Sewage pump control cabinets
- Pump logic: one duty one standby with alternating operation; two duty one standby staged by level; both pumps forced on together at high-high level
- Level detection: float switches (economical and reliable), ultrasonic / submersible level transmitters (continuous measurement), selectable by application
- Protection: dry-run (low level) protection, overload, phase loss, short circuit, overheat, reverse rotation, with alarm output
- Environmental adaptation: moisture-resistant enclosure coating, downward-sealed cable glands, optional anti-condensation heater and IP65 outdoor enclosure
- Signal interface: dry contact outputs for run, fault and high-high level alarm; connectable to a duty room or remote monitoring
Specifications
The table below covers 80% of factory distribution room cases. Anything outside it we can still build — those are engineered items, quoted separately, with an indicative price the same day.
| Type | Wall-mounted sewage pump control box (low power) / floor-standing sewage pump control cabinet (multiple pumps) |
|---|---|
| Standard sizes (W×D×H) | Wall-mounted 500×400×250 / 600×500×300 mm; floor-standing 800×600×1800 mm |
| Enclosure construction | 1.5–2.0 mm cold-rolled carbon steel, bent and welded, electrostatic powder coated; stainless steel enclosure optional |
| Surface treatment | Degrease → derust → phosphating → electrostatic powder coating 60-80 μm, baked at 200 °C for 30 minutes |
| IP rating | IP54 standard / IP55 / IP65 optional (IP65 mandatory above a sump pit or outdoors) |
| Moisture protection measures | Downward-sealed cable glands, optional anti-condensation heater and thermostat inside the cabinet, three-proof treatment on the control board |
| Installation | Wall-mounted or floor-standing installation, mounted high enough to avoid flooding, with maintenance clearance in front of the cabinet |
| Cable entry | Bottom cable entry with a gland plate; sealing grommets compressed to keep moisture out |
| Suitable power | Submersible sewage pumps are typically 0.75–75 kW (direct-on-line or star-delta); soft starter or VFD options are available for larger ratings |
|---|---|
| Pump configuration | One duty / one standby, two duty / one standby, or three-pump rotation (selected by sump volume and inflow rate) |
| Level detection | Float switch (multi-stage: stop / start / both pumps start / high-high alarm); ultrasonic or submersible level transmitter optional |
| Control logic | Pumps are added in stages and cut out one by one based on level; dual-pump alternating duty rotates by accumulated run time or start count |
| High-high level | At high-high level, both pumps are forced to run together and an alarm signal is output to prevent overflow from flooding the pump room |
| Dry-run protection | Low-level pump stop with time-delay confirmation; optional current-based no-load detection for dual protection |
| Protection | Overload, phase loss, short circuit, overheat, locked rotor, and reverse rotation (phase sequence) protection |
| Signal interface | Volt-free contacts for run / fault / high-high level alarm; optional communication for remote monitoring |
| One duty / one standby float control | Two pumps alternate duty with three-stage float control (stop, start, both start) — the most common configuration |
|---|---|
| Two duty / one standby | Three pumps are staged in by level and staged out as the level drops, with two duty / one standby rotation |
| Ultrasonic level control | Continuous level measurement with precise pump-add and pump-cut setpoints, avoiding float switch jamming |
| Configuration with reverse rotation protection | If a submersible sewage pump is reversed after phase change, output drops sharply and the impeller is damaged — add a phase sequence protection relay |
| ATS changeover scheme | Critical pump rooms are fitted with ATS automatic transfer; the standby source takes over when the main source is lost |
| Remote monitoring solution | Level, run status, and faults are uploaded via communication so the control room can monitor the sump in real time |
| Reference standards | GB/T 7251.1 / IEC 61439-1 (assemblies); GB/T 5226.1 (electrical safety of machinery) |
|---|---|
| Clearance & creepage | Meets pollution degree 3 and overvoltage category III requirements |
| Insulation resistance | ≥1 MΩ (500V megohmmeter) |
| Power frequency withstand voltage | Main circuit 2500V / 1 min, control circuit 1500V / 1 min |
| Logic verification | Before shipment, level signals are simulated to verify each stage: pump start, rotation, both pumps start, high-high alarm, dry-run pump stop |
| Routine tests (every unit) | Circuit checks, insulation and withstand voltage, protection operation, simulated level start/stop, and on-load trial run |
| Documents with shipment | Electrical schematic, terminal wiring table, level setpoint table, BOM, test report, and pre-shipment photos |
Five steps to specify your run
A configuration summary is generated as you go. It travels with your inquiry, saving a round of confirmation.
Build details
Systems have been in service for decades, and the failure points are always the same few: poor busbar contact, water ingress at the door seal, high temperature rise in the correction cabinet, and mis-phased outgoing feeders. The six hard rules below are written for exactly these points — every cabinet can be traced to them.
No pump left running itself to death
The two pumps alternate based on accumulated running hours. Submersible sewage pumps tend to fail whether they sit idle too long or run continuously too long, and alternating duty is the cheapest way to extend service life.
Both pumps run together at high-high level
When the level reaches the high-high setpoint, both pumps are forced to run simultaneously and an alarm is output — this stage exists to prevent overflow from flooding the pump room, so the logic includes no delay whatsoever.
Cut power immediately on pump-out
The low-level signal stops the pump first, then a time delay confirms the stop, preventing false stops from float bounce while ensuring the mechanical seal never runs dry.
Moisture-proof treatment on the control board
Humidity in a wastewater room stays above 90% year-round. Components and the control board inside the cabinet receive three-proof treatment, and the cable glands are tightened downward to seal out moisture.
Mount it above any height water can reach
The cabinet must be installed above the highest water level that could occur. This is an installation requirement written into the drawings — mount it too low and no amount of moisture protection will help.
Dual level signal backup
For critical pump rooms, we recommend float switch plus ultrasonic dual level signals. If one path jams, the other can still start the pump, and a mismatch alarm between the two signals prompts inspection.
Photos & enclosure construction
Below are photos taken in our own shop — from the complete unit down to the internal busbars and secondary wiring. Every build detail can be checked item by item.
Image key: 01–05 are shop photos (the numbers match the shot list). The line drawing shows the front elevation of the enclosure; dimensions match the specification table above.
Where these cabinets go
These are the routine applications — we can talk scheme and configuration directly. For the industry view, see the industry pages.
Basement sump pit
The most common application: sump drainage in basements, garages, and equipment rooms.
Wastewater lift pump station
Pump control for mid-line lift stations on municipal sewage networks.
Septic tanks and grease traps
Pumping control for restaurant and domestic wastewater treatment facilities.
Factory wastewater collection pit
Lift and discharge control for workshop wastewater and cooling water reuse.
Tunnels and underground utility tunnels
Drainage and remote alarm for tunnel sumps and utility corridor collection pits.
Mine underground water sump
Level control and dual-pump simultaneous start protection for mine sump drainage pumps.
Commercial terms
Specification dated September 2026; quotations follow this.
| Drawings & design | Free |
| MOQ | 1 unit (5 or more recommended for production) |
| Production lead time | 15-25 days after drawing approval |
| on-time delivery | 98% |
| Warranty | 12 months |
| Loading port | Ningbo / Shanghai, China |
| Component brands | Schneider / ABB / Siemens / Chint |
| Factory visit & dispatch confirmation | Factory visits welcome; finished-cabinet photos and video before dispatch |
| Capacity | 5,800+ units / year |
Documents for your engineering team
Selection manual, outline dimensions and RFQ checklist — for the customer's electrical engineer. All three documents are being organized by product line; download links go live once complete.
Six questions procurement and electrical engineers ask most
How do I choose between a float switch and an ultrasonic level meter?
Float switches are inexpensive and reliable, and suit pits with dirty media, little foam, and limited space; the drawbacks are fixed setpoints and the risk of being jammed by debris. Ultrasonic meters measure continuously and offer flexible setpoints, but are sensitive to foam, steam, and mounting position. For dirty media in unattended locations, we recommend a float switch as the primary device with ultrasonic as backup or alarm.
How is pump alternation calculated?
Two methods: alternate by accumulated running hours (the pump with fewer hours starts first), or alternate by number of starts. You can set it to switch after every complete start/stop cycle, or after a set number of hours. The default is running hours — tell us if you need start-count logic instead.
What happens if the pump runs dry?
Once a submersible sewage pump runs dry, the mechanical seal and bearings lose the liquid that cools them and can be damaged within a short time. The control cabinet stops the pump at low liquid level and confirms the condition with a time delay; an optional current-based dry-run detection adds a second layer of protection — current below the no-load threshold is also treated as a dry-run condition.
The sewage room is damp — will the cabinet hold up?
It needs to be addressed specifically: raise the enclosure to IP55 or IP65, seal the cable glands downward, add an anti-condensation heater and thermostat inside the cabinet, apply a three-proof coating to the control board, and mount the cabinet above any possible flood level. In a sewage room these are standard, not optional.
Can remote alarms be added?
Yes. Run status, fault status and high-high liquid level can all be output as dry contacts to drive a sound-and-light alarm in the duty room or feed a PLC. Where phone monitoring is needed, add a communication module to connect to a cloud platform, so liquid level and operating status can both be viewed remotely.
The sewage contains debris — will the pump clog often?
This is a site issue, solved mainly through pump selection and operating practice: choose a pump with a cutter impeller or a large-passage impeller, install a bar screen at the wet well inlet to catch debris, and avoid running at low frequency for long periods. On the control cabinet side, what we can provide is reverse-phase/phase-sequence protection and locked-rotor protection, so a clog raises an alarm in time instead of burning out the motor.
Other cabinet types in the same main circuit
Related products use color-block placeholders for now (product photos not yet complete; they will be replaced together). Internal links will be filled in once live URLs are confirmed.
The sump keeps overflowing, or the pumps keep failing?
Send us the pit dimensions, inflow rate, and pump power and quantity, and we will provide the control logic and liquid level scheme free of charge · quotation within 24 hours. Direct from the source factory, MOQ 1 unit, 15–25 day delivery, 1-year warranty.
ISO 9001:2015 · CE(LVD+EMC) · CQC · IP65
When you write, include: single-line diagram or primary scheme, switch room layout, load list, and component brand requirements. You do not need complete drawings — capacity and cabinet type are enough to start.