Electrical Troubleshooting

it is a star to star connected transformer. It having two neutrals. One is at Primary side and another is at secondary side to balance the loads.

Y= Primary star connection

N=Primary Neutral

y=secondary star connection

n=secondary neutral

and

0=No phase shift between primary and secondary.

So,finally this meaning is star to star connected with two neutrals and zero phase displacement.

Please refer below i detailed some notations to calculate any other vector groups

D= Primary Delta connection

d=Secondary Delta connection

a=Auto transformer

Z=Zig zig connection

11=30 degrees phase shift b/w primary & secondary

1= 30 degrees phase shift b/w primary & secondary

1) Consider capital letters for Primary notations

2) Consider small letters for secondary notations

3) Consider Clock reference at 12.00 for calculation of degrees

I think this procedure is very useful to calculate for other vector groups.

A 'polarity test', as it applies to a switch, is performed to confirm that the switch is located in the line conductor and not in the neutral conductor.

The starter motor of a diesel generator is a DC motor. Depending on the size of the diesel engine the starter motor could be 12 volts or 24 volts. Sometimes more that one battery is used at the specific voltage. These batteries are connected in parallel to create more amp hour cranking power.

A transient voltage is a time varying voltage value. Transient says that the voltage value changes, especially from a steady state, to a new value, then back again.

Contact your power provider or power company. 3 phase sometimes is not available in certain areas (mostly rural). They have to run extra wires from the power pole or grid to your place where you want 3 phase.

Different material welds differently depending on polarity. There are also different types of welding rods, so polarity must be tested.

Not usually, but it may depend on the context. For instance, surge current might be used for a generator that is going to start a motor. Motors draw high current as they start, then the current drops to a normal level, called RLA, or running load amps. Generators have a watt rating for continuous operation called running watts, but they also have a 'surge' rating. You might see a generator listed as a '6000/5200 watt. The 6000 watts is the 'surge' rating. This means the generator can supply 6000 watts for a few seconds, such as might be needed to start a motor, but cannot supply more than 5200 watts continuously. Short circuit current on the other hand simply means how many amps will flow instantaneously if you drop a wrench across the two wires! For a normal utility power service, the short circuit current, also called fault current, can be several tens of thousands of amps, even though the main breaker is only a couple hundred amps.

A megger test is done to check the insulation factor of wires or devices. This is to make sure that when the working voltage is applied, a short circuit to ground will not occur due to a problem with the insulation of the device or wire.

The current capacity of a cable varies depending on the type of conductor material, and the type and rating of the insulation. An excellent table that shows the capacity of different types of cables can be found here:

http://www.myelectrical.com/pages/cables/cableCurrents.aspx?id=061112125012.

Also, the current capacity of a cable will be limited by the electrical code that one is using, this varies in each developed country. Most American companies use NEC (National Electric Code) as there source for electrical codes (the most recent version being NEC2008), and much of the rest of the world will use ICC EC (International Code Council Electric Code).

The end the shaft comes out.

Simply test it with a multi meter. Set to DC and see if it is holding voltage. Then,...Set the meter on Ohms to check the continuity between the leads. If it shows little or no resistance, or doesnt beep, normally youre ok. If it beeps or shows resistance, its fried. Afterwards, since the voltage should have been drained by the meter on Ohms setting, see if it builds back up.

Try to think of a diversity factor as similar to a noncoincidental load factor. If your thermostat phyically limits you to only using either heat or AC at one time, then you can simply use the largest of the two as your load factor. With diversity, think of a college campus environment. If you are in class then the odds are your TV, oven, microwave, etc back in your dorm are probably not being used. R, Bill

There is only two test you can do measure on the Ohm scale the resistance at the power connection if there is a reading then it means it's not open but that's not an indication that the motor is Ok, then measure on the MOhm scale between the body of the motor and any of the power connections if there is a reading then the motor have a internal short, the best is to open the motor and inspect it for black spots on the coils your nose is the best test smell it

The amperage rating of a copper wire is related to its resistance and to the type of insulation used (i.e., what temperature the insulation can handle) and the ambient temperature. The fatter the copper wire, the more amps it can handle, everything else being equal. A mineral-insulated wire, buried underground, would handle more amps than a similarly sized copper wire in thermoplastic insulation in air.

There are electrician charts available to determine the MINIMUM size of copper (or aluminum) wire necessary for a particular load.

Consider also that longer the wire, the more resistance there is, so a very long wire would need to be larger to handle the same load safely.

DC Motor works on DC source and AC motor works on AC source

You have to wire both the run and start windings. The start windings will automatically be removed from the circuit once the motor is at 75% of normal speed. The start winding gives you more torque to start the motor.

Well that is probably a very complicated circuit. You should just look for a Inverter with 220V single phase input and 415V three phase output. It should be that hard to find.

The only way to determine the cable wire size needed for a 1000 watt air conditioner is to find the load size. To get the load size you will need to use the formula Amps = Watts or Volts. With that being said, you will need a number 14 copper wire.

It is very difficult to have residential voltage that is too high. Utility companies go to great lengths to keep voltages and frequency within very close tolerances. In the US residential voltage for lighting and outlets is a nominal 115 Volts, and normally doesn't vary more than 3 to 5 volts. That won't hurt anything. The other voltage present in residential buildings is 220 Volts. That voltage is used almost exclusively for electric dryers, water heaters, and electric ranges. It is used to provide large amounts of power and still keep the size of the electrical conductor reasonable. If you had to use 115 Volts you would draw twice the amps requiring a conductor capable of twice the capacity of a conductor destined for 115 Volt use. Those are more expensive and much harder to work with. DO NOT MIX THE TWO VOLTAGES! Plugging a 115 volt device in a 220 volt circuit will probably destroy the device. Plugging a 220 volt device in a 115 volt circuit will destroy the wiring if not properly protected, and may cause a fire. All wiring used in a residential setting is rated at 600 Volts. That means that the insulation will withstand 600 volts without breaking down. Therefore you can use the wire for any application in the house PROVIDED is is the proper size for the expected current. Fixtures (Switches, Outlets etc.) are rated by voltage and current. The rating is right on the device. You may have noticed that outlets have different blade patterns. That is to prevent plugging the wrong thing in an outlet. Since appliances are rated by voltage and current (amps), or voltage and power (watts) do not plug appliances in the wrong voltage or current. The appliance manufacturer has installed the proper plug for his appliance. You must use the properly configured outlet. Building inspectors insure that the residential circuits have the correct pattern devices on each circuit. If you must replace a device make sure that the black wire goes to the gold connector, silver goes to silver connector, and green goes to green. If you are really uncomfortable with your home wiring, hire a licensed electrician to verify that everything is correct. After that you can replace any device as long as you turn the device off first and then make sure you install the new device EXACTLY as the old one was installed.

On an average, the following assumptions will stand good for an induction motor: * Starting current (Ist) will be 5 times of the Full Load Amps (IFLA) * No Load Amps (INLA) can be any where between 0.3 to 0.5 times of IFLA; To the most, this figure depends upon the frame size of the motor; larger the frame size, smaller will be the INLA. This is also true for the wound rotor type induction motors. Manufacturers normally give two different current figures, one for the motor running with full load, and one for 'locked rotor'. Locked rotor current is the very high current drawn when power has been applied, but the motor has not had time to start spinning. <><><> No load current is important since this portion of the energy consumed will not be reflected in the process output, for a machine which is running continuously, no one can neglect whatever low value it is. Usually, the efficiencies will be mentioned and one can apply basic thumb rules to arrive no load current from those figures <><><> Manufacturers don't usually publish 'current at no load' for their motors. Since a motor with no load is not doing anything useful, no one really cares how much current is being drawn. It's kind of like putting your car up on a jack so the wheels are off the ground and asking how much fuel will the car burn sitting still with the wheels turning at 10 miles an hour - or at 100 miles per hour - who cares? !!!

A beeping sound in a wall socket could indicate a faulty electrical connection, a short circuit, or a wiring issue. It is important to disconnect any devices plugged into the socket and contact a qualified electrician to inspect and address the problem to prevent potential safety hazards.

In the USA houses would have 120/240 volts. 120 volts at most receptacles and lights and 240 volts for larger equipment like your stove, dryer, hot water heater.

Various flammable gasses, flammable liquids, and combustible dusts can ALL explode when mixed with sufficent air, and an electrical spark creates enough heat to ignite the mixture. Examples would include hydrogen, propane, gasoline, alcohol, powdered sugar and flour.