Why Choose the ABB CM-SRS.12S Current Monitoring Relay?
The ABB CM-SRS.12S (1SVR730841R0300) is a compact, dependable single-phase current monitoring relay designed to detect overcurrent and undercurrent conditions in industrial electrical systems. Part of the ABB CM-SRS measuring and monitoring relay range, it provides reliable current supervision for machinery, electrical loads and automation equipment.
Operating from a 110–130 V AC control supply, the CM-SRS.12S monitors both AC and DC currents using an RMS measuring principle. Three selectable measuring ranges of 0.3–1.5 A, 1–5 A and 3–15 A allow the relay to be configured for different load monitoring requirements. Adjustable current thresholds and hysteresis provide flexibility when setting the switching response.
The relay features one changeover (SPDT) output contact rated at 250 V / 4 A, enabling integration with PLC inputs, contactor control circuits and industrial alarm systems. Its compact 22.5 mm housing, DIN rail mounting arrangement and secure screw terminals make it a practical choice for industrial control panels where space, reliability and straightforward commissioning are important.
Key Advantages
- Reliable single-phase current monitoring for industrial automation and electrical control systems.
- 110–130 V AC control supply for compatible industrial control circuits.
- Three selectable current measuring ranges covering 0.3–15 A.
- Selectable overcurrent or undercurrent monitoring to suit different applications.
- RMS measurement supports monitoring of both AC and DC currents.
- Adjustable hysteresis from 3–30% helps reduce unwanted switching near the threshold.
- One changeover (SPDT) output contact rated at 250 V / 4 A.
- Open-circuit operating principle for defined relay switching behaviour.
- Front-mounted adjustment controls simplify configuration and commissioning.
- Compact 22.5 mm DIN rail housing conserves space inside control cabinets.
- Secure screw terminals with double-chamber cage connections.
- Suitable for load supervision, fault signalling and industrial process monitoring.
Key Features
- ABB CM-SRS.12S single-phase current monitoring relay.
- Manufacturer order code: 1SVR730841R0300.
- Rated control supply voltage: 110–130 V AC.
- Measuring range 1: 0.3–1.5 A.
- Measuring range 2: 1–5 A.
- Measuring range 3: 3–15 A.
- RMS measuring principle for AC and DC current monitoring.
- Selectable overcurrent or undercurrent monitoring function.
- Adjustable switching threshold.
- Adjustable hysteresis: 3–30% of the threshold value.
- Output configuration: 1 changeover (SPDT) contact.
- Output contact rating: 250 V / 4 A.
- Open-circuit operating principle.
- Front-mounted controls for monitoring function and threshold adjustment.
- Operating and relay status indication.
- Screw terminal connections with double-chamber cage technology.
- Housing width: 22.5 mm.
- DIN rail mounting for electrical control cabinets.
- Compatible with an optional sealable transparent protective cover.
Technical Specifications
- Manufacturer: ABB
- Product series: CM-SRS
- Model: CM-SRS.12S
- ABB order code: 1SVR730841R0300
- ABB product group: 310921-Measuring & Monitoring Relays
- Product type: Single-phase current monitoring relay
- Rated control supply voltage: 110–130 V AC
- Monitoring function: Overcurrent or undercurrent
- Measuring principle: RMS measurement for AC and DC currents
- Current measuring range 1: 0.3–1.5 A
- Current measuring range 2: 1–5 A
- Current measuring range 3: 3–15 A
- Hysteresis: Adjustable, 3–30% of threshold value
- Output contacts: 1 changeover (SPDT) contact
- Contact rating: 250 V / 4 A
- Rated operational current AC-12: 4 A at 230 V
- Rated operational current AC-15: 3 A at 230 V
- Rated operational current DC-12: 4 A at 24 V
- Rated operational current DC-13: 2 A at 24 V
- Minimum switching capacity: 24 V / 10 mA
- UL/CSA contact rating: B300
- Maximum output operating voltage (UL/CSA): 300 V AC
- Operating principle: Open-circuit principle
- Terminal type: Screw terminals with double-chamber cage connections
- Mounting type: DIN rail mounting
- Operating ambient temperature: −20 to +60 °C
- Storage temperature: −40 to +85 °C
- Dimensions (H × W × D): 85.6 × 22.5 × 103.7 mm
- Net weight: 0.168 kg
- EAN: 4016779852296
- Customs tariff number: 85364900
Reliable Current Monitoring for Industrial Equipment Protection
The ABB CM-SRS.12S continuously supervises the current flowing through a monitored circuit and provides a switching signal when the measured current crosses a configured threshold. This allows industrial control systems to identify abnormal loading conditions, unexpected reductions in current or changes in equipment operation before they develop into more serious process interruptions.
With selectable overcurrent and undercurrent monitoring, the relay can be configured to detect current levels that are either too high or too low for the intended application. Overcurrent monitoring can help identify excessive electrical loading, while undercurrent monitoring can be useful for recognising unloaded machinery, loss of load or unexpected reductions in process demand.
The three measuring ranges provide flexibility across applications requiring current supervision between 0.3 A and 15 A. The RMS measuring principle supports AC and DC current monitoring, while adjustable hysteresis helps prevent repeated relay switching when the measured current fluctuates around the selected threshold.
The relay's single changeover output contact can be incorporated into a PLC monitoring circuit, alarm system or contactor control arrangement. Its output is intended for signalling and control within the specified contact ratings; appropriate switching and protective devices should be used for higher-power electrical loads.
For installations using a 110–130 V AC control supply, the CM-SRS.12S provides a compact and configurable solution for current supervision. Its DIN rail mounting design and screw terminal connections support straightforward installation in industrial electrical panels and automation enclosures.
Typical Applications
- Single-phase current monitoring in industrial electrical systems.
- Overcurrent detection in machinery and electrical control circuits.
- Undercurrent detection for loss-of-load supervision.
- Monitoring AC and DC current in industrial equipment.
- Motor load supervision and abnormal operating condition detection.
- Pump and fan load monitoring in automated installations.
- Conveyor and material handling equipment supervision.
- Industrial control panels and automation cabinets.
- PLC-based current fault signalling and alarm circuits.
- Manufacturing and production equipment monitoring.
- OEM machinery with integrated current supervision.
- Electrical maintenance and condition monitoring applications.
