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What does 50 hertz or 60 hertz mean in an electrical generator?
The unit hertz means "cycles per second" and is a measure of the frequency of variation of anything which changes during a set period of time, including electric current and voltage. Saying that a generator of electricity runs at 50 hertz means that its current and voltage changes regularly at a rate of 50 times per second. Saying that a generator of electricity runs at 60 hertz means that its current and voltage changes regularly at a rate of 60 times per second. The Hertz value can be changed on the generator by increasing or decreasing the speed (RPM) of the prime mover. The generator has a feed back unit that monitors the frequency and automatically applies more power to the prime mover if the load increases and the generator RPM starts to slow down. The reverse happens if the load drops off and the generator starts to speed up, the power to the prime mover will be reduced. On a diesel generator it is the fuel flow that is increased and decreased to keep the frequency at a constant value. On a water turbine it is the water flow that is increased and decreased to keep the frequency at a constant value.
For resistances in a series circuit how are the voltage drops across the resistance related to the total voltage?
The voltage drops across each resistance sum to the total voltage.
Why terminal voltage of the self-excited shunt generator lower than that of the separately excited shunt generato?
Some generators are self excited; this means their terminal voltage is fed back to the excitation system to supply power to the rotor of the generator (which makes it into an electromagnet); the more power that is fed back, the stronger the electromagnet becomes, which makes it harder to turn the generator, which causes the generator to push out more power (simplified, really quick version). If there is a fault electrically near the terminal of a self excited generator, the terminal voltage will sage to near zero; this means the voltage supplied to the excitation system will drop by the same percentage (say the terminal voltage is 30% of what it should be, then the maximum supplied voltage to the excitation system drops to 30% of what it normally is, since P = V*I). Since the input power is less, the output of the generator will decrease (current will decrease). The terminal voltage is determined by the impedance between the generator and the fault such that V = I*Z; As I decreases, V will also continue to fall, causing the terminal voltage to sag even more. A non-self excited generator gets its' excitation power from the grid, specifically from a location that is electrically separated from its' terminal voltage. If the terminal voltage sagged to 30% (same fault location as above example), the excitation system voltage may be impacted slightly (say 2%) so the excitation system power is near maximum (98% for this example). Since the excitation system is much farther removed from the terminal voltage, it is not dependent upon it, thus the terminal voltage will not continue to sag as with a self excited system.
When two alternator running in parallel the power factor from 8 drops to 5 or less why is it so?
power factor 0.8 drops to .05 when two alternator running in parallel
How do you make a candy DNA Model?
out of licorice and gum drops
What happens to air if it reaches more than 100 percent?
The water vapor contianed in the air starts falling out in the form of little drops. The little drops combine into larger drops, and we call that 'Rain', or 'Dew'.
How soon after baby drops do you go in labor?
There is no hard and fast answer to that. Babies can drop weeks before labor starts, or right before (or even during) labor.
What percent drops 130 to 91?
42%
Why do leaves fall off of the tree before winter?
When the average temperature drops to a certain point and the average amount of sunshine drops to a certain point a hormone is released that starts the process of shutting down for dormancy. The tree drops its leaves to stop evaporation.
How a rain alarm works?
It's based on the air pressure measurement of the environment. Before it starts to rain pressure dramatically drops. That's particularly why some people have headaches before rains.
How much load will a 7000 watt generator run?
To calculate what devices the generator will operate, add up all of the wattage's of the devices you would like to operate. If the added load is higher than the 7000 watt output, the generator breaker will trip. If the wattage load is lower than the calculated output of the generator, the connected devices will operate.If there is a motor being connected to the generator keep in mind that you have to use the motors full load amperage x volts to find the watts and multiply it by a factor of 3. This is because when a motor first starts, the generator will be looking at an almost dead short, with a high amperage draw, until the motor starts turning. Once the motor starts turning the amperage drops down to its normal operating amperage.To find the wattage of the devices you want to operate, use the following equation. Watts = Amps x Volts. The device that you want to connect to the generator will have its amperage on the nameplate of the device.
What happens when the temperature drops?
If temp drops , it becomes cooler .The more the temp drops the cooler. If the temp drop continues (for many many months) then it starts to freeze.
When the well water pump starts it drops to a very low pressure-volune before recapturing. Why?
this is caused when the rubber bladder in the tank has ruptured. the tank must be replaced
Why terminal voltage of a generator drops when load is increase?
The greater the load thegreater the resistance to electrical flow, voltage drop
When the power of a system drops by 90 percent its dB value changes by?
-10
What does a barometer do before a storm?
it drops sharply before a storm. (I think)
What do you do when you battle Mordred?
you pick up the bombs he drops then get above him. when it starts flashing drop it
