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Specialized Energy Construction Services

Non-Segregated Bus Systems

Without any moving parts, the non-segregated bus duct system can be overlooked by operators when it comes to preventative maintenance.

However, with emergency repairs often costing up to five times as much as those made during routine outages (between lost revenue due to the unplanned outage and expedited material cost), the non-seg bus deserves attention.


Polyphenylene oxide (PPO) insulation has been used in non-segregated bus duct by nearly all manufacturers for the last 30-40 years.

Unfortunately, PPO type insulation has a known and documented history of becoming brittle and cracking or degrading over time. Many bus duct failures have been documented as a result of insulation degradation.

Typically, NO preventative or routine maintenance or inspections is performed on bus systems. Even more troubling, bus systems are a critical point for most power plants as there is no redundant backup.

Additionally, plants often uprate for a higher output, but fail to uprate their medium-voltage bus bars, making your BUS an even more critical component.


VISUAL INSPECTION – Assess current status and vulnerability of bus system:

  • Arc tracking and other indicators
  • Cracked and damaged insulation
  • Moisture and debris buildup inside enclosure

PLAN OF ACTION – Preventative Maintenance/Repairs

  • Determine the areas that require re-insulation
  • Remove existing bus bar insulation and replace with TE’s BPTM material on site
  • Replace all bolting hardware and boots
  • Replace cover gaskets and cover hardware if necessary

SE Energy Trailer

Mobile Bus Bar Refurbishing Unit

Our new Mobile Bus Bar Refurbishing Unit was designed specifically to offer insulation replacement on site.

With our expert team mobilized to work on site, we are able to considerably cut down on re-insulation time by more than half.

By improving our efficiency, we’re able to significantly reduce our time and labor.