answersLogoWhite

0


Best Answer

240 volts is a typical single phase voltage (one phase wire and one neutral wire, possibly a ground wire as well) while 208 is a three phase voltage (you will have three phase wires, plus possibly a neutral wire)

208v in a grounded system is actually 120 volts referenced to ground. That is, there are three 120 volt voltages referenced to ground 120 degrees apart.

A typical house will have 120 and 240 volts. These are both single phase, but the utilitiy company's transformer providing this power has a center tap - so three wires from it, one at 0 volts (the neutral or return - usually the center), one at 120 volts, and one at -120 volts referenced to ground.

User Avatar

Wiki User

13y ago
This answer is:
User Avatar
User Avatar

Anonymous

Lvl 1
3y ago
There are still 2 phases in 240 volt single phase. Yes its confusing to some.
More answers
User Avatar

Wiki User

14y ago

One way would be to use a voltmeter to measure the voltage between each phase and neutral. <><><>

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.

This answer is:
User Avatar

User Avatar

Wiki User

14y ago

208V is typically found in three-phase systems, mostly found in commercial settings. 220V (actually 240) is a single phase system typically found in most homes. 208 is the net voltage developed between any pair of the three legs of a 120V three phase distribution. The individual legs are 120V to neutral and 120 degrees out of phase with each other. The 208V is in essence a single phase voltage when used as such. 220/240 is the distribution in a residence where its split single phase - 110/120 between either hot leg and neutral, and 220/240 across the two hot legs which are 180 degrees out of phase. Using equipment rated for 208 with 220/240 service or vice versa is generally not a good idea. Some equipment may be made with an acceptable input range encompassing both but equipment with motors will have trouble getting full performance out of that large a range, heaters sized for the higher end will not work to but about 75% of capacity when run on too low a range (or have a short life when sized for lower volts but used at higher) and incandescant bulbs will burn out quickly or provide vastly decreased light when run on the wrong range. Strictly speaking without some form of regulation or conversion, the input range is too wide for motors, heaters and lights to work comfortably. Electronic equipment with switching regulators are now common that will handle this range, though. However, most electronics are generally run on 110/120 in the US since they don't require high power.

This answer is:
User Avatar

User Avatar

Wiki User

12y ago

In a three-phase system, the three phases are displaced from each other by 120 electrical degrees, whereas in a two-phase system, the two phases are displaced form each other by 90 electrical degrees.

Three-phase systems may be three-wire or four-wire systems. Two-phase systems may also be three-of four-wire systems. However, a two-phase three-wire system is the equivalent of a three-phase, four-wire, system.

For a three-phase, four-wire, system, the line voltage is 1.732 times the phase voltage.

For a two-phase, three-wire, system, the line voltage is 1.414 times the phase voltage.

Two-phase systems are extremely rare, so the point of your question is unclear.

A two-phase system is not the same as the system (240/120 V) used in North America to supply residential premises, although it is occasionally but incorrectly referred to as such

This answer is:
User Avatar

User Avatar

Wiki User

15y ago

You will need a piece of equipment that can read voltage. A multimeter with a voltage scale of 300 volts will do. The safest way for you to do this without opening up your house panel is to (in a new house) go to your kitchen counter plugs. Put one lead of your meter into the top right hand slot in the plug. Put the other test lead into the bottom right hand slot of the plug. If the receptacle is a split receptacle you should read the voltage across the two circuits. The reading on the meter will either read 208 or 240 or nothing. If it reads nothing then the receptacle is not split and you should get some one qualified to help you out.

This answer is:
User Avatar

User Avatar

Wiki User

11y ago

480v 3phase is dangerous than 120v 3phase.

This answer is:
User Avatar

Add your answer:

Earn +20 pts
Q: What is the difference between 208 volts and 240 volts?
Write your answer...
Submit
Still have questions?
magnify glass
imp
Continue Learning about Engineering

What is a 208 circuit?

The 208 volt configuration is one phase of a three phase source at 240 volts, where the 208 volt circuit is connected between the center tap of one 240 volt phase (usually a grounded neutral, in the style of a standard 120/240 split phase system) and the high delta connection on either of the other two phases. 208 circuit would consist of two phases of a 208 volt wye system or could be all three phases. The voltage between conductors would be 208 volts. The voltage to ground from any phase would be 120 volts. A 240 volt delta system would give you a high leg to ground, somewhere around 190 volts and the other two would be 120 volts to ground.


What is the difference between 277 volts and 240 volts?

These voltages are both wye connection three phase voltages. The voltage difference comes from the primary three phase voltage supplies. 277 volts is obtained from 277 x 1.73 = 480 and 240 volts is obtained from 240 x 1.73 = 415. 480/277 volts is a common three phase American voltage. 415/240 volts is a European voltage. In Canada a common three phase voltage is 347/600. The 240 volts could also be a single phase voltage in North America derived from a split phase secondary on a distribution transformer that supplies 120/240 volts to homes.


Can a 240 Volts delta motor run on 440 Volts star connection?

If it is a 240 v delta motor it needs a 240 v three-phase supply, which has 139 v between line and neutral, so 440 v would not be acceptable.


On a standard three prong AC outlet what should the AC voltage measure between hot and ground?

Any where between 220 and 240 volts are a nominal figure in the same voltage range. It is brought about by the power company, as they have a responsibility to keep voltages within a certain 10% range. The load will only notice a difference of 1% on the load current. eg. Wattage load of 2400. Amps = watts/volts. 2400/240V = 10 amps. 2400/220V = 10.9 amps.


Are there tri-voltage motors?

On some motor nameplates you may see 120/208-240. These are not true tri-voltage motors. They are dual voltage motors with a leniency on the 240 volt range to be derated to run on 208 volts. At this voltage the current drops and you don't get the full horse power rating of the motor. To answer your question I have never seen one that would do true three voltages like 120/240/480.

Related questions

What is the difference between 120 and 240 volts?

voltage is the PUSH on electrons seriously 120 volts is the difference of 240...Simply said 240 volts is 2 times as strong as 120 volts.


Amp meter is showing 208 volts I need 240 volts?

There is some equipment that will operate on 208 volts even though it is rated to be use 240 volts.See discuss question below.


What is a 208 circuit?

The 208 volt configuration is one phase of a three phase source at 240 volts, where the 208 volt circuit is connected between the center tap of one 240 volt phase (usually a grounded neutral, in the style of a standard 120/240 split phase system) and the high delta connection on either of the other two phases. 208 circuit would consist of two phases of a 208 volt wye system or could be all three phases. The voltage between conductors would be 208 volts. The voltage to ground from any phase would be 120 volts. A 240 volt delta system would give you a high leg to ground, somewhere around 190 volts and the other two would be 120 volts to ground.


What is the maximum volts that can be used on a 208 230 volt motor?

You should not go above 240 volts for that type of motor.


What is the standard voltage?

In the USA it is usually 120/208 or 120/240 volts In Europe I think it's 220 volts


What the difference between a 120 volt and a 240 volt waffle iron?

One has an element designed to work on 120 volts, the other has an element designed to work on 240 volts.


Do all electric ovens cooktops ranges and clothes dryers operate on 208v as well as 240v?

No, use only the voltage for the appliance that your utility system is supplying to your residence. If your system is 208 volts use 208 volt appliances. Likewise if the utility system is 240 volts use only 240 volt appliances. 208 appliances on 240 will overheat the appliances and 240 appliances on 208 will not produce the wattages that the manufacturer recommends for cooking and drying.


In your home your stove and electric clothes dyer usually run on how many volts?

208 to 240 volts depending on your local power supply.


What is the performance like of an electric stove rated for 240V that is connected to a 208V supply?

Not good. The heating elements expect 240 volts. Possible, alternate burners elements can be purchased. (Read contact manufacturer.) Otherwise a buck/boost transformer can increase the voltage to 240 volts and the stove will run fine. Essentialy, 208 volts has 86 % of the energy of 240 volts.


I have a electrical dryer 240 receptacle that reads 208 on voltmeter and the dryer display reads Pwr Failure and will not operate were did the other 30 volts go?

I am assuming that you have just moved into a new apartment building. Commercial building power systems are changing to 3 phase. The 3 phase voltages are 120/208. 240 volt equipment will run on 208 voltages but at a reduced wattage output. For example Watts = amps x volts. Say your dryer draws 20 amps x 240 volts = 4800 watts. Now at reduced voltage, 20 amps x 208 volts = 4160 watts. As you can see your dryer won't get as hot and will take longer to dry. Most apartments that come with appliances will be rated at 208 volts. See what your dryer manufacturer has to say about getting around the Power failure alarm or whether it can be bypassed to operate on the lower voltage. Other option is to sell the 240 volt dryer and buy a 208 volt dryer. at 208 volts it will not draw 20 amps either


How many volts are supplied to the average household?

In the USA it is either 120/208 or 120/240 depending on your local unility company


How can I wire a 240 V single-phase outlet from a commercal building with 3-phase service 4- wire?

A three phase four wire commercial distribution service will not give you 240 volts. The nearest voltage you can get is 208 volts. It is a wye connection which gives you 208 volts between the three legs and 120 volt between any of the three legs and ground. This ground point is the systems neutral point.