1SVR450117R5300 ABB CM-CT 500/5 Current Transformer 500/5 A

Why Choose the ABB CM-CT 500/5 Current Transformer?

The ABB CM-CT 500/5 (1SVR450117R5300) is a reliable 500/5 A current transformer designed for accurate measurement and monitoring of alternating current in industrial electrical installations. As part of the ABB CM-CT current transformer series, it converts high primary currents into a proportional, standardised secondary current suitable for compatible measuring instruments, monitoring relays and electrical control systems.

This industrial current transformer provides dependable AC current measurement while electrically isolating connected measuring equipment from the primary circuit. Its compact construction and standard 5 A secondary output make it suitable for industrial current monitoring, electrical distribution systems and automation applications where reliable measurement of high-current circuits is essential.

With a 500 A rated primary current, a 5 A rated secondary current and a 100:1 transformation ratio, the ABB CM-CT 500/5 enables effective monitoring of industrial AC electrical loads. Its plug-in current transformer design allows installation around suitable conductors or busbars, making it a practical solution for electrical control panels, distribution boards and industrial monitoring equipment.

Key Advantages

• Reliable 500/5 A current transformer designed for industrial AC current measurement.
• 500 A rated primary current suitable for monitoring high-current electrical circuits.
• 5 A rated secondary current compatible with appropriately rated measuring instruments and monitoring relays.
• 100:1 transformation ratio provides proportional conversion of primary current into a measurable secondary current.
• Galvanic isolation between primary and secondary circuits supports safer integration with measuring equipment.
• Compact plug-in current transformer construction simplifies installation around suitable primary conductors.
• Suitable for electrical distribution, industrial load monitoring and motor feeder measurement.
• Compatible with industrial current monitoring relays and electrical measuring instruments.
• Electromagnetic measurement principle requires no separate auxiliary power supply for current transformation.
• Supports accurate current monitoring when installed with a suitable secondary burden and measuring circuit.
• Suitable for integration into industrial electrical control cabinets and switchgear assemblies.
• Robust construction supports dependable operation in demanding industrial electrical installations.

Key Features

• ABB CM-CT current transformer series.
• 500 A rated primary current.
• 5 A rated secondary current.
• 500/5 A current transformation ratio.
• 100:1 current ratio.
• Designed for alternating current measurement.
• Standardised secondary output for compatible industrial measuring instruments.
• Electromagnetic current transformation with galvanic isolation between primary and secondary circuits.
• Plug-in design for installation around a suitable primary conductor or busbar.
• Secondary terminals for connection to measuring and monitoring equipment.
• Primary polarity identification using K/P1 and L/P2 markings.
• Secondary polarity identification using k/S1 and l/S2 markings.
• Suitable for industrial electrical load monitoring and power distribution applications.
• Compatible with appropriately configured current monitoring and measuring systems.
• Compact construction for installation within electrical panels and industrial switchgear.
• No separate auxiliary electrical supply required for the current transformation function.

Technical Specifications

• Manufacturer: ABB
• Series: CM-CT Current Transformers
• Model: CM-CT 500/5
• ABB order code: 1SVR450117R5300
• ABB product group: 310921-Measuring & Monitoring Relays
• Product type: Current transformer
• Transformer design: Plug-in current transformer
• Application: AC current measurement and monitoring
• Rated primary current: 500 A
• Rated secondary current: 5 A
• Current transformation ratio: 500/5 A
• Transformation factor: 100:1
• Measured current type: Alternating current (AC)
• Measurement principle: Electromagnetic current transformation
• Primary connection: Conductor or busbar through transformer opening
• Secondary connection: Secondary measuring terminals
• Primary polarity markings: K/P1 and L/P2
• Secondary terminal markings: k/S1 and l/S2
• Electrical isolation: Galvanic isolation between primary and secondary circuits
• Auxiliary power supply: Not required
• Installation type: Electrical panel or switchgear installation
• Application category: Industrial electrical current measurement

Reliable AC Current Measurement for Industrial Electrical Systems

Current transformers such as the ABB CM-CT 500/5 are essential components in industrial electrical measurement and monitoring systems. They allow high alternating currents to be measured using standard instruments by transforming the primary circuit current into a lower, proportional secondary current. This enables compatible ammeters, monitoring relays and electrical measuring devices to measure high-current circuits without carrying the full primary current through the instrument.

The CM-CT 500/5 operates with a 500/5 A transformation ratio, meaning that a primary current of 500 A corresponds to a nominal secondary current of 5 A under rated conditions. At a primary current of 250 A, the corresponding secondary current is approximately 2.5 A. This proportional relationship allows connected measuring instruments to determine the primary circuit current when configured for the correct transformer ratio.

The transformer uses electromagnetic induction to produce its secondary current and provides electrical isolation between the primary conductor and connected measurement equipment. This makes it suitable for industrial electrical installations where direct measurement of high currents would be impractical. The accuracy of the complete measurement system depends on the transformer's specified performance, connected burden, secondary wiring and measuring equipment.

The ABB CM-CT 500/5 can be incorporated into electrical distribution systems, motor feeder monitoring circuits and industrial control panels. Correct installation is essential for safe operation. The secondary circuit must be connected to a suitable measuring burden or safely short-circuited whenever primary current is flowing. Current transformer secondary terminals must never be left open-circuit while the primary conductor is energised, as dangerous voltages may develop.

Typical Applications

• Industrial AC current measurement and monitoring systems.
• Electrical distribution boards and switchgear assemblies.
• Industrial control panels and automation cabinets.
• Current monitoring relays and electrical measuring instruments.
• High-current electrical load monitoring in manufacturing facilities.
• Industrial motor feeder current measurement.
• Power distribution and electrical energy monitoring equipment.
• Building electrical management and monitoring systems.
• Industrial machinery requiring isolated AC current measurement.
• OEM electrical panels and industrial monitoring installations.