Does anyone know if a 240V wall oven would run of 240V (hot to neutral) instead of 240 (L1/L2, hot/hot, split phase). I just have 120 and I can't think of any other 240V appliances I would want so I was wondering if a oven would run off a step up transformer. I realized the step up transformer will require double the average on the line (supply). Do most of the electronics in the oven run off 110 though? I may be able to supply the board separately if that's the case. Has anyone ever switched out 240 heating elements for 120? I understand that the amperage of the 120 elements can exceed that of the rating of the circuitry. Thanks
Will 240 (120/240 appliance run off a transformer?
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zanydroid
Solar Wizard
EDIT: reordered the paragraphs
As you described - 240V L-N. If it's an imported appliance then that would probably be fine. 120/240V appliance will not work obviously. If the appliance has a neutral in its wiring whip, forget about it.
Why not step up in a way where neutral is center tap? To avoid having to worry about this. EG on a center tap autotransformer connect N to center and L1 to one of the end taps. You'll get L2 at the other end. Victron has diagrams for this.
If you go the 240V hot to neutral route, circuit breakers need to be 240V rated. 120/240V (like most of what you'll find at bigbox) are not suitable. And there are probably things you don't know about that need to be addressed.
As you described - 240V L-N. If it's an imported appliance then that would probably be fine. 120/240V appliance will not work obviously. If the appliance has a neutral in its wiring whip, forget about it.
Why not step up in a way where neutral is center tap? To avoid having to worry about this. EG on a center tap autotransformer connect N to center and L1 to one of the end taps. You'll get L2 at the other end. Victron has diagrams for this.
If you go the 240V hot to neutral route, circuit breakers need to be 240V rated. 120/240V (like most of what you'll find at bigbox) are not suitable. And there are probably things you don't know about that need to be addressed.
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Hedges
I See Electromagnetic Fields!
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Some appliances have 120V controls and 240V heating elements. Does it have L1/N/L2/G?
If so, first try running it on 120V. Tie L1 to N, feed 120V into L2. They try tying L2 to N, feed 120V into L1.
It would take 4x as long to heat up, but then thermostat would maintain temperature.
Or use a transformer to turn your 120V L1/N to 120/240V L1/N/L2 as Zany suggested. Should work fine for 120/240V appliance (don't know why Zany thought not.)
If your breaker is on 120V, and transformer steps that up to 240V just for the oven, no need for breaker on the 240V side. But step it to 120/240V split phase and you can use 120V breakers.
Powered from an inverter, you can get an autotransformer meant or that purpose. Or, get a 240/480V to 120/240V isolation transformer, and use the two 240V primary windings in series for 120/240V. Current is limited and VA is reduced, but it will be nicer for the inverter than running windings at their rated voltage.
Yes, I could imagine that 120V element of same wattage would be too much current for the other parts. Look for half the wattage.
If so, first try running it on 120V. Tie L1 to N, feed 120V into L2. They try tying L2 to N, feed 120V into L1.
It would take 4x as long to heat up, but then thermostat would maintain temperature.
Or use a transformer to turn your 120V L1/N to 120/240V L1/N/L2 as Zany suggested. Should work fine for 120/240V appliance (don't know why Zany thought not.)
If your breaker is on 120V, and transformer steps that up to 240V just for the oven, no need for breaker on the 240V side. But step it to 120/240V split phase and you can use 120V breakers.
Powered from an inverter, you can get an autotransformer meant or that purpose. Or, get a 240/480V to 120/240V isolation transformer, and use the two 240V primary windings in series for 120/240V. Current is limited and VA is reduced, but it will be nicer for the inverter than running windings at their rated voltage.
Yes, I could imagine that 120V element of same wattage would be too much current for the other parts. Look for half the wattage.
zanydroid
Solar Wizard
Bad edit. That paragraph was meant for the 240V L-N idea. I reordered the paragraphs in the post
I like your suggestion. I didn't really understand what auto transformers do and how they were designed. I read a bunch upon and watch the videos. Not that I think I'm a expert or anything now. I'm "split" between having the inverters parallel or split phase now. I could use the auto transformer to balance between the two phases rather than just run the stove. That way I could run the water pump off 240 too. Most small mini splits run off 110 but that gives me options. If I use the auto transformer to balance between phases, does the cfgi/ground fault breaker go between the inverters and the auto transformer or after between the panel and breaker box. All the diagrams that I could find didn't show where the inverter AC breakers go with an autotransformer.
Thanks for your help.
I don't actually have a stove yet. I'm doing the wiring but I will keep that in mind.
MichaelK
Solar Wizard
I really think I should suggest you take a step back, and first ask if an electric stove is really a good idea, before actually talking about how to wire it. Let's assume you have a standard 4-burner stove, with 2500W and 1250W elements. Let's also assume that you walk up to the stove and turn on just two burners, say one 2500W, and one 1250W.
That means suddenly, your 120V only system has to supply almost 4000W of power, which would be hard to supply even right at noon. Assuming you want to operate this stove around 5 or 6pm, even in summer, any system is going to be very hard-pressed to supply that amount of power.
What kind of battery bank are you expecting to have to support that kind of load? What size of solar array are you able to install? I'd think you need at least 7000-8000W of solar to support this.
That means suddenly, your 120V only system has to supply almost 4000W of power, which would be hard to supply even right at noon. Assuming you want to operate this stove around 5 or 6pm, even in summer, any system is going to be very hard-pressed to supply that amount of power.
What kind of battery bank are you expecting to have to support that kind of load? What size of solar array are you able to install? I'd think you need at least 7000-8000W of solar to support this.
It's only a oven. It doesn't have burners. Oven is only rated 20 amps at 240 and won't use that continuously once it heats up. Max of 40 amps at 1200. I won't use it at night only during the day on the weekends. Planning on about 4800 watt Solar and 24V 600 AH battery. The oven won't be used all the time for meals just when I feel like baking. I'll usually use microwave for instant pot for cooking.
MichaelK
Solar Wizard
Well, those numbers are even worse than what I was using. I can tell you right now, that 4800W of solar will NOT support a 4800W load. Assuming you only bake from between 10AM and 2PM, and you can expect at least 75% of rated output from the array, you really need a minimum of 4800W/75% = 6400W of panels. And I think that is actually a best-case situation. Normally I recommend at least 2X the solar, so that would mean 9600W of panels.
If you really want to try this at all, I'd suggest moving up to 48V, and get a split-phase 120/240V inverter. I would suggest forgetting about the transformer completely. The Outback Radian 8048 might be a good choice for this kind of load. It ain't gonna be cheap!
rustythorn
New Member
you said you have "multi pluses" if you have two victron multiplus you can set them up as a 120/240 split phase system
zanydroid
Solar Wizard
I don't understand the worries here.
Now I don't bake much, but I do cook a lot and look at the energy/power usage. You can prepare a meal with ~1 kWh and ~1800W, that corresponds to having a medium size induction burner on high or running microwave/kettle for 30 min. I usually usually only use one burner on high at once, and another on low to keep warm. 1kWh does not require a large system to collect. Doubling that to 2kWh since I haven't measured energy needs of baking, still not too bad.
OP will have 24V * 600Ah system. This is plenty of energy as long, let's assume it's banked from the day before for lunch, or collected same day for dinner.
In terms of power 4800W / 24V = 200A. That is... getting pretty up there. But for using a combination of 1 medium + 1 simmer burner on an induction stove, 100A of battery current for 30 min is perfectly normal.
I will agree that getting a transformer to push 5kVA through it fairly regularly may not be the best idea, vs going with 120/240. Though you CAN get transformers of that size fairly easily, and if you arrange the legs appropriately it may be passable.
Another option for baking with a smaller power output setup is getting a nice countertop oven for 120V, that will only take 1800W. It will heat up more slowly but should be fine at maintaining its heat. I've measured that Breville uses proportional control over the heaters so it will be pretty smooth power curve wise after coming up to heat.
If you already have a 240V oven purchased, you could consider running it at 208V. Then it will take fewer watts than when running at 240V. It gets slightly more complicated if it's a 120/240 oven.
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rustythorn
New Member
i'm kind of in a similar situation as i'm working on the items i want for my van conversion project. for cooking right now i'm thinking about skipping the microwave and just using an induction plate and a small convection oven. but i want an oven large enough to fit in most common uses of an oven, namely 13" x 9" pans or at the very least a 12" pizza. it seems like the ninja SP series 101, 201 and 301, will work for that. even the smallest SP101 should handle most things, albeit only one item at a time. there are several counter ovens that are small with similar inside space at cheaper prices, but i like the ninja because it has some space saving options and you can open it up for easier cleaning.
i also plan on having a solar oven. there is a wide variety of sizes for larger baking goals and its not to hard to make your own.
i also plan on having a solar oven. there is a wide variety of sizes for larger baking goals and its not to hard to make your own.
zanydroid
Solar Wizard
I actually think the “expensive” counter top options are a pretty good value over the traditional $100 toaster ovens.
You get more features and better baking, so it’s more space efficient.
They actually have better price/performance and features than built ins, which IMO justifies the premium cost. Although obviously builtins have advantages like durability, serviceability, size, and thermal etc design to be compatible with cabinet mounting.
For off grid the fact that you know that countertop oven X is capped at 1800W and will even only use half the elements in some modes or proportional power reduces the demand on the electrical system.
You get more features and better baking, so it’s more space efficient.
They actually have better price/performance and features than built ins, which IMO justifies the premium cost. Although obviously builtins have advantages like durability, serviceability, size, and thermal etc design to be compatible with cabinet mounting.
For off grid the fact that you know that countertop oven X is capped at 1800W and will even only use half the elements in some modes or proportional power reduces the demand on the electrical system.
That's what I decided to do. Do you know how many amps the 24V 3000 multiplus uses. I'm trying to size the battery cables to a lynx distributor. Some people say 125 amps while others 175. Should their be a factor for energy loss like (5, 10 or 15%). 10% extra 138 amps. I'm trying to size the battery cables to the lynx which will have to inverters and some small DC loads. I'm using 2/0 rather then 1/0 for the inverter says that is what I had laying around from a smaller system I never made.
zanydroid
Solar Wizard
I believe that the 3000 multiplus are continuous 2400W active power, 3000VA with appropriate power factor load. So it's probably safe to start with 2400 or 3000 continuous (I'm not sure if the extra 600VA will actually hit the battery or just oscillate in the inverter's circuitry, I'd just go with 3000. I'm not sure if 3000 is enough to not have to worry about the conversion efficiency, or if you should stack 10% on top of that)
I'm not sure about the energy loss factor, you might try the Victron forum. The efficiency listed in the data sheet is probably a good starting point.
I'm not sure about the energy loss factor, you might try the Victron forum. The efficiency listed in the data sheet is probably a good starting point.
