Triplex Used As Separate Building Feeder?

[dtontarski]

Is it o.k. to run an overhead triplex cable to a separate building as a feeder for a distribution panel providing that the grounds and neutrals are are not bonded in the distribution panel and a ground rod is installed at the separate building?

The triplex is protected by a double pole breaker in the home's main service panel. (with proper overcurrent protection)

A service entrance cable runs from the main service panel, up the side of the home and connects to the triplex. The triplex then runs through the air from the home to the property's garage, into the garage, across the garage's framing (unprotected) and into the distribution panel.

I've never observed this set-up before and it doesn't seem safe.

I thought 4-conductor feeders (buried) were required.

Please set me right on this.

Thanks,

Dave Tontarski

[Jim Katen]

Is it o.k. to run an overhead triplex cable to a separate building as a feeder for a distribution panel providing that the grounds and neutrals are are not bonded in the distribution panel and a ground rod is installed at the separate building?

That was never ok. Until recently, though, you could use the triplex and connect the grounds & neutrals as long as there weren't any other metallic pathways back to the first building.

The problem with the installation you described is that it depends on the earth to clear a fault. Not a good thing.

The triplex is protected by a double pole breaker in the home's main service panel. (with proper overcurrent protection)

A service entrance cable runs from the main service panel, up the side of the home and connects to the triplex. The triplex then runs through the air from the home to the property's garage, into the garage, across the garage's framing (unprotected) and into the distribution panel.

I've never observed this set-up before and it doesn't seem safe.

The grounding issue aside, the triplex shouldn't be used inside the building. It should transition to something else before it enters the building.

I thought 4-conductor feeders (buried) were required.

Four conductor feeders are required. They don't have to be underground though. You can use a quadraplex cable or you can run above-ground conduit.

- Jim Katen, Oregon

[dtontarski]

Jim -

Thanks for the quick response. Just so I make sure I have this right.

The triplex is o.k. as long as it transitions to something else prior to entering the garage, and the neutrals and grounds should remain bonded and no ground rod should be installed.

Do I have it?

Thanks,

Dave Tontarski

[Speedy Petey]

The triplex is o.k. as long as it transitions to something else prior to entering the garage, and the neutrals and grounds should remain bonded and no ground rod should be installed.

Do I have it?

Yes, other than the fact that a ground rod is always required when a feeder is run to a detached structure.

You need to break from the thinking that ground rods have anything to do with the circuit or feeder grounds. They do not. They serve a completely different purpose.

[dtontarski]

Thanks - got it.

[Jeff Remas]

What code cycle applies?