Electrical Engineering

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1 horsepower is equal to 0.7456 kWatts, therefore 1.1184 kWatts will be the power consumption of that motor.

The current draw depends on the voltage, simply use the P=UxI or I=P/U formulas to figure out the current draw (P=1118.4 Watts).

some voltages:

12Vdc draw 93.2Amps

24Vdc draws 46.6Amps

110Vdc draws 10.17Amps

230Vdc draws 4.86Amps

HMI / Human Machine Interface would imply two-way communication. A monitor only shows information to the user; the user cannot directly ask the monitor for information. an HMI will provide some way for the human to input data (such as a mouse). A monitor, with no way to input data would be more along the lines of an annunciator (old school ones were just a bank of lights for alarms).

The formula you are looking for is I = W/E

Probably the temperature sender. Should be two of them, one by the thermostat housing and probably one on the head. One is for the gauge and one for the sender. Check the fuse, relay and unplug the fan and run power and ground to it to make sure the fan itself is alright. Most likely is the sender.

Conductors are materials that will allow electricity to flow through them. Materials that contain 1, 2, or 3 valence electrons are good conductors. Some examples of good conductors are gold, silver, aluminum, and copper.

Insulators are materials, or combinations of materials, with a high number of valence electrons (5, 6, 7, and 8). Examples of good insulators are porcelain, glass, air, and rubber.

For single phase the formula is HP = I x E x %eff. x pf/746.

For three phase the formula is HP = I x E x 1.73 x %eff. x pf/746.

Where I = amps, E = volts, %eff. = efficiency of the motor and pf is the power factor of the motor.

To answer this question the voltage of the motor must be stated.

The speed is determined by the supply frequency and that must be divided by the number of pole-pairs.

So a 4-pole motor would run at 1500 rpm on 50 Hz or 1800 rpm on 60 Hz.

The secondary of a transformer is isolated (floating) relative to the primary, so there is no absolute reference relative to earth ground on the secondary side. By connecting the neutral to ground (earth ground that is) this creates an absolute reference. This also creates a leakage path to earth ground, now that the secondary voltage is referenced to earth ground, but that is more desirable than not because otherwise something else in the system might improperly provide that reference.

The task environment includes sectors with which the organization interacts directly and that have a direct impact on the organization's ability to achieve its goals. The task environment typically includes the industry, competitors, customers, techniques of production, suppliers, stock market, raw materials, market sectors, and perhaps the human resources and international sectors.

The big difference is that the synchronous motor's rotor can have a variable current applied to it through its field slip rings. Both types of motors have their own advantages. With a synchronous motor in the system, the systems power factor can be regulated.

Centrifugal force pulls water out of the washing basket carrying dirty water out in the cleaning process.

In a chilled water system, the chillers are happiest with a constant-volume flow. In a primary-secondary loop system, the chiller has a primary pump that is constant-speed. If that were the only pump, and it circulated chilled water through the chiller and the load (air handler, etc.), imagine what would happen as the temperature setpoint was reached. The control valve starts to close, reducing the flow. This deadheads the pump, which is bad in itself, but it also reduces flow through the chiller. The chiller could be damaged, or it would trip on a low flow safety, or at the very least it operates poorly, or inefficiently. You could change the control valve to a three-way diverting valve. Now instead of closing, upon reaching setpoint the valve diverts some of the flow, bypassing the load, and recirculates it back to the chiller. This maintains full flow through the system, but it wastes energy because you are always pumping full-load flow even in the dead of winter when you may only need a fraction of the system's capacity. What if there was a way to maintain a constant flow through the chiller, yet only supply just the needed flow to the building? Well, let's change the control valve(s) back to standard 2-way, and add a secondary pump with VFD. We will also need a pressure sensor on the secondary loop. We add a bypass pipe between the two pumps. Can you visualize the piping? Water leaves the primary pump, goes through the chiller, heads out on the CHW supply line. Then it can either circulate through the bypass line and back to the pump (that's the primary loop), or keep on going out to the building, then back from the building, through the secondary pump, past the bypass line, and to the suction on the primary pump. The beauty of the primary-secondary system is we can reduce secondary flow to the building as the cooling load reduces. As the control valve(s) close, the pressure in the secondary loop rises. The pressure sensor detects this and slows the pump down to maintain a constant pressure. As less and less water flows from the chiller out to the building, more and more of the primary flow goes through the bypass pipe, maintaining constant GPM through the chiller. You save money several ways. It takes horsepower ($) to overcome pumping friction losses as you move all that water through the hundreds or even thousands of feet of building piping. Reducing the secondary flow saves energy. Two-way valves are cheaper, less complex, and easier (cheaper) to install. The chiller always operates at design flow, where it is more efficient. So, the VF drive is needed to allow the control system to vary the secondary pump GPM to maintain constant secondary loop pressure as the load requirements change.

1 Kilowatt is the same as 1000 Watts. The answer depends on two (actually three) things. What is the supply voltage, is the power source single or 3-phase, and is the load reactive (like a motor) or resistive (like a heating element or incandescent lamp)? For single-phase power feeding a resistive load: Amps = Watts / Volts Example: 1KW 120V baseboard heater: 1000W / 120V = 8.3A If the load is reactive, then you must take power factor into consideration. VA (Volt-Amperes) = Watts / PF (power factor) Amps = VA / Volts Example: A 240V motor that draws 3KW and has a PF of 0.83: 3000W / 0.83PF = 3615VA 3615VA / 240V = 15.06A The formulae for 3-phase power is exactly the same except you must divide the answer by 1.73. For instance, our 240V motor, if it were 240V 3-phase (for the sake of discussion) would be: 15.06 / 1.73 = 8.71A As you can see, power factor makes a big difference. VA is called "apparent power" because it's what you appear to have if you take measurements with a voltmeter and ammeter and do the calculations. Watts is called "true power", this is what you, the typical residential customer, pay the utility company for. Oh yeah, sometimes you will see PF expressed as a percentage. In our above example with PF = 0.83, you might find either 0.83 OR83% on the motor nameplate. If you run across the percentage figure, mentally convert it to the decimal number before using it in the formula.

This seeming contradiction occurs on most physics tests. But it's true, and here's why:

Lamp A by itself has power of P=IxE ; 60=IxE ; so I=60/220=0.27 amperes. Thus the lamp has a resistance E=IxR ; R=220/0.27 = 807 ohms.

Lamp B by itself has a power of P=IxE ; so I=100/220 = 0.45 amperes. Thus the lamp has a resistance E=IxR ; R=220/0.45 = 489 ohms.

Since the resistance in series is added up, the total resistance is 807+489 =1296 ohms and the current I= E/R = 220/1296 = 0.17.....

Phew... Since P= IxIxR

For 60W lamp A, P= 0.17 x 0.17 x 807 = 23.3 watts.

For 100W lamp B, P=0.17 x 0.17 x 489 = 14.1 watts.

So, when they are wired in series, the bright one and the dim one appear to be reversed as to their respective "normal rated powers".

Their normal rated powers are only correct when both of them are supplied with their normal rated voltage of 220 volts, i.e. when they are wired in parallel. This makes a lot of sense if you think about it.

yes

The voltage measured across an open in a series circuit is the equivalent of the sourse voltage.

The effective current is the square-root of the average value of the current-squared, root-mean-square or rms for short. That is because the power in a resistive load like a water heater is proportional to the square of the current.

The rms voltage of an ac supply gives the same heating effect as a dc supply of the same voltage.

The peak current is sqrt(2) times higher.

The rms voltage and current are always quoted when referring to an ac power supply.

You're looking for what some folks call a voltage converter, international voltage converter or international voltage adapter (and there are more names). For smaller equipment, an "adapter" like folks get in those little travel kits will probably do the trick. Electrical outlets in Europe are different from the U.S. outlets (both in voltage as well as in the shape of the plug), and the kit contains the stuff to make your little shaver or your laptop work over there. For larger equipment, a step-down transformer is required. These come in various sizes, and they are usually not super cheap. The unit is made of copper wire and a ferromagnetic (iron) core, and it will be fairly heavy, bulky and even a bit inconvenient. Ask a local electronics outlet representative to help you sort it out. They have the stuff for sale and are in "sales mode" when they're working, but they can be helpful by supplying information (even if they don't make a sale), and that is part of their job, too. Certainly there are a number of online resources that vend the products that can help.

Not necessarily. A UPS is primarily designed to produce a short period of power in the case of the mains failing.

Thet resistor opposes the flow of current through it becoz of its internal construction. Its material has opposing property.

At the moment, the largest operating nuclear generation station is Bruce Power Nuclear Generating Station in Ontario, Canada. It has 6 units online out of 8 and is producing 4,640 MW, two more untis are being restarted and when they come back online in 2010 the capacity for Bruce Power will be 7,276 MW. The largest nuclear reactor station ever constructed is the Kashiwazaki-Kariwa Nuclear Power Plant in Japan, but it was shut down in 2007 due to earthquake damage.

Transformers rated 1 KVA and larger single phase,3 KVA and larger three phase can be reverse connected without any adverse effects or loss in KVA capacity. The reason for this limitation in KVA size is, the turns ratio is the same as the voltage ratio. On transformers rated below 1 KVA single phase, there is a turns ratio compensation on the low voltage winding. This means the low voltage winding has a greater voltage than the name plate voltage indicates at no load. Terminals on a single wound transformer, primary side are labeled H1,and H2 and on the secondary side X1 and X2. Just reverse the input voltage to the X1 and X2 terminals and the take the load off of the H1 and H2 side.