answersLogoWhite

0


Best Answer
for USA, Canada and countries running a 60 Hz power service.A service drop to a home is done with wire that is called triplex. This means that there are three wires twisted together that go from the service pole to the mast head on your home. This is called a three wire system. There are 2 hot legs and a neutral. The voltage between the hot leg (one) and the neutral is 120 Volts. The voltage between the hot leg (two) and the neutral is 120 Volts. The voltage between hot leg (one) and hot leg (two) is 240 volts. The single pole breaker is a safety device that connects to the (load, at 120 volts) and returns from the load back to the neutral. The load in most cases will be lights, plugs small appliances. The two pole breaker is a safety device that connects hot leg (one) to the (load, at 240 volts) and returns from the load back to the hot leg (two) at the two pole breaker. The loads in this case will be oven, range tops, hot water tank, clothes dryer, and in many homes baseboard heaters.

<<>>

In USA 240V comes into your home even though most of your equipment is 120V. I say most because your clothes dryer for one, if you have an electrically-heated one, most likely runs on 240V. The answer to your question is that 2 legs (power lines) come into your house. One leg is colored Black, the other is Red.

Each leg is 120V to common (ground). The voltage is AC (Alternating Current) so it is always going from +120V to -120V on each leg. But at opposite times, so that at some point in the cycle one leg is +120V while the other leg is -120V. And if you measure the voltage difference between +120V and -120V you get 240V.

The US wiring system works like this: to turn on your lights you switch into one leg, the current goes through your wiring to your lights and back to common. But your dryer switches into one leg and returns the current to the other leg. If you look in your breaker box you see breakers on both sides. Looking straight across, these breakers are on the same leg (L1). The next set down the panel are on the opposite leg (L2). Adjacent breakers all the way down the panel are on opposite legs. A two pole breaker spans these adjacent legs and that is how you arrive at 240 volts. Your dryer is connected to a two pole breaker that taps into both Black and Red legs.

<><><>

To accurately specify a voltage, you have to specify two points to measure, and the voltage is the difference between the two. If only one point is given it is usually implied that the second point is a grounded or 0 volt point. In the U.S., the three wires that enter most homes can be thought of as at +120V, -120V and 0V relative to ground. The 0V line is the "grounded" conductor, sometimes also called "neutral" and must be well connected to the earth where the wires enter the building (and no where else!) The +120 and -120 are actually different phases of an AC voltage wave. So by choosing which two points to connect to, a load can receive 120V or 240 V. Since there are two ways to get 120V, the breaker panel is usually set up to distribute the load between the two 120V phases.

<><><>

As always, if you are in doubt about what to do, the best advice anyone should give you is to call a licensed electrician to advise what work is needed.

Before you do any work yourself,

on electrical circuits, equipment or appliances,

always use a test meter to ensure the circuit is, in fact, de-energized.

IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB

SAFELY AND COMPETENTLY

REFER THIS WORK TO QUALIFIED PROFESSIONALS.

.

User Avatar

Wiki User

8y ago
This answer is:
User Avatar
More answers
User Avatar

Wiki User

16y ago

On a pure 240V circuit, no. There is no neutral. On a 240/120V circuit, yes. You have the needed neutral. Tapping 120volts off an existing 240volt branch circuit with a neutral is possible but is not a proper method. It does not comply with most electrical codes.

This answer is:
User Avatar

User Avatar

Wiki User

10y ago

Yes, it is done with a step up transformer. The transformer is sized by the load that is connected to the secondary side of the transformer. Smaller control size Transformers are rated in VA (volt amps) and larger transformers are rated in KVA (kilovolt amps). VA is derived from amps times volts.

This answer is:
User Avatar

User Avatar

Wiki User

8y ago

A 240 volt breaker can be removed and replaced with 2 - 120 volt breakers.

The existing 240 volt breaker should not be used to supply 2 separate circuits.

This answer is:
User Avatar

User Avatar

Wiki User

18y ago

In simple words, NO!!! On the first day of Electricity 101 they tell you if you do not know what you are doing, DON'T DO IT!!!

This answer is:
User Avatar

User Avatar

Wiki User

14y ago

You DO use the old wire. You must not run new wire and outlets of proper load rating for the job. Doing anything else is dangerous.

This answer is:
User Avatar

User Avatar

Wiki User

15y ago

A far as I know, you can't. If a wire is used in a 120v circuit, the wire itself is only rated up to 15 amps, therefore it can't carry a full load without tripping the breaker.

This answer is:
User Avatar

User Avatar

Wiki User

9y ago

Absolutely NOT. The 240 outlet pin configuration would be different from the 120 volt pin configuration. They would physically not fit into each other.

This answer is:
User Avatar

Add your answer:

Earn +20 pts
Q: How do you change 120V volt lines to 240V?
Write your answer...
Submit
Still have questions?
magnify glass
imp
Continue Learning about Natural Sciences

Can you convert a 120 volt Yamaha clavinova to 240 volts?

Electronic technician will convert in no time. You need 240v power transformer in place of same wattage 120V. Super easy.


Can you convert an existing 120V plug on an appliance to a 240V plug not speaking of a converter but actually changing the plug so there are no long term effects on the appliance?

If I understand your question, Can you run a 110 appliance off of a 220 volt outlet? You could by only using one leg of the 220. You may also consider changing the outlet. Put in a regular 110 outlet and capping off one leg of the 220 in the wall box. You still have a neutral and a ground to work with. I read this as the questioner doesn't want to modify the outlet. Check the voltage ratings on the device. Many electronic devices nowadays can havdle 120V or 240V as it is cheaper to manufacture one powersupply and sell it everywhere. If your device is rated for 240V, you can put a 240V plug on it. If it only says 120V, no dice. 240V will burn it up.


Is it cheaper to run a 240 volt window air conditioner than a 120 volt widow air conditioner with same BTU?

Your electric bill is computed in kilowatt-hours. This is a measure of power over a period of time, which is a combination of volts and amps. Amperage at 240v would be half that of 120v, but obviously the voltage is double. So the net watts are the same. As a result, your net kilowatt-hours will be the same whether you use 120v or 240v.


How do you connect a 240V electric cooktop with four wires to the 120V services from the electric panel which is 2 wires?

If your electrical service is only 120 volts you have a problem. There is no way that you can connect a 240 volt cook top to that service. You have two options, one is to upgrade to a new 120/240 volt electrical service. Your other option is to find a 120 volt electrical cook top.


What is the normal voltage of house electricity in the US?

The voltage in North America can be as low as 110 and as high as 125 volts. The average is about 115 to 117 volts. &lt;&gt;&lt;&gt;&lt;&gt;&gt;&lt;&gt; House voltage in the US is generally 120v line to neutral and 240v line to line. It is referred to as a "120/240v single phase service." Actual voltage can be as low as 110/220 or as high as 125/250.

Related questions

120V light fixtures wall mounted you want to convert to 240V for a house overseas?

It will work it you use 240 volt light bulbs.


How can you wire one half of a 20 amp 120 v duplex wall socket to run 240 volts over 2 legs 2 separate 120 v legs?

You can't. I'm not sure exactly what you're trying to do, but the way it is written is not possible. It seems you might want to use half of a duplex receptacle for 120 and half for 240. This would not be code compliant, nor would it make sense. A plug designed for 240v will not even fit into a 120v receptacle. You need a 240 volt receptacle rated for the amperage you will need. Also, an existing 120v receptacle has nothing to do with your 240v receptacle. For a 240 volt receptacle, you'll need to run 2 new 120v lines (in the same cable). The existing 120v circuit cannot be used here, even if you added another 120v circuit, because when a load uses 240v, both 120v circuits supplying the 240v must be controlled by a common disconnect (a 2 pole breaker designed for 240v circuit). My advice would be to show an electrician what you want done. I'm sure they can tell you how to make that happen.


Can you convert a 120 volt Yamaha clavinova to 240 volts?

Electronic technician will convert in no time. You need 240v power transformer in place of same wattage 120V. Super easy.


Is there adapters for 250 volt to 120 volts?

No. There are no "adaptors". To get 240V from a 120v supply you use a 120-240V step up transformer. &lt;&gt;&lt;&gt;&lt;&gt; Clothes dryers, water heaters and and other high-power 240 volt appliances cannot be run on a transformer from a 120 volt circuit. They must be powered from a separate branch circuit that has the right size breakers, cable and socket outlet to suit the appliance.


How do you produce 120V lines from 240V lines without using a transformer?

220 volt AC current is achieved by having two 110 volt lines with opposite waves or phases. One line will be positive while the other is negative then they flip or alternate 60 times a second (60 hertz). When connecting a volt meter to each of these lines it will read 220volts. Connecting a volt meter from either line to ground will read 110. I don't know if your question is backwards, but in a home you shouldn't have any lines that read 220 volts to ground. In a business or shop there can be 240 volt lines which combined can make 480 for industrial equipment. If your 220 is an older style and only has two hots and a ground (red,black,bare/green) you can't make a 110. If your 220 has 2 hots (red,black), a neutral (white), and a ground (bare/green), you can get 110 from either of the hots (black,red) to neutral (white).


Can you convert an existing 120V plug on an appliance to a 240V plug not speaking of a converter but actually changing the plug so there are no long term effects on the appliance?

If I understand your question, Can you run a 110 appliance off of a 220 volt outlet? You could by only using one leg of the 220. You may also consider changing the outlet. Put in a regular 110 outlet and capping off one leg of the 220 in the wall box. You still have a neutral and a ground to work with. I read this as the questioner doesn't want to modify the outlet. Check the voltage ratings on the device. Many electronic devices nowadays can havdle 120V or 240V as it is cheaper to manufacture one powersupply and sell it everywhere. If your device is rated for 240V, you can put a 240V plug on it. If it only says 120V, no dice. 240V will burn it up.


Can you plug a 240V amplifier into a 220 volt outlet?

Yes.


Is it cheaper to run a 240 volt window air conditioner than a 120 volt widow air conditioner with same BTU?

Your electric bill is computed in kilowatt-hours. This is a measure of power over a period of time, which is a combination of volts and amps. Amperage at 240v would be half that of 120v, but obviously the voltage is double. So the net watts are the same. As a result, your net kilowatt-hours will be the same whether you use 120v or 240v.


How do you connect a 240V electric cooktop with four wires to the 120V services from the electric panel which is 2 wires?

If your electrical service is only 120 volts you have a problem. There is no way that you can connect a 240 volt cook top to that service. You have two options, one is to upgrade to a new 120/240 volt electrical service. Your other option is to find a 120 volt electrical cook top.


Does a pool pump on 220 volts use the same amount of energy as a 110 volt?

Assuming it is also rated for 120V., yes. The wattage doesn't change with an increase or decrease in voltage. However, the current draw does. When you double the voltage a load is hooked up to, the Amperage draw (current) drops in half. Example: if a 240 volt heater draws 6 amps, it will draw 12 amps if connected to 120V. If a 120V heater draws 15 amps, it will draw only 7.5 amps when connected to 240V. But power, or wattage stays the same, regardless. And this is what is used to calculate energy usage and therefore, cost. Please note the above answer says "if it is also rated for"


You have 240v and you need to convert to 230v for an air compressor?

Yes, you can use a 230 volt device on a 240 volt supply.


A transformer has a primary volt of 240v and a secondary volt of 48v what is the turn ratio?

3