using a transformer to use a 240 volt central vacuum on a 120 volt outlet

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my breaker box

Ok, well I got curious and headed to my apartment building's basement, I found the four breaker boxes, one for each apartment. Since I'm blind, I couldn't read the label to determine which box was for my apartment so I did the only thing I could, I opened the first box and flipped a few switches, fortunately I got mine on the first try, I could tell because my central air blower turned off. Glad I didn't do that to someone else in the building, they probably would not have been happy, lol. Anyway, here is how the box is laid out. There is a large breaker on top, that's for the air conditioner compressor and I'm guessing it's 240 volts. There are four other regular breakers, one of them is for the central air blower, I'm guessing that's a dedicated circuit but can't confirm that, this weekend I will probably do some experimenting to see which breaker controls what, but assuming that the blower is a dedicated circuit, that would leave three left. That seems like a low number for all of the outlets and lights in my apartment, but maybe that's typical. Here is what I have. There is no ceiling light in the living room so I use a lamp there. That room has four outlets. The dining room has a light in the ceiling and three outlets. When I say outlet, I'm referring to the typical pair of them on one cover plate. The kitchen has a ceiling light and two outlets, the refrigerator uses one of those. One bedroom has a ceiling light and three outlets, and the other bedroom has a ceiling light and two outlets. The bathroom has a ceiling light and just one outlet rather than a pair of them with a GFCI. That sounds like quite a bit to have on just three breakers, unless the breaker for the blower controls other things as well. I have no way to tell if the phase is different for those breakers, or if they are 15 or 20 amp, I would need sighted help for that.
Mike
 
First off, remember that ordinarily there is a paired breaker (two breakers that have their levers connected with a bar across them) on the absolute top, usually separated from the rest of them - that one is the main breaker for everything. Anything that's 240v, like the air conditioner, will also have a paired breaker, probably that's the big one you're referring to.

Three breakers for a 2 bed 1 bath apartment isn't that far fetched. Of course that does kind of mean that if you wanted to use the two circuit method, you would need to unplug or turn off just about everything in your apartment to use the central vac.

The good news is that if you have the central air running from your breaker box, which is very likely, you have 240v available. So there's that.
 
another discovery nd lay out of my breakers

So, I decided to find out what each of my breakers controled, and I did discover something else. Next to the breakers I mentioned in the previous post there are four other large breakers, from what I can tell, only one does anything though. I guess none of this will indicate if the phases are different but here is what I found.
In my previous post I mentioned that my dining room has three outlets. One of them is a three prong grounded outlet, that's the one that is controlled by the separate large breaker, it's 120 volts though so not sure why it's the large switch.
As I suspected, the central air compressor and central air blower both have dedicated breakers, so that leaves us with three more. I would have liked to have written this while I was actually testing each switch but since the breakers were off, my computers wouldn't work, guess I could have used my laptop on batteries but I think I remember it well enough. Turning on the first of the three remaining breakers gave power back to the ceiling lights in the kitchen, hall and dining room along with two of the four outlets in the living room. Turning on the second breaker restored power to the remaining two living room outlets, the ceiling fan and lights in both bedrooms and all five of the outlets in both bedrooms. It also restored power to the ceiling light in the bathroom and the GFCI outlet in the bathroom. Finally, turning on the third breaker restored power to the two outlets in the kitchen and the remaining two outlets in the dining room. I'm actually surprised I have not tripped that third breaker. This indicates that when I use the central vacuum unit I have in my kitchen, that and the refrigerator are using the same circuit, I would think that would definitely trip the breaker but it hasn't. Anyway, that's my lay out, do you think the phase is different for any of those circuits? I'd be inclined to use that three prong outlet in the dining room that has a dedicated circuit for one of the phases.
Mike
 
First off, if you have ANYTHING 240v running off of your breaker box (like central air) you automatically know for sure that you have the 2 phases.

Second, when you say 'large breaker' do you mean a double or paired breaker? One which is two breakers that have their switch levers connected with a bar across them? It should seem like two separate breakers with one very wide lever.

Now the single outlet you say is on the 'large breaker' in the dining room, would that outlet happen to be under the windows? If so, there's a very good chance that was originally meant to be a 240v outlet for a window air conditioner on a dedicated circuit. If it is indeed on a paired breaker, all by itself, that hints that it likely still has the wiring in the wall for 240v. It would be a simple matter for someone with electrical skills to wire it back to being a 240v outlet, and that would solve your problems. Even if it is a 15 amp circuit, it would probably manage the central vac without tripping the breaker. And you could have the breaker changed to a 20 amp one, provided the wires feeding the outlet are big enough.

Then you could just hook up a very long cord to the central vac unit you want, and plug it into the dining room outlet whenever it's cleaning time.
 
Also, forgot to mention, if you have other unused paired breakers, the apartment likely is wired for either an electric stove or dryer, or both. So that's also good news.
 
large breaker

Yes, the large breaker that I mentioned that is connected to the one dining room outlet looks just like the large breaker switch for the central air compressor, and yes, interestingly enough it is very close to a large window. Perhaps I should see if I can find someone with electrical skills to see what kind of wiring is on that outlet. I think there may be a drier hook up in the basement as well so perhaps I could make use of that. I think those driers use a nema 14 plug and central vacuums use a nema 6 plug but there is an adapter available to handle that. Apparently the nema 6 plugs have two hot wires and a ground but no neutral where as the nema 14 plugs do have a neutral wire.
Mike
 
having a 240 outlet installed

I have decided that I'm going to see if I can have a 240 volt outlet installed, perhaps rewiring that outlet in the dining room rather than trying to take a shortcut. Interestingly, one electrician company told me it would be thousands of dollars because my apartment is on the second floor and the box is in the basement because they would have to run the dedicated circuit wire on the outside of the building, I'm going to check around a bit more, I have a hard time believing that to be the case.
Mike
 
Mike, if the outlet in the dining room is under the windows I can almost guarantee that it was once a 240v outlet. In that case, rewiring it to be 240v again is a simple affair, perhaps a 5 minute job, would be equally as safe and effective a solution as running a whole new line, and shouldn't cost you much at all.

However, I'm still betting that you do have an outlet for an electric dryer or stove, given those apparently unused large breakers you described. Checking behind the stove wouldn't be a bad idea.

Having an electrician visit your home, or at least someone moderately familiar with electrical work, would also be a good idea. Describe your situation to them and mention all I've said here.
 
that's teh plan

I do have a company in mind, I have talked to them and they say that what I'm asking for should not be a problem. I think you might be right about that dining room outlet, it has another unique trait to it that no other outlet in the apartment has. There is a metal strip that comes out of the outlet and goes in to the wall, so it was definitely set up differently than the others. I need to get some time off work and see when they could come and take a look.
Mike
 
Just be sure not to spend money for no reason. I'm still banking on that outlet being wired for 240v. I'm also still assuming you have a 240v outlet behind the stove.
 
outlet

I looked behind the stove, there is nothing there, my stove is gas. I think I have decided which company here I will ask to see if it's possible to have an outlet installed, and the first thing I'm going to ask them to check is that outlet in the dining room. As you said, why install an entire new circuit if we don't have to?
Mike
 
great news

I'm happy to report that I now have a 240 volt outlet in the dining room, and it was very interesting how things were wired. Madman was correct, that outlet had once been a 240 volt outlet, to make a 120 volt, whoever did the wiring actually used the ground wire for neutral. That doesn't sound like the proper way to do things but it's been that way since I was here. Now here is where it gets interesting. The breaker for that outlet is a 40 amp breaker for an electric range, and it turns out I did have a range outlet I just didn't recognize it. It's a separate box behind the stove and actually uses two fuses, and that outlet in the dining room feeds off of that same circuit. I'm not exactly sure what the electrician did, but somehow he was able to get the second hot wire back again, probably from that neutral ground wire, and the meter showed it as 239 volts. He installed two new 20 amp fuses in that box in the kitchen and left the 40 amp breaker in the box. He literally did not have to drill any holes or run any new wires, the way he described it, he made things the way they were originally when that outlet was installed. It took about 15 minutes, and cost $190. I'm guessing it would have been much more expensive if he had needed to run a whole new circuit, but we were able to use what was already there. So I now have a NEMA 6-20 amp plug in my dining room and can get some 240 volt central vacuum units, really excited.
Mike
 
drier hook up and range plug

Here is a bit more information. There is definitely a drier hook up in the basement and a dedicated breaker for that, there are two other large breakers and I have no idea what they do and the electrician was not totally sure either. I'm not sure what a range outlet is supposed to look like, now that I know I have one, I took a look at it, from what I can tell, it has three fairly large rectangular prong holes, the two on top are somewhat diagonal, and the one below it is more straight. I'm guessing that might be a NEMA 14 plug but not sure.
Mike
 
another update

According to UPS, I should get my Drainvac twin turbo on Tuesday, really excited. Besides having the 240 volt outlet installed, I did purchase the quick 220 power supply as well, this connects to two 120 volt outlets that are out of phase and combines them to give you 240 volts. I received that yesterday and was able to find two outlets in my apartment that were out of phase so I will now have two ways to power my 240 volt units. I'm still glad I have the dedicated 240 volt outlet since that will be easier to hook the units to without having extension cords all over the place. If anyone is interested, I will include a link to the quick 220 model that I purchased.
Mike

https://www.quick220.com/-P-106.html
 
This same J-box for converting 2-120V to 240V is shown in the Hypervac duct cleaner vacuum site-on another thread here.It allows you to run their 240V portable duct vacuum from two opposing 120V outlets.Since the Hypervac 240V unit has a Variable Speed Drive on its motor can be set to a speed that won't blow breakers or fuses.And the motor starts gently and graduately.3 Hp.
 

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