Information required to Assess the Reliability of a RAS Guideline
... generators, batteries). Identify paths or segments routed through common equipment chassis such as Digital Cross-connect System, SONET node, or ...
... generators, batteries). Identify paths or segments routed through common equipment chassis such as Digital Cross-connect System, SONET node, or ...
Breakers, Relays, and Disconnects
... • Ensures the system is not re-energized before the fault is isolated ...
... • Ensures the system is not re-energized before the fault is isolated ...
Voltage Sag Source Location in Power Systems
... However, several studies have shown that some other characteristics associated with sags, such as phase-angle jump, point-on-wave of initiation and recovery, waveform distortion and phase unbalance, may also cause problems for sensitive equipment [2]. The magnitude of the voltage sag is governed by ...
... However, several studies have shown that some other characteristics associated with sags, such as phase-angle jump, point-on-wave of initiation and recovery, waveform distortion and phase unbalance, may also cause problems for sensitive equipment [2]. The magnitude of the voltage sag is governed by ...
Improving Breaker Failure Protection for Generator Applications
... In modern microprocessor-based relays, the synchronismcheck element has the ability to calculate slip between the two sides, in addition to the angle. Slip is the movement of the angle of one system relative to the other and is measured in hertz. The magnitude of the voltage signals used in the meas ...
... In modern microprocessor-based relays, the synchronismcheck element has the ability to calculate slip between the two sides, in addition to the angle. Slip is the movement of the angle of one system relative to the other and is measured in hertz. The magnitude of the voltage signals used in the meas ...
Surge Suppression Catalog
... Seller’s place and point of delivery shall be deemed to be delivery to a carrier at Seller’s plant in Canton, NC, USA or such other designated shipping point designated by Seller. If Buyer fails to furnish complete shipping directions to Seller within a reasonable time of placing the order, Seller, ...
... Seller’s place and point of delivery shall be deemed to be delivery to a carrier at Seller’s plant in Canton, NC, USA or such other designated shipping point designated by Seller. If Buyer fails to furnish complete shipping directions to Seller within a reasonable time of placing the order, Seller, ...
Breakers, Relays, and Disconnects
... Power plant and industrial systems need overcurrent delay relays to allow for starting large loads. When a large induction motor starts, it draws a starting current that is several times larger than its normal running current. This starting current persists until the motor is up to its normal runni ...
... Power plant and industrial systems need overcurrent delay relays to allow for starting large loads. When a large induction motor starts, it draws a starting current that is several times larger than its normal running current. This starting current persists until the motor is up to its normal runni ...
Breakers, Relays, and Disconnects
... Interrupt the current flow quickly enough to prevent or minimize damage to the component. Interrupt current flow quickly enough to contain any damage to that component alone, as well as protect the rest of the electrical system. Choices include fuses, overloads, or a protective relay to trip the m ...
... Interrupt the current flow quickly enough to prevent or minimize damage to the component. Interrupt current flow quickly enough to contain any damage to that component alone, as well as protect the rest of the electrical system. Choices include fuses, overloads, or a protective relay to trip the m ...
Circuit Breakers
... protective relays, circuit breakers, and overload devices. 1.3 Describe the function of the following types of switches: disconnect switch, automatic transfer switch and manual transfer switch. 1.4 Describe the personnel safety and equipment protection precautions associated with circuit interruptin ...
... protective relays, circuit breakers, and overload devices. 1.3 Describe the function of the following types of switches: disconnect switch, automatic transfer switch and manual transfer switch. 1.4 Describe the personnel safety and equipment protection precautions associated with circuit interruptin ...
191008 - Breakers, Relays, and Disconnects
... o Protects operator's eyes and face from arc that may occur during switch operation • Before disconnect can be opened, all electrical loads fed by disconnect must be verified off, or not operating • Opening disconnect under load can result in damage to disconnect and injury to personnel ...
... o Protects operator's eyes and face from arc that may occur during switch operation • Before disconnect can be opened, all electrical loads fed by disconnect must be verified off, or not operating • Opening disconnect under load can result in damage to disconnect and injury to personnel ...
Fuse Selection Guide
... standard glass and ceramic fuses as well as a variety of leaded subminiature and micro fuses. These same options are available in resettable fuses as well. Additionally, the fuse mounting can also play a part in the designers’ decision especially if the fuse needs to be field-replaceable. Does the ...
... standard glass and ceramic fuses as well as a variety of leaded subminiature and micro fuses. These same options are available in resettable fuses as well. Additionally, the fuse mounting can also play a part in the designers’ decision especially if the fuse needs to be field-replaceable. Does the ...
GENERATOR PROTECTION
... machine applications Requires only phase CTs, or terminal side zero-sequence CT 67N directionalized to trip for zero-sequence (ground) current toward a generator 67N is set faster than 51N May be short definite time delay Ground current should not flow into a generator under normal operati ...
... machine applications Requires only phase CTs, or terminal side zero-sequence CT 67N directionalized to trip for zero-sequence (ground) current toward a generator 67N is set faster than 51N May be short definite time delay Ground current should not flow into a generator under normal operati ...
Low Voltage Surge Protection Products
... If the site requires filtering at the point of entry, select an PPFI with the appropriate current rating for the load, then select the model appropriate for the protection category. For DC solar panel arrays with Grid Interactive inverters it is recommended that Cat C / Class II, DC type SPD’s are u ...
... If the site requires filtering at the point of entry, select an PPFI with the appropriate current rating for the load, then select the model appropriate for the protection category. For DC solar panel arrays with Grid Interactive inverters it is recommended that Cat C / Class II, DC type SPD’s are u ...
Breakers, Relays, and Disconnects
... overvoltage, or underfrequency failures unless those failures lead to an overcurrent condition. Circuit Breaker Protective Relays Various types of protective relays detect fault conditions then send signals to trip one or more circuit breakers to isolate the fault, protecting equipment from damage a ...
... overvoltage, or underfrequency failures unless those failures lead to an overcurrent condition. Circuit Breaker Protective Relays Various types of protective relays detect fault conditions then send signals to trip one or more circuit breakers to isolate the fault, protecting equipment from damage a ...
The Connecticut Light and Power Company The United Illuminating
... For voltages equal to or less than 600 volts on the EPS, the Generator shall own, install, operate and maintain an external Isolation Device (or comparable device mutually agreed upon by the parties) for the Generating Facility that can be opened for isolation. The Isolation Device shall be operated ...
... For voltages equal to or less than 600 volts on the EPS, the Generator shall own, install, operate and maintain an external Isolation Device (or comparable device mutually agreed upon by the parties) for the Generating Facility that can be opened for isolation. The Isolation Device shall be operated ...
Xcel Energy New Mexico Interconnection Manual
... Installations over 10 MW are covered by the rules found in NM 17.9.569: Case Specific Review Process: For Generating Facilities with a Rated Capacity greater than 10 megawatts (MW), which shall be conducted pursuant to 17.9.569 (569) NMAC. The NM 569 Rules derive from the original Public Utility Reg ...
... Installations over 10 MW are covered by the rules found in NM 17.9.569: Case Specific Review Process: For Generating Facilities with a Rated Capacity greater than 10 megawatts (MW), which shall be conducted pursuant to 17.9.569 (569) NMAC. The NM 569 Rules derive from the original Public Utility Reg ...
Guide and Requirements for Service at 69000 to 287000
... incoming transmission line insulation. At 230 kV and 287 kV it is BC Hydro's practice to install overhead ground wires on transmission structures from the station out 500 m. Customers may wish to use the same practice at their stations. The critical flashover levels for standard BC Hydro line constr ...
... incoming transmission line insulation. At 230 kV and 287 kV it is BC Hydro's practice to install overhead ground wires on transmission structures from the station out 500 m. Customers may wish to use the same practice at their stations. The critical flashover levels for standard BC Hydro line constr ...
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.