All Member Open Forum

Is there a formula to capture the cost of an electrical failures?
If we constantly lose power at a facility, what is the toll on electrical/electronic equipment?

Gary

That is a tough question - especially as we know that there is an impact.  In fact, I am in the field this week working on this specific problem as part of a larger study related to the impact of grid/local grid power quality on plant equipment (and internal power quality).  What we do know is that outages provide a significant shock on electrical/electronic/mechanical equipment and systems - yes, I know, vague.  What we also know is that in the USA right now this is minor compared to other power quality issues such as over/under voltage, sags/swells, harmonics (major impact), voltage unbalances, ground/neutral voltages and currents (including harmonic content), impulses (spikes and 'lightning strikes'), power factor (apparent and true), and a few other concerns.

In one facility we identified two large soft starts for compressors that failed as a direct result of incoming power quality.  Most metering and relays ignore harmonic content (newer smart meters can, if configured correctly) and also over/under voltages and unbalanced plant loading.  In this case, daily over-voltages and extreme voltage unbalances at the PCC without internal plant power conditioning caused at least the two larger controls (soft starts) to fail.  Tests on machines (on and off-line) identified latent failures.  Unfortunately, most of the peer-reviewed work in this area has been limited to individual equipment impact and very little on plant-wide equipment.

The impact of repetitive outages will primarily relate to something called 'latent' faults.  This is damage to systems and equipment that does not immediately appear.  For instance, the high gas prices that hit us in the mid-west in 2010-ish was the direct result of an outage of a petro-chem plant in Illinois following a summer storm lightning strike.  Two large (20,000 hp synchronous and 7000 hp induction) motors were damaged - latent from the lightning strike and then catastrophically from the second outage related to the storm (power on, off then on again - including phases combining during a second strike).  It took us weeks to repair one and find a temporary replacement for the other.  However, there were other considerations including the poor maintenance practices on the motors that reduced their resistance to the condition and the lack of tests on lightning arrestors (failed on both machines).

We expect the draft of the paper that we are working on should be out in 2024.  In the meantime, a solid electrical and mechanical reliability program will identify most changes (other than electronic) to the condition of equipment.  If the relationship between the power issue and changes to equipment condition can be established then the business case between the utility and company (or company's insurance) can usually be managed.  We were able to do so in the case of the soft starts and the two motors (except for my darned gas bill).

Here is a reference to an IEEE paper on the topic: Summary of the economic impacts of power quality on consumers | IEEE Conference Publication | IEEE Xplore  with the citation: S. Elphick, P. Ciufo, V. Smith and S. Perera, "Summary of the economic impacts of power quality on consumers," 2015 Australasian Universities Power Engineering Conference (AUPEC), Wollongong, NSW, Australia, 2015, pp. 1-6, doi: 10.1109/AUPEC.2015.7324875.

Is there a formula to capture the cost of an electrical failures?
If we constantly lose power at a facility, what is the toll on electrical/electronic equipment?