MV Switchgear — Live-Cleaned, Insulation Resistance Improved
Three medium-voltage switchgear panels at a distribution facility cleaned live. Insulation resistance improved across all three. Zero shutdown.
Three medium-voltage switchgear panels at a distribution facility cleaned live. Insulation resistance improved across all three. Zero shutdown.
The brief
A distribution facility had been deferring its switchgear cleaning maintenance for two years because the only window for shutdown was a planned outage that kept getting pushed. Dust accumulation on insulators and busbars was reaching levels that the reliability engineer was uncomfortable with.
The ask: clean the equipment without shutdown. The site had an existing safety case for live cleaning of LV equipment, but had never extended to MV. We worked with the asset owner’s electrical authority to develop the procedure and run the work.
The work
We approached this the way we approach every live electrical job — slowly and with extensive risk assessment.
Pre-work. Site walk-through with the asset owner and electrical authority. Risk assessment, safety case extension to cover MV with our specific equipment and procedure. PPE requirements: arc-rated suits, face shields, voltage-rated gloves, hot-stick technique for any contact with the panel.
IR baseline. Insulation resistance test on each of the three panels before any cleaning. Recorded for handover.
Cleaning. Pellet feed at low pressure (60-70 PSI) — much lower than industrial cleaning. Worked from top of each panel down, with a 60-degree spread nozzle. Particulate captured by a HEPA-filtered vacuum positioned at the base of each panel.
IR retest. Insulation resistance test after each panel. All three panels showed measurable improvement in IR — typical when accumulated dust has been carrying surface conductivity.
Documentation. Per-panel photo log, IR test sheets, and cleaning record signed by the asset owner’s representative.
The result
- All three panels cleaned in a single day
- Zero shutdown of the facility’s MV system
- IR readings typically improve across cleaned panels (8-15% improvement is a representative range)
- Safety case formally extended to cover annual MV switchgear cleaning under the site’s electrical authority
Sites that adopt live-cleaned MV switchgear in their reliability schedule typically move from ad-hoc cleaning during deferred outages to scheduled annual cleaning across all switchrooms — the procedure itself doesn’t change, only the cadence. The harder part is always the first safety-case extension; once that’s signed, every subsequent panel is process repetition.
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About this scenario. Dry Ice Blasters launched in 2026. This piece illustrates how a typical electrical equipment cleaning job runs — drawn from industry-standard work patterns, our team's prior operator experience and equipment specs. Process, scope and outcomes reflect what you can expect when you book us. Be our first published customer and we'll document your job with permission.