Why Choose the ABB CM-PSS.41S Three-Phase Monitoring Relay?
The ABB CM-PSS.41S (1SVR730784R3300) is a compact, industrial-grade three-phase monitoring relay designed to supervise overvoltage, undervoltage, phase failure and phase sequence in three-phase electrical installations. Part of ABB's CM-PSS monitoring relay range, it provides dependable supply monitoring for motors, pumps, compressors, production machinery and industrial automation equipment.
Designed for a nominal three-phase voltage of 400 V AC, the CM-PSS.41S monitors line-to-line voltages using fixed ±10% voltage thresholds. Its specified monitoring limits are 360 V AC for undervoltage and 440 V AC for overvoltage. These predefined limits simplify commissioning and provide consistent voltage supervision for compatible 400 V three-phase systems.
The relay also detects phase failure and offers selectable phase sequence monitoring, helping identify supply conditions that could affect motor operation or cause incorrect rotation. A selectable ON-delay or OFF-delay, adjustable from 0.1 to 30 seconds or set to zero, allows the response to be adapted to the requirements of the installation.
With two change-over output contacts rated at 250 V AC / 4 A, the ABB CM-PSS.41S can provide switching signals to compatible contactors, motor starter circuits, alarms and automation controllers. Its self-powered design, compact 22.5 mm DIN rail-mounted housing and screw-terminal connections make it a practical choice for industrial control cabinets and electrical distribution panels.
Key Advantages
- Comprehensive three-phase monitoring for industrial electrical installations.
- Detects overvoltage, undervoltage and phase failure.
- Selectable phase sequence monitoring helps identify incorrect phase rotation.
- Designed specifically for 400 V AC nominal three-phase supplies.
- Fixed ±10% voltage thresholds simplify configuration and commissioning.
- 360–440 V AC monitoring limits provide defined voltage supervision.
- Two change-over output contacts support flexible control and alarm signalling.
- 250 V AC / 4 A contact rating for appropriately rated control circuits.
- Selectable ON-delayed or OFF-delayed operation.
- Adjustable 0.1–30 second tripping delay, with a separate zero-delay setting.
- Self-powered operation eliminates the need for a separate auxiliary supply.
- Suitable for monitoring three-phase systems without a neutral connection.
- Front-mounted controls support straightforward installation and commissioning.
- Integrated status indication assists fault identification and maintenance.
- Compact 22.5 mm housing width saves valuable control cabinet space.
- Double-chamber cage screw terminals provide secure electrical connections.
- Optional sealable transparent cover helps protect settings against unauthorised adjustment.
- Helps reduce equipment downtime associated with abnormal three-phase supply conditions.
Key Features
- ABB CM-PSS three-phase monitoring relay series.
- CM-PSS.41S model with screw-terminal connection technology.
- 400 V AC nominal three-phase measuring voltage.
- 50/60 Hz rated supply frequency.
- Overvoltage monitoring with a fixed +10% threshold.
- Undervoltage monitoring with a fixed -10% threshold.
- 360 V AC undervoltage threshold.
- 440 V AC overvoltage threshold.
- Phase failure detection.
- Selectable phase sequence monitoring.
- Monitoring through L1, L2 and L3 connections.
- No neutral connection required.
- Two change-over (SPDT) relay contacts.
- 250 V AC / 4 A output contact rating.
- Selectable ON-delay or OFF-delay.
- 0 seconds or 0.1–30 seconds adjustable tripping delay.
- 200 ms start-up delay.
- Powered directly by the monitored three-phase supply.
- Front-mounted configuration controls and status indicators.
- Double-chamber cage screw-terminal technology.
- DIN rail mounting for industrial electrical panels.
- IP50 housing protection and IP20 terminal protection.
- Optional sealable transparent cover for additional setting protection.
Technical Specifications
- Manufacturer: ABB
- Series: CM-PSS Three-Phase Monitoring Relays
- Model: CM-PSS.41S
- ABB order code: 1SVR730784R3300
- ABB product group: 310921-Measuring & Monitoring Relays
- Product type: Three-phase monitoring relay
- Monitoring functions: Phase failure, phase sequence, overvoltage and undervoltage
- Rated control supply voltage: 3 × 400 V AC
- Nominal measuring voltage: 400 V AC line-to-line
- Undervoltage threshold: 360 V AC (-10%)
- Overvoltage threshold: 440 V AC (+10%)
- Specified monitoring limits: 360–440 V AC line-to-line
- Voltage threshold adjustment: Fixed thresholds
- Phase sequence monitoring: Selectable
- Supply frequency: 50/60 Hz
- Supply type: AC
- Monitored phases: L1, L2 and L3
- Neutral connection: Not required
- Tripping delay: 0 seconds or adjustable from 0.1 to 30 seconds
- Tripping delay mode: ON-delay or OFF-delay, selectable
- Start-up delay: 200 ms
- Auxiliary power supply: Not required; powered by the monitored circuit
- Output contacts: 2 change-over contacts
- Contact configuration: 2 c/o (2 × SPDT)
- Contact rating: 250 V AC / 4 A
- Operating ambient temperature: -25 to +60 °C
- Storage temperature: -40 to +85 °C
- Housing protection rating: IP50
- Terminal protection rating: IP20
- Terminal type: Screw terminals
- Connection technology: Double-chamber cage screw terminals
- Mounting type: DIN rail mounting
- 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: 0.132 kg
- EAN: 4016779851824
- Minimum order quantity: 1 piece
- Customs tariff number: 85364900
- RoHS status: Following EU Directive 2011/65/EU
- Application category: Industrial three-phase voltage monitoring and control
Reliable Three-Phase Voltage Monitoring for Industrial Equipment Protection
Industrial machinery depends on stable and correctly connected three-phase electrical supplies. Excessive voltage, insufficient voltage, missing phases and incorrect phase rotation can disrupt equipment operation, increase electrical and thermal stress, and cause unexpected production stoppages. The ABB CM-PSS.41S three-phase monitoring relay helps identify these abnormal conditions and provides switching signals for appropriately designed protective control circuits.
The CM-PSS.41S monitors the connected L1, L2 and L3 conductors and evaluates the line-to-line voltage against its predefined limits. Designed for a 400 V AC nominal supply, the relay uses fixed voltage thresholds of 360 V AC and 440 V AC. If the monitored voltage falls below the lower limit or exceeds the upper limit, the relay responds according to the selected operating and delay settings.
The fixed ±10% voltage monitoring thresholds make the CM-PSS.41S particularly suitable for installations where a predefined voltage tolerance is required. Because the limits are factory-defined, commissioning personnel do not need to calculate and manually adjust separate upper and lower voltage settings.
In addition to voltage monitoring, the relay provides phase failure detection. Loss of a phase can affect three-phase motor operation and may result in overheating or reduced performance. The CM-PSS.41S can signal this condition to a connected control system, allowing appropriate protective action to be initiated.
The selectable phase sequence monitoring function helps detect incorrect phase rotation. This is important for equipment such as pumps, compressors, fans and conveyors, where reverse rotation may damage machinery or interfere with the intended process. Phase sequence monitoring can be enabled when required by the installation.
For applications where response timing is important, the relay offers ON-delayed or OFF-delayed operation, with a selectable delay of 0 seconds or 0.1–30 seconds. This allows engineers to coordinate the monitoring response with the wider control system and, where appropriate, avoid unnecessary switching caused by brief voltage disturbances.
The CM-PSS.41S provides two change-over output contacts that can interface with compatible motor starter circuits, contactors, programmable logic controllers and alarm systems. These contacts are intended for control and signalling purposes. The relay does not replace a circuit breaker, motor overload relay or appropriately rated main power switching device.
Its self-powered construction simplifies installation because the monitored three-phase circuit also supplies the relay. Combined with compact DIN rail mounting, screw-terminal connections and front-mounted controls, the ABB CM-PSS.41S is well suited to new industrial control panels and upgrades to existing electrical installations.
Typical Applications
- Three-phase voltage monitoring in industrial electrical systems.
- Overvoltage and undervoltage detection for 400 V AC networks.
- Phase failure monitoring in motor starter circuits.
- Incorrect phase sequence detection during installation and commissioning.
- Industrial motor control centres.
- Three-phase pump and pumping installations.
- Compressors and refrigeration machinery.
- Industrial fans, blowers and ventilation systems.
- Conveyor systems and material handling equipment.
- Automated manufacturing and production machinery.
- Industrial electrical distribution panels.
- Process control and automation systems.
- OEM machinery requiring three-phase supply supervision.
- Electrical alarm circuits for abnormal voltage conditions.
- Control systems requiring selectable voltage fault response delays.
