Littelfuse 202-RP - The 202 Series is a 3-phase, auto-ranging, dual-range voltage monitor that protects 190-480VAC, 50*/60Hz motors regardless of size. The 202-RP (and the 202-575-RP for 475-600VAC) monitors the phase rotation of 3-phase systems and trips on reverse-phase only. Critical applications include fan motors, scroll compressors, grinders, conveyor systems, elevators and escalators. Both products provide a user selectable nominalvoltage setpoint and automatically select between the 200V and 400V range. This unique microcontroller-based voltage and phase-sensing device constantly monitors the 3-phase voltages to detect harmful power line conditions. When a harmful condition is detected, the MotorSaver’s output relay is deactivated after a specified trip delay. The output relay reactivates after power line conditions return to acceptable levels for a specified amount of restart delay time (or a manual reset). The 202 Series includes advanced single LED diagnostics. Five different light patterns distinguish between faults and normal conditions. The statuslight turns green and the relay is activated when rotation is correct.
Littelfuse

202-RP

Alternate Item Number: 202-RP

UPC: 079458990294

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Overview

The Littelfuse 202-RP (SKU: 202-RP) is a 3-phase, auto-ranging voltage monitor designed to protect motors operating on 190-480VAC, 50/60Hz systems from harmful power line conditions, including reverse-phase rotation. This microcontroller-based device provides constant monitoring of phase voltages to detect faults such as single-phase, low/high voltage, voltage unbalance, and phase reversal. The 202-RP is specifically engineered to trip on reverse-phase only, making it ideal for critical applications like fan motors, scroll compressors, grinders, conveyor systems, elevators, and escalators. The device features a user-selectable nominal voltage setpoint and automatically switches between 200V and 400V ranges, simplifying setup and ensuring compatibility with a wide range of systems. Its proprietary microcontroller-based circuitry ensures reliable detection of harmful conditions, with the output relay deactivating after a user-adjustable trip delay. The relay reactivates automatically once power line conditions return to acceptable levels for a specified restart delay time, or via manual reset. The 202-RP includes advanced single-LED diagnostics, offering five distinct light patterns to distinguish between normal operation, restart delay, reverse-phase trip, and other faults. The status light turns green when phase rotation is correct, providing clear operational feedback. The compact, quick-mounting design with single-screw mounting saves time and panel space, making it easy to integrate into control panels. Manufactured in the US, the 202-RP is a reliable solution for protecting 3-phase motors in demanding industrial environments.
  • Auto-ranging voltage monitor for 190-480VAC, 50/60Hz 3-phase systems
  • Trips on reverse-phase rotation only for targeted motor protection
  • Microcontroller-based constant monitoring detects low/high voltage, unbalance, and phase faults
  • User-selectable nominal voltage setpoint with automatic 200V/400V range selection
  • Compact, single-screw mounting design with advanced LED diagnostics for quick fault identification

Specifications

Brand Name
Littelfuse
Color
Green
Color
Green (status light)
Connection Type
Screw Terminal
Frequency
50/60 Hz
Material
Poly
Mounting Type
Single-screw mounting
Operating Temperature
-40 to 158
Operating Temperature, Maximum
158
Operating Temperature, Minimum
-40
Poles
3-Phase
Series
202
Series
202 Series
Standard
UL
Sub Brand
Symcom
Voltage Rating
190-480 VAC
Package Dimensions (L x W x H)
1.4 IN x 2.5 IN x 2.5 IN
Package Dimensions (L x W x H)
35.6 mm x 63.5 mm x 63.5 mm
The 250A is a 3-phase, auto-ranging, dual-range voltage monitor that protects 190-480VAC, 50*/60Hz motors regardless of size from low and high voltage, unbalance/single-phase, and reverse-phase. The product provides a user selectable nominal voltage setpoint and the voltage monitor automatically selects between the 200V and 400V range. The 250A also features adjustable or manual restart delay. This unique microcontroller-based voltage and phase-sensing device constantly monitors the 3-phase voltages to detect harmful power line conditions. When a harmful condition is detected, the Littelfuse’s output relay is deactivated after a specified trip delay. The output relay reactivates after power line conditions return to acceptable levels. The Model 250A includes advanced single LED diagnostics. Five different light patterns distinguish between faults and normal conditions.

250A

The 250A is a 3-phase, auto-ranging, dual-range voltage monitor that protects 190-480VAC, 50*/60Hz motors regardless of size from low and high voltage, unbalance/single-phase, and reverse-phase. The product provides a user selectable nominal voltage setpoint and the voltage monitor automatically selects between the 200V and 400V range. The 250A also features adjustable or manual restart delay. This unique microcontroller-based voltage and phase-sensing device constantly monitors the 3-phase voltages to detect harmful power line conditions. When a harmful condition is detected, the Littelfuse’s output relay is deactivated after a specified trip delay. The output relay reactivates after power line conditions return to acceptable levels. The Model 250A includes advanced single LED diagnostics. Five different light patterns distinguish between faults and normal conditions.
Three Phase Monitor Relay; DIN-Mount; 190-500V; 10A DPDT; Phase Loss; Reversal; Unbalance; Under/Over Voltage

PMDU

Three Phase Monitor Relay; DIN-Mount; 190-500V; 10A DPDT; Phase Loss; Reversal; Unbalance; Under/Over Voltage
CM-PVE UNDER & OVERVOLT. 3PH.

1SVR550871R9500

CM-PVE UNDER & OVERVOLT. 3PH.
Relay 460V 3 Phase Monitor

18883000015

Relay 460V 3 Phase Monitor

Frequently Asked Questions about Littelfuse

What certifications and standards do Littelfuse products comply with?

Littelfuse products are certified to multiple international standards, including UL (Underwriters Laboratories), CSA (Canadian Standards Association), CCC (China Compulsory Certification), and EAC (Eurasian Conformity). Customers can verify specific product certifications by consulting individual product datasheets on Littelfuse.com, which provide comprehensive details about standards compliance for each component.

What industries and applications are Littelfuse products used for?

Littelfuse products are critical for electrical protection and safety across multiple industrial sectors, including manufacturing, automation, power distribution, and electrical control systems. Their comprehensive product portfolio serves industries that require robust electrical protection, including motor and pump applications, solar installations, programmable logic controllers (PLCs), electrical switch panels, and critical infrastructure environments. Key product lines protect against overcurrent, voltage transients, ground faults, and temperature-related electrical risks, ensuring equipment safety and operational reliability.

What technical support does Littelfuse offer?

Littelfuse offers comprehensive technical support through multiple channels. Their Technical Hotline (800-TEC-FUSE) provides direct access to engineers who can help identify issues and recommend solutions. Additionally, Littelfuse offers extensive online Technical Resources at Littelfuse.com, including datasheets, product manuals, whitepapers, application guides, and online design tools. Their experienced product and application engineers also provide step-by-step support from design to installation.

What are the main product lines offered by Littelfuse?

Littelfuse offers comprehensive industrial protection and control product lines, including fuses, fuse holders, protection relays, temperature sensors, and electrical safety components. Their key product categories span surge protective devices, custom OEM products, electrical switch panels, medium voltage fuses, ground-fault protection relays, motor and pump protection devices, and temperature sensors. These products are designed to minimize electrical safety hazards, limit equipment damage, improve productivity, and safeguard personnel from electrical faults.

What are the key features of Littelfuse products?

Littelfuse products feature exceptional circuit protection technologies with key characteristics including UL/IEC safety standard compliance, low internal resistance, and advanced protective capabilities across multiple product lines. Their components provide critical protection for industrial systems, offering features like overcurrent protection, voltage transient suppression, and resettable protection devices with ultra-low resistance and compact designs. Key product lines include fuses, metal oxide varistors (MOVs), TVS diodes, PolySwitch devices, and specialized electronic protection components that enhance system reliability and safety.

What environmental ratings do Littelfuse products have?

Littelfuse products feature comprehensive environmental ratings, including NEMA Type 1, 2, 3, 3R, 4/4X, 12, and 13 certifications, as well as IP65 protection. These ratings ensure superior protection in diverse industrial environments, with an operating temperature range of -40°F to +131°F (-40°C to +55°C). Many products also include UV-stabilized materials and neoprene gaskets for enhanced durability in outdoor and challenging conditions.

What accessories are available for Littelfuse products?

Littelfuse offers several key accessories across their product lines, including fuse holders, voltage monitoring modules, and terminal connectors. Specific accessories include the LPSM003ZXID (indicating) and LPSM003Z (non-indicating) POWR-SAFE Dead Front fuse holders for Class CC and Midget-Style fuses, the VRM6048 voltage monitor accessory module, and female quick connect terminals (P1015 series) in various wire gauge sizes. These accessories are designed to enhance protection, monitoring, and connectivity for Littelfuse electrical components.

What is Littelfuse's warranty policy?

Littelfuse provides comprehensive warranty details on their official website at www.littelfuse.com/warranty. Customers should visit this page to review the specific warranty terms and conditions for their specific product lines. For direct warranty support or questions, customers can contact Littelfuse Technical Support at 1-800-TEC-FUSE or email [email protected].

What communication protocols do Littelfuse products support?

Littelfuse supports a comprehensive range of industrial communication protocols, including PROFIBUS, PROFINET, EtherNet/IP, DeviceNet, Modbus RTU, and CANopen. Our products provide flexible connectivity solutions across multiple industrial automation platforms, enabling seamless integration with various control systems and network architectures.

How are Littelfuse products typically installed?

Littelfuse products are typically installed using specialized mounting hardware like fuse holders, blocks, and panels designed for specific industrial applications. The POWR-SAFE Dead Front holders, for example, provide optimum protection for Class CC and Midget-Style fuses, supporting installations up to 600 VAC/DC. Installation often involves using precision terminals with strain relief, such as 0.25 in. female quick connect terminals, to ensure secure and safe electrical connections in industrial control systems.