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Usually yes. A typical 480 volt panel is a 3 phase panel with 480 volts line-to-line and 277 volts line-to-neutral. However, I did once see a panel that was 480 volts, 3 phase, but because it served only motors it did not have a neutral. (a 3 phase motor doesn't use a neutral.)
Similarly, if a panel uses only 2 legs of a 3 phase 480 volt system, which would be called single phase, it would not require a neutral if it only feeds 480 volt single phase loads.
But I find the idea of no neutral to be extremely unusual and in my one personal experience, I blamed it on the age of the system. In 16 years of commercial and industrial construction I have never installed a 3 phase panel without a neutral and all my work is designed by engineers.
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How is a 15 amp 277 volt lighting circuit wired at the panel?
The voltage of 277 volts is the wye voltage of a three phase 480 volt distribution. In the 480 volt CDP (Central Distribution Panel), you will need a 600 volt rated single pole 15 amp breaker installed in the CDP. The load will be connected to the output terminal of the breaker and the other conductor will be connected to the neutral bus in the CDP. The minimum size conductor for the 15 amp circuit will be a #12 copper conductor.
How do you hook up a water heater with red black and white wires?
Sounds like it is a 220-240 Volt hot water heater. The black and red are connected to the 220 volts supply and the white is connected to Neutral. At the breaker panel red and black connect to the 2-pole 220 volt breaker and white goes to the neutral bus bar.
I am adding a 30 amp sub panel - the problem I have is the neutral bus is full what are my options?
Best answer - If panel can accept, add an additional bus on the other side and bond the two together. Least desirable answer - split bolt the neutral to one of the existing. Under no circumstances should you place multiple wires under one terminal. <<>> The neutral wire for the sub panel will only be a #10 conductor. Neutral wires can be doubled up under a single screw in the neutral bus. Turn the main breaker off to do this installation. Double up two #14 neutrals to make room for the #10 neutral wire. There is no code rule as to how many wires can be installed under a terminal on the neutral bus. There is a code rule though about not doubling up circuit feeders under one breaker terminal.
What color should the wires be in a 120v system?
It depends. In a typical US residence with 120/240v single-phase power, the ground wire will be green, the neutral will be white, and the hot conductor will be either black or red depending on which phase it is connected to. Odd numbered breakers (1,3,5, etc.) are black, and even numbered breakers are red. You will measure 120v from black to white, also 120v from red to white, but 240v from black to red. In a commercial building with 3-phase 120/208 power, ground and neutral are the same color, but there are 3 hot colors - black (a-phase) red (b-phase) and blue (c-phase). As you run down a line of breakers from top to bottom they will be wired: black red blue black red blue etc. You will measure 120v from any of the 3 hot colors to white (neutral) but 208v from black to red, red to blue and blue to black.
What type panel does a 4 pole breaker require?
The panel and breaker have to be of the same manufacturer. This way the breaker will fit into the panel. If the panel has a push in bus bar, the breaker must also be the type to accept the bus bar. If the bus bars in the panel are of the bolt in type then the breaker also has to be a bolt in breaker.
What is the wiring diagram of a 277V panel in layman's terms?
A 277 panel looks exactly like a 480 3 phase delta panel except that it has a neutral bus (the neutral is generated at the supply tansformer, usually by a zig-zag configuration.) If you measure phase to phase you get 480. If you measure any phase to neutral, you get 277. There are a lot of exceptions, but usually the 480 supply to the 277 transformer is not grounded, but the neutral from the zig-zag windings of that transformer is grounded. I just spent 15 minutes trying to google a zig-zag wiring diagram for a transformer, but couldn't come up with one. So I will let that be your project. The short answer is that the 277 panel looks exactly like a 480 panel with a neutral bus, but if you don't know what that looks like, it is saying that zebra tastes exactly like lion. Us lektrick enjineers know that zebra tastes more like hyena, but you mite think that it tastes more like giraffe. The even shorter answer is that you have to use a 480 panel because that is the voltage in the panel. So go to the local electric supply house and ask to see the wiring diagram for a 480 panel and you will find that you are looking at the diagram for a 277 panel. You owe me a six pack for this answer even tho I did not explain it in layman's terms. A special tap off of a 480 volt supply panel using one hot leg and a neutral much the same as 120 volt, but has more power.
How is a 15 amp 277 volt lighting circuit wired at the panel?
The voltage of 277 volts is the wye voltage of a three phase 480 volt distribution. In the 480 volt CDP (Central Distribution Panel), you will need a 600 volt rated single pole 15 amp breaker installed in the CDP. The load will be connected to the output terminal of the breaker and the other conductor will be connected to the neutral bus in the CDP. The minimum size conductor for the 15 amp circuit will be a #12 copper conductor.
How is a 208 volt 3 phase electrical sub-panel wired?
Mark the phases red (phase) black (phase) and blue (phase) along with a white (neutral) and a ground (wire size depends on the main breaker amperage) the phases attach to the main breaker unless it is a breakerless panel attach the phases to the lugs on the bus bars top or bottom then connect the neutral to the neutral bus and the ground to the panel
How do you run a two circuit from a thee phase box for a water well?
A 3-phase panel can supply 3-wire loads, 2-wire loads and 4-wire loads. The 2 most common voltages for these panels is 480 and 208. The voltage of the panel indicates the voltage measured between any 2 of the 3 buses (copper bars) in the panel so for a 480 volt panel you would measure (with a voltmeter) 480 VAC or volts of alternating current. Most 3 phase panels also have a neutral bus which is essentially tied to ground. If you measure between any of the phase buses and the neutral you will get 277 volts in a 480 volt panel and 120 volts in a 208 volt panel. So, if you have a pump motor that is 2-wire and rated for 208 volts you can just install a double pole breaker in the 3-phase panel. if you want to power a normal receptacle from a 208 volt 3-phase panel you just install a single pole breaker. With the receptacle outlet you must have a neutral bus in the panel to connect neutral conductor from the receptacle. The 480 volt panel works the same way except the single pole breaker will provide 277 volts of power which can be used for many types of industrial lighting but never for receptacles. If you did, your blow dryer would work really good for about a minute, then it would burn up. Pump motors will have a voltage rating as well as a horse power rating. Many motors these days have a dual rating and will have something like 208/230 V on the nameplate. These pumps can be operated on 208 or 240 volts which is the normal voltage level for a house. If the pump only shows the 230 volt rating it still may work on 208 volts but may have a shorter life expectancy. I would always call the manufacturer and ask them if it can be run on the available voltage if not listed on the nameplate. There are also 240 volt 3-phase panels (mostly in industrial plants and some older commercial buildings) that connect exactly the same way as a 208 volt panel with a few exceptions. The neutral is only used for single pole and double pole loads and care must be used because one of the phases will give you 208 volts to neutral (code requires this phase to be "B phase" and marked orange). Many devices have been burned up, by careless electricians who connected circuits to the wrong panel bus.
Where do you hook your neutral in your breaker panel if there is no neutral bar?
Unless the panel is the Main Panel (first panel in the system after the service feed) all panels have a neutral bar. Otherwise you are missing pieces. If this is the Main Panel, the neutral bar is bonded to the ground by a bus-bar. If this is the case, neutrals should all be connected to the same side of these bonded bars. Electrically it makes no difference, however it is a good practice to keep electrical panels neat and organized. If this is not the Main Panel and there is no neutral bar, STOP, PUT DOWN THE TOOLS, CALL A PROFESSIONAL. This panel is missing pieces and may be dangerous. It is possible to have a panel without a neutral. This panel would serve only 240 volt loads where no neutral is needed, however I have not seen this done in residential applications.
How do you hook up a water heater with red black and white wires?
Sounds like it is a 220-240 Volt hot water heater. The black and red are connected to the 220 volts supply and the white is connected to Neutral. At the breaker panel red and black connect to the 2-pole 220 volt breaker and white goes to the neutral bus bar.
How do you wire a 220v connection into the main panel?
I assume you mean you are wiring a 220 volt circuit. You will install a 220 volt double pole breaker of the correct size for the circuit. An example would be for an electric dryer that requires a 30 amp double pole breaker wired with 10/3 wire. You connect the Red & Black wires to the breaker. One on each screw. You now connect the White wire to the neutral bus bar in the service panel. Then connect the bare copper ground wire to the ground bus bar in the service panel. At the dryer outlet connect the black & red to the hot screws, white to the neutral, and ground to ground. They will be labeled on the back of the outlet.
Should you ground the neutral bus bar to the service panel?
Answer for USA, Canada and countries running a 60 Hz supply service.The simple answer is...YOU SHOULD BOND THE NEUTRAL BUS-BAR TO THE SERVICE PANEL.Your question makes a mistake common even among electricians. You do not GROUND the neutral bus to the panel. You BOND the neutral bus to the panel. The term "ground" or "grounding" is often applied to "bonding" but bonding serves a different purpose than grounding.To make things more complicated, the rules do not require that you bond the neutral bus to the panel. The rules require that both the neutral bus at the service and any panel be bonded to ground. The panels are bonded to ground usually by direct connection, meaning the ground bars are directly connected to their panels. So for smaller systems the simplest method to bond the neutral bus at the service is to make a direct connection between it and the panel. For larger systems you must use a conductor of an appropriate size to bond the neutral bus to the grounding electrode conductor.I know this may be confusing but that is the reason that grounding and bonding take up more pages in the NEC than any other topics.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 JOBSAFELY AND COMPETENTLYREFER THIS WORK TO QUALIFIED PROFESSIONALS.
Why would you have 115 vac on my neutral bus in the panel that has a separate ground buss?
Certainly your neutral bus is not properly bonded to the ground buss and grounding electrode conductor. But the size of your voltage worries me. You need a competent electrician to check this one for you.
Why would you have 115 vac on your neutral bus in the panel that has a separate ground buss?
Certainly your neutral bus is not properly bonded to the ground buss and grounding electrode conductor. But the size of your voltage worries me. You need a competent electrician to check this one for you.
I am adding a 30 amp sub panel - the problem I have is the neutral bus is full what are my options?
Best answer - If panel can accept, add an additional bus on the other side and bond the two together. Least desirable answer - split bolt the neutral to one of the existing. Under no circumstances should you place multiple wires under one terminal. <<>> The neutral wire for the sub panel will only be a #10 conductor. Neutral wires can be doubled up under a single screw in the neutral bus. Turn the main breaker off to do this installation. Double up two #14 neutrals to make room for the #10 neutral wire. There is no code rule as to how many wires can be installed under a terminal on the neutral bus. There is a code rule though about not doubling up circuit feeders under one breaker terminal.
Can you pigtail grounds in a panel in order to prevent double lugging on the neutral bus.?
The ground wires should not be terminated on the neutral bus. They should be terminated on to the ground bus which should be located on the back wall of the distribution panel. The wires don't have to be pigtailed when inserted into the ground bus. More that one wire can go under the terminal screws if you are running out of room. Shut the panel off and remove any ground wires that are now under the neutral bus terminals and move them to the ground bus. Some panels use a lug for a ground bus. All ground wires into the lug and tighten. In a ground fault condition it is the ground wires that are connected to the ground potential that trip the breaker, not ground wires connected to neutrals. Be safe.
