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Electrical Wiring
Ask questions here about proper wiring and electrical installation here.
4,935 Questions
It depends on the motor. You need to look at the specifications of the particular motor. In general, if there are only three conductors, not counting earth, then it is delta; if there are four, then it is star; if there are six, then it is star-delta and you need a star-delta starter.
How do you connect bulb in 3 phase power?
by using star connection
AnswerIt depends on the type of three-phase supply. If it's a three-wire system, then you can connect the lamp between any pair of line conductors. If it's a four-wire system, then you can connect the lamp either between any pair of line conductors or between any one line conductor and the neutral conductor. Of course, the voltage rating of the lamp must match the line-to-line voltage or the line-to-neutral voltage.
What is the color assigned to the high leg conductor of a 4-wire delta secondary three phases?
Assuming you are talking about a 120/240v delta system the color coding is as follows.
Phase A(120v)-Black
Phase B(208v "Wild leg/High phase")-Orange
Phase C(120v)-Blue
There are other color coding methods but this is the most common.
How far can power line be from house to pole without transformer?
It depends on the total load spread along the line and the voltage drop at full load at the end of the line. Generally up to 3 % voltage drop is considered ok. Anything beyond you need another transformer center.
What is the most common element of a semiconductor?
One element that is semiconducter is Silicon.
2nd answer:
One common element used to manufacture a semiconductor is silicon. Germanium has also been widely used, and is more sensitive to tiny voltage changes than silicon. The compound gallium arsenide is very common in the manufacture of semiconductor material, as well.
How do you wire an emergency stop switch in a 3 phase 480 volt circuit?
the ugly"s book is a good reference.from the contactor /overload relay you need 3 wires and L1 is always your STOP.need a jumper wire which is always the lowest number on your contactor. on a siemens that would be #2. different manufactors have different numbers,your start would be #3 on a siemens contactor or the terminal on the left side of L1. jumper is needed to bring the power to your stop/start. hope this helps!! always consult the experts if not sure. start is no,stop is nc jumper is auxilary contact
Can you run a three phase appliance off single phase by linking the terminals?
Yes, of course.
A single-phase load is connected between any two lines of a three-phase, three-wire, system, or between any two lines or between any one line and the neutral of a three-phase, four-wire, system. It's important, of course, that the resulting voltage matches the requirements of the load.
Can you re wire a 3 phase panal to single phase?
You can't in any simple way. You must have three phase electrical supply from the local power company to install a three phase panel and employ three phase power. Virtually all residences in the U.S. have single phase power supply only. (Even if you have 220/240 V service that's still single phase.) The primary advantage to three phase power is it's ability to run electric motors more efficiently and provide them a longer life. That's why it's only supplied to commercial properties. If you need three phase power from a single phase panel then that can be done. It is said money can make anything happen. Depending on the amount of money you want to spend to make this happen there is a device on the market called a VFD ( Variable Frequency Drive). On the three phase input terminals you apply your single phase voltage. On the output terminals you connect your three phase motor. When run in this configuration there is an internal switch that has to be changed to let the VFD know that it should be looking for only two lines on the input to be hot. Other wise the VFD thinks that there is a line loss on the three phase input terminals and the unit will not start.
What is the time required from changing star to delta?
The change over time will vary with the type of motor, size of motor and the connected load to the motor. The time should be adjusted so that the motor is up to speed and stabilized at the star speed. It is at this point that the change to delta should take place. One thing to note is, do not leave the motor running is the star position any longer that it needs to.
What is static Phase Converter?
A phase converter converts single-phase, alternating current power to three-phase power. There are two general types, static converters and rotary phase converters. A basic form of rotary phase converter is a single-phase electrical motor with its shaft coupled to a three-phase alternator.
A static phase converter converts single-phase power to three-phase power by using electronic switching. They typically convert the single-phase, alternating current to direct current and then electronically synthesize three phase power output for use with three-phase equipment.
How do you balance a three phase board?
Depends if it is the supply cable you are wiring or a cable to the outgoing side. If it is the supply cable you are connecting, call your electricity supply company. They are the only ones authorised to do that work. <><><> Three phase will be at 415V. So proceed with caution! If you want to install a new branch circuit cable you need to be sure you have a three phase supply with a triple pole breaker. If you don't know what you are doing then don't try it as you can easily damage the equipment or yourself! Call a licensed electrician to advise you and quote for doing the job safely and correctly. <><><>
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.
How can the output voltage of a DC generator's polarity be reversed?
The polarity of DC generator can be reversed by reversing the field current as well as direction of rotation
How do you make a 380v motor run on 220v?
Yes just connect any line to neutral you have 230volts already.
How do you do staircase wiring?
A two way switch is required for staircase wiring. A staircase switch will have two terminals. Connect the line wire with the center terminal. Connect the two ends of a wire with the top two terminals and two ends of a wire with the bottom two terminals. The line wire at the center terminal can now be connected with one terminal of the light bulb or light holder.
How to change the speed of a three phase motor?
A typical 2 speed three phase motor will have 6 leads on the motor windings which will require 3 contactors to incorperate both the "high" and the "low" speeps.
Inorder for the motor to run on "low" speed you need to have a contactor (c1) that pulls in for the L1, L2,L3 leads... that should achieve the "low" speed of the motor..
To achieve the "high" speed you will need a contactor (c2) to shun or short L1,L2,L3 together... and another contactor (c3) to pull in the L4,L5,L6 leads...
to recap ... Low speed will requrie c1= L1,L2,L3 powered by phase 1, phase 2, phase 3 of the primary source voltage.
High speed requires c2 to short or shun L1,L2,L3 together while c3= L4,L5,L6 to be powered by Phase 1, Phase 2, Phase 3 fo the primary source voltages.
Be sure to check for proper rotation of the motor and by reversing any 2 leads of the primary source voltage you will change the rotation for the motor.
This can also be done using two contactors by having L1,L2,L3 connected to the first contactor and also the additional contacts mounted on top of the second contactor.
L4,L5,L6 are connected to the second contactor. The important thing to remember is to use an interlock which fits into both contactors when they are clipped together. This stops both contactors operating at the same time!!! ( the additional contacts mount on top of a contactor and are mechanically connected to it so that they act together)
== d. large ground faults. This is kinda tricky, but let's give it a shot. Do fuses protect against a short circuit? Yep. A short circuit creates a low resistance path in the electrical route(s) inside the unit. Lower (like almost zero in a short) resistance means more current and the fuse opens. How about overloading? An overload is, in general, a drawing of more current than is "normal" and that will burn the fuse open, regardless of the cause. Yes, the fuse provides protection. In a lightning surge, high voltage appears on the power buss and "punches through" to anywhere it feels like going. The voltage transient will easily knock the fuse open. Additional damage could result because appliances are not designed to withstand thousands of volts on the input, but the fuse has opened and made things safe. Let's look at the last one, the large ground fault. Here's a quickie review. A ground wire "grounds" an appliance to earth ground. That leaves the hot and neutral wires to provide power to an appliance in a standard 115 volt AC application. (The hot side is fused, by the way.) In an AC circuit, the current changes direction, but let's skip past that and look at the hot and neutral. Let's say the hot is the "supply side" and the neutral is the "return" and run with that. Here's another point of fact. Inside the power panel the neutral and ground have a common connection. They're at the same potential. For an appliance, power would normally "come in" on the hot side and "go out" on the neutral side, but if there is something wrong with the neutral wire, the power could "go out" on the ground leg instead of the neutral. This idea is at the heart of ground fault interruption (gfi). A 3-wire circuit (hot, neutral and ground) could operate normally if the neutral is open and there is no gfi. That means the kitchen microwave could work with a broken neutral (if there was no gfi protection). A fuse would not "protect" against the ground leg carrying the current the neutral leg would normally carry. The appliance could operate normally without anyone being the wiser. (Apologies for the long winded explanation.)
Answer
Fuses are overcurrent protection devices and, therefore, protect circuits against overload currents and short circuits (including ground faults, as they are classified as short circuits to ground). They do not, however, protect against overvoltages due to lightning strikes, etc. Whilst it is true that an overvoltage most certainly will 'punch through' insulation resistance, by the time the fuse has operated due to any resulting overcurrent, the damage has already been done (to the insulation)!
So the answer to your question is (c) lightning surges.
What is the difference between an definite purpose contactor and a lighting sontactor?
A definite purpose contactor is designed (and rated) for a specific load. So a lighting contactor is one example of a definite purpose contactor. A motor starter contactor is another example. So, a lighting contactor is a definite purpose contactor, but a definite purpose contactor is not necessarily a lighting contactor (it might be a motor starter, for instance).
Can you run a 460 volt 3 phase 60 hertz refrigeration compressor on 460 volt 3 phase 50 hertz?
Possibly. You need to check the rating on the device. Many compressors can operate on either 50 or 60 Hz.
How many earthing are required to install transformer?
Four number earthing are essential for installation of transformer as under :
1) Two earthing for transformer body.
2) Two earthing for Neutral Point.
Note : Numbers of earthing may be increase as per the client requirement.
How do you know you have got an earth leakage?
there will be current that isn't carried by the current carrying conductors
What happens if two 120 volt loads are connected in series to a 240 volts service?
Burn correctly if they were ordinary light bulbs having the same power rating.
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However, if the loads were different, such as a 100 watt lamp and a 40 watt lamp - neither of them would produce the same amount of light.
If the loads were of very different types - say a 120 volt motor, which is a magnetic device, and a 120 volt computer, which is an electronic device - you can't say for sure how well they would each work when connected together in series across a 240 volt service without knowing a lot more facts about them.
What happens will always depend on the individual resistances and impedances of each load and how different they are.
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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.
What is the voltage rating of a motor on a 3 phase 4 wire 277V lighting circuit?
If the motor is a three phase the most likely voltage the motor operates on will be 480 volts.
Can you run a 415v 3 phase motor on 480 3phase?
It would not be immediately dangerous but there is a possibility of overheating with the 9% overvoltage so it isn't a good idea unless the motor is lightly loaded and watched very carefully. The safe voltage range should be marked on the motor.
What are the inspections and test you will carry out on an electrical installation?
Some common inspections and tests carried out on an electrical installation include visual inspections for damage, checking for proper earthing and bonding, conducting insulation resistance testing, verifying circuit continuity, and testing the operation of RCDs (residual current devices). These tests help ensure the safety and compliance of the electrical installation.
