Why Choose the ABB CM-PSS.41P Three-Phase Monitoring Relay?
The ABB CM-PSS.41P (1SVR740784R3300) is a compact industrial three-phase monitoring relay designed to supervise the electrical condition of nominal 400 V AC three-phase power supplies. Part of ABB's CM-PSS measuring and monitoring relay family, it combines phase failure detection, selectable phase sequence monitoring, overvoltage monitoring and undervoltage monitoring in one DIN rail-mounted device.
Designed for a 3 × 400 V AC nominal supply, the CM-PSS.41P monitors line-to-line voltages within a specified 360–440 V AC measuring range. Its fixed overvoltage and undervoltage response thresholds are based on ±10% of the nominal voltage, making it a practical solution for installations requiring straightforward supervision of acceptable three-phase supply conditions without independently adjustable voltage thresholds.
The relay provides two changeover (SPDT) output contacts rated at 250 V / 4 A, an adjustable 0 s or 0.1–30 s tripping delay, and selectable ON-delayed or OFF-delayed tripping. ABB's Easy Connect push-in terminals, compact 22.5 mm housing width and self-powered three-phase supply arrangement make the CM-PSS.41P suitable for motor control panels, OEM machinery and industrial electrical distribution systems.
Key Advantages
- Four monitoring functions: Phase failure, phase sequence, overvoltage and undervoltage.
- Designed for nominal 400 V AC three-phase supplies, commonly used in industrial installations.
- 360–440 V AC line-to-line measuring range for nominal 400 V AC systems.
- Fixed ±10% voltage thresholds simplify commissioning.
- Phase failure detection helps identify loss of a supply phase.
- Selectable phase sequence monitoring helps identify incorrect phase rotation.
- Two changeover contacts allow flexible fault signalling and control integration.
- 250 V / 4 A contact rating for compatible industrial control circuits.
- Adjustable tripping delay from 0.1–30 s or instantaneous operation.
- Selectable ON-delayed or OFF-delayed tripping supports different control requirements.
- Self-powered operation eliminates the need for a separate auxiliary supply.
- No neutral connection required for the standard three-phase monitoring arrangement.
- Easy Connect push-in terminals simplify wiring and panel assembly.
- Compact 22.5 mm DIN rail housing conserves cabinet space.
- −25 to +60 °C operating temperature range supports demanding industrial environments.
- Optional sealable transparent cover helps protect the configured settings.
Key Features
- Manufacturer: ABB.
- Product model: CM-PSS.41P.
- ABB order code: 1SVR740784R3300.
- Product category: Three-phase monitoring relay.
- Nominal supply and measuring voltage: 3 × 400 V AC.
- Line-to-line measuring range: 360–440 V AC.
- Supply frequency: 50/60 Hz.
- Phase failure monitoring: Integrated.
- Phase sequence monitoring: Selectable.
- Overvoltage monitoring: Integrated.
- Undervoltage monitoring: Integrated.
- Voltage response thresholds: Fixed at ±10% of nominal voltage.
- Nominal undervoltage threshold: 360 V AC.
- Nominal overvoltage threshold: 440 V AC.
- Start-up delay: 200 ms.
- Tripping delay: 0 s or 0.1–30 s.
- Tripping delay configuration: ON-delayed or OFF-delayed.
- Output contacts: 2 changeover (SPDT).
- Output contact rating: 250 V / 4 A.
- Terminal technology: ABB Easy Connect push-in terminals.
- Mounting: DIN rail.
- Housing width: 22.5 mm.
Technical Specifications
- Manufacturer: ABB
- Product series: CM-PSS
- Model: CM-PSS.41P
- ABB order code: 1SVR740784R3300
- ABB product group: 310921-Measuring & Monitoring Relays
- Product type: Three-phase monitoring relay
- Rated control supply voltage: 400 V AC, line-to-line
- Rated three-phase measuring voltage: 3 × 400 V AC
- Measuring range: 360–440 V AC, line-to-line
- Rated frequency: 50/60 Hz
- Supply and measuring connections: L1, L2, L3
- Separate auxiliary supply: Not required
- Neutral connection: Not required for standard operation
- Phase failure monitoring: Yes
- Phase sequence monitoring: Selectable
- Overvoltage monitoring: Yes
- Undervoltage monitoring: Yes
- Voltage threshold adjustment: Fixed, not independently adjustable
- Nominal undervoltage response level: 360 V AC (−10%)
- Nominal overvoltage response level: 440 V AC (+10%)
- Start-up delay: 200 ms
- Tripping delay: 0 s or 0.1–30 s
- Tripping delay functions: ON-delayed or OFF-delayed
- Output configuration: 2 changeover (SPDT) contacts
- Output contact rating: 250 V / 4 A
- UL/CSA contact rating: B300
- Maximum UL/CSA output operating voltage: 300 V AC
- Rated insulation voltage, input/output circuits: 600 V
- Rated insulation voltage, between output circuits: 300 V
- Terminal type: Screwless Easy Connect push-in terminals
- Connection technology: Spring-clamp connection
- Housing protection rating: IP50
- Mounting type: DIN rail mounting
- Operating ambient temperature: −25 to +60 °C
- Storage temperature: −40 to +85 °C
- Dimensions (H × W × D): 85.6 × 22.5 × 103.7 mm
- Product net weight: 0.123 kg
- EAN / GTIN-13: 4016779852005
- Minimum order quantity: 1 piece
- Customs tariff number: 85364900
- RoHS status: Following EU Directive 2011/65/EU
Comprehensive Three-Phase Supply Monitoring
The ABB CM-PSS.41P supervises key electrical parameters of a nominal 400 V AC three-phase supply, providing switching signals when monitored conditions move outside the relay's defined operating limits.
Phase failure detection helps identify the loss of one of the three supply phases. Phase loss can cause abnormal operation in three-phase motors, including reduced torque, excessive current in the remaining phases and overheating.
Phase sequence monitoring detects incorrect phase rotation when the function is enabled. This is useful for equipment where the direction of motor rotation is important, including pumps, compressors, fans and conveyors.
The relay also monitors overvoltage and undervoltage. These functions help identify supply conditions that may affect connected motors, contactors, power supplies and other industrial equipment.
The CM-PSS.41P provides monitoring and control signals rather than direct power-circuit protection. Suitable circuit breakers, overload protection and other protective devices remain necessary where required by the installation.
Fixed ±10% Voltage Thresholds for 400 V AC Systems
The CM-PSS.41P is designed for a nominal 400 V AC line-to-line supply and uses fixed voltage monitoring thresholds corresponding to ±10% of nominal voltage.
The nominal response levels are:
- Undervoltage: 360 V AC line-to-line.
- Nominal supply: 400 V AC line-to-line.
- Overvoltage: 440 V AC line-to-line.
This fixed-threshold arrangement reduces the number of settings required during commissioning and is suitable where the specified voltage limits align with the equipment's operating requirements.
The thresholds are not independently adjustable. Applications requiring user-adjustable upper and lower voltage limits should be evaluated using a suitable ABB CM-PVS monitoring relay instead.
Because the response levels are based on the nominal 400 V AC rating, the CM-PSS.41P should not be treated as a universal three-phase monitoring relay for arbitrary nominal voltages.
Selectable Phase Sequence Monitoring
The ABB CM-PSS.41P includes selectable phase sequence monitoring to help detect incorrect phase rotation in the three-phase supply.
Incorrect phase rotation can cause connected motors to turn in the opposite direction from that intended. Depending on the machinery, this may lead to reduced performance, incorrect process operation or mechanical damage.
When phase sequence monitoring is enabled, the relay can signal an incorrect phase rotation condition through its output contacts.
The function can also be disabled where phase sequence monitoring is not required by the application.
This flexibility allows the CM-PSS.41P to be used in a broad range of three-phase monitoring arrangements while retaining phase failure and voltage supervision.
Adjustable Tripping Delay and Configurable Response
The CM-PSS.41P provides an adjustable tripping delay with settings of 0 s or 0.1–30 s.
The delay can help accommodate short-duration supply disturbances that do not require an immediate control response, while the instantaneous setting supports applications where rapid signalling is preferred.
ON-delayed and OFF-delayed tripping are selectable, allowing the output response to be configured for the control arrangement.
The relay also has a specified 200 ms start-up delay.
Tripping delay settings should be selected according to the operating characteristics of the connected equipment. Excessive delay may be unsuitable where rapid disconnection is needed to prevent damage or hazardous operation.
The ABB CM-PSS.41P provides two changeover (SPDT) contacts rated at 250 V / 4 A.
These contacts can be incorporated into suitable motor control circuits, PLC inputs, alarm systems and electrical interlocking arrangements.
The two changeover outputs allow the monitoring relay to provide switching signals for more than one compatible control function, subject to the applicable contact ratings and wiring arrangement.
For example, the relay may be used to signal an abnormal three-phase supply condition to a PLC while also participating in a suitably designed motor contactor control circuit.
The output contacts are intended for control and signalling duties within their rated limits and should not be used to switch a motor's main power conductors directly unless the complete application and ratings specifically permit it.
Easy Connect Push-In Terminals and Compact DIN Rail Installation
The CM-PSS.41P features ABB's Easy Connect Technology, using screwless push-in terminals to simplify installation in industrial electrical panels.
The spring-clamp connection system supports efficient wiring and maintenance-free terminal connections when installed with compatible conductors in accordance with ABB's instructions.
The relay measures 85.6 × 22.5 × 103.7 mm, occupying only 22.5 mm of DIN rail width.
Its compact housing is particularly useful in motor control centres, machinery cabinets and electrical distribution enclosures where panel space is limited.
The operating ambient temperature range is −25 to +60 °C, and the device has an IP50 housing protection rating.
An optional sealable transparent cover is available to help prevent unauthorised changes to the configuration controls.
Typical Applications
- Three-phase supply monitoring in nominal 400 V AC industrial installations.
- Phase failure detection for industrial motors.
- Phase sequence supervision for direction-sensitive machinery.
- Overvoltage monitoring in electrical distribution panels.
- Undervoltage monitoring in industrial control systems.
- Motor control centres and electrical control cabinets.
- Pump motor control and protection arrangements.
- Fan and ventilation systems.
- Compressor control panels.
- Conveyor and material handling machinery.
- Manufacturing and processing equipment.
- OEM machinery requiring fixed voltage monitoring thresholds.
- PLC-based supply fault signalling.
- Industrial alarm and interlocking circuits.
- Three-phase electrical installations requiring configurable tripping delays.
- Compact DIN rail control panels using push-in terminal connections.
