Why Choose the ABB CM-EFS.2P Voltage Monitoring Relay?
The ABB CM-EFS.2P (1SVR740750R0400) is a versatile and reliable single-phase AC/DC voltage monitoring relay designed to detect overvoltage and undervoltage conditions in industrial electrical systems. As part of the ABB CM-EFS measuring and monitoring relay series, it provides accurate voltage supervision to help protect electrical equipment, improve operational reliability and support automated fault detection.
The CM-EFS.2P features four selectable measuring ranges covering 3–600 V AC/DC, with independent adjustment of upper and lower voltage thresholds. Its true RMS measuring principle, configurable relay outputs and adjustable tripping delays enable flexible monitoring of electrical supplies and control circuits. The device also incorporates selectable operating principles and a configurable latching function for applications requiring controlled fault indication.
With a rated control supply voltage of 24–240 V AC/DC, two changeover output contacts and push-in connection terminals, the CM-EFS.2P is suitable for industrial control panels, machinery protection and electrical distribution systems. Its compact 22.5 mm-wide DIN rail housing allows straightforward installation where reliable voltage monitoring and efficient use of panel space are essential.
Key Advantages
- Reliable overvoltage and undervoltage monitoring for single-phase AC/DC circuits.
- Wide 24–240 V AC/DC control supply range supports flexible installation.
- Four selectable measuring ranges covering voltages from 3–600 V.
- True RMS measurement provides dependable voltage monitoring.
- Two configurable changeover contacts allow common or separate fault signalling.
- Adjustable upper and lower voltage thresholds for customised monitoring.
- Selectable ON-delay or OFF-delay helps prevent unnecessary switching during transient conditions.
- Configurable latching function supports fault indication and reset requirements.
- Push-in terminals simplify wiring and reduce installation time.
- Compact DIN rail construction saves space inside electrical control cabinets.
Key Features
- ABB CM-EFS.2P voltage monitoring relay.
- 24–240 V AC/DC rated control supply voltage.
- 3–600 V AC/DC overall measuring range.
- Four selectable measuring ranges: 3–30 V, 6–60 V, 30–300 V and 60–600 V.
- Simultaneous monitoring of overvoltage and undervoltage conditions.
- True RMS voltage measuring principle.
- Two changeover (SPDT) output contacts rated at 250 V / 4 A.
- Configurable outputs for common fault signalling or separate upper and lower voltage alarms.
- Adjustable tripping delay: instantaneous or 0.1–30 s.
- Selectable ON-delay and OFF-delay functions.
- Configurable open-circuit or closed-circuit operating principle.
- Selectable latching function.
- Fixed 5% hysteresis relative to the threshold value.
- Three front-panel LEDs for operating and relay status indication.
- Front-face controls for threshold and function adjustment.
- Easy Connect Technology push-in terminals for convenient wiring.
- Tool-free DIN rail mounting and removal.
- Compact 22.5 mm housing width.
Technical Specifications
- Manufacturer: ABB
- Series: CM-EFS Measuring and Monitoring Relays
- Model: CM-EFS.2P
- ABB order code: 1SVR740750R0400
- Product type: Electronic voltage monitoring relay
- Monitoring function: Overvoltage and undervoltage monitoring
- Monitored voltage type: Single-phase AC/DC
- Rated control supply voltage: 24–240 V AC/DC
- Measuring range 1: 3–30 V AC/DC
- Measuring range 2: 6–60 V AC/DC
- Measuring range 3: 30–300 V AC/DC
- Measuring range 4: 60–600 V AC/DC
- Measuring principle: True RMS
- Voltage thresholds: Independently adjustable upper and lower limits
- Hysteresis: Fixed 5% of threshold value
- Output contacts: 2 changeover (SPDT) contacts
- Output configuration: 1 × 2 c/o common signal or 2 × 1 c/o separate signals
- Contact rating: 250 V / 4 A
- Tripping delay: 0 s or adjustable 0.1–30 s
- Delay functions: Selectable ON-delay or OFF-delay
- Operating principle: Selectable open-circuit or closed-circuit
- Latching function: Configurable
- Terminal type: Push-in, screwless terminals
- Connection technology: ABB Easy Connect Technology
- Status indication: 3 LEDs
- Mounting type: DIN rail mounting
- Housing protection rating: IP50
- Terminal protection rating: IP20
- Operating temperature: −20 to +60 °C
- Storage temperature: −40 to +85 °C
- Dimensions (H × W × D): 85.6 × 22.5 × 103.7 mm
- Net weight: 0.146 kg
- Housing material classification: UL 94 V-0
- EAN: 4016779876513
- Product category: Measuring and Monitoring Relays
Reliable Voltage Monitoring for Industrial Electrical Systems
Voltage monitoring relays such as the ABB CM-EFS.2P continuously supervise electrical voltages and respond when measured values exceed configured upper or lower thresholds. By detecting abnormal voltage conditions, the relay can provide alarm signals or initiate external control actions to help protect connected equipment against unsuitable operating voltages. Its true RMS measuring principle supports reliable measurement of AC voltages, while its selectable ranges allow the same device to be used across different voltage monitoring applications.
The CM-EFS.2P provides flexible fault signalling through two configurable changeover contacts. These can operate together for common voltage fault indication or separately to distinguish overvoltage and undervoltage conditions. Adjustable delays, selectable operating principles and optional latching enable the relay to be configured for different protection and automation requirements. Combined with push-in terminals and compact DIN rail mounting, these functions make the CM-EFS.2P suitable for industrial control cabinets, electrical distribution assemblies and automated machinery.
Typical Applications
- Industrial electrical supply voltage monitoring.
- Overvoltage and undervoltage protection circuits.
- Single-phase AC and DC control systems.
- Electrical distribution panels and switchboards.
- Industrial machinery and equipment protection.
- PLC-controlled automation and alarm systems.
- Battery and DC power supply voltage supervision.
- Control transformer secondary voltage monitoring.
- Process control and manufacturing equipment.
- OEM control panels and industrial automation assemblies.
