Corpus sync: neutrality remakes, note hygiene, datasheet relocation, transformer-split cross-refs
---
title: Selective Electrical Demolition
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description: >
When to use: Planned, sequenced removal, abandonment-in-place, capping, temporary support, and relocation of existing 0-600/1000 V electrical systems within a defined limit-of-work boundary on renovation, tenant improvement, adaptive reuse, occupied-building phased, and systems-replacement projects. Covers pre-demolition hazard assessment (arc flash, energized work permit, lockout/tagout sequence), deenergization verification, coordination with the live system remaining in service, salvage decisions, abandoned cable identification and removal, penetration patching, and as-built documentation of modified or abandoned circuits.
− Not intended for: Full structure demolition and non-electrical systems demolition (sync/selective-demolition); hazmat abatement of PCB ballasts, mercury lamps, and lead-jacketed cable (sync/selective-demolition); new electrical installation after demolition (sync/conductors-and-cables, sync/raceways-and-conduit, sync/low-voltage-panelboards); arc flash incident-energy and short-circuit studies (sync/electrical-safety-program); the project-wide Electrical Safety Program and written LOTO procedures (sync/electrical-safety-program); enclosure types, seismic restraint, and new firestopping common to new work (sync/common-work-results-electrical); grounding electrode and bonding design (sync/grounding-and-bonding); fire alarm demolition and continuity (sync/fire-alarm-systems); and medium-voltage demolition above 1000 V (sync/medium-voltage-switchgear).
+ Not intended for: Full structure demolition and non-electrical systems demolition (sync/selective-demolition); hazmat abatement of PCB ballasts, mercury lamps, and lead-jacketed cable (sync/selective-demolition); new electrical installation after demolition (sync/conductors-and-cables, sync/raceways-and-conduit, sync/panelboards); arc flash incident-energy and short-circuit studies (sync/electrical-safety-program); the project-wide Electrical Safety Program and written LOTO procedures (sync/electrical-safety-program); enclosure types, seismic restraint, and new firestopping common to new work (sync/common-work-results-electrical); grounding electrode and bonding design (sync/grounding-and-bonding); fire alarm demolition and continuity (sync/fire-alarm-systems); and medium-voltage demolition above 1000 V (sync/medium-voltage-switchgear).
---
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## This Standard establishes the sequencing obligation - that abatement be complete and documented before electrical demolition begins - but does not specify abatement methods. {note}
−## New electrical installation following demolition is excluded: new conductors and cables are the work of [[sync/conductors-and-cables]], new raceways the work of [[sync/raceways-and-conduit]], and replacement panelboards the work of [[sync/low-voltage-panelboards]]. {note}
+## New electrical installation following demolition is excluded: new conductors and cables are the work of [[sync/conductors-and-cables]], new raceways the work of [[sync/raceways-and-conduit]], and replacement panelboards the work of [[sync/panelboards]]. {note}
## Arc flash incident-energy calculations and the short-circuit study are produced upstream under [[sync/electrical-safety-program]] and consumed here; this Standard does not duplicate the calculation methodology. {note}
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### The pre-demolition electrical survey shall be performed by a qualified person and reconciled against the available record drawings, with every undocumented circuit reported to the Engineer of Record before removal.
−### The arc flash risk assessment shall confirm that existing equipment labels reflect the present available fault current and upstream protective-device settings, or shall be updated to do so. {note}
+### The arc flash risk assessment shall confirm that existing equipment labels reflect the present available fault current and upstream protective-device settings, or shall be updated to do so.
### Panels in renovated buildings frequently carry obsolete or absent arc flash labels. Available fault current and breaker settings may have changed since the original study, so an unverified label cannot be relied upon to select PPE. {note}
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## Test instruments used to verify deenergization shall be rated for the circuit under test and shall be within their calibration interval.
−## The Contractor shall verify operation of each voltage tester on a known live source immediately before and immediately after each deenergization check. {note}
+## The Contractor shall verify operation of each voltage tester on a known live source immediately before and immediately after each deenergization check.
## A live-dead-live check confirms the tester itself is functioning, so that an absence-of-voltage reading is trusted rather than masking a defective instrument. {note}
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# Environmental and Service Conditions {toc}
−## The Contractor shall treat every conductor and every enclosure within the limit of work as energized until proven deenergized by test. {note}
+## The Contractor shall treat every conductor and every enclosure within the limit of work as energized until proven deenergized by test.
## Adjacent live systems, back-fed circuits, mislabeled panels, and undocumented additions are routine in renovation. A test-before-touch posture is the only defensible default. {note}
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### Hospitals, occupied tenant spaces, and data centers contain loads that cannot tolerate an unplanned interruption. A phased partial shutdown with a temporary feed is often safer than a full shutdown, and an energized task under an EEWP is a last resort, not a convenience. {note}
+### The deenergization strategy for each phase of demolition shall be specified, with energized work under an EEWP permitted only for circuits that cannot be interrupted.
+
```datasheet
label: Deenergization strategy
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# Pre-Demolition Hazard Assessment {toc}
−## The Contractor shall complete an arc flash risk assessment for every panel, switchboard, disconnect, and enclosure to be opened before any cover is removed. {note}
+## The Contractor shall complete an arc flash risk assessment for every panel, switchboard, disconnect, and enclosure to be opened before any cover is removed.
## The assessment fixes the arc flash boundary and the PPE category for the specific equipment, voltage, and available fault current. It is the gate that every other deenergization step passes through. {note}
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```
−## The PPE category selected for each task shall meet or exceed the minimum for the system voltage and equipment class involved. {note}
+```datasheet
+label: Arc flash boundary at controlling equipment
+type: range
+unit: in
+min: 12
+max: 120
+step: 6
+default: 42
+```
−## Branch-circuit work at 120-208 V typically falls in PPE Category 1 (minimum 4 cal/cm² arc-rated clothing, face shield, safety glasses, and Class 00 rubber gloves). Interior work on a typical bolted-bus 480 V commercial panelboard typically falls in PPE Category 2 (minimum 8 cal/cm² arc-rated clothing). Calculated incident energy governs where it exceeds the table value. {note}
+## The PPE category selected for each task shall meet or exceed the minimum for the system voltage and equipment class involved.
```datasheet
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```
−```datasheet
−label: Arc flash boundary at controlling equipment
−type: range
−unit: in
−min: 12
−max: 120
−step: 6
−default: 42
−```
+## Branch-circuit work at 120-208 V typically falls in PPE Category 1 (minimum 4 cal/cm² arc-rated clothing, face shield, safety glasses, and Class 00 rubber gloves). Interior work on a typical bolted-bus 480 V commercial panelboard typically falls in PPE Category 2 (minimum 8 cal/cm² arc-rated clothing). Calculated incident energy governs where it exceeds the table value. {note}
## Hazardous Material Pre-Clearance {toc}
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# Deenergization and Lockout/Tagout {toc}
−## The Contractor shall verify the identity of every circuit at the source panel before applying a lock, by circuit tracing and not by panel-directory label alone. {note}
+## The Contractor shall verify the identity of every circuit at the source panel before applying a lock, by circuit tracing and not by panel-directory label alone.
## De-energizing the wrong breaker on a mislabeled panel is the most common cause of unexpected energized exposure. Directories in renovation buildings are frequently wrong; a circuit tracer confirms the conductor at the work location corresponds to the breaker being locked. {note}
−## The Contractor shall apply lockout/tagout to each source device, then perform a test-before-touch absence-of-voltage check at each conductor before any contact. {note}
+## The Contractor shall apply lockout/tagout to each source device, then perform a test-before-touch absence-of-voltage check at each conductor before any contact.
## The lock prevents re-energization; the test confirms the conductor is actually dead at the point of work. Two-person verification of the absence-of-voltage check is best practice under NFPA 70E. {note}
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## Multi-Wire Branch Circuits {toc}
−### Where a device on a multi-wire branch circuit is removed, the grounded (neutral) conductor shall be spliced through with a pigtail so that its continuity does not depend on the device. {note}
+### Where a device on a multi-wire branch circuit is removed, the grounded (neutral) conductor shall be spliced through with a pigtail so that its continuity does not depend on the device.
### NEC 300.13(B) prohibits the continuity of the grounded conductor of a multi-wire branch circuit from depending on device connections. Removing a receptacle without a pigtail severs the shared neutral and can energize the neutral on the remaining circuits at line potential - a routine and dangerous demolition error. {note}
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## Conductors and Cables {toc}
−### Conductors and cables to be removed shall be deenergized, verified dead, and removed entirely back to their source unless designated for abandonment or future use. {note}
+### Conductors and cables to be removed shall be deenergized, verified dead, and removed entirely back to their source unless designated for abandonment or future use.
−### Abandoned cables above accessible ceilings and in accessible spaces shall be removed unless tagged "Identified for Future Use" in accordance with NEC 800.25, 820.25, and 830.25. {note}
−
−### Communications, CATV, and network-powered broadband cable left abandoned and untagged is a routine cause of failed final inspection. The default expectation is complete removal; tagging for future use is the exception and must be explicit. {note}
−
−### Open wiring methods are prohibited; no removed conductor shall be left with an exposed energized or unterminated end. {note}
−
−### NEC 300.12 prohibits open wiring methods and abandoned conductor ends must be made safe - removed, capped, or properly terminated - never left bare. {note}
−
```datasheet
label: Abandoned power and signal cable disposition (accessible spaces)
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```
+### Abandoned cables above accessible ceilings and in accessible spaces shall be removed unless tagged "Identified for Future Use" in accordance with NEC 800.25, 820.25, and 830.25. {note}
+
+### Communications, CATV, and network-powered broadband cable left abandoned and untagged is a routine cause of failed final inspection. The default expectation is complete removal; tagging for future use is the exception and must be explicit. {note}
+
+### Open wiring methods are prohibited; no removed conductor shall be left with an exposed energized or unterminated end.
+
```datasheet
label: Concealed cable in walls and slabs disposition
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```
+### NEC 300.12 prohibits open wiring methods and abandoned conductor ends must be made safe - removed, capped, or properly terminated - never left bare. {note}
+
## Raceways and Conduit {toc}
−### Raceways and conduit serving removed circuits shall be removed entirely where accessible, or abandoned in place and capped where removal requires destructive access to slabs, chases, or concealed construction. {note}
+### Raceways and conduit serving removed circuits shall be removed entirely where accessible, or abandoned in place and capped where removal requires destructive access to slabs, chases, or concealed construction.
### Conduit cast in slab or buried in inaccessible chases is commonly left in place; the governing requirement is that its disposition be deliberate and recorded, not that it always be removed. {note}
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### Equipment designated for Owner salvage shall be removed intact, protected, and delivered to the location directed by the Owner; equipment not salvaged shall be disposed of or recycled as directed. {note}
−### Intact panelboards, fixtures, and conduit may carry reuse or recycling value the Owner elects to capture. The salvage-versus-disposal decision belongs to the Owner and is recorded in the salvage schedule, not made unilaterally in the field. {note}
+### Intact panelboards, fixtures, and conduit may carry reuse or recycling value the Owner elects to capture. The salvage-versus-disposal decision belongs to the Owner and is recorded in the salvage schedule, not made unilaterally in the field.
```datasheet
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# Grounding and Bonding Continuity {toc}
−## Before a metallic raceway that serves as an equipment grounding conductor path is cut, the Contractor shall install a bonding jumper to maintain continuity to equipment remaining in service. {note}
+## Before a metallic raceway that serves as an equipment grounding conductor path is cut, the Contractor shall install a bonding jumper to maintain continuity to equipment remaining in service.
## A metallic conduit run frequently doubles as the equipment grounding conductor for downstream loads. Cutting it without first bridging the path breaks grounding continuity to equipment still energized - a hidden hazard that no voltage test on the demolished circuit will reveal. Grounding electrode and bonding design for the remaining system is the work of [[sync/grounding-and-bonding]]. {note}
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# Testing {toc}
−## Circuits that are modified, re-spliced, or re-terminated as part of the work shall be tested before the area is re-occupied or returned to service. {note}
+## Circuits that are modified, re-spliced, or re-terminated as part of the work shall be tested before the area is re-occupied or returned to service.
## Adjacent demolition can damage the insulation of circuits left in service, and re-spliced joints must be proven sound. ANSI/NETA ATS-2021 provides the acceptance protocols. {note}
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## Penetration Firestopping {toc}
−### Every fire-rated wall, floor, or assembly penetration disturbed or opened by conduit or cable removal shall be restored to its original or better fire-resistance rating. {note}
+### Every fire-rated wall, floor, or assembly penetration disturbed or opened by conduit or cable removal shall be restored to its original or better fire-resistance rating.
### When conduit is pulled through a rated barrier and the sleeve is left open, the opening becomes a code violation that later requires destructive access to remedy. The firestopping obligation must be assigned at the time of removal, not discovered at inspection. Firestop system selection is the work of [[sync/firestopping]]. {note}
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## As-Built Documentation {toc}
−### The Contractor shall record every circuit removed, abandoned, relocated, re-spliced, or capped on as-built documentation and shall deliver it before final acceptance. {note}
+### The Contractor shall record every circuit removed, abandoned, relocated, re-spliced, or capped on as-built documentation and shall deliver it before final acceptance.
### The as-built is the permanent record that lets the next renovation crew trust what is live and what is dead. Abandoned-in-place conduit and cable are only acceptable when their location is documented. {note}
+### The as-built deliverable format for documenting removed, abandoned, relocated, re-spliced, and capped circuits shall be specified.
+
```datasheet
label: As-built deliverable format
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## Equipment designated for Owner salvage shall be handled to prevent damage, protected from weather and impact, and stored or delivered as directed by the Owner.
−## Removed materials not designated for salvage shall be removed from the building promptly and shall not accumulate in egress paths or occupied areas. {note}
+## Removed materials not designated for salvage shall be removed from the building promptly and shall not accumulate in egress paths or occupied areas.
## Demolition debris in an occupied building is both a fire-load and an egress hazard governed by NFPA 241; prompt removal keeps the active areas safe during phased work. {note}
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# Spare Parts {toc}
−## Salvaged components retained by the Owner for reuse shall be inventoried, labeled with their original designation and rating, and delivered with the salvage schedule. {note}
+## Salvaged components retained by the Owner for reuse shall be inventoried, labeled with their original designation and rating, and delivered with the salvage schedule.
## Selective demolition is not a product-supply activity, so the only "spare parts" obligation is the orderly turnover of equipment the Owner elects to keep - labeled well enough to be reusable rather than scrapped by default. {note}
## The Contractor shall deliver any manufacturer nameplate data, original circuit directories, and panel schedules recovered from removed equipment to the Owner with the closeout documents.