0
You don't. If the three phase power has one of the phases center-tapped as a neutral for 120/240 you can do it. This is known as quadraplex wiring. Without that neutral, you must have a transformer.
<><><>
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.
Wiki User
∙ 14y ago
Wiki User
∙ 11y agoThree phase in the USA have two common voltages; either 277/480 or 120/208.
if the panel the power is to be taken from is rated at 120/208 then a single pole breaker in the panel will supply 120 volts from any of the phases where as the circuit is complete through the neutral.
although not common to have, some of the three phase system having 120/208V set up could have the High phase B. that means that Phase B alone has a 208V phase to neutral; in other words a single pole breaker installed on phase B will supply 208V and not 120.
Should the electrical system be 277/480V; then a step down transformer is required to produce the desired voltage.
Wiki User
∙ 18y agoYou need a three phase step down transformer to give you, your 110vac to 240vac.
Wiki User
∙ 14y agoWhat specifically are you wiring? A light bulb would operate dim, a motor will burn up. The current increases thereby requiring larger wire and current protection.
Add your answer:
Earn +20 pts
How do you convert 480v to 120v?
to derive 120 volts from 480 volts you have to use a transformer, based on your needs. If you needed 100 amps at 120 volt single phase you would need a 12kva transformer. This is just an example.
Why do you use a neutral wire in a circuit?
The power company uses a single transformer outside your home to reduce the voltage from the transmission line voltage down to the 240/120 volts that you can use when you plug in your appliances. The power company is trying to be responsible with their money when they put that transformer out there, so they use a transformer that can provide both 240 Volts and 120 Volts, at the same time. To do that, the output of the transformer is divided into two halves; one half provides 120 Volts, and the other half provides 120 Volts, with a "common" or "center tap" in the center of the 240 Volt transformer winding. It isn't a coincidence that your 240 volt plug that operates the electric range or electric dryer is twice the voltage of the 120 volt plug that operates your TV. By using half of the output from the transformer to provide your 120 Volt service, you are technically using the center tap/Common wire as one of the current carriers for the circuit. In theory, the common wire should be identical to the ground wire, but because real life isn't quite the same as the theoretic, it is necessary to treat them differently. In some VERY OLD neighborhoods there were no 240 volt transformers, and as such, no neutral/common wire.
How do you convert 277v to 120v for an outlet?
i think you just have to change the breaker from a 277 to a 120. 277 breakers are usually a 2 pole breaker and 120 is a single pole breaker. NO. 277v is not two poles, it is one pole, one single pole breaker in a 480 volt 3 phase system (typically). If you want 120 volts from a 277 volt source you need a step down transformer 277 volt to 120 volt , or 480/277 to 120/208 .
Can you use 240 volts with a 120 volt supply?
Only if the cable going to your well pump is a three wire. The third wire could carry the neutral and you will have 120 volts from either 240 leg to the neutral.
Is there a neutral on a three phase transformer?
It depends on whether you are wye or delta connected. A transformer is a transformer, and a three phase transformer is simply three transformers. The key is in how you hook them up.AnswerIt depends on how the transformer is connected. If one set of windings is connected in star (or wye), then the star point is/canbe earthed and becomes the neutral for that particular connection; this is the standard connection for the secondary (low-voltage) of European distribution transformers. In North American three-phase distribution transformers, the secondary windings are connected in delta, and one phase is centre tapped, earthed, and that becomes the neutral point for a 240/120-V split-phase supply to a residence.This answer applies to both three-phase transformers, and to single-phase transformers which have been connected to form a three-phase transformer bank. (It is incorrect to say that a three-phase transformer is simply three single-phase transformers!)
Can you convert three phase 480 volts to single phase 110 volts?
If you have a 220v three phase delta system, the phase-to-phase voltage is 220v single phase; hence, no conversion is necessary. Don't worry about 220-240v rating, the voltage rating is nominal. Your 110v single phase has actually already be taken from a center-tapped transformer on your three phase system.
How can you get a 240V single-phase power from a 120V 3-phase service?
First of all there is no common three phase 120 volt service. There is in North America a three wire 120/240 volt single phase service. That being said, if you want to change a 120 volt source to 240 volts it must be done with a transformer. Its classification is a step up transformer. The primary side of the transformer H1 - H2 will be connected to the 120 volts. The secondary side of the transformer X1 - X2 will be connected to the 240 volt load. The transformer is sized by the current required by the 240 volt load.
What is the difference between step up and step down?
in transformers for instance a stepup transformer does exactly that, steps up the voltageAND/OR theamperage and a step down transformer reduces the same. if you have a machine that operates on say 120 volts alternating current single phase and your building or power supply in your buildingis set up for or delivers480 volts alternating current-three phase you will need a step down transformer to operate the machine.
Can a 3 three phase motor be run with a scot t transformer on a 2 phase supply?
A Scott transformer converts 3-phase to 2-phase and vice versa, so if you get a Scott transformer it can convert a 2-phase supply into 3-phase for the motor. Caution: the 2-phase supply has to be a genuine 2-phase as defined, with 90 degrees phase between the two phases, and these are extremely uncommon. A Scott transformer CANNOT be used with the split-phase supply found in many US homes which have a 240 v single-phase transformer with the centre earthed and connected to a neutral wire to produce two 120 v circuits.
How do you calculate amperage of a 3 phase transformer?
Total KVA of the transformer divided by (square root of 3 times the voltage). This will give the individual phase currents. These individual phase currents will be 120 degrees out of phase with each other.
Can you step up 12 volts AC TO 120 volts AC?
Yes this can be done with a step up transformer. Keep in mind that it is a 10 : 1 ratio. For every 1 amp that you want out of the 120 volt secondary there will have to be 10 amp input on the primary. This can lead to a very big wire size on the primary coil.
Can you get 110 volts from 277volts?
The voltage of 277 is the wye connection of a 480 volt three phase supply. The only way to reduce 277 to 120 volts is with a step down transformer.
Does a 3 phase motor starter with a 120 volt coil need a neutral to the coil?
Usually for this type of installation there is a control transformer installed in the starter enclosure. The primary of the transformer is the motors line voltage and the secondary is the control voltage which is usually 120 volts. In Canada the control transformer needs fusing on the secondary side of the transformer. In the US the transformer needs fusing on the primary and secondary sides of the transformer. The secondary side of the transformer's terminals are labeled X1 and X2. The X2 lead is grounded to the starter's enclosure. From this point out the wire is then termed the circuit's neutral wire. This wire then connects to one side of the magnetic starters draw in coil. Yes, 120 volt coil would require a neutral, this could be derived from the control transformer if it has one or from an external source.
Why is a three phase four wire distribution system used?
A three phase four wire system allows for two voltages from a single three phase transformer. The transformer configuration is a wye or star connection. It is used in commercial and industrial applications. Apartment buildings are now starting to use a three phase four wire service distribution system. Some wye connection voltages are 120/208 volts, 480/277, and 600/347. The lower voltage is derived from the sq root of 3 divided into the three phase voltage.
Is home electricity 3 phase?
No, in North America most homes are wired to a single phase transformer. That transformer is connected to a three phase power grid. Some of the newer apartment buildings and condominium complexes have three phase systems in them. Their voltages are 120/208 as compared to a homes single phase connection of 120/240 volts.AnswerSome European countries, such as here in Cyprus, have three-phase residential supplies as standard for some reason -can't quite figure out why it should be necessary, though!
How do you convert 480v to 120v?
to derive 120 volts from 480 volts you have to use a transformer, based on your needs. If you needed 100 amps at 120 volt single phase you would need a 12kva transformer. This is just an example.
How do you wire a 277 to 120 volt transformer?
The voltage 277 volts is a three phase line to neutral voltage of a 480 volt system. What is needed for the protection of the transformer is a two pole breaker from the 480 volt CDP (Central Distribution Panel). The breaker will be sized to the KVA of the transformer. The wire will be sized to the breaker plus 25%. The electrical code requires that on motor and transformer feeders, they be sized to 125% of the total current capacity of the equipment.
