Md anderson project No. XX-XXXX md anderson project name
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| uit breaker to isolate the inverters, and a system bypass circuit breaker in parallel with the static bypass switch. The static bypass switch shall denote the solid-state device that can instantaneously connect the alternate AC source to the load.
Manual Load Transfers. A manual load transfer between the inverter outputs and the alternate AC source shall be initiated from the control panel. Manually initiated transfers shall be make-before-break utilizing the UPS output and system bypass circuit breakers. The static switch shall not be used for manual transfers. Automatic Load Transfers. An automatic load transfer between the inverter outputs and the alternate AC source shall be initiated if an overload condition is sustained for a time period in excess of the system output capability or due to a malfunction that would affect the output voltage. Transfers caused by overloads shall initiate an automatic retransfer of the load back to the system only after the load has returned to a level within the rating of the SCC (System Control Cabinet). The UPS system logic shall allow 0 to 5 retransfers (adjustable) within anyone-hour period to prevent cyclical transfers caused by overloads Momentary Overloads. In the event of a load current inrush or branch load circuit fault in excess of the system rating, the static bypass switch shall connect the alternate AC source to the load for up to 40 milliseconds. This pulsed parallel operation shall allow up to 1000% of the nominal rated output current to flow for subcycle faults, and up to 500% of normal rated output current for up to three cycles. Output voltage shall be sustained to the extent the alternate AC source capacity pen-nits. If the overload condition is removed in less than 40 milliseconds, the static bypass switch will turn off the load shall remain on UPS system power. If the overload remains, then an automatic transfer to the alternate AC source will be completed by closing the system bypass circuit breaker. Back Feed Prevention. The critical output bus shall be protected from the flow of excess current through the static bypass switch path that may be caused by a low impedance fault at the output of the UPS system. Each phase of the bypass circuit shall be protected by individual fuses and circuit breakers. Blown fuse monitors shall indicate when a blown fuse will prevent the static bypass switch path from being available for automatic transfers. As required by UL 1778 and CSA, the static bypass switch shall not back feed UPS power to the bypass distribution system while the UPS system is operating on battery during a bypass source power outage. The purpose of this requirement is to prevent the risk of electrical shock on the distribution system when the normal source of power is disconnected or has failed. The static bypass switch shall be provided with redundant bypass power outage sensing circuits and disconnects. The back feed prevention system shall operate even if two component failures exist simultaneously. If a shorted SCR is detected, the static bypass switch shall be isolated and an alarm message shall be annunciated at the SCC (System Control Cabinet). The load shall remain on conditioned and protected power after detection of a shorted SCR and isolation of the static bypass switch. Display and Controls. UPS Control Panel. The term UPS control panel denotes that portion of the UPS containing the display panel and control functions. Membrane switches shall be used to select and execute operations Directory: depts -> cpm -> standards -> specs depts -> Black Panther Party Lesson Plan Aligned to Grade 11 gles Targeted Length: Two 90-Minute class periods created by Teresa Frizell depts -> Data Analysis (Math 206) Exam 2 Name Spring 2002 Hartlaub depts -> Engineering Library Reference Manual depts -> Megan andreas moreno, md, msed, mph depts -> New Media Power: The Internet and Global Activism depts -> Catalog description depts -> The evolution of gaming computers depts -> Winery Forklift/Power Industrial Truck Safety Program sample depts -> Csulb elementary Science & stem leadership Academy June 27 – July 8, 2016 plus 15 hours during the 2016-2017 School Year specs -> Md anderson project No. XX-XXXX md anderson project name Download 0.87 Mb. Share with your friends:
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