Relays, Contactors & Transformers

Relays, contactors, and transformers reliably control the flow and distribution of electrical current, ensuring a safer and optimal operation. You will find our products protecting people and equipment across a wide range of industries, including construction, food and beverage, eMobility, HVAC, mining, manufacturing, renewable energy, oil and gas extraction, and transportation.

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Accessories - Protection Relays

Using the proper accessories improves the organization, safety, and performance of electrical systems. Littelfuse helps you achieve the best results by offering an extensive line of cable ties and a high-performance battery post adapter. Our nylon cable ties come in lengths of 98 mm to 540 mm, widths of 2.5 mm to 7.8 mm, and tensile strengths of 8 kg to 55 kg. Our battery post adapters attach to threaded positive terminals and connect to standard battery cable clamps.

Adapters & Sockets

Littelfuse offers a variety of relay accessories including covers, mounting adapters, and sockets for use with Littelfuse relay products. This accessory group includes the following: 1. The NDS series is an 8-pin octal socket. 2. The OT series is an octal or magnal socket (for plug-ins). 3. The P0500 series is a surface or DIN rail mount adapter. 4. The P1011 is an 8-pin octal socket for surface mount. 5. The SD series is a 12-pin surface rectangle socket. Each series offers varied ratings, mounting features, and screw/snap attachments.

Covers

Littelfuse offers a variety of relay accessories including covers and enclosures for use with Littelfuse protection relay products. This accessory group includes eight series with a broad range of features for protection, safe control, and distribution of electrical power in industrial applications. These products include tamper-resistant covers, watertight covers, electrical enclosures boxes, steel enclosure boxes to house communications monitors, covers for dusty environments, IP65 protection covers, and covers specifically designed for outdoor applications. Browse our selection of quality covers and enclosures.

Current Transformers

Littelfuse offers a variety of current transformers to detect phase currents, ground-fault currents, and low levels of earth-leakage currents before they cause serious damage. Installing one of our current transformers maximizes protection of electrical components.

CT secondary current ratings from 50 mA to 5 A
Inner diameters from 25.4 mm to 210 mm
Typical insulation levels of 600 V

Wide range of turns ratios up to 800:1
Flux conditioner available or included with several versions
Low weight

Electrical Accessories

Ground Reference Modules

Littelfuse delivers vital products to address customer needs for protection, safe control, and distribution of electrical power in industrial applications. Protection relay accessories such as the Littelfuse ground reference modules are designed to connect dc ground-fault monitors to a dc bus. These modules help provide ground-fault protection and minimize electrical hazards. This product accessory group includes seven POWR-GARD® ground reference module series that connect to an ungrounded dc bus with ampere ratings from 24 – 1000 V dc.

High-Tension Couplers

Littelfuse delivers vital products to address customer needs for protection, safe control, and distribution of electrical power in industrial applications. The Littelfuse protection relays product portfolio includes accessories that help to minimize electrical hazards, equipment damage, and ground faults. This product accessory group includes two series of high-tension couplers, PGH-5000 and PGH-6000, that allow 5 kV and 6 kV systems, respectively, to connect to a protection relay unit for ground-fault protection. The PGH family of high-tension couplers are required for systems greater than 1.3 kV.

Input Modules

Current and temperature input modules acquire and share information used by protection and control relays. In addition to resistance temperature detectors (RTDs), the modules include sensing circuits that detect current unbalance, ground faults, overloads, overcurrent events, overvoltage events, phase differential, phase loss, phase reverse, undercurrent events, and undervoltage events. Each Littelfuse input module can be mounted remotely, used in hazardous environments, and interface with multiple types of relays.

Ac input voltages from 65 V ac to 265 V ac
Dc input voltages from 18 V dc to 32 V dc and 80 V dc to 275 V dc
Remote monitoring at up to 1.2 km from equipment being monitored
Conformally coated

DIN rail-mounted, panel-mounted, and surface-mounted versions available
3-, 5-, and 8-contact versions available
5- or 10-year warranties

Mounting

Littelfuse offers a variety of relay mounting accessories for use with Littelfuse protection relay products. This accessory group includes 24 product series with a broad range of features for protection, safe control, secure placement, and distribution of electrical power in industrial applications. This product group includes DIN Rails, panel mounting adapters, mounting brackets, mounting hold-down clips, mounting plates, specialty mounting kits, and many other items. Browse our selection of quality mounting accessories for your specific application.

Relay Software

We deliver vital products to address customer needs for protection, safe control, and optimal distribution of electrical power in industrial applications. The Protection Relays product portfolio includes 14 relay software programs that allow protective relays to isolate faults, prevent unnecessary trips, and protect equipment from damage. These software programs provide a variety of functions including configuring networks, remotely accessing data logging, displaying relay set points, receiving input from ground monitors, communicating with modules, availability to valuable system information, and more.

Relay Test Equipment

We deliver vital products to address customer needs for protection, safe control, and optimal distribution of electrical power in industrial applications. The Protection Relays product portfolio includes relay test equipment that are designed to test current pickup level, time-delay, and coordination of ground-fault protection. These ground-fault relay test units are used on substations, motor control centers, central distribution panels, switchboards, and test benches to verify relay operations. This product group also includes an impact resistance case and selector switch for more testing options.

Remote test input
Adjustable current setpoint
Adjustable time duration setpoint

Testing can be conducted from a different location
Tests the entire ground-fault circuit
Maximum ground-fault protection

Remote Indication & Monitoring

We deliver vital products to address customer needs for protection, safe control, and optimal distribution of electrical power in industrial applications. The Protection Relays product portfolio includes 21 different remote indication and monitoring devices that provide (remotely) valuable system information for monitoring, assessing, and troubleshooting conditions. These accessory products are used in conjunction with Littelfuse protection relays and monitor many operating functions such as overcurrent, undercurrent, phase imbalance, phase loss, overtemperature, and much more.

Retrofit Kits

Littelfuse designs and manufactures essential products to address customer needs for protection, safe control, and optimal distribution of electrical power in industrial applications. The Protection Relays product portfolio includes 12 accessory retrofit kits that are an excellent choice when upgrading technology of existing systems to improve efficiency and performance. The PGK family of retrofit kits can be used for a variety of systems including motor protection, ground-fault protection, and ground-check systems. Browse the Littelfuse selection of retrofit kits to find the one specific to your requirements.

POWR-GARD® performance accessory
Watertight, tamper resistant, outdoor needs

More efficient ground-fault protection
Used for a variety of industrial systems

Sensing Resistors

Littelfuse delivers vital products to address customer needs for protection, safe control, and optimal distribution of electrical power. The Protection Relays accessory product portfolio includes 14 sensing resistor series that are used as accessories with specific neutral grounding resistor monitor relays to prevent unwanted fault damage. They are a required interface between the power system and the monitoring relay and eliminate hazardous voltage levels at the relay. Sensing resistors are matched to the system voltage. Browse the Littelfuse selection of sensing resistors to meet your specific needs.

Termination Assemblies

Littelfuse offers a variety of relay accessories including termination assemblies for use with Littelfuse relay protection products. This accessory group includes 16 termination assemblies with many different features such as temperature compensation, convenient mounting holes and screw terminals, wire leads, and much more. These assemblies work in conjunction with Littelfuse ground-fault, ground-check relay and monitor products and come in a range of watt ratings.

Shock Block GFCI

Protection Relays

Jobsites that lack durable, dependable protection relays put personnel at risk for injuries from electrical faults. Additionally, productivity falls when machinery, pumps, and motors fail due to overvoltage events, arcing, or short circuits that electrical current relays would have prevented. Littelfuse provides the full range of solutions. Manufacturers, construction companies, mining and fossil fuel operations, and solar power providers rely on Littelfuse relays, relay software, ground-fault circuit interrupters (GFCIs), and ground-fault, time-delay, and intrinsically safe relays to control essential equipment.

Industrial Fuse Blocks

Littelfuse POWR-GARD industrial fuse blocks provide superior protection for wiring in electrical circuits and increase the life of electrical equipment. Littelfuse also offers a variety of fuse block covers to protect personnel from accidentally coming into contact with energized parts. Littelfuse industrial fuse blocks are designed to hold a variety of fuses including Class CC/CD, G, H/K5, J, R, T, and Midget (10×38) sizes. Features include indication, snap-to-release, DIN-rail mounting, space-saving design, universal mounting holes and touch-safe covers.