What is the consensus regarding the testing of variable fault interrupters (VFI)?

Our shop was having a discussion regarding the testing of a VFI today, and it brought up a good question. NETA does not have a section for VFIs so our guys will test them as medium volt vacuum/SF6 switches. The disagreement comes when talking about the fault interruption system. Some say you should test the controller either by primary injection to test the CTs/times & pickups, or testing of relays such as a SEL 751. Some say since its not in NETA, its not a requirement to test the controller at all. What do you think and why?

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Well, VFI’s are merely a combination of equipment. Switches, CT’s, and relays. Are people really looking for a “VFI” section? VFI’s must be setup and tested. This is a new one to me. I’m not going to test a VFI because it’s not in NETA, yet every component that makes up a VFI is listed specifically in NETA.

Don’t take this as an attack on you personally, I just don’t understand the logic.

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We are working with some G&W Gas Insulated Switches (6-Ways) that have VFI’s. After calling the manufacturer and speaking with a technical support person, we were told: Overpotential Test, Megger, Contact Resistance Test, and Primary Injection to prove VFI (CT;s, CT Secondary Wiring to Relay, Relay Trip to VFI).