• Study Resource
  • Explore
    • Arts & Humanities
    • Business
    • Engineering & Technology
    • Foreign Language
    • History
    • Math
    • Science
    • Social Science

    Top subcategories

    • Advanced Math
    • Algebra
    • Basic Math
    • Calculus
    • Geometry
    • Linear Algebra
    • Pre-Algebra
    • Pre-Calculus
    • Statistics And Probability
    • Trigonometry
    • other →

    Top subcategories

    • Astronomy
    • Astrophysics
    • Biology
    • Chemistry
    • Earth Science
    • Environmental Science
    • Health Science
    • Physics
    • other →

    Top subcategories

    • Anthropology
    • Law
    • Political Science
    • Psychology
    • Sociology
    • other →

    Top subcategories

    • Accounting
    • Economics
    • Finance
    • Management
    • other →

    Top subcategories

    • Aerospace Engineering
    • Bioengineering
    • Chemical Engineering
    • Civil Engineering
    • Computer Science
    • Electrical Engineering
    • Industrial Engineering
    • Mechanical Engineering
    • Web Design
    • other →

    Top subcategories

    • Architecture
    • Communications
    • English
    • Gender Studies
    • Music
    • Performing Arts
    • Philosophy
    • Religious Studies
    • Writing
    • other →

    Top subcategories

    • Ancient History
    • European History
    • US History
    • World History
    • other →

    Top subcategories

    • Croatian
    • Czech
    • Finnish
    • Greek
    • Hindi
    • Japanese
    • Korean
    • Persian
    • Swedish
    • Turkish
    • other →
 
Profile Documents Logout
Upload
Ground Fault Protection
Ground Fault Protection

... A fault-protected relay includes fast contact opening to reduce the fault duration and accurate sensing in a fault current environment. The ability to function is required under adverse environmental conditions and in an electromagnetic environment that may include power line interference, High Inte ...
What’s in it for me?
What’s in it for me?

GEI-31073A - GE Grid Solutions
GEI-31073A - GE Grid Solutions

... fault. The coils of the 79X units are current oper ated and are placed in series with the phase relay trip circuits so that should a three-phase fault oc cur, all three 79X units become energized. The 79Y unit has a one cycle pickup and may be oper ated by a contact of any of the 79X units. One con ...
relays
relays

... number of poles – the number of separate circuits that can be switched by energizing the coil a. SP = single pole (one circuit is switched) b. DP = double pole (two circuits are switch) throw – throw describes what happens to the contacts when the coil is energized a. Single Throw – energizing the c ...
Installation and Operation Instructions ATL
Installation and Operation Instructions ATL

... If the 24 VAC power is shared with devices that have coils such as relays, solenoids, or other inductors, each coil must have an MOV, AC Transorb, or other spike snubbing device across each of the shared coils. Without these snubbers, coils produce very large voltage spikes when deenergizing that c ...
Power System Protection
Power System Protection

CK system interface
CK system interface

... terminal block marking, CNU/8 marking tags are available;CNU/8 marking tags are available in blank format for pen or plotter marking, or with the Cabur Jet marking printer. • If the input and output power supply cables of the interface assembly are directly connected to eg. the first module, two cab ...
AUTO TURNOFF WATER PUMP WITH FOUR DIFFERENT TIME
AUTO TURNOFF WATER PUMP WITH FOUR DIFFERENT TIME

... pump. Contrast of the LCD can adjust by using a preset which is connected to it. A transistor is used to drive the relay during the active time period. 5V double pole – double through relay is used to control the AC liquid pump. LED indication is provided for visual identification of the relay / loa ...
DYNALCO
DYNALCO

SW1/SW2 - Mega El
SW1/SW2 - Mega El

Photorelay White Paper Draft 3.qxd
Photorelay White Paper Draft 3.qxd

Distance Protection
Distance Protection

... In general, all electromechanical relays respond to one or more of the conventional torqueproducing input quantities: (a) voltage, (b) current, (c) product of voltage, current and the angle θ between them and (d) a physical or design force such as a control spring. Similar considerations hold for so ...
Development of Environment-Friendly Latching Relay 1
Development of Environment-Friendly Latching Relay 1

... with a mechanical lock mechanism to maintain the operation status and those with an electromagnetic lock mechanism. Since mechanical lock types usually have high cost due to their complex structures, electromagnetic lock types using permanent magnets are more commonly used. They are also called pola ...
PIC-IO PIC DEVELOPMENT BOARD WITH 4 RELAYS AND 4 OPTO
PIC-IO PIC DEVELOPMENT BOARD WITH 4 RELAYS AND 4 OPTO

... PIC-IO board was designed as simple platform which to allow control of appliances and devices with PIC, the idea was to build something like tiny PLC controller which is possible to program in C or assembler instead of the weird PLC relay language. Let’s see what we have on board: Four High voltage/ ...
NX-M700 Series Master Control Panel
NX-M700 Series Master Control Panel

E290-32-20/8
E290-32-20/8

... Latching relays are electromagnetically operated devices. The E290 range from ABB can b e used to realise a simple, energy saving and efficient lighting control system. These devic es are mainly used in private houses, factory premises and commercial and public building s as well as in industrial pl ...
Document
Document

Circuit Monitor - E-MAX Instruments, Inc.
Circuit Monitor - E-MAX Instruments, Inc.

Overcurrent and Ground Fault Protection
Overcurrent and Ground Fault Protection

Relays
Relays

... • Control method for machinery that creates a sequential operation of events. • The RELAY is the major component for this control method. • The main purpose of a PLC was to replace the relay. • The relay is a mechanic device that wears out • Changing the relay control structure required shutting do ...
PDF
PDF

Download PGR-6130 Datasheet
Download PGR-6130 Datasheet

wiring diagram
wiring diagram

Electrical Interference from HVAC Relays
Electrical Interference from HVAC Relays

DUKE ENERGY.
DUKE ENERGY.

... A review of all installed Allen Bradley 700RTC relays was completed. This review was not limited to known, affected Allen Bradley 700RTC relays (i.e., those with CPLDs). The review consisted of an analysis of relevant prints to determine any existing electrical coils (i.e., solenoid, relay, breaker) ...
< 1 ... 59 60 61 62 63 64 65 66 67 >

Protective relay



In electrical engineering, a protective relay is a device designed to trip a circuit breaker when a fault is detected. The first protective relays were electromagnetic devices, relying on coils operating on moving parts to provide detection of abnormal operating conditions such as over-current, over-voltage, reverse power flow, over- and under- frequency. Microprocessor-based digital protection relays now emulate the original devices, as well as providing types of protection and supervision impractical with electromechanical relays. In many cases a single microprocessor relay provides functions that would take two or more electromechanical devices. By combining several functions in one case, numerical relays also save capital cost and maintenance cost over electromechanical relays. However, due to their very long life span, tens of thousands of these ""silent sentinels"" are still protecting transmission lines and electrical apparatus all over the world. An important transmission line or generator unit will have cubicles dedicated to protection, with many individual electromechanical devices, or one or two microprocessor relays.The theory and application of these protective devices is an important part of the education of an electrical engineer who specializes in power systems. The need to act quickly to protect circuits and equipment as well as the general public often requires protective relays to respond and trip a breaker within a few thousandths of a second. In these cases it is critical that the protective relays are properly maintained and regularly tested.
  • studyres.com © 2025
  • DMCA
  • Privacy
  • Terms
  • Report