What is the preferred location for lightning arresters installed on underground cable taps off overhead lines?
For years, the standard circuit was: overhead conductor tap -> fused (or solid) cutout -> lightning arrester -> underground cable. That's the way I've always spec'd them.
I guess the idea was that the arrester would continue to protect the cable from lightning even if the cutout was opened. In addition, the cutout fuse would protect the overhead feeder in the event of an arrester failing shorted.
Recently, I observed our local utility (their contractors, actually) connecting these in the following sequence: overhead conductor tap ->
lightning arrester -> fused cutout -> underground cable.
Here, if the cutout is opened, the cable is no longer protected by the arrester. In addition, a shorted arrester must be cleared from the feeder by the station breaker.
We don't get much lightning in the Pacific Northwet, so this isn't as big an issue as in the midwest or southeast. But then, our utility people don't get as much experience in getting this stuff right either. What's everyone's opinion on either way of hooking these up?