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ABB CM-PFE (1SVR550824R9100) is a three-phase 208–440 V AC monitoring relay with phase failure and phase sequence detection, one SPDT output contact and self-powered operation, designed to protect industrial motors and automation systems against abnormal three-phase supply conditions.
£54.12
The ABB CM-PFE (1SVR550824R9100) is a compact and reliable three-phase monitoring relay designed to detect phase failure and incorrect phase sequence in industrial AC electrical systems. As part of the ABB CM-PFE three-phase monitoring relay series, it provides essential supply supervision for three-phase motors, industrial machinery and automation equipment, helping prevent operational problems caused by missing phases or incorrect phase rotation.
This phase monitoring relay continuously evaluates the connected three-phase supply and operates according to the closed-circuit principle. When all three phases are present in the correct sequence, its output relay energises, allowing the connected control system to operate. If a phase failure or incorrect phase sequence is detected, the relay de-energises, enabling a connected contactor or control circuit to initiate protective action.
With a three-phase 208–440 V AC measuring and supply voltage range, a single change-over (SPDT) output contact and a compact 22.5 mm housing width, the ABB CM-PFE is ideal for industrial motor control panels, electrical distribution systems and automated machinery. Its self-powered design eliminates the need for a separate auxiliary supply, while DIN rail mounting enables straightforward installation inside electrical control cabinets.
Three-phase electrical systems depend on the correct phase sequence and the availability of all three supply phases for reliable operation. A missing phase can cause excessive current in the remaining motor windings, reduced torque and overheating, while an incorrect phase sequence can cause motors to rotate in the wrong direction. The ABB CM-PFE phase monitoring relay helps protect industrial equipment by supervising these critical supply conditions.
The CM-PFE monitors the three-phase supply through its L1, L2 and L3 measuring connections. When the supply is present within the specified operating range and the phase sequence is correct, the output relay energises and the yellow LED indicates its operating state. If the phase sequence becomes incorrect or a detectable phase failure occurs, the output relay releases and the LED switches off. This change of contact state can be used to interrupt a motor contactor control circuit or provide a fault signal to an automation system.
The relay operates according to the closed-circuit principle, with its output contact energised under healthy supply conditions. The integrated 500 ms start-up and tripping delays provide defined response timing, while fixed monitoring thresholds simplify installation and operation without the need for complex parameter configuration.
For motors that continue rotating after a phase is lost, residual or regenerated voltage may remain on the disconnected phase. The CM-PFE can detect phase failure where the reverse-fed voltage is below approximately 60% of the nominal voltage. Applications with higher reverse-fed voltages may require additional phase unbalance monitoring to ensure suitable protection.
The ABB CM-PFE is designed for integration into motor starter circuits, industrial control panels and electrical distribution equipment. Its compact DIN rail-mounted construction, screw-terminal connections and self-powered monitoring function make it a practical solution for machine builders and automation engineers requiring dependable phase sequence and phase failure supervision.
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| Monitoring Function | Three-phase supply | |
|---|---|---|
| Monitored Supply | Three-phase | |
| Signal / Input Range | 208–440 V AC | |
| Time Delay | Fixed |
The ABB CM-PFE monitors three-phase AC electrical supplies for phase failure and incorrect phase sequence. It helps protect industrial motors and machinery by providing a relay switching signal when an abnormal phase condition is detected.
The ABB CM-PFE operates with a three-phase 208–440 V AC supply at 50/60 Hz. The monitored line-to-line voltage also supplies the relay, so no separate auxiliary control supply is required.
When the three-phase supply is healthy and the phase sequence is correct, the relay output is energised. If an incorrect phase sequence or detectable phase failure occurs, the output relay de-energises and the yellow status LED switches off, allowing a connected control circuit to initiate protective action.
The relay provides one change-over (SPDT) output contact with a rating of 250 V AC / 4 A. The contact can be used for compatible motor contactor control circuits, alarm signalling and industrial automation inputs.
Yes. The ABB CM-PFE can be integrated into a motor starter or contactor control circuit to respond to phase loss and incorrect phase sequence. However, phase failure detection can be affected by voltage regenerated by a rotating motor, so additional protection may be necessary in applications with significant reverse-fed voltage.
ABB CM-PFE three-phase monitoring relays provide dependable phase failure and phase sequence supervision for industrial electrical systems. Combining self-powered operation, fixed monitoring thresholds, relay output signalling and compact DIN rail installation, the CM-PFE helps protect industrial motors and supports reliable operation of machinery, electrical distribution equipment and automation systems.
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