Atlas Copco WEDA S04N | Submersible Sludge Pump — 0.5 HP, 115V 1-Phase, 2" Discharge, 1" Solids

The Atlas Copco WEDA S04N is a 0.5 HP (0.4 kW) submersible sludge pump engineered for the wet, gritty, semi-solid liquids that wreck ordinary drainage pumps — wet mud, mining residues, thickened sewage, tank cleanout, and pond bottoms. With a 1-inch solids-handling capacity, a 115V single-phase plug-and-play motor, and a 2-inch NPT discharge, the S04N is the smallest pump in the WEDA Sludge range and the most accessible entry point into Atlas Copco's industrial dewatering line.

Performance Snapshot

Why a Sludge Pump and Not a Drainage Pump

Drainage pumps are designed around impellers that maximize hydraulic efficiency for clean water — they jam, abrade, or wear out quickly when they hit grit, fibrous matter, or thickened liquids. The WEDA S04N uses a vortex impeller in high-chrome cast iron, set back into the volute so solids pass through the eye of the rotation rather than being chopped by the blade. This costs a small amount of peak efficiency at clean-water duty but gives the S04N something a drainage pump can't match: the ability to keep pumping when the fluid thickens, scums up, or carries 1-inch particulates.

Built for the Worst of It

• Double mechanical seal in a stainless-steel cartridge — the primary seal runs in oil; the secondary blocks any path between the medium and the motor. The cartridge design means the seal is replaced as a unit, not piece-by-piece.
• Vortex-style high-chrome cast-iron impeller — abrasive-resistant alloy, low-clog geometry, optimized for solids up to 1".
• Aluminum-alloy body — light enough that one person can carry and place the pump; corrosion-resistant for sustained immersion.
• Class E motor insulation with thermal protection — automatic shutdown on overtemperature, then auto-restart when the motor cools.
• Dry-running tolerance — the carefully oversized motor and heat-dissipating jacket design allow the S04N to run dry without immediate damage if the sump drops below the inlet.
• 33 ft of integrated power cable — long enough for typical pit and tank applications without dragging out an extension cord.

Common Applications

The S04N is at home wherever the fluid is too dirty for a clean-water pump but too thin to call a slurry pump:

• Construction site sumps with mud and sediment
• Sewage and bypass pumping — gravity-line maintenance, lift-station service
• Alum sludge removal at potable water and wastewater treatment plants
• Tank and basin cleanout — process tanks, settling basins, retention ponds
• Light dredging and waterway maintenance — sediment removal, surface contaminant clearing
• Mining and quarry trench cleanout — small-bore work where the larger S30N is overkill
• Agricultural and dairy operations — manure pit edges, washdown sumps
• Emergency response — flood cleanup where water is mixed with mud and debris

WEDA Range Compatibility

The S04N shares the WEDA Sludge family architecture with the S08N, S30N, S50N, and S60N — meaning operators familiar with one are productive on all. Common service kits, common cable terminations, common float-switch accessories. If your job site grows into a bigger pump, the operating knowledge transfers directly.

What Ships in the Box

The pump comes ready to run: 33 ft of cable terminated for a standard 115V outlet, integrated thermal protection, factory-set seal cartridge, and the 2" NPT discharge connection. Float switches, control panels, level regulators, and longer cable runs are available as accessories — contact us if your install needs more than what's standard.

SKU 8162172900 · WEDA S04N · 115V 1-Phase 60 Hz · 2" NPT discharge · 1" solids · UL listed. Backed by Atlas Copco's North American service network.