SEL751A's don't require a battery and neither does the Vista. The 751A will take both AC and DC power for operation. You can plug one into a wall if you so desired and power it up (obviously this should not be done for an actual installation, but if you want to play with it at your desk it can...
The relay is a SEL751A and is powered by the same CPT as the trip circuit and will have the same ride through setup either the CTD or the voltage sag corrector. But the relay isn't the issue, it's the input to the shunt trip for the fault interrupters themselves on the Vista. The spec says that...
We aren't using S&C's LVE. The voltage sag corrector actually outputs a 120VAC. I tried to upload it but it will only let me upload one document, and I can't figure out how to take out the CTD, but here's a link to the Voltage Sag Protector...
We are designing a power distribution system,12.47kV and 480V,and we are spec'ing an S&C Vista switch for the MV side. It has become our standard that for arc-flash mitigation on the 12.47kV-480V transformer secondary conductors bushing CT's be installed on the low side bushings of the...
We are working on a project where a new 3000A swtichboard is being installed at an industrial facility, but the customer wants to use the existing conductors and rigid steel conduit for the feeders to all of the loads. None of them have equipment grounding conductors (EGC's) installed. While...
The surge arrestor is used for overvoltage protection, if a lightning strike happens the arrestor acts as a short to ground. I've always sized the surge arrestors based on the line voltage and the manufacturers table.
Thank you for the responses. I think I need to clarify a bit. The vast majority of the sites I work at are in Oregon (paper and wood products mostly) and they are all fed from overhead lines by the utility. The biggest thing that we really have to worry about would be lightning strikes...
I am working on a fire pump design for an industrial facility fed by overhead conductors. NFPA 20 considers a source to be reliable if it is not supplied by overhead conductors immediately outside the protected facility. As this is an industrial facility with various buildings and outdoor...
