{"id":"switchgear-lv","version":"0.1.0","classification":{"uniformat":"D5010"},"names":["Switchgear, low voltage"],"aliases":["switchgear","main switchboard","MSB","switchboard"],"service_life":{"median_years":30,"range_years":[25,35],"range_basis":"source_spread"},"pm_tasks":[{"task":"Check warning signs are in place","frequency":"P1Y","reference":"TM 5-692-1 Maintenance of Mechanical and Electrical Equipment at Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities: Recommended Maintenance Practices","url":"https://www.wbdg.org/FFC/ARMYCOE/COETM/tm_5_692_1.pdf","page":173,"checklist":"Table 21-1 Typical secondary distribution maintenance"},{"task":"Inspect enclosure for damage, openings and corrosion","frequency":"P1Y","reference":"TM 5-692-1 Maintenance of Mechanical and Electrical Equipment at Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities: Recommended Maintenance Practices","url":"https://www.wbdg.org/FFC/ARMYCOE/COETM/tm_5_692_1.pdf","page":173,"checklist":"Table 21-1 Typical secondary distribution maintenance"},{"task":"Clear blocked air passages","frequency":"P1Y","reference":"TM 5-692-1 Maintenance of Mechanical and Electrical Equipment at Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities: Recommended Maintenance Practices","url":"https://www.wbdg.org/FFC/ARMYCOE/COETM/tm_5_692_1.pdf","page":173,"checklist":"Table 21-1 Typical secondary distribution maintenance"},{"task":"Investigate unusual odors","frequency":"P1Y","reference":"TM 5-692-1 Maintenance of Mechanical and Electrical Equipment at Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities: Recommended Maintenance Practices","url":"https://www.wbdg.org/FFC/ARMYCOE/COETM/tm_5_692_1.pdf","page":173,"checklist":"Table 21-1 Typical secondary distribution maintenance"},{"task":"Inspect electrical connections for degradation and tightness","frequency":"P1Y","reference":"TM 5-692-1 Maintenance of Mechanical and Electrical Equipment at Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities: Recommended Maintenance Practices","url":"https://www.wbdg.org/FFC/ARMYCOE/COETM/tm_5_692_1.pdf","page":173,"checklist":"Table 21-1 Typical secondary distribution maintenance"},{"task":"Inspect insulation for discoloration","frequency":"P1Y","reference":"TM 5-692-1 Maintenance of Mechanical and Electrical Equipment at Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities: Recommended Maintenance Practices","url":"https://www.wbdg.org/FFC/ARMYCOE/COETM/tm_5_692_1.pdf","page":173,"checklist":"Table 21-1 Typical secondary distribution maintenance"},{"task":"Inspect equipment grounding conductors and connections","frequency":"P1Y","reference":"TM 5-692-1 Maintenance of Mechanical and Electrical Equipment at Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities: Recommended Maintenance Practices","url":"https://www.wbdg.org/FFC/ARMYCOE/COETM/tm_5_692_1.pdf","page":173,"checklist":"Table 21-1 Typical secondary distribution maintenance"},{"task":"Check indicating lights","frequency":"P1Y","reference":"TM 5-692-1 Maintenance of Mechanical and Electrical Equipment at Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities: Recommended Maintenance Practices","url":"https://www.wbdg.org/FFC/ARMYCOE/COETM/tm_5_692_1.pdf","page":173,"checklist":"Table 21-1 Typical secondary distribution maintenance"},{"task":"Clean equipment","frequency":"P1Y","reference":"TM 5-692-1 Maintenance of Mechanical and Electrical Equipment at Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities: Recommended Maintenance Practices","url":"https://www.wbdg.org/FFC/ARMYCOE/COETM/tm_5_692_1.pdf","page":173,"checklist":"Table 21-1 Typical secondary distribution maintenance"},{"task":"Tighten electrical connections","frequency":"P1Y","reference":"TM 5-692-1 Maintenance of Mechanical and Electrical Equipment at Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities: Recommended Maintenance Practices","url":"https://www.wbdg.org/FFC/ARMYCOE/COETM/tm_5_692_1.pdf","page":173,"checklist":"Table 21-1 Typical secondary distribution maintenance"},{"task":"Verify equipment grounding","frequency":"P1Y","reference":"TM 5-692-1 Maintenance of Mechanical and Electrical Equipment at Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities: Recommended Maintenance Practices","url":"https://www.wbdg.org/FFC/ARMYCOE/COETM/tm_5_692_1.pdf","page":173,"checklist":"Table 21-1 Typical secondary distribution maintenance"},{"task":"Infrared scan","frequency":"P1Y","reference":"TM 5-692-1 Maintenance of Mechanical and Electrical Equipment at Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities: Recommended Maintenance Practices","url":"https://www.wbdg.org/FFC/ARMYCOE/COETM/tm_5_692_1.pdf","page":173,"checklist":"Table 21-1 Typical secondary distribution maintenance"},{"task":"Overcurrent test critical-load molded-case breakers","frequency":"P1Y","reference":"TM 5-692-1 Maintenance of Mechanical and Electrical Equipment at Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities: Recommended Maintenance Practices","url":"https://www.wbdg.org/FFC/ARMYCOE/COETM/tm_5_692_1.pdf","page":174,"checklist":"Table 21-2 Low voltage switchgear, switchboards, and panelboards"},{"task":"Contact resistance test critical-load breakers","frequency":"P1Y","reference":"TM 5-692-1 Maintenance of Mechanical and Electrical Equipment at Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities: Recommended Maintenance Practices","url":"https://www.wbdg.org/FFC/ARMYCOE/COETM/tm_5_692_1.pdf","page":175,"checklist":"Table 21-2 Low voltage switchgear, switchboards, and panelboards"},{"task":"Operate each breaker by its handle","frequency":"P1Y","reference":"TM 5-692-1 Maintenance of Mechanical and Electrical Equipment at Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities: Recommended Maintenance Practices","url":"https://www.wbdg.org/FFC/ARMYCOE/COETM/tm_5_692_1.pdf","page":175,"checklist":"Table 21-2 Low voltage switchgear, switchboards, and panelboards"},{"task":"Measure and record neutral currents","frequency":"P1Y","reference":"TM 5-692-1 Maintenance of Mechanical and Electrical Equipment at Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities: Recommended Maintenance Practices","url":"https://www.wbdg.org/FFC/ARMYCOE/COETM/tm_5_692_1.pdf","page":175,"checklist":"Table 21-2 Low voltage switchgear, switchboards, and panelboards"},{"task":"Perform harmonics analysis","frequency":"P1Y","reference":"TM 5-692-1 Maintenance of Mechanical and Electrical Equipment at Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities: Recommended Maintenance Practices","url":"https://www.wbdg.org/FFC/ARMYCOE/COETM/tm_5_692_1.pdf","page":175,"checklist":"Table 21-2 Low voltage switchgear, switchboards, and panelboards"},{"task":"Inspect barriers and shutters","frequency":"P1Y","reference":"TM 5-692-1 Maintenance of Mechanical and Electrical Equipment at Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities: Recommended Maintenance Practices","url":"https://www.wbdg.org/FFC/ARMYCOE/COETM/tm_5_692_1.pdf","page":174,"checklist":"Table 21-2 Low voltage switchgear, switchboards, and panelboards"},{"task":"Test phase bus insulation","frequency":"P1Y","reference":"TM 5-692-1 Maintenance of Mechanical and Electrical Equipment at Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities: Recommended Maintenance Practices","url":"https://www.wbdg.org/FFC/ARMYCOE/COETM/tm_5_692_1.pdf","page":174,"checklist":"Table 21-2 Low voltage switchgear, switchboards, and panelboards"},{"task":"Inspect drawout contacts for wear and discoloration","frequency":"P1Y","reference":"TM 5-692-1 Maintenance of Mechanical and Electrical Equipment at Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities: Recommended Maintenance Practices","url":"https://www.wbdg.org/FFC/ARMYCOE/COETM/tm_5_692_1.pdf","page":174,"checklist":"Table 21-2 Low voltage switchgear, switchboards, and panelboards"},{"task":"Inspect, adjust and lubricate breaker linkages","frequency":"P1Y","reference":"TM 5-692-1 Maintenance of Mechanical and Electrical Equipment at Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities: Recommended Maintenance Practices","url":"https://www.wbdg.org/FFC/ARMYCOE/COETM/tm_5_692_1.pdf","page":174,"checklist":"Table 21-2 Low voltage switchgear, switchboards, and panelboards"},{"task":"Test power breaker trip and close operation","frequency":"P1Y","reference":"TM 5-692-1 Maintenance of Mechanical and Electrical Equipment at Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities: Recommended Maintenance Practices","url":"https://www.wbdg.org/FFC/ARMYCOE/COETM/tm_5_692_1.pdf","page":174,"checklist":"Table 21-2 Low voltage switchgear, switchboards, and panelboards"},{"task":"Insulation resistance test","frequency":"P1Y","reference":"TM 5-692-1 Maintenance of Mechanical and Electrical Equipment at Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities: Recommended Maintenance Practices","url":"https://www.wbdg.org/FFC/ARMYCOE/COETM/tm_5_692_1.pdf","page":174,"checklist":"Table 21-2 Low voltage switchgear, switchboards, and panelboards"},{"task":"Calibrate protective devices","frequency":"P1Y","reference":"TM 5-692-1 Maintenance of Mechanical and Electrical Equipment at Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities: Recommended Maintenance Practices","url":"https://www.wbdg.org/FFC/ARMYCOE/COETM/tm_5_692_1.pdf","page":175,"checklist":"Table 21-2 Low voltage switchgear, switchboards, and panelboards"}],"basis":[{"type":"public_document","life_type":"design","title":"Design standards: employer's requirements – Technical Manual (ER-DFE-XX-XX-T-X-0201, revision A-C01)","by":"Department for Education (England)","url":"https://assets.publishing.service.gov.uk/media/6971f649d8adeaf266040501/ER-DFE-XX-XX-T-X-0201-Technical_Manual-A-C01.pdf","page":275,"code":"5.7.4","label":"Low voltage (LV) main switchgear and switchboards: 35 years","years":35,"note":"Printed page 275. LV main switchgear and switchboards. Minimum life expectancy (design requirement) for DfE-funded school buildings. Minimum design requirements placed on contractors for school buildings, not observed replacement ages. Section 5.1.4 (sanitaryware) refers to CIBSE Guide M Appendix 12.A1 'in general'."},{"type":"public_document","life_type":"accounting","title":"General depreciation rates (IR265), July 2021","by":"Inland Revenue (Te Tari Taake), New Zealand","url":"https://www.ird.govt.nz/-/media/project/ir/home/documents/forms-and-guides/ir200---ir299/ir265/ir265-2021.pdf","page":34,"code":"POWR","label":"Switchgear","years":25,"note":"Printed page 34. Power generation and electrical reticulation category; voltage not stated (network switchgear, which includes low voltage). Printed DV 8%, SL 6%. Tax depreciation lives set by the Commissioner of Inland Revenue for New Zealand income tax, not engineering or asset-management lives; they are banded and often short (e.g. reticulation piping 25 years). The July 2021 edition was the newest PDF reachable; the online Depreciation Rate Finder may hold later determinations."}],"confidence":{"grade":"C","sample_size":null},"open_questions":["Every source here is a published planning, design or accounting life. None is observed replacement data.","Some maintenance intervals come from TM 5-692-1, an Army manual for mission-critical (C4ISR) facilities; they may be tighter than typical commercial practice."],"contributors":["unfinished.one editors"],"last_reviewed":"2026-10-22","canonical_url":"https://unfinished.one/c/switchgear-lv","versioned_url":"https://unfinished.one/c/switchgear-lv/v/0.1.0","licence":"CC-BY-4.0","citation":"unfinished.one (2026). Switchgear, low voltage, v0.1.0. https://unfinished.one/c/switchgear-lv/v/0.1.0"}