Electrical Troubleshooting

The current in each resistor in a series circuit is the same. Kirchoff's Current Law states that the sum of the currents entering a node must add up to zero. The connection between two resistors in a series circuit is a node. The current entering the node from one resistor is equal to the current leaving the node into the next resistor.

Heaters use a lot of power and can easily exceed the capacity of an already loaded circuit. Anything with a motor or fan will use more power when starting up than after it is already running. If the circuit breaker or fuse is tripping when you plug in or turn on the heater, then you may have too many things on that circuit. Look at every electrical device on the circuit and add up the total watts of each one (it's listed somewhere on each, usually the back or bottom). Divide the total wattage by 120 to get the total amperage needed on that circuit. The fuse or circuit breaker should be rated for at least as many amps needed or it will trip when the total is exceeded. You may have to find another place to plug the heater in or have a circuit added to handle the extra load.

DON'T replace the fuse or circuit breaker with one rated for a higher load, the wiring may not be able to handle it and you could start a fire within the walls or attic. (Using extension cords for heaters in a house is a bad idea because the cord can overheat and start a fire.) If you aren't comfortable with this, find someone that knows what they are doing or hire a licensed electrician.

Only if you want very dim orange light instead of white light, as the 240 volt bulb will operate at only one quarter its power rating when operated at 120 volts. But its life will be greatly increased.

The following faults occur in transformer.

1. Temperature rise in winding

2. Temperature rise in oil

3. Overload

4. Insulation failure in oil

5. Earth fault

6. Short circuit

7. Failure of tap changing.

8. Open circuit

Assuming both batteries are alike in voltage, and preferably current:

For twelve volts, connect the negative to the positive of the other. That will be a series connection, and then use the open negative and positive connections for 12 volt operation.

For 6 volts, but twice the power, connect the positive to the positive and the negative to negative, and use this combination for six volt operation but twice the available current.

NEVER, NEVER, NEVER connect two batteries together with one's positive to the other's negative and the negative to the other's positive. Results? BOOOM!!!!! (And I'm not joking.)

I assume you have something like a V12 with two banks of 6 cylinders each fed with a separate coil. I suggest you pull the lead off one of the plugs (with the engine off, naturally) and push a big nail inside the plug lead. Hold the end of the lead between two pieces of wood to insulate it and start her up. Point the nail as close to the spark plug as you can without touching it (or to any clean point on the engine block, like a bolt head you have sanded shiny) and see if you get a rhythmic spark (or any spark at all). No spark = no electicity. It doesn't actually prove the COIL is faulty because it might be that the coil is not getting any electricity supplied to it, but it's a start.

RMS and peak voltage for a square waveform are the same. There is a small caveat, and that is that you'd have to have a "perfect" square wave with a rise time of zero. Let's have a look. If we have a perfect square wave, it has a positive peak and a negative peak (naturally). And if the transition from one peak to the other can be made in zero time, then the voltage of the waveform will always be at the positive or the negative peak. That means it will always be at its maximum, and the effective value (which is what RMS or root mean square is - it's the DC equivalent or the "area under the curve of the waveform") will be exactly what the peak value is. It's a slam dunk. If we have a (perfect) square wave of 100 volts peak, it will always be at positive or negative 100 volts. As RMS is the DC equivalent, or is the "heating value for a purely resistive load" on the voltage source, the voltage will always be 100 volts (either + or -), and the resistive load will always be driven by 100 volts. Piece of cake.

The symbol, kV.A (not 'kva'), represents kilovolt amperes, which is the unit of measurement for apparent power -i.e. the product of supply voltage and load current in an a.c. circuit. The symbol, kV (not'kv'), represents kilovolts, which is the unit of measurement for potential difference.

A tariff is a duty imposed on goods when they are moved across a political boundary. They are usually associated with protectionism, the economic policy of restraining trade between nations. For political reasons, tariffs are usually imposed on imported goods, although they may also be imposed on exported goods.

I assume you are asking about AC generators.

The controller is wired up with suitable transducers and other control wiring to obtain required signals from the electrical bus.

Three DG sets are feeding the common bus bar through isolating breakers.

Conditions for a successful synchronization are equal voltage, equal frequency (Hertz) defined by the speed, same phase sequence. (say R Y B phases must match with R Y B of the incoming DG set)

One DG is started with some load (at least 60 to 70 % of load) and the common bus is energized. The second DG to be brought in by closing the breaker either manually or automatically. Start the second DG. The controller reads the bus parameter and incoming DG parameter in real time and moment the incoming DG parameters match with running DG parameters, controller allows the incoming breaker to close. Both DG are now synchronized and load is shared. Same way put on third DG set and synchronize.

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