{"id":"transformer-dry","version":"0.4.0","classification":{"uniformat":"D5010"},"names":["Transformer, dry-type"],"aliases":["dry type transformer","XFMR","transformer"],"service_life":{"median_years":32,"range_years":[32,32],"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":"Inspect solid insulation for discoloration","frequency":"P6M","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":176,"checklist":"Table 21-3 Secondary system transformers"},{"task":"Inspect forced cooling 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":176,"checklist":"Table 21-3 Secondary system transformers"},{"task":"Test cooling fans by simulating high temperature","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":176,"checklist":"Table 21-3 Secondary system transformers"},{"task":"Verify transformer alarms","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":176,"checklist":"Table 21-3 Secondary system transformers"}],"basis":[{"type":"public_document","life_type":"planning","title":"Energy Conservation Program: Energy Conservation Standards for Distribution Transformers (final rule), 89 FR 29834, April 22, 2024","by":"U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy","url":"https://www.govinfo.gov/content/pkg/FR-2024-04-22/pdf/2024-07480.pdf","page":113,"code":"IV.F.8","label":"Transformer Service Lifetime: \"a distribution of lifetimes, with an estimated average of 32 years and a maximum of 60 years\"","years":32,"note":"Printed page 29946. Covers all distribution transformers, including low-voltage dry-type (building dry-type) and medium-voltage liquid-immersed (pad-mounted). Mean of a distribution; the maximum is 60 years. Same value also stated on p.5 (printed 29838) and in Table IV summary on p.101 (printed 29934)."}],"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/transformer-dry","versioned_url":"https://unfinished.one/c/transformer-dry/v/0.4.0","licence":"CC-BY-4.0","citation":"unfinished.one (2026). Transformer, dry-type, v0.4.0. https://unfinished.one/c/transformer-dry/v/0.4.0"}