cabela's. It takes about 16 minutes using stove top burner, but it is extremely quiet and costs a lot less than a generator, inverter, and new wiring.

16 minutes, that might as well be an hour.

I installed an inverter to get my coffee when I want it. The DW brews me up a cup while I'm at the gas pump.

While living on my Trawler, I had the microwave on the inverter too. I wasn't going to start the Honda, or light the stove, for morning oatmeal.

[jelag]

So I have a 2000 Watt inverter and next to the inverter is a circuit panel that's got a label for each circuit that the inverter runs... Microwave, TV's, outlets... etc... the inverter is the only source for those circuits...
So each time you turn on one of the items on that circuit... power from the inverter powers it... if your connected to shore power, or the generator is running ..... those 2 sources immediately will supply power to the converter and recharge the batteries....

Does this help...

[Kahoona]

Originally Posted by riverdancer

the 12 Volt switch only powers the control circuits for the water heater. In 12V mode the water heater is operated by propane, but still needs the 12vdc to operate the control. Your batteries are really bad if they wont hold that load. the load in this circumstance is negligible.

Brand new NAPA fully charged reading 13v. Nothing else draws it down below cut off including a small 120v fridge (temporary replacement for dead dometic.)

[riverdancer]

So if a 120v fridge wont draw down your batteries, I suspect there is something else drawing the batteries down and NOT the 12V toggle for the water heater. I have the 2006 National sea breeze and I can leave my 12v switch on for days without a large drain on my batteries. When I first bought my RV, I tested all that stuff in my driveway. I went 6 days with the fridge and 12v water heater set. (I actually took showers in there for those days) and I had Ice cream in the freezer. After 6 days my batteries went below function level and I had to plug in before the ice cream melted.
But who knows how your rig is wired. I did what I did so that I at least know my original configuration before I started modifying it. I know the limitations of my rig before I started camping with it, It seems to me that your rig already has been modified with your outstanding battery setup. So schematics for your rig my not help, since you don't know how it's been modified before you bought it.

[Persistent]

Originally Posted by Kahoona

We got a National Tropical 33' DP. We got it used. The dealer told us that the Microwave worked with the 4 batteries through the 200w Zantek inverter. We hired a tech to help us Install a new inverter and make sure that there we rent any surprises in the electrical system. When he got it going the kitchen outlets and Microwave did not work. They do work on shore. He said that those outlets weren't made to work. on inverter. Does anyone have one of these models and does your inverter power the kitchen? I was so looking forward to not waking up the wildlife while boondocking just to get coffee!!

Kahoona,

The service technician and Riverdancer has it right. The typical wiring plan an RV with a 2000 watt inverter and 350 amp hour batteries is to not put high consumption 120 volt appliances on a 2000 watt inverter.

Certainly you can change that. Certainly a 1300 watt microwave will run on a 2000 watt inverter as long as no other high draw appliances are running at the same time. However, many things will conspire to cause the inverter to shut down.

The entire inverter system must be designed to handle the high 12 volt current the inverter will draw. Wire sizes and the distance from batteries to inverter are a major player. Battery bank size and battery type matter a lot.

Of course battery voltage drops as stored energy is consumed. Battery voltage also drops suddenly and dramatically when high currents are drawn from batteries as inverters do. Deep draw RV batteries are especially subject to this. Voltage may rise again after draw stops in this case, but the inverter circuit breaker may still trip well before 2000 watts when battery voltage drops.

On the 120 volt side, 2000 watts is not much. It is about the same as one lighting circuit in your home. One residential refrigerator or one microwave is all that circuit can handle. Unsuspecting users may not understand the carful management of load required. You may have to unplug the refrig and or other appliances to run the micro, etc.

A small home service entrance is probably well above 50 amps at 240 volts or 12000 watts.

So, it is not that you can't do it. It is complicated and inconvenient to do it.

You have options.
You can install a larger battery bank, a larger inverter, and possibly a more complicated transfer switch like the big motor coaches.
You can learn to manage batteries and 120 volt load on the inverter.
You can run a generator.
You can add large solar arrays and only run the micro during the daylight.

Monitoring voltage and current on your battery bank can help you learn what it is capable of. Installing one of the better battery monitoring systems would be a good way to learn. It would teach you what voltages are present during charging, discharging, and when static. It is complicated.

It is still cheaper and easier to use a percolator for coffee. It is even possible to get a 12 volt coffee maker.

[Kahoona]

I have a 520 ah bank and am very good at power management. This is, as mentioned, only for special circumstances as in National parks which do not allow generators or restrict their use to a few hours or when I don't wish to disturb the neighbors. It is do-able under those circumstances.

[vermilye]

One solution for those wanting to use a microwave with a minimal battery & inverter capacity is to switch to an inverter microwave. A typical microwave on defrost or other than full power runs at full power, and switches off & on to provide reduced power. That short full power cycle can drop the voltage from a small battery bank to the alarm or shut off voltage.

An inverter microwave can be set at lower power, and continuously draws less than full power. I have a 950 watt Panasonic Genius Prestige NN-SD372S Microwave Oven that can be dialed down to as little as 600 watts. Another advantage is they do a much better job of defrosting, avoiding cooking the edges of things before the middle is defrosted. While I chose the 950 watt version to match my 1500 watt trailer inverter, they make larger wattages.

[mr. seaview]

hey twinboat

i have a question for u. i have a 31 foot national seaview with the original 30 amp
service. i have 2 roof air conditioners . i can only run one ac at a time unless i run '
generator.

my question is if i purchase one of those 50 amp leg splitter cables from amazon
can i safely run both of my ac at the same time with this 50 amp splitter?

thanks for your help. i do not like running my generator as it is noisy and i do not
want to disturb my other camping neighbors with my noisy generator running all night.

thanks again i think i should purchase the 50 amp splitter as it is cheaper than
converting my rig to 50 amp service. thanks

[twinboat]

You don't have 2 power cords to plug in, do you ?

You will need to bring that second air conditioner power wire out to the adaptor, while disconnecting it from the switching controls.

Then that can be plugged into one side of the adaptor.