Planned Outage With a Customer-Owned Generator on the Tap

1. Write down every source. Recloser, both air-break switches, the customer's 400 kW generator, any secondary-side generation behind the customer's service (rooftop solar, a second standby set), and backfeed through transformer banks from the parallel circuit or from downstream. A switching order that misses one source is exactly how this job kills someone.

2. Establish a visible open at each source you control. A recloser status on a SCADA screen is not a visible open. Someone must confirm the switch blades are fully open and tag them. Air-break switches give a visible break only if the blades can actually be seen.

3. Deal with the generator before anything else. A manual transfer switch in a room you have not seen is not a point of isolation. Require the customer's electrician to open it in your presence, apply a utility lock and tag, and place a protective ground on the line side of the switch. If that cannot be confirmed, treat the generator as an energized source feeding your section.

4. Test-before-touch. Prove the detector on a known live source, test phase-to-phase, phase-to-neutral and phase-to-ground on all conductors, then re-prove the detector afterward. A detector reading dead is trustworthy only if it responded correctly after the test.

5. Apply protective grounds - ground end first to the system neutral or a bonded driven ground, conductor end second, with a live-line stick from outside the minimum approach distance. Ground the worksite first so the worker on the pole is inside an equipotential zone, then every open point that can be a source, including the customer side.

6. Barricade, tag, brief the crew on the sources and the parallel circuit before anyone climbs.

A verbal assurance and a locked door prove nothing. The manual transfer switch can be closed by anyone with a key, it may already be closed, and there is no switching record. The only two things that protect you are a visible open and a protective ground between that open and your body.

What I require: the customer's electrician opens the transfer switch while I watch, we confirm the blade position, the utility applies its own lock and tag, and I place a ground on the line side of the switch. That gives me a visible open plus a ground that will take the generator's fault current if someone closes the switch, and it also covers a later closure by the customer.

If the customer refuses access, the answer is not 'proceed carefully.' Options in order:

• Place the protective ground between the transfer switch and the work location anyway, if that ground can actually be reached and applied from outside the MAD. If it can, the customer's switch position stops mattering for the ground's effectiveness.
• If no such ground point exists (the tap leaves the pole and runs onto private property with no accessible switching point), the work is not permitted. Escalate to the supervisor and the account representative, and either negotiate access or move the isolation point so that a visible open and a ground can be established on the utility side.

I would also check whether the customer's service has a bonded neutral that could carry current back onto the primary through a fault, and I would not rely on the customer's ground rod as a return path.

Placement. One ground set at the work location covering all conductors of the section (cluster bar with individual leads, not one lead shared), and grounds at every open point that can be a source - the upstream open, the downstream open and the customer side of the transfer switch. With 1.6 km of isolated conductor running 2 m below another utility's energized 25 kV circuit, induction is real, so the work location ground is mandatory even after the switches are open and tagged; on a section that long, bracket the work with a ground on each side as well.

Capacity. Run the check against the utility grounding table rather than by eye: #2/0 copper at 6,500 A for 12 cycles is comfortably inside the conductor withstand, so the cable is not the limiting item. The weak points are the clamps, the ferrules, the connection to the multi-grounded neutral, and whether the set has been inspected for broken strands. Confirm the clamps accept the conductor size and that the set is within its inspection date; a ground set that looks fine but has a corroded ferrule is a hazard, not protection.

The parallel circuit also changes the work method, not just the grounding. At 60 km/h gusts with ice still on conductors, the clearance between your conductor and the other utility's circuit can close below the minimum approach distance from conductor swing alone. If that clearance cannot be maintained for the duration of the work, stop and arrange for the other utility to de-energize or defer the job. Never treat the other circuit as someone else's problem; it is 2 m from your hands.