The following update on the power interruptions has been provided by a resident who reported to TECO 10 specific power interruptions that he has experienced and then spoke at length with one of TECO’s electrical engineers.  He notes that each resident is responsible for working with TECO independently and that he did not represent our community, only his specific residence in this matter.

Power Interruption Analysis:

  • TECO has researched all 10 of the specific power interruptions I reported (from April 7 through July 14) and has accounted for 9 of the 10 interruptions. The interruption reported on 06/20 14:14 is not accounted for and could be a local incident.
  • We are located on the TECO circuit based from the station near Citrus Park Mall, it is a 15 mile circuit and includes 2,240 customers. 75% of our circuit is underground, 25% raised/above ground.
  • Of the 9 power interruptions accounted for, all 9 were due to normal safety devices executing on the circuit and all were circuit-wide interruptions.
  • About half of the 9 are attributed to single circuit breaker “blinks” or trips lasting less than 1 second.
  • The other half of the 9 were multiple circuit breaker “blinks”, which occurs as described below to identify and isolate and limit the impacted area. All root causes of these were resolved.

Explanation of the electrical safety/protection system:

  • Every “circuit”, including our 15 mile/2,240 customer circuit, has a single circuit breaker which is acts as an initial protection mechanism. Within any given circuit area there are many “fuses”, our specific circuit has over 500 fuses which aids in isolation and protection.
  • When the circuit breaker on the circuit detects any kind of fault or issue, it “blinks” or turns power off/on, this “detection-off-on” process happens very quickly in nano seconds. If, when power is resumed the fault/issue is still present, it cycles power off/on again, this time for 1 second. If, when power is resumed the fault/issue is still present, the circuit breaker turns the power off until the issue can be identified and resolved. This serves multiple purposes, most importantly being human safety, but also protection of equipment. This process is designed to provide safety and protection while allowing enough time for the system of “fuses” to react to the issue.
  • When a fuse encounters a fault/issue it trips or shuts off the power. These are to isolate any outage to a smaller customer footprint and smaller area, which allows the majority of the circuit customers to retain power.
  • There are also other safety devices he mentioned, lightning arrestor stations, etc. Too many to mention.
  • In general, single “blinks” are not investigated as are considered normal.

Specifics to our area and proactive steps being taken by TECO:

  • Average power interruptions in our are 2-4 per month, with increases during bad weather season and bird nesting seasons.
  • Our circuit falls within or better than the average.
  • Our circuit has not been inspected for a few years since it is performing at or above average.
  • TECO has ordered an inspection of all overhead portions of our circuit, this includes visual inspections and infrared inspections. Any issues identified will be proactively addressed. It will be worked in order of priority, but they anticipate completing it within 1-2 months.