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no you must run a dedicated line
NO
Yes, with a caveat. The current ratings must be the same, the the 110V outlet must be a dedicated circuit, i.e. nothing else on that breaker. You can safely upgrade a dedicated 110V 15A circuit to a 220V 15A circuit by re-using the same wiring. You will have to just replace the breaker and the outlet. You cannot, however, increase the current load or have a 110/220V (4-prong) outlet. Note that if you move a non-dedicated circuit up to 220 you will start a fire.
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Can you take single phase of 120V with a hot wire and a neutral step up to 480v and then step down to 2 phases of 120V or do you have to input 2 phases of 120v to get 240V out?
Theoretically that can be done with transformers, but the power available would still be limited by the circuit breaker on the original 120 v supply.
What is the difference between a 220 hot to hot and a 270 hot to ground?
Most residences have two 110-120V separate supplies that are combined to provide double the voltage or 220-240V. So you get 220V between hot of each 110V supply. Hence, hot to hot. A 270V system would typically not be in a residence, but a commercial establishment and is provided as a separate supply from a transformer. Hence the 270V is supplied hot to ground.
What is the color assigned to the high leg conductor of a 4-wire delta secondary three phases?
Assuming you are talking about a 120/240v delta system the color coding is as follows. Phase A(120v)-Black Phase B(208v "Wild leg/High phase")-Orange Phase C(120v)-Blue There are other color coding methods but this is the most common.
Can step down transformer be used as a step up transformer?
If the transformer has two separate windings, then, YES a step-down can be used as a step-up, and vice-versa.It is more correct to say you are reversing the high and low sides.By definition Primary is the "IN" side and Secondary is the "OUT" side.The Primary could be the high voltage side if it is a step-down,or it could be the low voltage side, if it is a step-up.Design ConsiderationsCare must be taken when reversing the operation of a step-down transformer to insure that it does not exceed the ratings of the transformer. For example, let's say we have a 12 VA step-down transformer that takes 120Vac in and is rated to provide 12V at 1 amp at the secondary. If we were to reverse it and apply 12Vac to the new primary (the old secondary), we would have 120Vac at the new secondary, but to keep within the original ratings it could only be loaded to 0.1A @ 120Vac.As long as you treat the output rating of the step-down transformer as the input rating as a step-up transformer, and don't try to draw current beyond what would normally have been applied to the high voltage primary, you should be fine. Potentially one could push up the voltage on such a transformer beyond what its stated application specified, while making sure not to exceed the power rating of the transformer and not exceeding the breakdown voltage of the transformer's insulation, for example driving the above transformer at 24V to get 0.05A @ 240Vac. It is important to realize though that the rated input voltage for a step-down transformer will likely not be a safe input voltage if you use it as a step-up transformer - for example, applying 120V to the above transformer with the windings reversed would generate 1.2KV!One important point to remember when reversing a three-phase transformer to a step-up is what kind of windings it has. Most three-phase transformers use a "delta" configuration on the primary side. This means that there are three "hot wires" and a ground, but not a neutral. (The white wire in a circuit). On the secondary side, transformers are usually wired up in a "Wye" (sometimes called a "star" configuration. Doing this allows the transformer to create a Neutral connection. If a step-down transformer is reversed to make it a step-up, the high (output) side will not have a Neutral connection. If one is not needed, say for a three-phase welding machine, this would not be a probem. However, if a Neutral IS needed ,say for lighting, reversing this transformer would not work. In this case, a listed step-up transformer will be needed. One final thing, if a step-down transformer is used as a step-up, a Neutral wire is not required to be connected to the input side.
What is the neutral in a electrical circuit for?
Good question! In US residential wiring, you have 3 wires feeding your home off the transformer: two hots and neutral. The transformer is a 240V center tapped transformer. The neutral is the center tap. Well, that's all fine and good, but your probably asking "what does that mean?" right about now. Well, since the transformer is 240V, you have 240V in between the two hots. The center tap divides the transformer winding in the middle. So between either hot and neutral you get 120V. Neutral is kind of a return wire for 120V circuits. (I say "kind of" because this is AC, current is flowing in both directons.) Well, why is it called neutral, then? At your main service panel a fourth wire comes into play: ground. Ground is simply a heavy safety wire that goes to a 8ft long copper rod driven into the ground. This ground wire is connected to all metal surfaces you touch (panels, screws, metal junction boxes, metal cases on appliances, etc.) In the main panel (and only the main panel) neutral is bonded to ground. So, while neutral is not ground, when everything is correct it should be "neutral," i.e. it has no potential on it. You cannot assume neutral is grounded or safe to touch, however. By the very nature of wire, if there is a current in a wire there is a potential across it. This potential is usually very small, but is still there. The bigger problem is if the neutral connection becomes very resistive or open. Then the neutral will be live as it cannot "return" the energy to the transformer. (Again, not a totally correct analogy, but it gets the point across.) This is why you shouldn't just bond ground to neutral when you don't have a ground wire at a fixture. When a hot wire goes open, fixtures simply fail to operate. When a neutral goes open, the fixture and the neutral between the fixture and the break go live. The fixture will not work, however, giving people a false sence of security. (No the light is not on, yes it can knock you on your butt.) This is why you want to keep your neutrals in good shape. With the neutral you have two hot wires both capable of producing 120V to neutral. Because the hots have 240V across them (and not 0), one hot goes positive while the other hot goes negative. So, let's say you take two loads with a resistance of 60 ohms. You hook the neutrals of the loads up to neutral, one load to one hot, and the other load to the other hot. How much energy flows through the neutral conductor? 0W. This is because the load is "balanced." The amount of energy flowing through load one is equal to the energy flowing through load two. Let's do a testcase for a specific point in time. Let's say hot 1 for load one is at +60V, and hot two for load two is -60V. Ignoring load two, load one has a current of 1A (60V/60ohms=1A) flowing from hot one through the load and back to the transformer through the neutral. We will call current into the transformer on the neutral positive, and current out of the transformer on the neutral negative. So our neutral has a current of 1A on it for load one. Load two has a current of 1A flowing out of the neutral, through load two, and back into the transformer on hot 2. So, by our signing above, load 2 has a current of -1A on the neutral. To calculate the actual current on the neutral, we add the currents for the two bulbs: 1A + -1A = 0A. Current is flowing out hot one, through bulb one, through bulb two, and back to the transformer on hot 2. Make sense? Now, let's say you have the same setup as above, only load 1 is 30ohms. Well, now the neutral has to carry the extra amp of current. The loads are no longer balanced, so the neutral has to carry the difference. At our 60V test case, the current of load one is now 2A. The neutral current is 2A + -1A = 1A. So, this means that the neutral only carries the difference in power between the two hots. This is also why your neutral doesn't need to be twice as heavy as your hots. Let's say you have 200A service. While you can have 400A of current flowing to 120V appliances all over your home, it is actually +200A to half and -200A to the rest. Your neutral carries 0A, not 400A. Let's go back to our last example, with the 60ohm and 30ohm light bulbs. Let's say some unscroupulous DIYer used the conduit the feed is in for a neutral instead of a dedicated neutral wire. Let's say a clamp to the pipe came off and now we have no neutral connection. Now, we had +60 on hot 1 and -60 on hot 2. So our loads have 120V across them. Now, in this ideal test case, our loads appear as a single 90ohm load to the supply. This means that there is 1.334A flowing through our circuit (120V/90ohms = 1.334A). This also means that load 1 us underpowered by 2/3 of an an amp, while load two is overpowered by one third of an amp. If loads one and two were lightbulbs, bulb one would be dim while bulb two would be brilliant. As both loads have 1.334A flowing through them, load one has 40V across it, while load 2 has 80V across it. Remember, at this point they are both supposed to have 60V across them. Our little set up above is how 240/120V applances work. In, say, your dryer, you would have a third load that is directly across the two hots. Load 3 would be your heater, load 1 would be your timer, and load two could be the light in the drum. If your neutral comes open you could toast your timer or bulb. Most appliance manufacturers actually avoid using both hots for 120V, if possible, for this very reason. You can never be sure, though. Now, the other thing to keep in mind is your whole home functions as a 240V/120V appliance. Load 3 is your heavy appliances, the heaters in your dryer, oven, waterheater, etc.. Loads one and two are all your 120V appliances, light fixtures, etc. So while an open neutral doesn't cause too much of a headache on your dryer, it does cause a big headache in your home. Let's say your service neutral comes open, and you have 1500W of appliances on for load 1, and a 100W porch light on for load 2. That porch light is going to burn out very quick. Now it is impossible to garuantee that load 1 will equal load 2 without being obsessive-compulsive. What you can do is when you plan your load and circuits, try to balance them. This will keep current in the neutral low, which will prevent bad connections from burning open. Also, in the event neutral does fail, if the loads are close to balanced you may only see 90V/150V instead of 10V/230V across your 120V loads. Your appliances my be able to tolerate the former until you notice, they can't tolerate the latter. A resistive neutral is a nasty little problem. It has ultimately the same effects as an open neutral, but is much more subtle. With a resisive neutral, there is a connection, but it is bad. When no current is flowing through the neutral, it appears OK. The more current flows through the neutral, the more potential develops across it by ohms law. This means that if your neutral has 25A flowing through it, and has 2 ohms of resistance, the neutral wire has 50V across it. This also means that your neutral bus in your panel is not at 0V (with respect to the transformer), but is at 50V favoring whichever load (1 or 2, as above) is heavier. This means that the lighter load will be overvoltaged. Also note that resistive neutrals get worse with time. Since our example neutral has 25A at 50V on it, it is dissipating 1250W at some point in the wire. This point is the resistive connection, and will get hot as it dissipates all this power. As it gets hot, it will burn a little further open, and the circle continues. NOTE: This procedure involves probing your service panel or heavy outlet while live. This is dangerous. If you are not comfterable with this, call an electrician. They can check for this quickly and tell you exactly what you need to do to fix it. The easiest way is with a AC voltmeter. Leaving everything on as you normally would. Check the voltage from one hot to neutral, then from the other hot to neutral. This can be done at your panel, at a dryer outlet, at an oven outlet, or at any other 240/120V outlet. If the voltages differ by more than a volt or two, you may have a problem. Call an electrician, as work on your main service must be done by someone licenced, and they have lots of experience with this.
Why are you not getting 240v between the two hot wires?
Because they are "in-phase". In order to get 240v, you need two 120v Alternating Current lines that are 180° out of phase, that is, opposite phases. Only when one line is +120v and the other -120v will you see 240v between the wires.
Can you take single phase of 120V with a hot wire and a neutral step up to 480v and then step down to 2 phases of 120V or do you have to input 2 phases of 120v to get 240V out?
Theoretically that can be done with transformers, but the power available would still be limited by the circuit breaker on the original 120 v supply.
What adapters do you need to plug your 240V Ac plug into a 110V AC supply?
There are no adptors to plug a 240v plug into a 120v receptacle. 240v requires two hot wores and a neutral and ground. 120v requires one hot wire, a neutral and a ground. If you have something that runs on 240/120 you need the cord and adaptor that came with the equipment as you willl need the wires to mate up accordingly.
What is the difference between a 220 hot to hot and a 270 hot to ground?
Most residences have two 110-120V separate supplies that are combined to provide double the voltage or 220-240V. So you get 220V between hot of each 110V supply. Hence, hot to hot. A 270V system would typically not be in a residence, but a commercial establishment and is provided as a separate supply from a transformer. Hence the 270V is supplied hot to ground.
What does a transformer between utility wires and your house do?
The transformer steps down the voltage from 600kilo volts which is what is at the power pole/lines to multiple strands of 120v or hot wires which is what your house runs off of.
Can you use a 120v cord that will fit a 240v socket the appliance is 240 and the cord is thick?
120v and 240v cords usually have different end configurations and will not plug into the different recepticles. However, if you changed the plug end, and the cord has the proper size rating, then yes, you could use the same cord. But, it also depends on the cord too. Most 120v cords only have three wires in them. One "hot one "neutral" and one "ground" wire. A 240v cord would have FOUR wires, two "hot" wires, one neutral wire, and one ground wire. Therefore, if you changed the voltage from 120v to 240 using a 3 wire cord, you'd not have a ground wire and that could be VERY dangerous. Note that occasionally a 240v device (e.g. some motors) will only need three wires (red,black,green, no neutral) and can be wired with a 120v cord if the cord is rated for 240v.
What if your electrician has fitted a 240v socket in your rec room you want to use your 240v deck and amp but find 2 hot 120v wires and 1 earth How can you use your prized stereo?
Not a hard job or complicated but could be hazardous. Hire a professional.
The motor states 120v single phase to operate.can you use it using 230v supply in Singapore?
Absolutely not. In the U.S. all power is 120v on a single line (one hot, one neutral, one ground) overseas all power is 230v on a single line. Will fry your unit. You can however by a step down or up transformer fairly cheaply at radio shack.
What makes a 480 motor with up down and stop 120v switch work?
I think I understand what you are asking. 3-phase motors usually are equipped with a starter or contactor, since all 3 hot wires need to be switched. The control voltage that runs the starters is 120V, because it's safer and also 120V switches and relays are cheaper. You would have a 480-120V transformer (called a control transformer) in the starter box to provide the 120V "control voltage". So the arrangement you describe would have two contactors, with two phases reversed between them. Energize one, and the motor runs forward. Energize the other, and it runs reverse. The switch sends 120V to each of the contactors, which are equipped with 120V coils.
If you have a 240V dryer and installed 30A breakers on both sides of the line reads 120 and 120 how do you get 240 and you have a receptacle that reads 30A 125250 and still does not work?
you do NOT put two 110v breakers in. you put 1 two pole breaker in. the panel is designed to give you 220v off one side OR the other side if you use a 2 pole breaker on one side or the other side. If you look at both 120V lines on an oscilloscope you will notice that they are both 120V to the neutral, but they are 180 degrees out of phase. This means that when one hot is at +120V the other is at -120V. So between the two you have 240V. If you put your meter across both hots you should see 240V. If you do not see 240V across both hots you (or an unlicenced electrician) has wired the outlet without using a proper 220V breaker. You do not see 240V because the hots are in phase, to the voltage differential is 0V, not 240V. 220V breakers cannot do this, unless forcebly installed in the wrong type panel. More than likely someone tried to wire it with 110V breakers.
What is info on a 120V through its double 20A breaker and 10-2 plus a separate bare ground inside plastic flex conduit to a three-prong 240V outlet box?
So what's your question? 110V would be hot to neutral/ground. 220V is hot-to-hot (phase to phase).
How many wires do you need if you are stepping up single phase 120-240V to 480volts?
Five wires. Two on the primary side, connected to each 120V leg, giving a primary voltage of 240V. Two on the secondary side, one connected to neutral, and the other the new 480V hot. One connecting the frame of the transformer and the box containing it to ground. Note: you will only get one phase power out of this configuration - to get three phase output, you need three phase input, three transformers, and a lot more wires.
