Does anyone know if domestic household microwave ovens are sinewave sensitive or will they
work perfectly well off a cheap Aldi petrol driven generator ?.

G'day Sam.
Pretty sure the only things that like a nice sine wave are electronic appliances like computers etc, a microwave should be ok.
But, be aware microwaves do use a fair bit of power, so make sure the genny can handle it!

How big is the generator?

I was once told (after I bought my true sine inverter of course) that a cheap genny or inverter can be run through a surge protector to achieve the same thing. It'd be good to know how true that is.

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saltiest1 said..
I was once told (after I bought my true sine inverter of course) that a cheap genny or inverter can be run through a surge protector to achieve the same thing. It'd be good to know how true that is.

Yeh, I don't think so.
If the generator / alternator is producing a "blocky" sine wave to start with, I'm pretty sure a surge protector won't improve it. It might stop interference in some cases though.
The frequency in Australia is 50 hz and it needs to be a nice sine wave up then down - like a swell in the ocean.
A poor sine wave will not have nice curves at the top and bottom of the wave, it will look like blocks and electronic appliances don't like it.
Your microwave should be ok as long as the genny has the power out put.
I think Toph will know a bit more about this subject.......

A real grown-up industrial surge protector might have a decent sized choke (inductor) to smooth out spikes, but such a unit would hardly be what your average yacht would want to carry around. Domestic-type surge protectors would do nothing. An isolating transformer might help a little bit.
But why go down that complex path, when 12 V microwaves exist? The RV world has lots of such goodies that are relevant to us, go look there.
Cheers, Graeme

I would never use a microwave or coffee machine through inventor on agm battery's , however it maybe possibly with lithium now. Best to use Honda 4 stroke for those applications.

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NowandZen
I think Toph will know a bit more about this subject.......

You give me far too much credit

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southace said..
I would never use a microwave or coffee machine through inventor on agm battery's , however it maybe possibly with lithium now. Best to use Honda 4 stroke for those applications.

I use my Microwave / Grill / Convection Oven, as well as the induction cook tops through my inverter on AGMs all the time!!

Why do you say that Southace??

Thanks everybody. the generators are rated at 2.5 kva. and the microwave oven does not have to be big. Missus has a
problem that needs the use of a microwave oven and if I can sort it she will be able to spend some time out on the water.
Thanks for your input.

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wongaga said..
A real grown-up industrial surge protector might have a decent sized choke (inductor) to smooth out spikes, but such a unit would hardly be what your average yacht would want to carry around. Domestic-type surge protectors would do nothing. An isolating transformer might help a little bit.
But why go down that complex path, when 12 V microwaves exist? The RV world has lots of such goodies that are relevant to us, go look there.
Cheers, Graeme

Like to know where you can purchase a 12v microwave in Oz. Only one's I have found is a microwave & inverter package, as per below. Might as well purchase them separately and size the inverter for running other systems ie washing machine, water maker etc.

wallcann.com.au/2500w-modified-sine-wave-inverter-12v-with-18l-microwave/

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samsturdy said..
Thanks everybody. the generators are rated at 2.5 kva. and the microwave oven does not have to be big. Missus has a
problem that needs the use of a microwave oven and if I can sort it she will be able to spend some time out on the water.
Thanks for your input.

2.5kva may not be enough.

Average microwave has 1.2kW. 2.5kva genny is massive unit.
also smaller microwave have 800w.

Sam, have a look at the cheapies at K-Mart!! www.kmart.com.au/product/20l-microwave/2341807

Your genny will run this little 20Lt job no problems. You could go a lot bigger if needed as well.

When using the convection oven on mine it uses 1450 Watts & I run it easily on my Honda 2 kva genny - I even run it on the inverter,

Thanks all for your reply's, I looked on Gumtree and found a little used ?? Honda 2kva unit fairly local to me, so I took a look at it and it was a good looking unit so I bought it. One advantage with the Honda units is you can lift them one handed as they don't have a frame. The unit works really well and is quiet. It doesn't have a users book so I'll see if I can bring one up on Google and print it. Also does anyone service their units, is it something I can do or do I get it serviced elsewhere ?.

I have plenty of solar power so I am thinking of this inverter run from the batteries with a Kmart microwave which should work out pretty cheap

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julesmoto said..
I have plenty of solar power so I am thinking of this inverter run from the batteries with a Kmart microwave which should work out pretty cheap

Jeez that's cheap!! Is there a model that does 240v??

4000w will run your microwave no troubles.

Like everything else things like this get cheaper. It's not gonna last like a Victron or whatever but at that price I'd be happy to get a year out of it!! I've had a cheapy 3500w for a few years now running my cooktop, microwave, sandwich maker, kettle etc & still going strong!!

I remember how much I paid for my first big screen TV & now they are dirt cheap!!

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Lazzz said..

julesmoto said..
I have plenty of solar power so I am thinking of this inverter run from the batteries with a Kmart microwave which should work out pretty cheap

Jeez that's cheap!! Is there a model that does 240v??

4000w will run your microwave no troubles.

Like everything else things like this get cheaper. It's not gonna last like a Victron or whatever but at that price I'd be happy to get a year out of it!! I've had a cheapy 3500w for a few years now running my cooktop, microwave, sandwich maker, kettle etc & still going strong!!

I remember how much I paid for my first big screen TV & now they are dirt cheap!!

So interestingly I surveyed both my induction cooktops, a portable griller a small portable oven and my microwave. 1 induction cooktop says 220 volts and nothing else but everything else says 220 volts - 240 volts except admittedly the microwave says 230-240 volts. I will survey the microwaves in Kmart next time I am there

4000w. That 333amps at 12 volts. Hope you got good batteries and battery cables going to the inverter.

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Crusoe said..
4000w. That 333amps at 12 volts. Hope you got good batteries and battery cables going to the inverter.

And that is the problem
they are are big numbers so everything has to be wired for those numbers

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lydia said..

Crusoe said..
4000w. That 333amps at 12 volts. Hope you got good batteries and battery cables going to the inverter.

And that is the problem
they are are big numbers so everything has to be wired for those numbers

True but only upstream of inverter as once it's 220-240 volts 10 amp house wire is fine. Put the inverter very close to the batteries with starter type car cables and it should be fine I would think. I don't think I would ever used multiple 240 volt appliances at once and I would keep it down to say a 1500 watt microwave

I bought a new inverter and it came with heavy battery cables about 50cm long. That would be the distance to mount the inverter from the battery.

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julesmoto said..

lydia said..

Crusoe said..
4000w. That 333amps at 12 volts. Hope you got good batteries and battery cables going to the inverter.

And that is the problem
they are are big numbers so everything has to be wired for those numbers

True but only upstream of inverter as once it's 220-240 volts 10 amp house wire is fine. Put the inverter very close to the batteries with starter type car cables and it should be fine I would think. I don't think I would ever used multiple 240 volt appliances at once and I would keep it down to say a 1500 watt microwave

4000 W at 220 V is about 18 A.

K.

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Ramona said..
I bought a new inverter and it came with heavy battery cables about 50cm long. That would be the distance to mount the inverter from the battery.

Thanks for that. Seeing as I respect your choices and ended up buying the same charge controllers as you after a false start which model inverter did you get? Also what are you planning to run off your inverter?

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julesmoto said..

Ramona said..
I bought a new inverter and it came with heavy battery cables about 50cm long. That would be the distance to mount the inverter from the battery.

Thanks for that. Seeing as I respect your choices and ended up buying the same charge controllers as you after a false start which model inverter did you get? Also what are you planning to run off your inverter?

GIANTZ pure sine wave 1500W continuous. Only panning on running a small vacuum cleaner so it will see very little use!

Also have a GIANDEL 200w pure wave invertor to run the monitor at my nav station.

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Ramona said..

julesmoto said..

Ramona said..
I bought a new inverter and it came with heavy battery cables about 50cm long. That would be the distance to mount the inverter from the battery.

Thanks for that. Seeing as I respect your choices and ended up buying the same charge controllers as you after a false start which model inverter did you get? Also what are you planning to run off your inverter?

GIANTZ pure sine wave 1500W continuous. Only panning on running a small vacuum cleaner so it will see very little use!

Also have a GIANDEL 200w pure wave invertor to run the monitor at my nav station.

Thanks :)

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Ramona said..

Only planning on running a small vacuum cleaner so it will see very little use!

Would a battery-charged vacuum cleaner do the job? Of course, the charger on a retail 12V vacuum cleaner is designed for a 240V household plug.

We have a cheapo 12V vacuum cleaner, charged at home. It's OK on the boat, but a bit weak. If I were to buy a new one, I might go for the Makita 18V version. www.bunnings.com.au/makita-18v-mobile-vacuum-cleaner-skin-only_p6240135?gclid=Cj0KCQjw4cOEBhDMARIsAA3XDRhKqT94J2i9QpmB874Ftl2W5ujxeGvgeM6PvfY9mcTuLA7yfg83RCoaAmlxEALw_wcB&gclsrc=aw.ds&store=8026. I have Makita tools, so already have batteries.

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Achernar said..

Ramona said..

Only planning on running a small vacuum cleaner so it will see very little use!

Would a battery-charged vacuum cleaner do the job? Of course, the charger on a retail 12V vacuum cleaner is designed for a 240V household plug.

We have a cheapo 12V vacuum cleaner, charged at home. It's OK on the boat, but a bit weak. If I were to buy a new one, I might go for the Makita 18V version. www.bunnings.com.au/makita-18v-mobile-vacuum-cleaner-skin-only_p6240135?gclid=Cj0KCQjw4cOEBhDMARIsAA3XDRhKqT94J2i9QpmB874Ftl2W5ujxeGvgeM6PvfY9mcTuLA7yfg83RCoaAmlxEALw_wcB&gclsrc=aw.ds&store=8026. I have Makita tools, so already have batteries.

I bought the Makita 18V vacuum cleaner, plus 2 x 4 Ahr batteries, to howls of derision from the crew. It has been great. Next purchase will be www.tradetools.com/makita-12-24v-automotive-car-charger-194618-8 so I can keep the batteries for the vacuum cleaner, drill and angle grinder charged.

I have already gone to the trouble of buying 18 volt tools such as angle grinder and drill for the boat as well as a gas and a 12v powered soldering iron but the boat has a great big gas oven and I have no intention of reconnecting the gas as I just don't like gas on a boat. I don't mind the little gas camp stoves which take the small aerosol butane cans. Given that inverters and 220-240v microwaves and induction cooktops are so cheap I figure I might as well add an inverter particularly as I now have an excess of solar charging power. The inverter won't be used for a fridge or anything that runs while I am not on the boat. A powerful vacuum cleaner might also be useful from time to time as Ramona says. The biggest issue I have is where to mount the inverter as it is kind of ugly, needs to be in a ventilated spot and needs to be really close to the batteries if it is to carry 130 amps odd to the inverter for the microwave.

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julesmoto said..
Given that inverters and 220-240v microwaves and induction cooktops are so cheap I figure I might as well add an inverter particularly as I now have an excess of solar charging power. The inverter won't be used for a fridge or anything that runs while I am not on the boat. A powerful vacuum cleaner might also be useful from time to time as Ramona says. The biggest issue I have is where to mount the inverter as it is kind of ugly, needs to be in a ventilated spot and needs to be really close to the batteries if it is to carry 130 amps odd to the inverter for the microwave.

Microwave & induction cooktops are the way to go these days!!
I run my oven, which is a microwave/grill/convection oven combo, no problems off my 3500 Inverter as well as the induction cook tops. I do have very HD cables connection to the house bank.
I also run a 240v vacuum cleaner, on special occasions for a good clean up, through this inverter but use my 18v battery vacuum for everyday use.
I have also run my 9" grinder through this inverter but prefer to use the genset for this!!

IMO I would go with the 4000w inverter you mentioned from eBay but run very HD cables to the batteries.

I tried an inverter that was not sine wave & my induction cook tops would not work.

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Lazzz said..

julesmoto said..
Given that inverters and 220-240v microwaves and induction cooktops are so cheap I figure I might as well add an inverter particularly as I now have an excess of solar charging power. The inverter won't be used for a fridge or anything that runs while I am not on the boat. A powerful vacuum cleaner might also be useful from time to time as Ramona says. The biggest issue I have is where to mount the inverter as it is kind of ugly, needs to be in a ventilated spot and needs to be really close to the batteries if it is to carry 130 amps odd to the inverter for the microwave.

Microwave & induction cooktops are the way to go these days!!
I run my oven, which is a microwave/grill/convection oven combo, no problems off my 3500 Inverter as well as the induction cook tops. I do have very HD cables connection to the house bank.
I also run a 240v vacuum cleaner, on special occasions for a good clean up, through this inverter but use my 18v battery vacuum for everyday use.
I have also run my 9" grinder through this inverter but prefer to use the genset for this!!

IMO I would go with the 4000w inverter you mentioned from eBay but run very HD cables to the batteries.

I tried an inverter that was not sine wave & my induction cook tops would not work.

Thanks that looks like a great setup. Probably more room than I have got though on my North Shore 38. Is yours a catamaran because I don't see any gimbals?