{"id":"transformer-pad-mounted","version":"0.1.0","classification":{"uniformat":"D5010"},"names":["Transformer, pad-mounted liquid-filled"],"aliases":["pad mount transformer"],"service_life":{"median_years":31,"range_years":[30,32],"range_basis":"source_spread"},"pm_tasks":[],"basis":[{"type":"public_document","life_type":"planning","title":"CNA e-Tool Estimated Useful Life Table","by":"U.S. Department of Housing and Urban Development","url":"https://www.hud.gov/sites/documents/eul_for_cna_e_tool.pdf","page":3,"code":"HUD CNA 3.2.8.2.3","label":"Transformer","years":30,"note":"Same life for family and elderly properties. US multifamily housing. HUD's row is a site electric utility transformer."},{"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.","No preventive maintenance tasks are sourced yet."],"contributors":["unfinished.one editors"],"last_reviewed":"2026-10-21","canonical_url":"https://unfinished.one/c/transformer-pad-mounted","versioned_url":"https://unfinished.one/c/transformer-pad-mounted/v/0.1.0","licence":"CC-BY-4.0","citation":"unfinished.one (2026). Transformer, pad-mounted liquid-filled, v0.1.0. https://unfinished.one/c/transformer-pad-mounted/v/0.1.0"}