Automatic Transfer Switches双电源自动切换开关

Automatic Transfer SwitchesAbstract: automatic Transfer Switches are an integral part of the power generation process, allowing smooth and immediate transfer of electrical current between multiple sources and the load. When the generator is operating, t he transfer switch prevents dangerous feedback of current to the utility’s system. It also ensures that different power sources are fully synchronized before their power is combined or loads are transferred, which is imperative for safe operation.Key word：Transfer；Switches；Generator；loadThe transfer switch senses when utility power is interrupted, and starts up the generator if the utility power remains absent. In about five to ten seconds, when the generator is producing full power, the transfer switch disconnects the load from the utility and connects it to the generator, restoring electricity to the load. The transfer switch continues to monitor utility power, and when it is restored, switches the load from the generator back to the utility. Once the generator is disconnected, it goes through a cool-down routine and is automatically shut down.Generac manufactures several types of transfer switches. Each kind operates in a different way, depending upon the requirements of the overall system, and how the load is transferred between the different power sources. Transfer switch types include open transition, momentary closed transition, soft load closed transition, and bypass isolation.Generacs automatic transfer switches are designed to be simple to monitor, operate and maintain. All controls needed for daily use are conveniently located on the front door, where bright lamps indicate the switch position. All components are front adjustable and front removable for optimum serviceability. As an extra measure of safety and quality, Generacs transfer switches are UL Listed by Underwriters Laboratories for use in emergency power systems. They are also CSA certified by the Canadian Standards Association. Generacs expertise in the design and manufacture of automatic transfer switches (ATS) is considerable. The company has produced its own fully instrumented 100 to 2600 amp switches since 1983.1.Open transition transfer switches are the simplest kind, and are mechanically interlocked. They disconnect the load from one power source before making the connection to the other.Generacs closed transition transfer switches (CTTS) eliminate momentary power interruption when both sources are present and synchronized, by transferring the loads with an overlapping contact arrangement. The momentary closed transition switch transfers the power within one hundred milliseconds, which does not require utility protective relaying.The soft load closed transition switch extends the overlap time to multiple seconds, for a smoother transition of load to the generator. These switches are available in 100 to 2600 amp configurations.There are many critical systems where interruption of power is not permitted, such as data transmission and hospital care. For those requirements, Generac offers its bypass isolation switch (BIS), which is designed to meet the National Electrical Codes requirements for the inspection and/or maintenance of the automatic transfer switch without the need to interrupt or cut power. Generac transfer switches are carefully constructed and tested to assure superior performance. By combining them with Generacs own generators, Generac is able to offer a complete power generation package。

2.TRANSFER SWITCHES / EXPRESS INSTALL KITThe best power generation equipment deserves the finest automatic transfer switches, and that is why we manufacture our own. Each one is an integral part of our power systems, designed to match perfectly with our Generac generator. This device allows for a smooth transfer of electrical current between multiple sources and loads, automatically. The transfer switch senses the loss of utility power and automatically starts up the generator, then transfers the load to it. When the power is restored, it switches the load back to the utility and shuts down the generator.For residential and light commercial applications, Generac offers standard UL Listed, remote-mounted 100 or 200 amp switches. On our air-cooled models, we also offer our exclusive automatic transfer switch with a pre-wired built-in load center. This allows for up to 12 separate circuits to be easily connected to the main distribution panel. The transfer switch includes an Express Install Kit with pre-wired conduit for simpler installation and connection to the generator and main distribution panel. Benefits of this kit are:· Saves on installation time and costs many cases up to 50% over traditional transfer switch installations.· Easy isolation of critical zones and appliances imply match circuits from the main distribution panel to the circuits in the load center. No need to install a sub-panel for critical circuits.The Express Install Kit, for automatic transfer switches with the built-in load center, includes the following:· Outdoor-rated connection box with a pre-wired 5 ft. seal-tight conduit designed to be mounted on an external wall and connected to the generator.· 30 ft. pre-wired conduit to connect the transfer switch to the home connection box.· 2 ft. pre-wired conduit to connect the transfer switch to the main distribution panel.HOW THE SYSTEM WORKS· The completely automatic Generac transfer switch monitors incoming voltage from the utility line ?around the clock.· When utility power is interrupted, the automatic transfer switch immediately senses the problem and signals the generator to start.· Once the generator is running at proper speed, the automatic transfer switch safely closes off the utility line and simultaneously opens a new power line from the generator.· Within seconds, your Generac generator system begins supplying electricity to the critical emergency circuits of your home or business. The transfer switch continues to monitor the utility line conditions.When the automatic transfer switch senses the utility line voltage has returned at a steady state, it re-transfers the electrical load back to the utility line and resumes monitoring for subsequent utility loss. The generator will continue to run for an engine cool-down period of several minutes while the entire system stands ready for the next power outage.3.Features and Benefits· UL 1008 listed and CSA certified – Product safety features are recognized by industry organizations· 7-day Exerciser Clock –Starts and tests the generator every week, insuring reliable performance when needed· In-phase Monitor - Provides instantaneous transfer between two live voltage sources· Utility Voltage Sensor – Monitors utility voltage to determine when retransfer of load can occur· Line Failure Sensing – Circuitry monitors all phases of the utility service with dropout and pickup points· Utility Interrupt Delay – Adjustable timer overrides momentary line failure· Engine Warm-up Timer –Adjustable timer allows engine to operate at no load before the transfer switch transfer the load to the generator set · Engine Warm-up Bypass – A switch allows the transfer switch to transfer the load to the generator as soon as the preset voltage and frequency levels are reached· Minimum Run Timer – Determines the shortest period of time the generator will run and ensures adequate exercise periods· Return to Utility Delay –Adjustable timer keeps the load on the generator set until a stable utility line is present· Engine Cool-down Timer – Adjustable timer allows the engine to run at no load after the transfer switch transfers the load back to the utility line· Frequency and Voltage Set –Sets the minimum frequency and voltage required before the transfer switch will be allowed to transfer the load to the generator set.4.Optional Equipment· Logic System Control - Fully adjustable timer settings. LED indication for system status and simple field service· NEMA Enclosures - NEMA 3R, NEMA 4, NEMA 4X and NEMA 12· Quick Change, Multi-Voltage Panel - Multiple phase / voltage configurations with a single switch. Available on switches up to 400 amps · Auxiliary Contacts - One SPDT is standard. Additional sets are available· Programmable Exerciser - Permits selection of "days of the week" and "time of day." isible digital chronograph used to select times. Allows exercising from one to seven days a week· Exterior Meter Package - Enables user to monitor the system parameters with the door closed· Fourth Pole - Fourth pole for switching the neutral conductor · Preferred Source Selector Switch - Ability to select which power supply will be considered the normal source· Manual Selector Switch - 3 positions: normal, automatic and standby· Manual "Return to Normal" (electrically operated) - Ability to select when the switch will transfer back to normal· Remote Automatic Control Circuit - Ability to start the generator and transfer the load to emergency from a remote location· Signal before Transfer Contacts - Adjustable from 0.1 –10 seconds. Signals to special loads prior to transfer. Often used to prevent elevators from stopping between floors· Generator Mounted Transfer Switch - Transfer switch may be mounted on the genset for both indoor and outdoor application双电源自动切换开关摘要：双电源自动切换开关是进行能源转换处理的组成部分，它允许在多个电源和负荷之间的电流的顺利和瞬时转移。