Microwave does not work off of inverter???

[JohnnyB1966]

We are new to the Keystone world. We have a 2023 Cougar 24SABWE. Trying to figure out the inverter usage. We are not plugged into shore power. We turn on the inverter using the ON/OFF switch up by the battery. We hear it power up, and the 120V AC outlets work (like for a hairdryer or blender).

But the microwave does not work at all. No microwave display lights are illuminated. The microwave does not turn on.

However, if we are just hooked up to shore power with the inverter turned off, the microwave and all other 120V AC outlets do work.

We have:
SmartSolar charge controller MPPT 100 | 30
Solarflex 400i Solar panels
Xantrex 2000 watt inverter.
Two 100A hour Dragonfly Lithium ion 12V batteries

What are we missing? I assume we have not done something right. Isn't the microwave supposed to work off of the inverter? Is there yet another switch or setting we need to toggle?

[flybouy]

No, the inverter circuit as installed by Keystone does not include the microwave.

[NH_Bulldog]

This is wired correctly, the microwave does not operate off the inverter. The system is designed, engineered and intended to be this way. I would not attempt to alter the system to try to operate the microwave off the batteries through the inverter.

[Max23]

The inverter does not include your microwave or A/C. This is absolutely correct. Also, if you don't want to drain your batteries rapidly, I would use high wattage items sparingly. A coffeemaker runs down 2 100ah lithium batteries about 20% just brewing a pot. Don't ask me how I know. LOL.

[JohnnyB1966]

I got some great responses from this group. Our local Camping World on I25 north of Denver store would have charged me $190/hour to answer this question (probably incorrectly). You guys are lifesavers!

[SargeW]

High amperage appliances like microwaves and AC units will drain a set of batteries quick. Therefore hooking up something like that would be totally excessive for the battery bank. The best and probably cheapest option is to pick up a 2000+ small portable generator to take with you. Fire that up and plug into it when you want to run the microwave, or even the coffee pot. It will handle it easily and leave your solar and lithium batteries to run the rest of your rig for an extended period of time.

[RacerX]

All of the above posts are absolutely correct. Keystone does not include the microwave on the inverted loop. However….

I had to replace our microwave under warranty due to a defective door latch. When I replaced it I also moved its receptacle and plug to the top of the adjacent cabinet where I “CAN” move its power to an inverted outlet for quick convenience warm ups Thru the inverter. However as mentioned it is a large draw. Our 900w Greystone microwave draws up to 1350 watts as it starts up which not only utilizes a good amount of our 2000w inverter but more importantly uses most of the maximum permissible 1440w thu the 15 amp circuit that is tied to the inverted loop.

So…. Can I rewarm some chicken nuggets for a few minutes without shore power? Yes… but I have to ensure that nothing else is running on that circuit and also am aware that 1350w will quickly put a drain on the batteries., but then so does the coffee maker as mentioned above.

Not necessarily recommending this approach to the faint of heart. This requires active power management which also explains why Keystone likely doesn’t include this option in their inverted loop. Too many would likely kill their batteries not to mention pop or overload circuit breakers by running the 100+W TV while microwaving popcorn and brewing coffee.

But if you don’t mind managing your power usage knowing the considerations, it is possible.

[flybouy]

Here's the deal with using a large wattage appliance with a "marginal" battery/inverter set up. You will drain the battery(s) rapidly. This can damage the battery(s) if drained they are drained too far. Afterwards you'll need to replenish the charge in the battery. Without sufficient solar and sunshine this will require a gener. It will be easier and take less generator run time to fire up the generator and run the appliance then go thru the exercise of draining down the battery with excessive high wattage use.

[RacerX]

Agreed. If you are going to need the generator anyway, it is best to let it carry the load. However with sufficient solar and lithium batteries the risks of damage to the batteries is significantly reduced. The convenience of being able to do some well managed large wattage is a nice to have. Been seeing a lot of situations where generator use is prohibited until after 10am. By then last weekend we used the MrCoffee drew the batteries down as expected but had them replenished via solar (roof plus portable) before that time. Generator stayed on the truck all weekend unused.

Of course it is summer….lots of sun but not too hot so no AC needed. Would be a different story in cloudy humid conditions. Still the ability to time shift the power usage outside “quiet time” is very useful.

[TXiceman]

This is totally stupid and cheap on the part of Keystone. If you are going to put in solar an inverter and battery pack, at least make sure that the system can support the microwave for at least short-term use.

I have not tried mine yet, but if it is not hooked to the inverter, looks like I will be doing some rewiring to get the microwave on an inverted circuit.

Ken

[Stangfire]

Originally Posted by TXiceman

This is totally stupid and cheap on the part of Keystone. If you are going to put in solar an inverter and battery pack, at least make sure that the system can support the microwave for at least short-term use.

I have not tried mine yet, but if it is not hooked to the inverter, looks like I will be doing some rewiring to get the microwave on an inverted circuit.

Ken

lol do you know how much power a Microwave uses? You would need a HUGE battery bank to support it. Not feasible.

If you want to run the Microwave or AC when boon docking get a generator.

[TXiceman]

Originally Posted by Stangfire

lol do you know how much power a Microwave uses? You would need a HUGE battery bank to support it. Not feasible.

If you want to run the Microwave or AC when boon docking get a generator.

I know how much a microwave draws and have had inverters in oter RVs that powered the microwave. The trailer has a larger battery bank now.

I also have a pair of Honda EU2000i generators with an extended run tank.

Ken

[Stangfire]

Originally Posted by TXiceman

I know how much a microwave draws and have had inverters in oter RVs that powered the microwave. The trailer has a larger battery bank now.

I also have a pair of Honda EU2000i generators with an extended run tank.

Ken

I have a Honda EU3200i I use strictly for Microwave or AC only. Everything else I run off solar and batteries. I have a permanent camp set up off grid.

[LadyCPA]

JohnnyB you are so right. This group did a great job explaining a couple of items I could not quite understand. We have upgraded our solar, batteries and the inverter, and the company told us we could run the microwave if we changed the outlet, but still not the AC. Now I understand the whys. Thanks Y'all

[Cheesehead4Life]

Originally Posted by RacerX

Not necessarily recommending this approach to the faint of heart. This requires active power management which also explains why Keystone likely doesn’t include this option in their inverted loop. Too many would likely kill their batteries not to mention pop or overload circuit breakers by running the 100+W TV while microwaving popcorn and brewing coffee.

But if you don’t mind managing your power usage knowing the considerations, it is possible.

Working in a support-focused role for a living, I totally understand Keystone's approach. But like RacerX I personally would like the choice myself to actively manage it. I use the microwave once every other day for 2 mins to warm up leftovers. At 1500watts for 2mins, that's 50Wh or 4Ah off my battery. My solar can cover that in about 15 minutes on most days. So that's why I'd rather have the choice than have to pull out the generator. I'd never use the microwave if I had to do that.

[TXiceman]

Like Cheesehead, I have a brain and read instructions and would like to use the microwave for a few minutes to warm lunch. But the world is full of people that are not smart enough to read instruction manuals, so the manufacturers need to protect themselves from these folks.

I think we need to remove all warning labels from everything and let the law of natural selection take over. The smarter ones will survive.

Ken

[LadyCPA]

Originally Posted by TXiceman

Like Cheesehead, I have a brain and read instructions and would like to use the microwave for a few minutes to warm lunch. But the world is full of people that are not smart enough to read instruction manuals, so the manufacturers need to protect themselves from these folks.

I think we need to remove all warning labels from everything and let the law of natural selection take over. The smarter ones will survive.

Ken

As my hubby says, remember when the owner's manual on the car told you how to gap the spark plugs - now it just tells you don't drink the battery acid.

[DrSmart1]

I agree with not having the microwave on the inverter circuit. For someone that knows what they're doing and understands power draw on the DC side of the inverter, they can add the microwave circuit if they wish.

[WJQ]

I don't have time to read all of the advice but here is my experience. I designed and installed my inverter system and batteries by looking at the nameplate wattage rating and power demand. WRONG.

I learned the hard way that a microwave draws 3 to four times the nameplate wattage for a few milliseconds. Just enough for the inverter to probably send it is being asked to supply too much current!

Even worse, the first version of my design had lead acid, 6-volt batteries. Plenty of Amp Hour capacity but lead acid batteries will not supply high amperage demand like the microwave.

After buying a smaller microwave and 100 amp hour lithium iron phosphate batteries, my microwave works most of the time. I also shortened the battery to inverter wire length.

Live and learn!

[HeadHam]

Welcome!

We also just bought a 2023 Cougar. As wired by Keystone, only the outlets that have the yellow Solarflex labels are powered off of the inverter. You aren't doing anything wrong.