Why Choose the ABB CM-PAS.41P Three-Phase Monitoring Relay?
The ABB CM-PAS.41P is a compact three-phase monitoring relay designed to supervise critical phase conditions in industrial three-phase electrical systems. Supplied under ABB order code 1SVR740774R3300, it monitors phase failure, phase sequence and phase unbalance, helping protect motors, machinery and electrical equipment against unsuitable supply conditions.
The CM-PAS.41P operates directly from the monitored three-phase supply, with a 300–500 V AC line-to-line measuring and control supply range. Its adjustable phase-unbalance threshold of 2–25% allows the protection level to be matched to the requirements of the connected equipment.
An adjustable tripping delay of 0 s or 0.1–30 s provides flexibility when responding to supply disturbances, while two changeover (SPDT) output contacts provide convenient integration with contactors, alarms and control systems. Maintenance-free Easy Connect push-in terminals and a slim 22.5 mm DIN rail housing simplify installation in industrial control panels.
Key Advantages
- Monitors phase failure, phase sequence and phase unbalance.
- Designed for 3 × 300–500 V AC three-phase systems.
- 2–25% adjustable phase-unbalance threshold for application-specific protection.
- Selectable 0 s or adjustable 0.1–30 s tripping delay.
- 200 ms start-up delay supports reliable monitoring after energisation.
- Two changeover (SPDT) output contacts for signalling and control.
- The monitored voltage also serves as the control supply, reducing additional wiring.
- Maintenance-free Easy Connect push-in terminals.
- Compact 22.5 mm width conserves DIN rail space.
- Suitable for protecting three-phase motors and machinery against phase-related supply faults.
Key Features
- ABB CM-PAS three-phase monitoring relay series.
- ABB order code 1SVR740774R3300.
- Phase failure detection.
- Phase sequence monitoring.
- Phase unbalance detection.
- 2–25% adjustable phase-unbalance threshold.
- 300–500 V AC line-to-line measuring range.
- Rated control supply voltage equal to the monitored measuring voltage.
- 50/60 Hz rated supply frequency.
- 200 ms start-up delay.
- 0 s or 0.1–30 s adjustable tripping delay.
- 2 c/o (SPDT) output contacts.
- Contacts rated at 250 V / 4 A.
- Push-in / screwless terminal technology.
- Sealable transparent protective cover available as an accessory.
Reliable Phase Failure, Sequence and Unbalance Monitoring
Three-phase motors and machinery can be adversely affected by loss of a phase, incorrect phase sequence or excessive phase unbalance. The ABB CM-PAS.41P continuously supervises these conditions across its 300–500 V AC measuring range and changes the state of its output contacts when a monitored fault condition occurs, allowing the control system to disconnect equipment or generate an alarm.
The adjustable 2–25% phase-unbalance threshold allows monitoring sensitivity to be matched to the application, while the selectable instantaneous or 0.1–30 s tripping delay helps distinguish persistent faults from short-duration disturbances. This combination makes the CM-PAS.41P a practical protection component for three-phase motors, pumps, compressors and industrial machinery.
Typical Applications
- Three-phase motor protection circuits.
- Pumps, fans and ventilation systems.
- Compressors and refrigeration machinery.
- Conveyors and material handling equipment.
- Industrial machinery and production equipment.
- Motor control centres and electrical control panels.
- Phase-sequence verification in three-phase installations.
- Applications requiring phase-failure and phase-unbalance supervision.
