Why Choose the ABB CM-ENS.11P Liquid Level Monitoring Relay?
The ABB CM-ENS.11P (1SVR740850R0100) is a compact and reliable liquid level monitoring relay designed for monitoring and controlling the levels of electrically conductive liquids in industrial tanks, reservoirs, pumping systems and process installations. As part of the ABB CM-ENS liquid level monitoring relay series, it provides dependable minimum and maximum liquid level supervision to help prevent tank overflow, protect pumps against dry running and improve the reliability of automated fluid handling systems.
This versatile monitoring relay operates with a 24–240 V AC/DC control supply and features an adjustable response sensitivity of 5–100 kΩ, allowing it to detect different conductive liquids through suitable electrode probes. Its conductive measuring principle enables liquid level detection without moving mechanical components, making it suitable for industrial water management, process control and automated pumping applications.
The CM-ENS.11P incorporates one changeover (SPDT) output contact rated at 250 V / 4 A, three LED status indicators and ABB's maintenance-free Easy Connect Technology with push-in terminals. Its compact 22.5 mm housing and DIN rail mounting provide straightforward installation inside electrical control panels, making it an excellent choice for machine builders, electrical engineers and industrial automation professionals.
Key Advantages
- Reliable liquid level monitoring for conductive fluids in industrial applications.
- Minimum and maximum level supervision supports automated tank and pump control.
- Wide 24–240 V AC/DC control supply provides flexibility across industrial electrical systems.
- Adjustable sensitivity from 5–100 kΩ accommodates different conductive liquid characteristics.
- Dry-running protection helps prevent pumps from operating without sufficient liquid.
- Overflow protection helps prevent tanks and reservoirs from exceeding their intended liquid levels.
- One changeover (SPDT) relay output enables integration with control and alarm circuits.
- Maintenance-free push-in terminals simplify electrical installation and reduce wiring time.
- Three LED indicators provide clear visual indication of operating and switching conditions.
- Compact 22.5 mm DIN rail housing saves valuable space inside control cabinets.
- Suitable for conductive liquid monitoring in water treatment, industrial processing and pumping installations.
Key Features
- ABB CM-ENS.11P liquid level monitoring relay from the CM-ENS series.
- ABB order code: 1SVR740850R0100.
- Rated control supply voltage: 24–240 V AC/DC.
- Adjustable response sensitivity: 5–100 kΩ.
- Monitoring function: Conductive liquid level supervision.
- Minimum and maximum level detection using suitable electrode probes.
- Filling and draining applications for automated liquid handling systems.
- Three-electrode monitoring arrangement for liquid level control.
- One changeover (SPDT) output contact.
- Output contact rating: 250 V / 4 A.
- Open-circuit operating principle for relay operation.
- Front-mounted potentiometer for adjusting response sensitivity.
- Three LED indicators for operating and relay status.
- ABB Easy Connect Technology with maintenance-free push-in terminals.
- High electromagnetic compatibility for industrial environments.
- Cascadable design for expanded monitoring arrangements.
- Tool-free mounting and removal from standard DIN rails.
- 22.5 mm housing width for space-saving installation.
- Housing material with UL 94 V-0 flammability classification.
- Optional electrode accessories and sealable transparent cover available separately.
Technical Specifications
- Manufacturer: ABB
- Series: CM-ENS Liquid Level Monitoring Relays
- Model: CM-ENS.11P
- Manufacturer part number: 1SVR740850R0100
- ABB product group: 310921 – Measuring & Monitoring Relays
- Product type: Liquid level monitoring relay
- Monitoring function: Minimum / maximum conductive liquid level monitoring
- Application function: Filling or draining monitoring
- Measuring principle: Conductive electrode measurement
- Rated control supply voltage: 24–240 V AC/DC
- AC supply frequency: 50 / 60 Hz
- Adjustable measuring sensitivity: 5–100 kΩ
- Number of electrodes: 3
- Output contacts: 1 changeover (SPDT)
- Contact rating: 250 V / 4 A
- Operating principle: Open-circuit principle
- Connection technology: Push-in terminals (Easy Connect Technology)
- Terminal type: Screwless push-in terminals
- Mounting type: DIN rail mounting
- Housing protection rating: IP50
- Terminal protection rating: IP20
- Operating ambient temperature: −25 to +60 °C
- Storage temperature: −40 to +85 °C
- Dimensions (H × W × D): 85.6 × 22.5 × 103.7 mm
- Housing width: 22.5 mm
- Net weight: approx. 0.117 kg
- Status indication: 3 LEDs
- Housing flammability classification: UL 94 V-0
- Country of origin: Germany
- EAN: 4013614502873
Reliable Liquid Level Monitoring for Industrial Tanks and Pumps
Liquid level monitoring relays such as the ABB CM-ENS.11P detect the presence of electrically conductive liquids through electrode probes installed at selected positions within a tank, reservoir or process vessel. When the liquid reaches or falls below a monitored electrode, the electrical conductivity between the electrodes changes, allowing the relay to respond and provide a switching signal to the connected control system.
The CM-ENS.11P supports minimum and maximum liquid level supervision, making it suitable for monitoring liquid levels and controlling filling or draining operations through an appropriately designed external control circuit. By detecting high and low liquid conditions, the relay can help prevent tank overflow, reduce the risk of pump dry running and support reliable operation of automated liquid handling equipment.
Its adjustable sensitivity range of 5–100 kΩ allows the monitoring response to be adapted to the conductivity of the liquid being measured. This makes the relay suitable for various conductive media, including water, wastewater and compatible industrial process liquids. Non-conductive liquids such as oils and fuels cannot be reliably monitored using this conductive measurement principle.
The integrated SPDT relay output provides a switching signal that can be used by external contactors, PLC inputs, alarm systems or suitable pump control circuits. The relay itself performs the monitoring and signalling function, while external switching equipment can be used to control larger electrical loads.
Designed for industrial control panel installation, the CM-ENS.11P combines front-mounted sensitivity adjustment, LED status indication and maintenance-free push-in terminals. Its compact DIN rail format and broad control supply range simplify integration into new equipment and existing automation installations.
Typical Applications
- Water storage tanks: Monitoring minimum and maximum water levels to support automated filling and overflow prevention.
- Pump dry-running protection: Detecting low liquid levels and providing a signal to prevent pumps from operating without sufficient fluid.
- Industrial wastewater treatment: Monitoring conductive liquid levels in collection tanks, treatment vessels and pumping stations.
- Tank overflow protection: Detecting high liquid levels and activating suitable alarm or control circuits.
- Automated filling systems: Supporting liquid level control in industrial storage and processing installations.
- Drainage and sump systems: Monitoring liquid levels for automatic pump operation and drainage management.
- Industrial process tanks: Supervising compatible conductive liquids in manufacturing and processing equipment.
- Building services: Monitoring water levels in suitable storage tanks and pumping installations.
- Food and beverage processing: Monitoring compatible conductive liquids where electrode materials and installation conditions are suitable.
- OEM machinery: Integrating compact liquid level monitoring into automated industrial equipment.
- PLC-based automation systems: Providing liquid level switching signals for process control, alarms and equipment interlocking.
