Kill A Watt
Encyclopedia
Electricity
Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...
usage monitor
Electricity meter
An electricity meter or energy meter is a device that measures the amount of electric energy consumed by a residence, business, or an electrically powered device....
marketed by P3 International. It features a large LCD display and it enables cost forecasting. It measures the energy used by individual appliances plugged into the meter, as opposed to in-home energy use displays, which display the energy used by an entire household. The name is a play on the word kilowatt.
Having a NEMA 5-15 plug and receptacle, and rated for 120 VAC, the Kill A Watt is sold for the North American market. The manufacturer is the Taiwanese company Prodigit,http://board.homeseer.com/showthread.php?p=829761#post829761 which also makes models suited for 240 V with European Schuko
Schuko
"Schuko" is the colloquial name for a system of AC power plugs and sockets that is defined as "CEE 7/4". A Schuko plug features two round pins of 4.8 mm diameter for the live and neutral contacts, plus two flat contact areas on the top and bottom side of the plug for protective earth...
, U.K. BS 1363
BS 1363
BS 1363 is a British Standard which specifies the most common type of single-phase AC power plugs and sockets that are used in the United Kingdom. Distinctive characteristics of the system are shutters on the line and neutral socket holes, and a fuse in the plug...
and Australian AS 3112
AS 3112
AS 3112 is an Australian standard for mains power plug. It is also known as a Type I plug.-Description:The plug matching the pictured socket, used in Australia, Argentina, New Zealand, Fiji, Papua New Guinea and Tokelau, has an earthing pin and two flat pins forming an inverted V-shape...
receptacles as well as a model compatible with 100 VAC for the Japanese market (2022-04, marketed there as the Watt Checker [ワットチェッカー] Plus by other companies).
The device can give an indication of the standby power
Standby power
Standby power, also called vampire power, vampire draw, phantom load, or leaking electricity , refers to the electric power consumed by electronic and electrical appliances while they are switched off Standby power, also called vampire power, vampire draw, phantom load, or leaking electricity...
used by appliances.
P4400
This is the original, most basic version, equivalent to the Prodigit 2000M. From the time it is plugged in, it measures:- VoltageVoltageVoltage, otherwise known as electrical potential difference or electric tension is the difference in electric potential between two points — or the difference in electric potential energy per unit charge between two points...
(VoltVoltThe volt is the SI derived unit for electric potential, electric potential difference, and electromotive force. The volt is named in honor of the Italian physicist Alessandro Volta , who invented the voltaic pile, possibly the first chemical battery.- Definition :A single volt is defined as the...
s) - CurrentElectric currentElectric current is a flow of electric charge through a medium.This charge is typically carried by moving electrons in a conductor such as wire...
(AmpereAmpereThe ampere , often shortened to amp, is the SI unit of electric current and is one of the seven SI base units. It is named after André-Marie Ampère , French mathematician and physicist, considered the father of electrodynamics...
s) - PowerElectric powerElectric power is the rate at which electric energy is transferred by an electric circuit. The SI unit of power is the watt.-Circuits:Electric power, like mechanical power, is represented by the letter P in electrical equations...
(WattWattThe watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...
s) - EnergyEnergyIn physics, energy is an indirectly observed quantity. It is often understood as the ability a physical system has to do work on other physical systems...
Used (Kilowatt-hours) - FrequencyFrequencyFrequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency.The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency...
(HertzHertzThe hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications....
) - Apparent power (Volt-ampereVolt-ampereA volt-ampere is the unit used for the apparent power in an electrical circuit, equal to the product of root-mean-square voltage and RMS current. In direct current circuits, this product is equal to the real power in watts...
s) - Power factorPower factorThe power factor of an AC electric power system is defined as the ratio of the real power flowing to the load over the apparent power in the circuit, and is a dimensionless number between 0 and 1 . Real power is the capacity of the circuit for performing work in a particular time...
- Elapsed time
Most users would use mainly the Power and Kilowatt-hour settings, to measure how much power devices use, and how much total energy they use over time. The P4400's measurements are lost and the time and power consumption accumulators reset when power is removed.
P4460 Kill A Watt EZ
This is an enhanced version, equivalent to the Prodigit 2022 which includes a backup battery to preserve measurements when unpowered. It has the same capabilities as the P4400, and can be programmed with electricity cost information, which enables it to display the cost of the electricity consumed to date, and cost extrapolated per hour, day, week, month, or year.P4320 Kill A Watt PS
This model (also known as the Prodigit 2024) is integrated into an eight-outlet surge protectorSurge protector
A surge protector is an appliance designed to protect electrical devices from voltage spikes. A surge protector attempts to limit the voltage supplied to an electric device by either blocking or by shorting to ground any unwanted voltages above a safe threshold...
. It does not display frequency or apparent power, protects against surges and EMI
EMI
The EMI Group, also known as EMI Music or simply EMI, is a multinational music company headquartered in London, United Kingdom. It is the fourth-largest business group and family of record labels in the recording industry and one of the "big four" record companies. EMI Group also has a major...
, has a configurable overcurrent shutdown limit, and also measures earth leakage current; one version acts as an earth leakage circuit breaker
Earth leakage circuit breaker
An Earth Leakage Circuit Breaker is a safety device used in electrical installations with high earth impedance to prevent shock. It detects small stray voltages on the metal enclosures of electrical equipment, and interrupts the circuit if a dangerous votlage is detected...
(ELCB). It switches power on or off at an AC zero crossing
Zero crossing
Zero-crossing is a commonly used term in electronics, mathematics, and image processing. In mathematical terms, a "zero-crossing" is a point where the sign of a function changes Zero-crossing is a commonly used term in electronics, mathematics, and image processing. In mathematical terms, a...
, minimizing current surges and interference.