{"id":6068,"date":"2026-09-06T10:35:38","date_gmt":"2026-09-06T07:35:38","guid":{"rendered":"https:\/\/aesinn.com\/trafo-ve-guc-sistemleri\/orta-ve-yuksek-gerilim-salt-tesisi-hucre-periyodik-kontrolu\/"},"modified":"2026-09-06T11:44:36","modified_gmt":"2026-09-06T08:44:36","slug":"orta-ve-yuksek-gerilim-salt-tesisi-hucre-periyodik-kontrolu","status":"publish","type":"page","link":"https:\/\/aesinn.com\/en\/trafo-ve-guc-sistemleri\/orta-ve-yuksek-gerilim-salt-tesisi-hucre-periyodik-kontrolu\/","title":{"rendered":"Periodic Inspection of Medium and High Voltage Switchgear (Cell)"},"content":{"rendered":"<h2 class=\"wp-block-heading\">Why is the periodic inspection of MV\/MV switchgear critical?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Medium voltage (MV) and high voltage (HV) switchgear facilities are installations that perform switching, protection, and measurement functions at the distribution and transmission points of electrical energy. The energy continuity of a business largely depends on the healthy operation of these cells; a circuit breaker failing to open, an incorrectly positioned disconnect switch, or a faulty protection relay can lead to both significant financial losses and serious occupational safety risks.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Contact wear, loose connections, insulation degradation, gas pressure loss, or deviations in protection settings that occur over time in switchgear cells are often not visible to the naked eye. Therefore, periodic inspections of the facility based on measurements and tests are both a legal obligation and a fundamental maintenance discipline that prevents malfunctions.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Periodic inspections aim to demonstrate, through objective data, that the facility is currently operating safely and as intended, and to report potential vulnerabilities at an early stage.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Included Equipment: What is Checked in the Cell?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">MV\/MV switchgear inspection encompasses not just a single device, but the entire interconnected switching and protection chain within the switchgear. The following main pieces of equipment are evaluated, primarily metal-clad and metal-enclosed switchgear:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n\n<li>Cutting devices (vacuum, SF6, etc.) and on\/off mechanisms.<\/li>\n\n\n<li>Disconnectors and load disconnectors<\/li>\n\n\n<li>Current and voltage (measuring) transformers<\/li>\n\n\n<li>Busbars, connections and conductor systems<\/li>\n\n\n<li>Protection relays and control circuits<\/li>\n\n\n<li>Grounding system and grounding disconnectors<\/li>\n\n\n<li>Mechanical and electrical interlocking systems<\/li>\n\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Legal Basis and Current Legislation<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">In T\u00fcrkiye, the periodic inspection of work equipment is regulated under the Regulation on Health and Safety Conditions in the Use of Work Equipment (Official Gazette dated 25.04.2013 and numbered 28628). This Regulation was updated with amendment number 33116 dated 23.12.2025. Electrical installations and the switchgear equipment included in these installations are also subject to periodic inspection obligations.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">With this change, periodic inspections are handled within the framework of the &quot;equipment inspection organization&quot; definition; and contract registration is required via the OHS-KATIP system prior to the inspection (at the latest one day in advance). The transitional provisions regarding T\u00dcRKAK&#039;s accreditation under TS EN ISO\/IEC 17020 are based on the date of 1\/1\/2027. Since the details of the legislation&#039;s implementation may be updated over time, we recommend confirming the latest text in effect before the inspection.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For MV\/MV installations, the Electrical Power Installations Regulation and the Grounding in Electrical Installations Regulation are also directly relevant; these regulations determine the criteria for the design, operation, and grounding conditions of the installation.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Items Tested During Inspection: Mechanical and Electrical Inspections<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Periodic inspections of switchgear begin with visual inspection and are deepened with measurement tests. The aim is to evaluate both the physical\/mechanical integrity of the cell and its electrical performance. The main checks performed are as follows:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n\n<li>Visual inspection: check for contamination, corrosion, loose connections, mechanical damage, and labeling.<\/li>\n\n\n<li>Detection of hot spots and overheated junctions via thermographic (infrared) imaging.<\/li>\n\n\n<li>Cutting machine mechanical operation and on\/off timing measurements.<\/li>\n\n\n<li>Contact resistance measurement<\/li>\n\n\n<li>Insulation resistance measurement<\/li>\n\n\n<li>Functional verification of interlocking schemes.<\/li>\n\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Protective Relays and Secondary Injection Tests<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Protection relays are critical components that protect both equipment and personnel by activating the circuit breaker at the right time and under the right conditions in the event of a malfunction. Shifting relay settings over time or incorrect coordination are as dangerous as the protection not working at all.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">During periodic inspections, the setpoints, characteristic curves, and tripping behavior of the protective relays are evaluated. This evaluation includes secondary injection tests to verify whether the relay responds as expected under signals similar to real-world conditions. The holistic function of the relay-breaker chain and protection coordination are considered together.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Grounding and SF6 Gas Controls<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Grounding is the fundamental safety barrier in MV\/MV installations that keeps touch and step voltages within safe limits. During inspections, grounding continuity and grounding resistance are measured; the integrity of the grounding network connections to the equipment is verified. These assessments are carried out within the framework of the Regulations on Grounding in Electrical Installations and related standards.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In SF6 insulated equipment, gas pressure and, if present, density gauges are checked; early detection is important as pressure loss directly affects insulation and extinguishing capability. These checks are evaluated in conjunction with the equipment manufacturer&#039;s instructions and relevant standards.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n\n<li>TS EN 62271 series (high voltage switching and control devices \u2014 circuit breakers, disconnectors, switchgear)<\/li>\n\n\n<li>IEC\/EN 61936-1 (AC high-voltage installations above 1 kV)<\/li>\n\n\n<li>EN 50522 (Earthing in installations above 1 kV)<\/li>\n\n\n<li>TS EN 62271-1 \/ TS EN 60694 (general requirements)<\/li>\n\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Inspection Period and Who Should Do It<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Under the Work Equipment Regulation, the general approach for electrical installations and equipment is periodic inspection at least once a year, unless otherwise specified. However, the exact period may vary depending on the type of equipment, operating conditions, manufacturer&#039;s instructions, and relevant standards. In facilities with critical or severe operating conditions, more frequent inspections may be required as a result of risk assessment. Therefore, it would not be correct to claim a single, unchanging period; the period should be determined on a facility-specific basis.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Electrical periodic inspections are carried out by a qualified electrical engineer using appropriate measuring devices and methods compliant with relevant standards. Following the inspection, an inspection report is prepared containing the findings, measurement values, and evaluation.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">AES Innovation&#039;s Competence<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">AES Innovation is a Type A Inspection Body accredited by T\u00dcRKAK under TS EN ISO\/IEC 17020, and its accreditation area covers electrical installation inspections (6.1 Electrical Installations). Our expertise in periodic electrical inspections, particularly grounding measurements and thermographic examinations, naturally extends to the evaluation of MV\/HV switchgear installations.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">These types of inspections are advanced examinations requiring expertise in electrical engineering. AES Innovation conducts these inspections impartially, in accordance with relevant legislation and standards, using qualified electrical engineers, and presents the findings in a traceable inspection report.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Closing and Information Note<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Periodic inspections of medium\/high voltage switchgear are one of the most effective ways to maintain energy continuity and fulfill occupational safety obligations. A regular, measurement-based, and reported inspection approach prevents failures and extends the lifespan of the facility.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Information note: The content on this page is for general informational purposes only and does not constitute binding opinions, commitments, or engineering\/legal advice. Since regulatory texts are subject to update, the latest regulations and standards in effect, as well as facility-specific conditions, should always be considered in practice. You can contact AES Innovation for the appropriate inspection scope and period for your facility.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Related Services<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n\n<li><a href=\"https:\/\/aesinn.com\/en\/trafo-ve-guc-sistemleri\/\">Transformers and Power Systems<\/a><\/li>\n\n\n<li><a href=\"https:\/\/aesinn.com\/en\/test-ve-olcum-hizmetleri\/termografik-kamera-ile-sicaklik-olcumu\/\">Thermography<\/a><\/li>\n\n\n<li><a href=\"https:\/\/aesinn.com\/en\/topraklama-sistemleri\/kacak-akim-rcd-testleri\/\">Residual Current RCD<\/a><\/li>\n\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Frequently Asked Questions<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">How often should periodic inspections of MV\/MV switchgear be carried out?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Under the Work Equipment Regulation, the general approach is at least one inspection per year unless otherwise specified. However, the exact period may vary depending on the type of equipment, operating conditions, manufacturer&#039;s instructions, and risk assessment. More frequent inspections may be required in critical facilities; the period should be determined on a facility-specific basis.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">What equipment is evaluated in switchgear cell inspection?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Circuit breakers, disconnectors and load disconnectors, current\/voltage measuring transformers, busbars and connections, protection relays, grounding systems, and mechanical and electrical interlocking devices are evaluated.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">What standards are used in the inspection?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The main standards used are TS EN 62271 series (high-voltage switching and control devices), IEC\/EN 61936-1 (high-voltage installations above 1 kV) and EN 50522 (earthing above 1 kV), as well as the general requirements TS EN 62271-1 \/ TS EN 60694. Relevant national regulations are also taken into consideration.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">What is a secondary injection test and why is it necessary?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The secondary injection test is a verification test that applies signals similar to real-world conditions to the protective relay to confirm whether the relay responds as expected according to its set values. It is critical because it confirms that the protection is activated at the correct time and under the correct conditions.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Who can conduct the check?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Electrical periodic inspections are carried out by a qualified electrical engineer using appropriate measuring devices and methods compliant with relevant standards. A comprehensive inspection report is prepared containing the findings and measurement values.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">What impact did the legislative change of December 23, 2025 have?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Amendment number 33116, dated 23.12.2025, updated the Work Equipment Regulation; periodic inspections are handled within the framework of &quot;equipment inspection organizations,&quot; contract registration is required via ISG-KATIP prior to the inspection (at the latest one day in advance), and the transition to T\u00dcRKAK 17020 accreditation is based on the date of 1\/1\/2027. Confirmation of the updated text prior to the inspection is recommended.<\/p>","protected":false},"excerpt":{"rendered":"<p>Orta ve y\u00fcksek gerilim \u015falt h\u00fccreleri, i\u015fletmenin can damar\u0131d\u0131r ve ar\u0131za halinde hem g\u00fcvenlik hem s\u00fcreklilik a\u00e7\u0131s\u0131ndan ciddi risk ta\u015f\u0131r. Bu sayfada OG\/YG \u015falt tesislerinin periyodik kontrol\u00fcnde nelerin test edildi\u011fini, hangi mevzuat ve standartlar\u0131n esas al\u0131nd\u0131\u011f\u0131n\u0131 ve kontrol\u00fcn kim taraf\u0131ndan yap\u0131lmas\u0131 gerekti\u011fini tarafs\u0131z bir dille a\u00e7\u0131kl\u0131yoruz.<\/p>","protected":false},"author":1,"featured_media":6071,"parent":2527,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"_kad_blocks_custom_css":"","_kad_blocks_head_custom_js":"","_kad_blocks_body_custom_js":"","_kad_blocks_footer_custom_js":"","_kadence_starter_templates_imported_post":false,"_kad_post_transparent":"","_kad_post_title":"","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"_kad_post_classname":"","slim_seo":{"title":"MV\/HV Switchgear (Cell) Periodic Inspection","description":"Periodic inspection of medium and high voltage switchgear (cell, circuit breaker, disconnect switch, protection): legal basis, tested elements, standards and period."},"_pplb_hide_from_list":false,"footnotes":""},"class_list":["post-6068","page","type-page","status-publish","has-post-thumbnail","hentry"],"acf":[],"taxonomy_info":[],"featured_image_src_large":["https:\/\/aesinn.com\/wp-content\/uploads\/aes-og-salt-2026-1024x1024.png",1024,1024,true],"author_info":{"display_name":"Emre Metin","author_link":"https:\/\/aesinn.com\/en\/author\/yonetim\/"},"comment_info":"","_hostinger_reach_plugin_has_subscription_block":false,"_hostinger_reach_plugin_is_elementor":false,"_links":{"self":[{"href":"https:\/\/aesinn.com\/en\/wp-json\/wp\/v2\/pages\/6068","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/aesinn.com\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/aesinn.com\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/aesinn.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/aesinn.com\/en\/wp-json\/wp\/v2\/comments?post=6068"}],"version-history":[{"count":4,"href":"https:\/\/aesinn.com\/en\/wp-json\/wp\/v2\/pages\/6068\/revisions"}],"predecessor-version":[{"id":6091,"href":"https:\/\/aesinn.com\/en\/wp-json\/wp\/v2\/pages\/6068\/revisions\/6091"}],"up":[{"embeddable":true,"href":"https:\/\/aesinn.com\/en\/wp-json\/wp\/v2\/pages\/2527"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/aesinn.com\/en\/wp-json\/wp\/v2\/media\/6071"}],"wp:attachment":[{"href":"https:\/\/aesinn.com\/en\/wp-json\/wp\/v2\/media?parent=6068"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}