{"id":5705,"date":"2021-10-28T04:10:20","date_gmt":"2021-10-28T10:10:20","guid":{"rendered":"https:\/\/limblecmms.com\/?p=5705"},"modified":"2025-05-30T13:06:06","modified_gmt":"2025-05-30T19:06:06","slug":"fault-detection","status":"publish","type":"post","link":"https:\/\/limblecmms.com\/blog\/fault-detection\/","title":{"rendered":"Fault Detection And Diagnostics In Equipment Maintenance"},"content":{"rendered":"

[vc_row kd_background_image_position=”vc_row-bg-position-top”][vc_column][vc_column_text]Understanding equipment failures<\/span><\/a> and developing strategies to detect and diagnose them is one of the key elements of equipment maintenance.\u00a0<\/span><\/p>\n

The purpose of this article is to present an overview of Fault Detection and Diagnostics as they are applied to improve the equipment maintenance process and boost asset reliability.\u00a0<\/span><\/span><\/p>\n

The story behind fault detection and diagnostics<\/span><\/h2>\n

In the early days, equipment maintenance was restricted to repairing faulty assets and performing basic <\/span>routine maintenance<\/span><\/a> based on rigid time intervals. Maintenance professionals couldn\u2019t have been more proactive even if they wanted to. Their capability to collect, store and analyze data on equipment health and performance was simply too limited.\u00a0<\/span><\/p>\n

However, due to consistent advancements in microprocessor-based controls, automation, real-time data acquisition, and systems like Fault Detection and Diagnostics (FDD), the way in which we <\/span>perform equipment maintenance<\/span><\/a> has been significantly transformed.\u00a0<\/span><\/p>\n

FDD in equipment maintenance<\/span><\/h2>\n

The objective of Fault Detection and Diagnostics in the context of equipment maintenance is to <\/span>optimize maintenance costs<\/span><\/a> while still improving the reliability, availability, maintainability and safety (<\/span>RAMS<\/span><\/a>) of the equipment.\u00a0<\/span>
\n<\/span>
\nThe FDD functions by continuously monitoring and analyzing condition monitoring data and detecting any anomalies (if present). The equipment condition datasets are then processed by fault diagnostics algorithms, sometimes embedded within the equipment itself, to produce failure alerts for the equipment operators and enable timely maintenance intervention.\u00a0<\/span><\/p>\n

In some cases, the algorithms are sophisticated enough to even initiate failure containment actions to auto-correct the failure itself and restore the equipment to its healthy condition.<\/span>[\/vc_column_text][\/vc_column][\/vc_row][vc_row content_placement=”middle” kd_background_image_position=”vc_row-bg-position-bottom” kd_top_separator_style=”skew-left” kd_top_separator_height=”separator-height-small” kd_bottom_separator_style=”skew-left” kd_bottom_separator_height=”separator-height-small” kd_top_separator=”true” kd_bottom_separator=”true” css=”.vc_custom_1682969636891{margin-bottom: 40px !important;padding-top: 120px !important;padding-right: 40px !important;padding-bottom: 50px !important;padding-left: 40px !important;background: #dde4e8 url(https:\/\/limblecmms.com\/wp-content\/uploads\/cta-laired-hex-4.webp?id=9077) !important;background-position: center !important;background-repeat: no-repeat !important;background-size: cover !important;border-radius: 0px !important;}” css_tablet_landscape=”.vc_custom_1682969636891{padding-bottom: 80px !important;}” css_tablet_portrait=”.vc_custom_1682969636891{padding-bottom: 80px !important;}” css_mobile=”.vc_custom_1682969636892{padding-bottom: 80px !important;}”][vc_column][vc_row_inner kd_background_image_position=”vc_row-bg-position-top”][vc_column_inner]

The Essential Guide to CMMS<\/h2>
The Essential Guide to CMMS<\/h6><\/header>[\/vc_column_inner][\/vc_row_inner][vc_row_inner content_placement=”top” kd_background_image_position=”vc_row-bg-position-top”][vc_column_inner width=”1\/2″ css=”.vc_custom_1631866454223{padding-right: 50px !important;padding-left: 0px !important;}” offset=”vc_col-lg-6 vc_col-md-12 vc_col-xs-12″ css_tablet_landscape=”.vc_custom_1631866454223{padding-right: 0px !important;}” css_tablet_portrait=”.vc_custom_1631866454223{padding-right: 0px !important;}” css_mobile=”.vc_custom_1631866454224{padding-right: 15px !important;}”][vc_raw_html]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[\/vc_raw_html][\/vc_column_inner][vc_column_inner width=”1\/2″][vc_single_image source=”external_link” alignment=”center” css_animation=”fadeIn” custom_src=”https:\/\/3975608.fs1.hubspotusercontent-na1.net\/hubfs\/3975608\/Content%20Downloads\/CMMS%20Guide%20mockup.png”][\/vc_column_inner][\/vc_row_inner][\/vc_column][\/vc_row][vc_row kd_background_image_position=”vc_row-bg-position-top”][vc_column][vc_column_text]<\/p>\n

Key elements of the fault detection and diagnostics system\u00a0<\/span><\/h2>\n

The FDD, as the name implies, contains the detection and diagnosis of equipment failures. The diagnosis of the failure can be broken down into failure isolation and identification.\u00a0<\/span><\/p>\n

The failure evaluation is often added within the scope of FDD as it helps to understand the severity of failure on system performance – an important aspect of <\/span>maintenance management<\/span><\/a>.\u00a0<\/span><\/span><\/p>\n

Nevertheless, the Fault Detection and Diagnostics algorithm for any equipment should contain at least the four key processes listed below (these can constitute a nonlinear process as well, provided that some steps happen at the same time):<\/span><\/p>\n

\"Key<\/p>\n

We need to discuss each element in more detail to really understand how fault detection and diagnostics work.<\/span><\/p>\n

1. Fault detection<\/span><\/h2>\n

Fault detection is the process of discovering the presence of a fault in any equipment before it manifests itself in the form of a breakdown. It is the most important stage of FDD as all of the downstream processes depend on its accuracy.\u00a0<\/span><\/p>\n

If the equipment is unable to discover the right failure mode (or if detection is incorrect and triggers false alarms), then the isolation, identification and evaluation will also be ineffective.\u00a0<\/span><\/p>\n

There are two main approaches to fault detection:<\/span><\/p>\n

    \n
  1. Model-based fault detection: <\/b>It is carried out through mathematical modelling of signals and processes.\u00a0<\/span><\/li>\n
  2. Knowledge-based fault detection:<\/b> It is a method that leverages historical data on equipment performance.\u00a0<\/span><\/li>\n<\/ol>\n

    Model-based fault detection<\/span><\/h3>\n

    In model-based detection, we define a set of engineering rules that are written in line with physical laws that define the relationships of subsystems and components within the equipment. Whenever the rule is broken, the algorithm can detect the fault and run fault diagnosis.\u00a0<\/span><\/p>\n

    One example of model-based fault detection is the use of <\/span>time-domain reflectometry (TDR)<\/span><\/a> to detect faults in underground cables. In TDR, the signal is sent across the test cable and is received after being reflected from the point of fault.\u00a0<\/span><\/p>\n

    If the cable has a discontinuity or high impedance, the portion of the signal will be reflected back to the test equipment or receiver. By analyzing the return-of-signal time and the reflected signal\u2019s velocity, the test equipment can detect the nature of faults in the cable as either an open-circuit fault or a short circuit fault.\u00a0<\/span><\/p>\n

    Another simple rule-based detection example comes from the series operation of bottle filling, capping, and packaging system on a conveyor belt system. A simple rule can be established that indicates the hierarchy of processes such as:<\/span><\/p>\n