1. Introduction
... Human beings aspiring to learn about the world surrounding them have made many formulations of scientific representations of the world. History shows that representations about energy have been very prominent. The abundance of different kinds of energy demanded comparison of their sizes. As a result ...
... Human beings aspiring to learn about the world surrounding them have made many formulations of scientific representations of the world. History shows that representations about energy have been very prominent. The abundance of different kinds of energy demanded comparison of their sizes. As a result ...
the Note
... 1. Batteries and cells are the main source of direct current. These are too expensive to provide large amounts of current. 2. Direct current cannot be transformed. Even when using a DC generator, transformers are less effective than when transforming current from an AC generator. 3. The potential di ...
... 1. Batteries and cells are the main source of direct current. These are too expensive to provide large amounts of current. 2. Direct current cannot be transformed. Even when using a DC generator, transformers are less effective than when transforming current from an AC generator. 3. The potential di ...
Lighting Load Protection
... Frequently, due to inherent limitations in various types of overcurrent devices for motor application, two or more separate protective devices are used to provide overload protection and short circuit protection. An exception is the dual-element fuse. For most motor applications, the beneficial feat ...
... Frequently, due to inherent limitations in various types of overcurrent devices for motor application, two or more separate protective devices are used to provide overload protection and short circuit protection. An exception is the dual-element fuse. For most motor applications, the beneficial feat ...
Synchronous Machine
... In this method , the choice of dimensions , materials and types of construction are made by the designer and these are presented to the computer as input data. Performance is calculated by the computer and is returned to the designer to examine Designer examines the performance and makes another cho ...
... In this method , the choice of dimensions , materials and types of construction are made by the designer and these are presented to the computer as input data. Performance is calculated by the computer and is returned to the designer to examine Designer examines the performance and makes another cho ...
Infranor Variable Speed Drive Implementation
... 2 – Vertical Load Configuration 2 – 1.Operating Principle . In order to offset the downward movement of the arm before it is raised, a vertical load compensation must be implemented. . This compensation adds a current offset which may be positive or negative depending on mechanical configuration. . ...
... 2 – Vertical Load Configuration 2 – 1.Operating Principle . In order to offset the downward movement of the arm before it is raised, a vertical load compensation must be implemented. . This compensation adds a current offset which may be positive or negative depending on mechanical configuration. . ...
Investment and Licensing Opportunities now available.
... self-powered drives can be utilized in areas where there is no electrical power available and where VFD’s cannot operate. The Coyote has been in use in thousands of applications throughout the U.S. and Canada since 1993 with a superior track record. Many air handler unit manufacturers (OEMS) now ins ...
... self-powered drives can be utilized in areas where there is no electrical power available and where VFD’s cannot operate. The Coyote has been in use in thousands of applications throughout the U.S. and Canada since 1993 with a superior track record. Many air handler unit manufacturers (OEMS) now ins ...
High-Temperature Superconducting Wind Turbine
... ratings. Indeed, the exploitation of wind energy has been high on many governments’ and organizations’ agenda. However, for onshore wind farms the interference with neighboring residents and low wind speeds may limit the number of acceptable sites available for development. On the contrary, high win ...
... ratings. Indeed, the exploitation of wind energy has been high on many governments’ and organizations’ agenda. However, for onshore wind farms the interference with neighboring residents and low wind speeds may limit the number of acceptable sites available for development. On the contrary, high win ...
Unit 39.pps
... Indoor fan must be on when the compressor is operating Outdoor fan is often on when compressor operates Indoor fan may operate continuously Thermostat – Operating control High-pressure switch – Safety control ...
... Indoor fan must be on when the compressor is operating Outdoor fan is often on when compressor operates Indoor fan may operate continuously Thermostat – Operating control High-pressure switch – Safety control ...
caribbean examinations council report on candidates` work in
... form a p-type semiconductor material. The majority of candidates, approximately 40 per cent, did not provide the expected answer. Candidates who responded incorrectly to this question, for example, placed phosphorus as the impurity to be added for a p-type material. Part (a) (ii) required candidates ...
... form a p-type semiconductor material. The majority of candidates, approximately 40 per cent, did not provide the expected answer. Candidates who responded incorrectly to this question, for example, placed phosphorus as the impurity to be added for a p-type material. Part (a) (ii) required candidates ...
MEASURING INSTRUMENTS
... A defined above, indicating instruments are those which indicate the value of quantity that is being measured at the time at which it is measured. Such instruments consist essentially of a pointer which moves over a calibrated scale & which is attached to a moving system pivoted in bearing. The movi ...
... A defined above, indicating instruments are those which indicate the value of quantity that is being measured at the time at which it is measured. Such instruments consist essentially of a pointer which moves over a calibrated scale & which is attached to a moving system pivoted in bearing. The movi ...
Technical guide No. 4, Guide to variable speed drives
... the motor and its control. Both drive and motor losses are thermal, so they appear as heat. Input power to the drive system is electrical in form, while output power is mechanical. That is why calculating the coefficient of efficiency (η) requires knowledge of both electrical and mechanical engineer ...
... the motor and its control. Both drive and motor losses are thermal, so they appear as heat. Input power to the drive system is electrical in form, while output power is mechanical. That is why calculating the coefficient of efficiency (η) requires knowledge of both electrical and mechanical engineer ...
MEASURING INSTRUMENTS
... A defined above, indicating instruments are those which indicate the value of quantity that is being measured at the time at which it is measured. Such instruments consist essentially of a pointer which moves over a calibrated scale & which is attached to a moving system pivoted in bearing. The movi ...
... A defined above, indicating instruments are those which indicate the value of quantity that is being measured at the time at which it is measured. Such instruments consist essentially of a pointer which moves over a calibrated scale & which is attached to a moving system pivoted in bearing. The movi ...
Per unit Calculation and Modeling of Apparatus
... The subtransient reactance X d" determines the current during the first cycle after fault occurs. In about 0.1sec reactance increases to transient reactance X d' . In about 0.5sec to 2sec, reactance increases to X d , the Synchronous reactance; this is the value that determines the current flow afte ...
... The subtransient reactance X d" determines the current during the first cycle after fault occurs. In about 0.1sec reactance increases to transient reactance X d' . In about 0.5sec to 2sec, reactance increases to X d , the Synchronous reactance; this is the value that determines the current flow afte ...
ER33863872
... damped in very short time. Although the torque amount can be negative in that time but average value remain positive because of motors stable operation. If we use from speed-torque curve for depict of motor behavior in steady state. In every applications these oscillations will not be appreciable an ...
... damped in very short time. Although the torque amount can be negative in that time but average value remain positive because of motors stable operation. If we use from speed-torque curve for depict of motor behavior in steady state. In every applications these oscillations will not be appreciable an ...
D N IAGNOSTIC EWS
... In past issues of the Diagnostic News we have discussed how modern inverter fed drives (IFDs) can lead to partial discharge (PD) and stator winding failure in random wound motor stators rated as low as 440 V. In this article I will concentration the effect of the voltage source type of pulse width m ...
... In past issues of the Diagnostic News we have discussed how modern inverter fed drives (IFDs) can lead to partial discharge (PD) and stator winding failure in random wound motor stators rated as low as 440 V. In this article I will concentration the effect of the voltage source type of pulse width m ...
Induction motor
An induction or asynchronous motor is an AC electric motor in which the electric current in the rotor needed to produce torque is obtained by electromagnetic induction from the magnetic field of the stator winding. An induction motor therefore does not require mechanical commutation, separate-excitation or self-excitation for all or part of the energy transferred from stator to rotor, as in universal, DC and large synchronous motors. An induction motor's rotor can be either wound type or squirrel-cage type.Three-phase squirrel-cage induction motors are widely used in industrial drives because they are rugged, reliable and economical. Single-phase induction motors are used extensively for smaller loads, such as household appliances like fans. Although traditionally used in fixed-speed service, induction motors are increasingly being used with variable-frequency drives (VFDs) in variable-speed service. VFDs offer especially important energy savings opportunities for existing and prospective induction motors in variable-torque centrifugal fan, pump and compressor load applications. Squirrel cage induction motors are very widely used in both fixed-speed and variable-frequency drive (VFD) applications. Variable voltage and variable frequency drives are also used in variable-speed service.