What is the operating life of the fiber optical current transformer? Is optical fiber exposed to aging?EFOCT sensing fiber element: hard case
There are no fundamental physical reasons for aging of the fiber. It can occur as a result of technology damages of the fiber's protection from external environment (including water penetration inside the construction of the optical fiber) and violation of the operating conditions (for example, unacceptable mechanical tension of the fiber). Degradation of the fiber's parameters, such as increased loss of optical radiation in the fiber (fogging), can be viewed as an aging indicator. To exclude the influence of such losses on the precision and stability of measurements we use the method of optical interferometer, which guarantees a low dependence on the value of optical attenuation of the fiber.
The problem of mechanical fracture of the fiber is eliminated using the unique technology of fiber laying with "zero tension". This technology was developed by PROFOTECH in the process of the optical instrument transformers construction and is considered commercial classified information.
The problem of moisture impact on the fiber's optical characteristics has been solved long ago, since using modern-day polymeric coatings (cable housings) and different types of hydrophobic fillers allows laying the optical cables even under deep water – and the operating life would still be estimated at decades.
The cables do not contain any metal or other conducting elements and have advanced dielectric characteristics.
EFOCT flexible sensing fiber element
The built-in online diagnostic system is very important for long-time work of the optical instrument transformers and condition monitoring of the fiber current transformers. The diagnostic monitoring consists of constant real-time measuring of nearly 20 EFOCT's status parameters, comparing the received values to maximum permissible ones, and output of the data about the state of the device's modules to the metrics of the flow measuring quality by IEC 61850-9-2, to the electronic processing unit's display (once every second), and to the LED indicators on the device's panel. It is possible to transmit the data to be monitored by external diagnostic systems.
Online monitoring of the transformer's working capacity is provided by the diagnostic port, which can work in remote diagnostics mode, or by creating an overall working capacity status by the IEC 61850-8-1 standard.