# 220 single phase wiring diagram

## Why is 220V called single phase when it has two phases?

Why is 220V called single phase when it has two opposing phases?

Click to expand...

It's because the term "phase" is being used to describe two different things. 120V/240V is 3-wire single phase, not two phase. True two-phase is an antiquated system (Tesla's original multiphase motors were two phase) that has largely been supplanted by three-phase. It's difficult to explain in words without reference to diagrams, and math or at least vectors.

At the risk of confusing the issue, "one-ten" and "two-twenty" volts are figures of speech and have not been used for eighty or so years. The present standards are 120V and 240V and have been since the 1950s. 115V and 230V were standardized in 1928 and before that, there was a mix of "standard" voltages from 110V to 125V.

Historically Thomas Edison selected 100V for his lamps, and allowed 10% drop in the supply lines, so the generators produced 110V. That's where all the multiples of 11 came from (110, 220, 440, 550, 2200).

Early carbon-filament lamps could not be produced uniformly, and the lamps were selected at manufacture to suit a particular voltage. Various cities were encouraged to standardize on different voltages, from 110V to 125V, to create a market for all lamps produced. Over time, higher voltages predominated, and by 1919 115V overtook 110V in popularity. By 1926 110V lamps accounted for only 12% of demand (35% were 120V).

The present US standard is 120V +/-5% or +/-6V, or 114V to 126V. Power companies like to keep the voltage as high as possible to get the maximum use of their distribution network. The line voltage here has been 123V since 1960 or so.

Use only 600 volt wire.
Lamp cord, extension cords are not rated 600 volt.
Use copper wire only. Aluminum wire is fire risk and should be avoided or installed by professional.
30 amp breaker use 10 gauge /
120-240 volt 30 amp outlet can be installed on 30 amp breaker only/ use 10 gauge wire ... cannot be connected to 15-20-40 amp breaker.

Orange/ #10 gauge wire, with ground ... 30 amp capacity. Safe maximum: 30 x 80% = 24 amps.
10-2 gauge/ 30 amp
10-3/ 30 amp
Southwire electric toolsYellow 12 gauge 20 amp
120 volt 20 amp outlet can be installed on 20 amp breaker, but not 15 amp breaker/ use 12 ga wire.
... cannot be connected to 30-40 amp breaker. 1

Yellow/ #12 gauge wire, with ground ... 20 amp capacity. Safe maximum 16 amps.
12-2 gauge/ 20 amp
12-3/ 20 amp

NMB is house wiring
UF is underground
Rolls of stranded wire
HOOK UP WiresWhite 14 gauge 15 amp
120 volt 15 amp outlet, AFCI, GFCI, timer, switch etc can be installed on 15 or 20 amp breaker. Never connect 15 gauge wire to 20-30-40 amp breaker.

White/ #14 gauge wire,  with ground ... 15 amp capacity. Safe maximum 12 amps.
14-2 gauge/ 15 amp
14-3/ 15 amp

NMB is house wiring
UF is underground50-60 amp breaker use 6 gauge /
240 volt 50 outlet can be installed on 50 amp breaker only

6-2 wire
Southwire electric tools
NMB is house wiring
UF is underground40-50 amp breaker use 8 gauge /
240 volt 40 amp outlet can be installed on 40 or 50 amp breaker only

8-2 wire
Southwire electric tools
NMB is house wiring
UF is underground
Copper ground wire.
Every device, load, metal enclosure etc must be grounded. Ground wire must be continuous throughout installation, never switched on-off, never used as a Neutral wire.
Generally ... use same size as other wire in circuit
12 gauge copper ground wire
Ground wire
Green ground wire
Ground pigtails
Ground rods/ ground clamps at Amazon
Non metallic flexible cables must carry ground wire, but do not have hazard of short circuit causing injury from shock.

Armored steel cable can be used as a grounded connection, and will protect wires from damage. Metal can be energized from an insulation failure.

All conduit ...metal, plastic ... flexible and rigid ... must be attached to structure, and attached to enclosures, boxes.
Movement, damage and deterioration are major cause of electrical failure.
Non-metallic flexible conduit
Power whip
Armored cable
Southwire armored cable cutter
Pull boxes
Electrical tools must be insulated.
Always best to disconnect power, but insulation failure, lack of proper grounding, grounded neutral, lack of GFCI, out-of-code wiring, generator operating without transfer switch, and other problems still pose a risk to anyone working on electric power ... even when breaker is off.

Electrician tools kits
KLEIN TOOLS
Tools kits
IRWIN tools
KNIPEX

Telephone cable knife
Low Voltage Mounting Bracket for Telephone

### Push-on wire connectors in place of twist-on connectors

Push on wire connectors Amazon
Red 3P connector for 10-14 gauge wire
Lever connectors for stranded wire at Amazon
HOOK UP Wires
Protect wiring from damage
Use nipper instead of pliers or screwdriver for removing staples (and nails). Do not damage cable or wires inside cable.

-Code says: Cable SHALL BE secured without damage to the outer covering. NEC sec. 336-15
End cutting nippers at Amazon

Electrically insulated tools
When removing insulation from wire, do NOT score or put cuts on surface of copper wire. Doing so increases resistance and heat on wire and creates possible weak point.
KLEIN TOOLS
Wire strippers at Amazon
Electric Wire Stripping Machine
Linesman pliers
Utility knife at Amazon
Multimeters
Voltage is tested across two separate wires. Ohms or resistance is tested across both ends of same wire. Amperage is tested along one or two points on same wire.
Analog multimeter
Multimeters at Amazon
Klein multimeter
Electric testers at Amazon
Clampmeter for testing amp flow on line
Sours: http://waterheatertimer.org/How-to-wire-240-volt-outlets.html

## Switching a motor between 240 and 120 volts

In North America, many single phase motors motors in the range of 1 hp to 2 hp can be rewired to run at either 120 volts or 240 volts (or 115 vs 230 volts, it depends on what voltage is assumed "nominal").

Such motors will typically have six leads coming out of the motor to the wiring box, or some of the connections may be screw terminals. The best way to change the voltage on a motor is to follow the wiring diagram on the label. But sometimes when you open up a motor, there's just six wires and no diagram! This happened to be the case for the 1.5 hp motor on my old table saw. 20 years ago I wired it to 240 volts, but I wanted to switch it back to 120 volts. for where I moved it to.

Internally, the motor has two 120 volt windings, which are in series when the motor is wired for 240 volts (left, at left). When switching it to 120 volts, the two windings are reconfigured to be in parallel.

It would be easier to connect A to C, and then connect power to B. But this will switch the polarity of the winding between A and B, which means winding A-B would be fighting winding B-C. If you then plugged it in like that, the motor would draw about 100 amperes, but it wouldn't run. If the circuit breaker didn't pop right away, the motor would start to smoke within ten seconds.

But it's not that simple: There is also a starter winding

But it's actually more complicated than illustrated above. The motor also has a starter winding, which is in series with a starter switch and starter capacitor (see red outline at left). The starter winding is only active while the motor is spinning up to speed.

If the starter winding and capacitor also needed to be reconfigured for voltage changes, the wiring would be quite a nightmare!

So instead, the starter winding in these motors is always a 120 volt winding, and the motors two 120 volt windings are used as an autotransformer to make the 120 volts for the starter winding. Reconfiguring between 240 and 120 volts is done the same way, but the starter winding stays connected to one of the windings.

If you don't have a wiring diagram, and the motor is currently wired for 240 volts, you can identify point "B" by the fact that it isn't connected to either power lead. Using an ohm meter, check which of the three wires from B lead to the power lead with just one wire attached to it. That's the one you need to disconnect and connect to C. And the winding end at A needs to be brought to B.

After working this out, I realized, 20 years ago, I moved the starter capacitor mount on this motor so it wouldn't protrude above the table saw table when the blade is tilted 45 degrees. And in moving the capacitor, I ended up mounting it right over the motor's label plate, which also shows the wiring. So removing the capacitor cover, I could see the label, complete with wiring diagram and I was able to check my work before I plugged it in.

Suppose you have a mystery single phase induction motor, 1750 rpm or 3500 rpm (or very close to those RPMs). There are six leads, or wires coming out of it. How do you wire it up? On some motors, it will be six connections, but some of them may be screw terminals in the wiring instead of wire leads. I'll just call them leads. If the motor has screw posts for attaching the leads to, it will typically have an additional screw post for connecting wires together in 240 volt operation, but the screw post doesn't connect to anything in the motor.

Using an ohm meter, find a pair of leads that has less than 5 ohms between them. The reading should not change as you hold the meter on those. Label these wires 1 and 2. 1 and 2 shouldn't have any conductivity to any other leads coming out. Now find another pair of wires with the same resistance as 1 and 2 between them, Label these 3 and 4. 1-2 and 3-4 are the main windings.

The remaining two leads should connect to the starting capacitor, starting switch, and straiting winding in series (with the motor not running, the starting switch will be closed). Label these remaining leads 5 and 6. If you measure the resistance between 5 and 6, you should see the reading on your meter continually increasing (set your meter to something other than the lowest ohm range). If you swap the meter probes between 5 and 6, the resistance reading will be lower again, but again go up. You are measuring resistance across the capacitor, and as it "charges up" from the meter applying current to measure, the resistance reading will go up.

For 120 volt operation, you need to either connect

1,3,5 to one power lead and 2,4,6 to the other OR 1,4,5 and 2,3,6.     But which one??

If you get it wrong, you will blow the circuit breaker or destroy the motor. Basically, if winding 1-2 is opposing winding 3-4, very bad things happen.

You can, for a short time, run the motor off 120 volts using just one of the 120 volt winding. So just leave leads 3 and 4 disconnected. Connect one power lead to 1,5, the other to 2,6, and plug it in to 120 volts. The motor should run.

Unplug the motor, now add lead 3 to 1 and 5 (1,3,5 and one of the power leads all together), and leave just 2,6 to the other power lead. Plug in the motor, while it runs, measure the voltage between the remaining unconnected lead 4 and the other lead supplying power, connected to leads 2,6). If the voltage is less than 10 volts, then you can connect lead 2,4,6 together. Your motor is now wired for 120 volts.

If the reading is over 200 volts, then you need to swap leads 3 and 4. Re-label lead 3 as 4, and 4 as 3, then repeat the step above and make sure the difference reading is less than 10 volts.

To reverse the motor, swap leads 5 and 6 (the ones that go to the starter winding)

To wire the motor for 240 volts, connect lead 1 to one power lead
Connect the other power lead to 4,6.
If the motor has screw posts in the wiring box, there will be an extra screw post, not connected to anything, for connecting leads 2,3,5 together.
And as before, to reverse the motor, swap leads 5 and 6

If this doesn't work for you, it's possible that the motor is not a dual voltage single phase motor, or there is something wrong with it. Feel free to email me. I probably won't be able to help you, but it's useful to know where you run into problems. That way, if a lot of folks get hung up on the same problem, I might be able to add some notes about that.

And if you blow up a motor or it catches fire, don't blame me!

Back to my woodworking website

Sours: https://woodgears.ca/motors/voltage.html
How to Wire 3 Phase Motor to 240 volt system (STEP by STEP)

## Single-Phase

Definition: This implies a power supply or a load that uses only two wires for power. Some “grounded” single phase devices also have a third wire used only for a safety ground, but not connected to the electrical supply or load in any other way except for safety grou

Single-phase electric power – Wikipedia
Single-phase Power Systems | Polyphase AC Circuits | Electronics Textbook
3 Phase Power vs Single Phase Power • OEM Panels
What’s the Difference Between Single Phase and Three Phase AC Power Supplies?
Single-Phase vs Three-Phase Power Explained | Tripp Lite Blog
Single Phase vs. Three Phase Power | Otterbine
Know the Difference Between Three-Phase and Single-Phase Power | Data Center Knowledge

• ### single phase meter wiring diagram | energy meter | energy meter connection by earthbondhon

Categories GlossarySours: https://electricalschool.org/single-phase/

## Wiring for 1 phase 220 volt bandsaw

The following is all for a "typical 240V circuit in a 120V/240V US system". For all practical purposes, that is what is referred as "single phase". There is a split (to get 2 x 120V out of 240V) but it is still just really single phase. The alternative is "three phase", which is unusual in residential applications.

I am a bit concerned about the "sounds like this might work" nature of some parts of the question. You may want to consider getting a professional involved, but doing a lot of the grunt work (e.g., running the conduit) yourself to save money.

1 - A device will typically use 120V = hot + neutral, 240V = hot + hot (your device) or 120V/240V = hot + hot + neutral (e.g., typical electric dryer or oven)

2 - When a device talks about current, that is the same whether it is a single hot = 120V or two hots = double-breaker = 240V. It isn't double=20A + 20A = 40A. Rather, the double is 20A @ 240V instead of 20A @ 120V.

3 - All modern circuits should include ground. That is a separate wire (green or bare), except that metal conduit can also perform the ground function (with ground wires attached to the metal boxes where needed).

4 - You can't combine neutral and ground, except with very limited grandfathered exceptions. But for a new circuit, if you need neutral (it appears that you do not for this particular device) then it must have a separate wire (white or gray) from ground (green or bare). In your specific case, it appears that the device does not use neutral. So you can't combine neutral and ground, but you can simply not run a neutral wire, provided the receptacle & device don't need one.

5 - Conduit is a good idea, as it lets you add neutral if you need it, upgrade to larger wires if you need them, etc.

6 - Breaker size is dependent (generally) on two things - it must be both no larger than permitted based on wire size (e.g., if you use 14 AWG wire then the largest breaker you can use is 15A, if you use 12 AWG wire then the largest breaker you can use is 20A, etc.) and it also must match the device specifications. If the device is a receptacle then normally that will determine the required breaker size, with some very specific exceptions. But determining the receptacle size (and if the receptacle can be paired with multiple breaker sizes, determining which breaker size) depends on the devices being connected. You, as the user, do not decide "motor startup needs more so I'll upsize things". It doesn't work that way! The manufacturer is supposed to design the equipment and work with UL/ETL/etc. guidelines to determine the appropriate connection method (including receptacle size/type for a plug-in device) and breaker size.

7 - I don't know where the 15A recommendation came from. Checking the specs on several web pages, it shows 12A motor with 20A recommended breaker.

8 - GFCI is gradually being required in more and more places. Whether you need it on this particular 240V circuit will depend on a bunch of factors. I would actually recommend it even if you don't absolutely need it, because there are certain failure modes where GFCI will provide a human safety fast shutdown that can save lives. Of course, with this type of equipment there are a lot of other safety issues to be concerned with - eye protection, hearing protection, etc.

9 - Make sure you have the correct breaker for your panel. The pictured breaker is right for certain panels. But there are others will it will seem basically correct but not actually function properly & safely.

10 - According to spec pages that I could find, this particular saw is not UL-listed. That may be simply paperwork. But it may be a sign of substandard construction that can't be properly listed. There may be alternative (e.g., ETL) certification that is just not included on the web pages. But it is worth investigating before spending that much on a potentially dangerous piece of equipment.

11 - Question talks about receptacles but never names the type. There should be something - e.g., NEMA 6-20. What does the manual say? What type of receptacle did you buy?

Sours: https://diy.stackexchange.com/questions/209900/wiring-for-1-phase-220-volt-bandsaw
Wiring 2 phase ( 380volt) motor to 1 phase (220 volt) Power with Diagram

## Split-phase electric power

Type of single-phase electric power distribution

Pole-mounted single-phase transformer with three-wire center-tapped"split-phase" secondary. On the three secondary terminals, the center tap is grounded with a short strap to the transformer case.

A split-phase or single-phase three-wire system is a type of single-phase electric power distribution. It is the alternating current (AC) equivalent of the original Edison Machine Works three-wire direct-current system. Its primary advantage is that it saves conductor material over a single-ended single-phase system, while only requiring a single phase on the supply side of the distribution transformer.[1]

This system is common in North America for residential and light commercial applications. Two 120 V AC lines are supplied to the premises which are out of phase by 180 degrees with each other (when both measured with respect to the neutral), along with a common neutral. The neutral conductor is connected to ground at the transformer center tap. Circuits for lighting and small appliance power outlets (ie. NEMA 1 and NEMA 5) use 120 V circuits - these are connected between one of the lines and neutral using a single-pole circuit breaker. High-demand applications, such as air conditioners, are often powered using 240 V AC circuits - these are connected between the two 120 V AC lines. These 240 V loads are either hard-wired or use NEMA 10 or NEMA 14 outlets which are deliberately incompatible with the 120 V outlets.

Other applications of a split-phase power system are used to reduce the electric shock hazard or to reduce electromagnetic noise.

### Connections

A transformer supplying a three-wire distribution system has a single-phase input (primary) winding. The output (secondary) winding is center-tapped and the center tap connected to a grounded neutral. As shown in Fig. 1, either end to center has half the voltage of end-to-end. Fig. 2 illustrates the phasor diagram of the output voltages for a split-phase transformer. Since the two phasors do not define a unique direction of rotation for a revolving magnetic field, a split single-phase is not a two-phase system.

In the United States and Canada, the practice originated with the DC distribution system developed by Thomas Edison. By connecting pairs of lamps or groups of lamps on the same circuit in series, and doubling the supply voltage, the size of conductors was reduced substantially.

The line to neutral voltage is half the line-to-line voltage. Lighting and small appliances requiring less than 1800 watts may be connected between a line wire and the neutral. Higher wattage appliances, such as cooking equipment, space heating, water heaters, clothes dryers, air conditioners and electric vehicle charging equipment are connected across the two line conductors. This means that (for the supply of the same amount of power) the current is halved. Hence, smaller conductors may be used than would be needed if the appliances were designed to be supplied by the lower voltage.[2]

If the load were guaranteed to be balanced, then the neutral conductor would not carry any current and the system would be equivalent to a single-ended system of twice the voltage with the line wires taking half the current. This would not need a neutral conductor at all, but would be wildly impractical for varying loads; just connecting the groups in series would result in excessive voltage and brightness variation as lamps are switched on and off.

By connecting the two lamp groups to a neutral, intermediate in potential between the two live legs, any imbalance of the load will be supplied by a current in the neutral, giving substantially constant voltage across both groups. The total current carried in all three wires (including the neutral) will always be twice the supply current of the most heavily loaded half.

For short wiring runs limited by conductor ampacity, this allows three half-sized conductors to be substituted for two full-sized ones, using 75% of the copper of an equivalent single-phase system.

Longer wiring runs are more limited by voltage drop in the conductors. Because the supply voltage is doubled, a balanced load can tolerate double the voltage drop, allowing quarter-sized conductors to be used; this uses 3/8 the copper of an equivalent single-phase system.

In practice, some intermediate value is chosen. For example, if the imbalance is limited to 25% of the total load (half of one half) rather than the absolute worst-case 50%, then conductors 3/8 of the single-phase size will guarantee the same maximum voltage drop, totalling 9/8 of one single-phase conductor, 56% of the copper of the two single-phase conductors.

### Balanced power

In a so-called balanced power system, sometimes called "technical power", an isolation transformer with a center tap is used to create a separate supply with conductors at balanced voltages with respect to ground. The purpose of a balanced power system is to minimize the noise coupled into sensitive equipment from the power supply.

Unlike a three-wire distribution system, the grounded neutral is not distributed to the loads; only line-to-line connections at 120 V are used. A balanced power system is used only for specialized distribution in audio and video production studios, sound and television broadcasting, and installations of sensitive scientific instruments.

The U.S. National Electrical Code provides rules for technical power installations.[3] The systems are not to be used for general-purpose lighting or other equipment, and may use special sockets to ensure only approved equipment is connected to the system. Additionally, technical power systems pay special attention to the way the distribution system is grounded.

A risk of using a balanced power system, in an installation that also uses "conventional" power in the same rooms, is that a user may inadvertently interconnect the power systems together via an intermediate system of audio or video equipment, elements of which might be connected to different power systems. The chance of this happening may be reduced by appropriate labelling of the balanced power outlets and by the use of a type of power outlet socket for the balanced system that is physically different from that of the "conventional" power system to further differentiate them.

### Europe

In Europe, three-phase 230/400 V is most commonly used. However, 230/460 V, three-wire, single-phase systems are used to run farms and small groups of houses when only two of the three-phase high-voltage conductors are used. A split-phase final step-down transformer is then used, with the centre-tap earthed and the two halves usually supplying different buildings with a single phase supply, although in the UK a large farm may be given a 230-0-230 (nominal) supply.

In the UK, electric tools and portable lighting at larger construction and demolition sites are governed by BS7375, and where possible are recommended to be fed from a centre-tapped system with only 55 V between live conductors and the earth (so called CTE or Centre Tap Earth, or 55-0-55). This reduced low voltage system is used with 110 V equipment. No neutral conductor is distributed. In high hazard locations, additional double pole RCD protection may be used. The intention is to reduce the electrocution hazard that may exist when using electrical equipment at a wet or outdoor construction site, and eliminate the requirement for rapid automatic disconnection for prevention of shocks during faults. Portable transformers that transform single-phase 240 V to this 110 V split-phase system are a common piece of construction equipment. Generator sets used for construction sites are equipped to supply it directly.

An incidental benefit is that the filaments of 110 V incandescent lamps used on such systems are thicker and therefore mechanically more rugged than those of 240 V lamps.

### North America

This three-wire single phase system is common in North America for residential and light commercial applications. Circuit breaker panels typically have two live (hot) wires, and a neutral, connected at one point to the grounded center tap of a local transformer. Usually, one of the live wires is black and the other one red; the neutral wire is always white. Single pole circuit breakers feed 120 volt circuits from one of the 120 volt buses within the panel, or two-pole circuit breakers feed 240 volt circuits from both buses. 120 V circuits are the most common, and used to power NEMA 1 and NEMA 5 outlets, and most residential and light commercial direct-wired lighting circuits. 240 V circuits are used for high-demand applications, such as air conditioners, space heaters, electric stoves, electric clothes dryers, water heaters, and electric vehicle charge points. These use NEMA 10 or NEMA 14 outlets that are deliberately incompatible with the 120 V outlets.

Wiring regulations govern the application of split-phase circuits. Since the neutral (return) conductor is not protected by a fuse or circuit breaker, a neutral wire can be shared only by two circuits fed from opposite lines of the supply system. Two circuits from opposing lines may share a neutral if both breakers are connected by a bar so that both trip simultaneously ([4]NEC 210.4), this prevents 120 V from feeding across 240 V circuits.

### Railways

In Sweden split-phase electric power is also used on some railways. The center tap is grounded, one pole is fed with an overhead wire section, while the other wire is used for another section.

Amtrak's 60 Hz traction power system in the Northeast Corridor between New York and Boston also uses split-phase power distribution. Two separate wires are run along the track, the contact wire for the locomotive and an electrically separate feeder wire. Each wire is fed with 25 kV with respect to ground, with 50 kV between them. Autotransformers along the track balance the loads between the contact and feeder wires, reducing resistive losses.

In the UK Network Rail are using autotransformers on all new 50 Hz electrification, and (as of 2014) are converting many old booster transformer [1] installations to autotransformers, to reduce energy losses [2] and exported electromagnetic interference, both of which increase when longer, heavier, or faster trains are introduced, drawing higher peak current from the supply. Note that booster transformers only "boost" the return of traction current through its intended path, the "return conductor", rather than randomly through the earth, and do not boost, but rather reduce, the available voltage at the train, and introduce additional losses. The autotransformer system enforces the traction return current taking its intended path, while reducing the transmission losses, and therefore achieves both required objectives, of controlling return current leakage to earth and ensuring low energy loss, simultaneously. There is an initial cost penalty, because the previous return conductor, insulated to a fairly modest voltage, must be replaced by an anti-phase feeder, insulated to 25 kV, and the autotransformers themselves are larger and more expensive than the previous booster transformers; but over time the lower loss of energy results in overall costsavings.

### References

1. ^Terrell Croft and Wilford Summers (ed), American Electricians' Handbook, Eleventh Edition, McGraw Hill, New York (1987) ISBN 0-07-013932-6, chapter 3, pages 3-10, 3-14 to 3-22.
2. ^Gonen, Turan. Electric Power Distribution System Engineering, 2nd ed. CRC Press, 2007, p. 284.
3. ^NFPA 70, National Electrical Code 2005, National Fire Protection Association, Inc., Quincy, Massachusetts USA, (2005). no ISBN , articles 640 and 647
4. ^http://ecmweb.com/code-basics/branch-circuits-part-1
Sours: https://en.wikipedia.org/wiki/Split-phase_electric_power

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