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Hi Can anyone pls tell me if a 45kVA 480v-208v remote transformer require a disconnecting means? Thanks

I wonder what is the salary of an electrical engineer with three years of experience (in Dallas,TX) in lighting and power.

While doing the arc flash study, I wonder what effect does the single line to ground fault has on arc flash current and incident energy? When I performed the arc flash study, I did a mistake of low resistance grounding the transformer and generator instead of solidly grounding them. There was...

Hi, I am currently doing a coordination study and I would like to know how to set the UPS instantaneous setting. I know I have to calculate and add the inrush current of all the pdu transformers and set the instantaneous setting of the static bypass switch circuit breaker to a level where it can...

Hi I am currently working on the coordination study using SKM power tool analysis. Questions regarding the ZSI settings. The SKM support told me that I have to input the Trip/Delay time(sec) for the breakers with ZSI module. The manufacturer said that the minimum trip time is 0.1. Please have...

Is it true that the outdoor pad mounted transformer do not have a short circuit rating? Instead, manufacturers provide us with ansi damage curves..

What is bus bracing rating?

There are two vista switchgears, one fed from A-side and the other one fed from B-side. These switchgears serves transformers. Since the B vista switchgear is energized through the closed loop switch in each transformer a fault on a primary conductor will be fed direct from the utility and...

Hi, I am trying to select a S&C vista device. Downstream of this device is a fused transformer rated at 2500kVA, 34500kV/480V. The transformer fuse is rated at 8A. The current on the primary side of the transformer is only 5A. Can I select a vista fuse rated at 100A? Is it too high?

What is a inverse definite time relay? How does it work?

I have a question regarding the protective device voltage. The utility is 34.5kV and the relay connected to the S&C vista SWGR is rated at 23000V. I always thought that the protective device voltage should always be higher than the bus voltage. Please advise... Thanks

I am currently working on coordination study of a project. The curves of few breakers are overlapped. So it is tough to say which one will trip first. But what I understood is that, since the breaker trip units used has the characteristic of Zone selective Interlocking (ZSI) , the breakers...

Hello everyone, can someone please let me know how to set the settings of a vista protective relay? On what basis is the pick-up, U2 inverse, Instantaneous and the definite time settings selected?