what inverter size needed for microwave?

[piratedude]

want to run a ac 110v microwave on my boat- what size inverter should i get? do i have to put a switch in line on the inverter to turn it on and off when i want to use the microwave or just wire it direct? thanks.

 

[18rabbit]

Re: what inverter size needed for microwave?

Installing an inverter is not considered a DIY project for someone not familiar with onboard AC. You are asking the right questions for someone interested in an inverter…the same questions that indicate you will need someone with marine AC experience to help you install it, or at least checkout your work if you do it yourself.<br /><br />An inverter is sized based on the AC (watts) needed. What size inverter you need depends on what size microwave oven you have…that kind of thing. Normally you would plan for all your AC needs, add them up, multiply by an inefficiency factor (usually 10%) and that is the size inverter…but not necessarily the type. Two kinds of inverters; modified sine wave and true sine wave. The modified sine wave (less expensive) works for most stuff, the true sine wave is necessary for sensitive electronics including laptops, video games, and some microwave ovens.<br /><br />You’re not done. You also need to consider your house battery bank. It needs to have minimum number of amp hours available to support the heavy draw of an inverter. Remember, if you pull more than 5% of the battery’s amps at a time, the batts can’t provide the total amps they are rated for. Not uncommon for the installation of an inverter to also mean you get to upgrade you house bank with more batteries…it depends on the expected inverter load.<br /><br />Good news…you’re almost there… If you update your house battery bank to support the inverter, you also need to consider your house bank’s charging system. Is the alternator on your engine big enough? Does the multi-stage charger you have plugged into shore power put out enough amps charge the house bank? Note: often the new inverter will also function as a perfect multi-stage charger for both the house and starting batteries. Great News: Since you updated the house battery bank to the appropriate size to support the inverter, the inverter/charger should be appropriately sized for charging the batteries...and you can put your old charger up for sell on Ebay. <br /><br />Edit: From West Marine Advisor: How to select an inverter:<br /><br /> http://www.westmarine.com/webapp/wc...alogId=10001&advisor=howtoselectinverters.htm

 

[waterone1@aol.com]

Re: what inverter size needed for microwave?

poi, While this does not always happen (LOL), I agree with Rabbit. Inverters are a great idea for a boat if they are part of the ELECTRICAL SYSTEM.<br />Since I have to believe that your microwave is wired to your 120V breaker panel that also has several other circuits for everything from the hot water heater....to the 12V converter to such other things as air conditioning, this can lead to problems or overloads. The other issue that is usually overlooked when installing inverters is the grounding system of the boat. This can also involve a galvonic isolator. Modifying your boats AC system is not the type of thing to be done without careful study and consideration.<br />Now that we have gone through all of the precautions.......if you would like to tell us what size Microwave you have ? what size breaker it is wired to on your AC panel ? what else is on your AC panel ? What size and how many batteries you have ? Is this boat trailered or marina stored ? We can probably find a way to make this work.

 

[Luna Sea]

Re: what inverter size needed for microwave?

Have you looked at the small portable Honda 1000W generators? Nice and quiet. Or is it strictly the microwave you want to run. Little gen's good for overnighting.......

 

[tommays]

Re: what inverter size needed for microwave?

http://www.vonwentzel.net/Battery/index.html <br /> <br /> this link really gives a very compleat run down about about doing this to meet ABYC standards<br /><br />its a bit of reading to get through but even has several excel sheets that will size out the wires correctly as well as and overall system<br /><br /><br />tommays

 

[piratedude]

Re: what inverter size needed for microwave?

thanks all for the posts! this boat is trailered and never hooked to shore power. i just want to disconnect the microwave from the boats ac wiring and hook it directly to the inverter, thats the only applience going to be run off it. just wondered if the inverter needs an on/off switch between the battery and inverter?

 

[rwidman]

Re: what inverter size needed for microwave?

Originally posted by poi9jkl:<br /> just wondered if the inverter needs an on/off switch between the battery and inverter?

Yes it does. The inverter continues to draw a small amount of power even when there is no load. If the inverter has a self contained power switch this will do the job.

 

[rwidman]

Re: what inverter size needed for microwave?

Originally posted by poi9jkl:<br /> i just want to disconnect the microwave from the boats ac wiring and hook it directly to the inverter, thats the only applience going to be run off it.

That's how mine is connected for now. I agree with 18rabbit's post, there is a lot more to it than buying an inverter and connecting it to your battery. You need to know what you're doing or get some on-site help from someone who does.

 

[imstillatwork]

Re: what inverter size needed for microwave?

you'll need at least 1000watts for most new small microwaves. Thats 110v @ at 10 amps for the Mwave alone. Plus wiring it safely, with breakers and all.

 

[jonjar2]

Re: what inverter size needed for microwave?

yep, the rabbit is right, yes, you will need a switch, and i would recommend one even if the inverter has a self contained one...<br /><br />and as far as wattage, 1000 watts should be sufficient for one of those new 600 watt microwaves, but i would recommend more, and it should have a spike capability of 2000 watts plus.<br /><br />i have a 700 watt microwave on my boat with a 2000 watt/4000 watt surge inverter and that does the trick for me just fine (the microwave is the only appliance run on the inverter)