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Midstates Energy

Can you overlook an Important repair needed on a bus duct system?

As power plants age, there can be problems in the plant’s bus duct system that may go unnoticed, as certain problems can occur slowly that are easily overlooked. On an Isolated Phase Bus system, for example, there are no moving parts, and everything may seem just fine — until it suddenly trips. Or there’s a phase-to-ground short that creates arching, which can destroy critical parts. 

Here are things to look for on an aging bus duct system:

– HEAT: The system is running warmer than it used to, or you’re noticing hot spots, discoloration of painted surfaces or discoloration of bolted connections. These symptoms could be indications of dust or dirt accumulating inside and causing more leakage current across the insulators. This can result in heat generation inside the system.  This problem can also cause heating of the grounding system, which may be seen on the grounding points of the bus steel that can get discolored and warm to the touch. You may also notice heat being generated where the transition boxes are attached to the transformer turrets. This happens as the insulating hardware ages and allows stray currents to bleed across, causing heat.

– WEAR: Connection points from bus to auxiliary systems are flex links that have a lifespan and can wear out. Vibrations from a generator, excessive moisture in system, loose bolting hardware, sagging and settling of bus system all can impact the flex links lifespan.  Our teams have seen numerous incidents in which these links have caused system shorts, resulting in plant trips and damage.   

– ENCLOSURE COVERS: Look for are warmer than usual heat on the enclosure covers near the flex locations, and movement or misalignment of covers on bus system, possibly due to settling of bus system support steel.
These are just a few of the indicators of trouble spots that when missed, could lead to damage and downtime. Get your bus system inspected by professionals who know what to look for. Contact MidStates Energy for an inspection today.