Why Choose the ABB CM-ESS.2S Voltage Monitoring Relay?
The ABB CM-ESS.2S (1SVR730830R0400) is a versatile single-phase AC/DC voltage monitoring relay designed to detect overvoltage and undervoltage conditions in industrial electrical systems. Part of ABB's CM-ESS measuring and monitoring relay range, it provides dependable voltage supervision for control circuits, machinery, power supplies and industrial automation equipment.
Operating from a wide 24–240 V AC/DC control supply, the CM-ESS.2S features four selectable voltage measuring ranges: 3–30 V, 6–60 V, 30–300 V and 60–600 V. These ranges allow one relay model to monitor a variety of AC and DC voltages, reducing the need for different monitoring devices across industrial installations.
The relay can be configured for either overvoltage or undervoltage monitoring, with an adjustable switching threshold, 3–30% hysteresis and a selectable 0-second or 0.1–30-second tripping delay. Its RMS measuring principle, open-circuit operating principle and two change-over output contacts support reliable integration into electrical control and alarm systems.
With two change-over (SPDT) contacts rated at 250 V / 4 A, three LED status indicators and a compact 22.5 mm DIN rail-mounted housing, the ABB CM-ESS.2S offers flexible monitoring and straightforward installation. Double-chamber cage screw terminals and front-mounted adjustment controls make it particularly suitable for industrial control cabinets, electrical distribution panels and OEM machinery.
Key Advantages
- Reliable AC and DC voltage monitoring for industrial electrical systems.
- Wide 24–240 V AC/DC control supply supports different control voltage arrangements.
- Four selectable measuring ranges provide flexibility across multiple applications.
- Monitors voltages from 3 V to 600 V using the appropriate selected range.
- Selectable overvoltage or undervoltage monitoring within one device.
- Adjustable voltage threshold allows application-specific fault detection.
- Adjustable 3–30% hysteresis helps prevent repeated switching near the threshold.
- Selectable instantaneous or delayed tripping supports different protection strategies.
- 0.1–30-second adjustable tripping delay helps accommodate temporary voltage fluctuations.
- RMS measuring principle supports dependable voltage evaluation.
- Two change-over output contacts provide flexible control and alarm signalling.
- 250 V / 4 A contact rating for appropriately rated control circuits.
- Open-circuit operating principle provides defined output switching behaviour.
- Three LED indicators provide convenient operating and fault status information.
- Compact 22.5 mm housing width saves space in electrical control cabinets.
- Double-chamber cage screw terminals support secure electrical connections.
- Front-mounted adjustment controls simplify commissioning and maintenance.
- Optional sealable transparent cover helps prevent unauthorised changes to settings.
- Suitable for industrial power supply supervision, machinery protection and automation systems.
Key Features
- ABB CM-ESS single-phase voltage monitoring relay series.
- CM-ESS.2S model with screw-terminal connection technology.
- 24–240 V AC/DC rated control supply voltage.
- AC and DC voltage monitoring.
- 3–30 V measuring range.
- 6–60 V measuring range.
- 30–300 V measuring range.
- 60–600 V measuring range.
- Four selectable measuring ranges in one device.
- Overvoltage monitoring.
- Undervoltage monitoring.
- Selectable overvoltage or undervoltage function.
- Adjustable voltage monitoring threshold.
- 3–30% adjustable hysteresis relative to the threshold.
- RMS measuring principle.
- Open-circuit operating principle.
- 0-second instantaneous tripping setting.
- 0.1–30-second adjustable ON-delay.
- Two change-over (SPDT) relay contacts.
- 250 V / 4 A output contact rating.
- Three LED status indicators.
- Front-mounted configuration controls.
- Double-chamber cage screw-terminal connections.
- 22.5 mm compact housing width.
- DIN rail mounting for industrial electrical panels.
- Optional ABB COV.11 sealable transparent cover.
Technical Specifications
- Manufacturer: ABB
- Series: CM-ESS Voltage Monitoring Relays
- Model: CM-ESS.2S
- ABB order code: 1SVR730830R0400
- ABB product group: 310921-Measuring & Monitoring Relays
- Product type: Single-phase voltage monitoring relay
- Primary function: AC/DC overvoltage or undervoltage monitoring
- Rated control supply voltage: 24–240 V AC/DC
- Supply type: AC/DC
- Measuring voltage type: AC or DC
- Overall measuring capability: 3–600 V, depending on selected range
- Measuring range 1: 3–30 V
- Measuring range 2: 6–60 V
- Measuring range 3: 30–300 V
- Measuring range 4: 60–600 V
- Number of measuring ranges: 4
- Monitoring functions: Overvoltage or undervoltage, selectable
- Voltage threshold: Adjustable within the selected measuring range
- Hysteresis: Adjustable from 3–30% of the threshold value
- Measuring principle: RMS
- Operating principle: Open-circuit principle
- Tripping delay: 0 seconds or adjustable from 0.1–30 seconds
- Delay type: ON-delay
- Output contacts: 2 change-over contacts
- Contact configuration: 2 c/o (2 × SPDT)
- Contact rating: 250 V / 4 A
- Status indication: 3 LEDs
- Operating ambient temperature: -20 to +60 °C
- Storage temperature: -40 to +85 °C
- Terminal type: Screw terminals
- Connection technology: Double-chamber cage screw terminals
- Mounting type: DIN rail mounting
- Housing width: 22.5 mm
- Product height: 85.6 mm
- Product width: 22.5 mm
- Product depth: 103.7 mm
- Dimensions (H × W × D): 85.6 × 22.5 × 103.7 mm
- Net weight: 0.153 kg
- EAN / GTIN: 4016779852166
- Minimum order quantity: 1 piece
- Customs tariff number: 85364900
- RoHS status: Following EU Directive 2011/65/EU
- Housing material: UL 94 V-0 fire protection classification
- Optional accessory: ABB COV.11 sealable transparent cover, 1SVR730005R0100
- Application category: Industrial single-phase AC/DC voltage monitoring and control
Reliable AC/DC Voltage Monitoring for Industrial Electrical Systems
Stable electrical voltage is essential for reliable operation of industrial control systems, automation equipment and electrical machinery. Excessive voltage can place additional stress on electrical components, while insufficient voltage can cause control devices to malfunction, contactors to release unexpectedly or connected equipment to operate outside its intended limits. The ABB CM-ESS.2S voltage monitoring relay helps detect these conditions and provides switching signals for appropriately designed protective control circuits.
The CM-ESS.2S is designed for single-phase AC and DC voltage monitoring. It offers four selectable measuring ranges: 3–30 V, 6–60 V, 30–300 V and 60–600 V. These overlapping ranges allow the monitoring threshold to be matched to the electrical system being supervised. The selected measuring range must be appropriate for the actual monitored voltage and installation requirements.
The relay uses an RMS measuring principle to evaluate the monitored voltage. This provides a consistent basis for AC voltage measurement while also supporting DC voltage monitoring. Unlike a three-phase monitoring relay, the CM-ESS.2S supervises a single voltage measuring circuit and does not provide phase sequence or three-phase imbalance monitoring.
For overvoltage monitoring, the relay can be configured to detect when the measured voltage exceeds the selected threshold. This is useful for supervising control supplies, industrial power systems and equipment that must remain below a specified maximum voltage.
For undervoltage monitoring, the relay can identify when the measured voltage falls below the configured threshold. This function is particularly useful for detecting insufficient supply voltage in automation panels, machine control circuits and other electrical installations where low voltage may affect reliable operation.
The adjustable hysteresis allows engineers to establish a defined difference between the switching and reset points. Adjustable from 3% to 30% of the threshold value, hysteresis helps prevent repeated output switching when the monitored voltage fluctuates close to the configured limit.
The CM-ESS.2S also provides a configurable ON-delay. The relay can operate without an intentional tripping delay or use a delay adjustable from 0.1 to 30 seconds. This helps coordinate the monitoring response with the wider control system and can reduce unnecessary switching caused by brief voltage fluctuations where delayed operation is acceptable.
With its open-circuit operating principle, the output relay energises when the configured monitoring condition is met. The exact switching response depends on the selected overvoltage or undervoltage function and the configured delay. Engineers should verify the intended contact behaviour during commissioning, particularly where the output is used in a protective shutdown circuit.
The two change-over output contacts provide flexible integration with external control equipment. For example, one contact may be used for an alarm circuit while the second supplies a status signal to a programmable logic controller. The contacts are intended for appropriately rated control and signalling circuits rather than direct switching of high-power loads.
The relay requires a separate 24–240 V AC/DC control supply connected to its supply terminals. This supply is distinct from the voltage measuring input, allowing the monitored circuit and relay control supply to be selected according to the installation design.
For convenient installation, the ABB CM-ESS.2S features a 22.5 mm-wide DIN rail housing, double-chamber cage screw terminals, front-mounted adjustment controls and three LED indicators. An optional ABB COV.11 sealable transparent cover can be fitted to help prevent unauthorised adjustment of the monitoring settings.
Typical Applications
- Single-phase AC voltage monitoring in industrial electrical systems.
- DC voltage supervision in industrial control circuits.
- Overvoltage detection for electrical equipment and control supplies.
- Undervoltage monitoring for machinery and automation systems.
- Industrial power supply monitoring.
- Electrical distribution and control panels.
- Programmable logic controller supply supervision.
- Machine control cabinets and OEM equipment.
- Industrial automation and process control systems.
- Battery-powered control circuits within the specified measuring ranges.
- Industrial DC power supply monitoring.
- Control voltage supervision for contactors and relays.
- Alarm circuits for abnormal voltage conditions.
- Electrical installations requiring adjustable voltage hysteresis.
- Applications requiring delayed response to temporary voltage disturbances.
- Industrial maintenance and electrical system upgrades.
