Why Choose the ABB CM-PVS.81P Three-Phase Monitoring Relay?
The ABB CM-PVS.81P (1SVR740794R2300) is a versatile industrial three-phase monitoring relay designed to supervise the voltage and phase conditions of three-phase AC power supplies. Part of ABB's CM-PVS measuring and monitoring relay range, it combines phase failure detection, selectable phase sequence monitoring, adjustable overvoltage monitoring and adjustable undervoltage monitoring in one compact device.
Operating across a 200–400 V AC line-to-line measuring and supply range, the CM-PVS.81P is powered directly by the monitored three-phase circuit. Its independently adjustable upper and lower voltage thresholds allow the relay to be configured for the acceptable voltage limits of connected machinery and industrial equipment. The true RMS (TRMS) measuring principle provides effective AC voltage evaluation.
The CM-PVS.81P features two changeover (SPDT) output contacts rated at 250 V / 4 A, a selectable instantaneous or 0.1–30 s tripping delay, and ON-delayed or OFF-delayed operation. With ABB Easy Connect push-in terminals, three LED status indicators and a compact 22.5 mm DIN rail housing, it is well suited to industrial motor control, electrical distribution, machinery automation and supply fault signalling.
Key Advantages
- Comprehensive three-phase supervision in a single compact relay.
- Wide 200–400 V AC measuring range supports compatible three-phase installations.
- Phase failure detection helps identify loss of a supply phase.
- Selectable phase sequence monitoring helps detect incorrect phase rotation.
- Adjustable overvoltage threshold for application-specific high-voltage supervision.
- Adjustable undervoltage threshold for application-specific low-voltage supervision.
- True RMS measurement evaluates the effective AC voltage.
- Self-powered operation eliminates a separate auxiliary supply connection.
- No neutral connection required for the standard three-phase monitoring arrangement.
- Two changeover output contacts provide flexible control and signalling options.
- 250 V / 4 A contact rating for compatible industrial control circuits.
- Adjustable 0.1–30 s tripping delay or instantaneous operation.
- Selectable ON-delayed or OFF-delayed response supports different monitoring requirements.
- Three LED indicators provide convenient operating status information.
- Easy Connect push-in terminals simplify panel wiring.
- 22.5 mm DIN rail housing helps conserve control cabinet space.
Key Features
- Manufacturer: ABB.
- Product model: CM-PVS.81P.
- ABB order code: 1SVR740794R2300.
- Product type: Three-phase monitoring relay.
- Rated control supply voltage: 3 × 200–400 V AC.
- Measuring voltage range: 200–400 V AC line-to-line.
- Rated frequency: 50/60 Hz.
- Phase failure monitoring: Integrated.
- Phase sequence monitoring: Selectable.
- Overvoltage monitoring: Adjustable threshold.
- Undervoltage monitoring: Adjustable threshold.
- Measuring principle: True RMS (TRMS).
- Supply arrangement: Powered by the measuring circuit.
- Start-up delay: 200 ms.
- Tripping delay: 0 s or 0.1–30 s.
- Tripping delay modes: ON-delayed or OFF-delayed.
- Output contacts: 2 changeover (SPDT).
- Output contact rating: 250 V / 4 A.
- Status indication: 3 LEDs.
- Connection technology: ABB Easy Connect push-in terminals.
- Mounting: DIN rail.
- Housing width: 22.5 mm.
- Operating ambient temperature: −25 to +60 °C.
- Optional accessory: Sealable transparent cover.
Technical Specifications
- Manufacturer: ABB
- Product series: CM-PVS
- Model: CM-PVS.81P
- ABB order code: 1SVR740794R2300
- ABB product group: 310921-Measuring & Monitoring Relays
- Product type: Three-phase monitoring relay
- Rated control supply voltage: 3 × 200–400 V AC
- Rated measuring voltage: 3 × 200–400 V AC
- Line-to-line measuring range: 200–400 V AC
- Rated frequency: 50/60 Hz
- Supply and measuring terminals: L1, L2, L3
- Separate auxiliary supply: Not required
- Neutral connection: Not required for standard monitoring
- Measuring principle: True RMS (TRMS)
- Phase failure monitoring: Yes
- Phase sequence monitoring: Selectable; can be switched off
- Overvoltage monitoring: Yes
- Undervoltage monitoring: Yes
- Upper voltage threshold: Adjustable as an absolute voltage value
- Lower voltage threshold: Adjustable as an absolute voltage value
- Start-up delay: 200 ms
- Tripping delay: 0 s or 0.1–30 s
- Tripping delay modes: 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 to output: 600 V
- Rated insulation voltage, between output circuits: 300 V
- Status indication: 3 LEDs
- Terminal type: Easy Connect push-in terminals
- Connection technology: Screwless spring-clamp connection
- Housing protection rating: IP50
- Terminal protection rating: IP20
- Housing flammability classification: UL 94 V-0
- 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: 0.128 kg
- EAN / GTIN-13: 4016779876490
- Minimum order quantity: 1 piece
- Customs tariff number: 85364900
- RoHS status: Following EU Directive 2011/65/EU
Comprehensive Three-Phase Power Supply Monitoring
The ABB CM-PVS.81P continuously supervises a compatible three-phase AC supply by measuring the voltages between L1, L2 and L3.
Phase failure monitoring helps detect the loss of a supply phase. This is important in industrial motor installations, where phase loss can result in abnormal current distribution, reduced torque, overheating and possible equipment damage.
Phase sequence monitoring helps identify incorrect phase rotation. Reversed phase rotation can cause three-phase motors to turn in the wrong direction, potentially affecting pumps, fans, conveyors, compressors and other direction-sensitive equipment.
The phase sequence monitoring function can be disabled where phase rotation supervision is not required.
In addition to phase-related faults, the CM-PVS.81P provides overvoltage and undervoltage monitoring to detect conditions outside the configured acceptable voltage range.
These monitoring functions make the CM-PVS.81P suitable for industrial applications requiring more comprehensive three-phase supervision than a basic phase failure relay.
Adjustable Overvoltage and Undervoltage Thresholds
The CM-PVS.81P features independently adjustable upper and lower voltage thresholds, allowing the acceptable operating voltage range to be configured for the installation.
Unlike three-phase monitoring relays with fixed percentage-based thresholds, the CM-PVS.81P allows the overvoltage and undervoltage response levels to be set as absolute voltage values.
The relay operates across a 200–400 V AC line-to-line measuring range. The configured thresholds must be selected within the device's permitted adjustment limits and should reflect the operating requirements of the connected equipment.
When the measured voltage exceeds the configured upper threshold or falls below the lower threshold, the relay changes its output state according to the selected timing and operating configuration.
This adjustable-threshold design is useful where equipment requires application-specific voltage limits rather than a fixed tolerance around a nominal supply voltage.
True RMS Measurement for Effective Voltage Evaluation
The ABB CM-PVS.81P uses a true RMS (TRMS) measuring principle to evaluate the monitored AC voltage.
True RMS measurement considers the effective value of the voltage waveform, providing a suitable basis for monitoring AC electrical supplies.
The relay is powered directly by the monitored three-phase circuit, meaning the measuring voltage also serves as the control supply.
This arrangement simplifies wiring because a separate auxiliary supply connection is not required.
The CM-PVS.81P is designed for three-phase AC installations with line-to-line voltages within its specified 200–400 V AC range. It should not be connected directly to a supply exceeding its rated operating limits.
Adjustable Tripping Delay and Configurable Switching Response
The CM-PVS.81P provides a selectable instantaneous tripping setting of 0 s or an adjustable delay from 0.1–30 s.
This flexibility allows the relay to be configured for different monitoring requirements. An instantaneous setting supports rapid fault signalling, while a suitable delay can help prevent unnecessary switching caused by brief supply disturbances.
The device also supports selectable ON-delayed or OFF-delayed tripping, providing additional control over the output response.
A specified 200 ms start-up delay is included in the relay's operating characteristics.
The selected tripping delay should reflect the requirements of the connected equipment. Where rapid fault detection is essential, an unnecessarily long delay may be unsuitable.
The ABB CM-PVS.81P provides two changeover (SPDT) output contacts, each suitable for switching within the device's specified ratings.
The output contact rating is 250 V / 4 A, allowing the relay to be integrated into compatible industrial control and signalling circuits.
Typical applications include signalling abnormal supply conditions to PLC inputs, activating industrial alarm circuits and participating in suitably designed motor contactor control arrangements.
The two changeover contacts provide flexibility where more than one compatible control or signalling function is required.
The CM-PVS.81P is a monitoring device rather than a replacement for correctly rated motor overload protection, circuit breakers or other protective equipment required by the electrical installation.
Easy Connect Push-In Terminals and Compact DIN Rail Installation
The CM-PVS.81P uses ABB's Easy Connect Technology, featuring screwless push-in terminals for efficient electrical panel wiring.
The spring-clamp terminal design supports maintenance-free electrical connections when installed with suitable conductors according to ABB's wiring instructions.
Its compact dimensions of 85.6 × 22.5 × 103.7 mm allow the relay to occupy only 22.5 mm of DIN rail width.
Three LED indicators provide information about operating and output states, while front-mounted controls allow adjustment of voltage thresholds and tripping delay settings.
The relay is designed for operation at ambient temperatures from −25 to +60 °C, with an IP50 housing and IP20 terminals.
An optional sealable transparent cover is available to help prevent unauthorised changes to the configured settings.
Typical Applications
- Three-phase voltage monitoring in compatible 200–400 V AC systems.
- Phase failure detection in industrial motor control circuits.
- Phase sequence monitoring for direction-sensitive machinery.
- Adjustable overvoltage monitoring in electrical control panels.
- Adjustable undervoltage detection in industrial installations.
- Industrial motor control centres.
- Pump motor supply monitoring.
- Fan and ventilation equipment.
- Compressor control systems.
- Conveyor and material handling machinery.
- Manufacturing and processing equipment.
- Industrial electrical distribution panels.
- PLC-based supply fault signalling.
- OEM machinery requiring configurable voltage thresholds.
- Industrial alarm and interlocking circuits.
- Compact DIN rail panels using push-in terminal monitoring relays.
