Seeing three rain-related trips on Feeder 12 in 48 hours, we traced one to a hot dead-end shoe; IR delta was 27°C at 2 pm and the tongue lug measured about 15 ft‑lb under spec. I’m tightening our night-call protocol — IR sweep on cutouts/arresters for the last two spans, torque verification on any suspect hardware, and positive protective grounding before any close — how are you structuring your pre-energization checks to stop the reclose-and-trip cycle?
We killed repeat rain trips on a 12 kV by re-dressing the arrester and cutout leads so there’s a pronounced ‘drip loop’ below the lug after torqueing; it breaks the water path and stopped the tracking. It won’t fix a cracked skirt, but it’s been our fastest field cure.
On a similar 12 kV, we chased a rain trip to a dead‑end shoe that looked fine on patrol; the IR showed a ‘27°C’ delta mid‑afternoon like yours. After torqueing to spec, we pulled the tongue, burnished the contact, smeared a thin coat of oxide inhibitor, and cold‑shrunk a short boot over the shoe/lug to break the water path — no repeats through two storms. If the shoe face is pitted or the tongue’s got hairline cracks, don’t clean it — swap the hardware.