Spec a 1,500–1,700 W electric demolition hammer delivering 11–20 J per blow at 1,500–1,900 BPM and weighing 10–13 kg for the bulk of electrical-installation demolition — conduit chases, junction-box pockets and underfloor trunking cuts in cured concrete and masonry [S6][S8].
Light-duty 25 lb class breakers — Bosch 11316EVS, Hilti TE 800-AVR, Makita HM1214C — already overlap the upper end of this band, with measured impact energy of 18.4 / 15.5 / 19 ft·lbs (≈ 25 / 21 / 26 J) and a 900–1,890 BPM operating window [S4]. 2,200 W class breakers such as the 61103 are useful where the host circuit is dedicated and the operator wants single-pass depth, but they are over-spec for switch-box and conduit work in slab-on-grade pours under 150 mm [S2].
Why the 11–20 J Band Fits Electrical Chasing
Impact energy classes below 11 J are tuned for plaster, tile and interior wall chasing, while the 11–20 J class — labeled "screeds, floors, concrete blocks" in trade guidance — is the band that maps onto electrical conduit chases and recessed box pockets cut into cured slab or block walls [S6]. Above 20 J, the hammer targets reinforced concrete and structural demolition; the higher recoil cycle fatigues the operator faster on repetitive 25–40 mm deep chases that are the daily output of an electrical crew [S6][S3]. For deeper pours, a rotary hammer with chipping mode is a better fit because the rotation can be declutched while keeping the percussive train alive; pure demolition hammers cannot drill pilot holes for sleeve anchors, so most electrical crews carry one of each.
Within the 11–20 J band, three sub-tiers are visible in the rental and OEM data. Entry consumer/light-trade units sit at 1,200–1,500 W with 5–10 J output and are usable on plaster and aerated block but stall on 25 MPa cured concrete [S6]. The 1,500–1,700 W mid-tier — represented by the 1,700 W Z1G-DS-65D (230 V/50 Hz, protection class II) and the 1,500 W WORKPRO 1500 W — is the value sweet spot for electrical-installation contractors [S7][S8]. The 1,900–2,200 W tier (61103-class) covers structural demolition and is rented by the day rather than carried on the truck [S2].
Bit System, Power and the 230 V vs 110 V Question
Bit shank determines both bit cost and the ability to use existing rotary-hammer stock. SDS-max is the dominant shank on the 25 lb class, while Hilti's TE-S is the proprietary equivalent on the TE 800-AVR [S4]. A crew that already runs demolition hammer SDS-max across the rest of the fleet should standardize on SDS-max for the electrical hammers as well, to avoid duplicating the bit inventory.
Supply voltage is a hard gate, not a preference. 230 V/50 Hz models such as the Z1G-DS-65D draw 7.4 A at full load and need a 16 A circuit on most European jobsites [S7]. North American sites fed from 120 V split-phase are limited to ~1,500 W continuous per circuit; 2,200 W breakers like the 61103 are explicitly listed at 220–240 V nominal and will not run on a 15 A 120 V branch [S2]. On temporary-site power, a GFCI/RCD-protected feeder is required by the tool manuals and is non-negotiable for any electrical-installation crew working in damp or outdoor conduit runs [S2].
Comparison: Three 25 lb Hammers Side-by-Side
The Sunbelt 25 lb demolition-hammer spec sheet lines up three mainstream models that bracket the field [S4]:
Bosch 11316EVS — 14 A, 18.4 ft·lbs (≈ 25 J) max impact, 900–1,890 BPM, SDS-max, 23 lb, 26 in length. Hilti TE 800-AVR — 15 A, 15.5 ft·lbs (≈ 21 J) max impact, 0–1,890 BPM variable, TE-S shank, 23.4 lb, 23.1 in. Makita HM1214C — 900–1,900 BPM, 19 ft·lbs (≈ 26 J) max impact, SDS-max, 27.5 in length. On the four criteria that matter for electrical chasing — impact energy, BPM, bit standardization and tool length — the Bosch is the energy leader with the widest bit cross-compatibility, the Hilti is the most compact with a variable trigger that helps on shallow box-pocket work, and the Makita sits between them with the longest reach for floor-tray cuts. All three are tagged "light-duty" in the rental catalog despite sitting at the upper end of the consumer 25 lb class [S4].
Operating Window, Vibration, and Crew Endurance
Impact rate of 1,500–3,000 BPM is the documented balance point between speed and operator control, with 1,500–1,900 BPM covering most medium work and 2,000+ BPM reserved for production demolition [S6]. For an electrical-installation crew running 4–6 hours of continuous chasing per shift, the 23–25 lb weight class (10.4–11.3 kg) is the longest sustained-use band; above 30 lb the vibration dose and grip force push operators past the A(8) action level on most hand-arm vibration surveys published by the tool OEMs.
Bit choice inside this window matters as much as the hammer. A narrow chisel bit at 20–30 mm width is the right tool for a single conduit run; a wide scaling bit accelerates floor-tray cutting but produces rougher edges that the electrician will later patch. Most published 1,500–1,700 W mid-tier models ship with both point and flat chisels as standard, and the 2,200 W 61103 lists "crushing concrete, chipping, digging and squaring" plus "installation of piping and wiring" in its application block [S2][S8].
When NOT to Spec a Demolition Hammer
Three cases should escalate the spec upward. (1) Reinforced slab with rebar 12 mm and above — a hammer drill or rotary hammer with chipping mode is the right tool because it can pre-drill rebar-clearing pilot holes. (2) Live switchgear rooms or any environment where a stray chip could strike energized busbars — here the spec is to route the demolition to a battery model (EmmetiStore lists professional 40 V cordless breakers at up to 10 J as the "rapid intervention" class for sites without mains) [S6]. (3) Hazardous-area sites — petrochemical, LNG, grain silos — where the tool itself must be explosion-proof electrical rated and any hammer action risks igniting fugitive vapor; spec a different work method, not a different hammer.
Daily rental on the 10–20 lb electric class is the price-point to compare against ownership. Hilti, Bosch and Makita dominate the rental fleet at the 25 lb class, with Hilti's TE 800-AVR and Makita's HM1214C showing up most often on national rental rate sheets [S4][S9]. A crew that needs more than 60 days of hammer time per year crosses the ownership break-even on a mid-tier 1,500–1,700 W SDS-max unit; below that, rental is the cheaper path and shifts the spec debate from "which model" to "which rental yard has stock".
Trackable signals for the next buying cycle: 40 V cordless demolition-hammer fleets are expanding from professional masonry into the electrical-installation channel, with OEM-rated 10 J output now available on the 40 V platform [S6]. The 2,200 W corded class remains the structural-demolition workhorse, with 230 V/16 A single-phase models documented in current product manuals [S2][S7]. For an electrical-installation spec in 2026, lock the band to 1,500–1,700 W, 11–20 J, 1,500–1,900 BPM, SDS-max shank, 23–25 lb weight, on a GFCI-protected 230 V or 120 V feeder matched to local grid — and treat anything outside that envelope as a different tool, not a different size of the same tool. For conduit, control and power cabling runs that pair with this hammer, the spec map in Control Cable Selection Guide: Spec Gates for 2026 Sourcing lines up the matching conductor and insulation classes.