Reliability is one of the most important aspects we should be focused on especially when it comes to Plant Maintenance. Frequent shutdowns in plant could be caused by poor maintenance management and lack of advance tools to keep the system running. For a plant working 24/7, most of the running equipments should be treated critically and monitored regularly. However, Redundant Systems are used to save the plant from shutdowns if failure occurs. Aside from back-up power we should always thought of back-up systems that will manually or automatically take over the operations in the event of fault or alarm. In this article, I will share with you the redundant systems that I have encountered by working in Maintenance Department and Engineering Design.
Substation
Measurements (CT, PT, and Tore)
This article will discuss about the three common Electrical Measurements we can found in Switchgears and Panel boards. I learned this electrical measurements when I worked with a gas manufacturing plant as a Cadet Engineer. However, this is just few of the measurement devices that we have in the field of Electricity. This article will focus on Current Transformer, Potential Transformer and Tore that are used as metering device. Table of contents 1. Current Transformer 2. Potential or Voltage Transformer 3. Tore or Residual Current Sensor Current Transformer The current transformer makes it possible to reduce a high intensity current to a value of 1A or 5A exploitable by the measurement apparatus and the protection relays. (1A and 5A being standardised values). It includes a primary
Machine Protection
Introduction Overheating of a motor due to an abnormal use shortens considerably the life time of its components and causes short-cuts. Overloads are tolerated only for a limited period of time. Concerning short-cuts, their effects are destructive and they must be quickly cut off. Fault types Internal Faults That type of internal faults generally appears when insulating components areageing. It is then preferable to release the protection as fast as possible. Those faults can be detected by comparing the ongoing and outgoing currents of the same phase. The protection is then provided by an percentage differential overcurrent relay connected to two sets of three current transformers placed on each input and output phases of the stator. Because of the imprecision linked to the TC, the fault current