Littelfuse 235P - The 235P pump monitor protects single-phase pumps with an input voltage value of 230 V ac, an input load range of 5–15 hp (external current transformer required), and the following dimensions: 2.93” H x 5.25” W x 2.91” D.
Littelfuse

235P

Alternate Item Number: 235P

UPC: 079458990379


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Overview

The Littelfuse 235P Pump Monitor is a robust, single-phase protection relay engineered to safeguard industrial and commercial pumps operating at 230V AC with load capacities between 5 and 15 horsepower. Designed for reliability and ease of integration, this compact device (2.93" H x 5.25" W x 2.91" D) delivers critical protection against electrical faults while optimizing pump performance and extending equipment lifespan. As a trusted solution in motor and pump protection, the 235P is ideal for applications where operational continuity and fault prevention are paramount, including water and wastewater systems, irrigation networks, HVAC systems, and industrial fluid handling processes. Engineered with Littelfuse’s reputation for high-quality industrial protection relays, the 235P offers comprehensive fault detection tailored for single-phase pumps. Its advanced monitoring capabilities include adjustable settings for underload (dry-well protection), overcurrent, overvoltage, and undervoltage conditions, ensuring pumps operate within safe parameters. The device supports up to four restarts within a 60-second window to mitigate rapid-cycling faults, with customizable trip and restart delays to accommodate diverse operational requirements. For dry-well protection, the underload threshold is adjustable between 70% and 90% of calibrated run power, providing flexibility to match specific pump characteristics and environmental conditions. The 235P is compatible with external current transformers (sold separately), enabling precise current monitoring across the full 5–15 HP range. Available CT ratios include 50:5 (for 7.5 HP), 75:5 (for 10 HP), and 100:5 (for 15 HP), ensuring accurate load measurement and protection. This modular approach allows professionals to tailor the system to their exact pump specifications, enhancing both safety and efficiency. The device also features a 125% overcurrent threshold relative to the calibration point, providing an additional layer of protection against motor overloads and electrical anomalies. Designed for durability, the 235P operates reliably in extreme temperatures from -40°C to 60°C (-40°F to 140°F), making it suitable for outdoor enclosures and harsh industrial environments. Its SPST output contact rating of 300V AC, 720A (10A max) ensures compatibility with a wide range of control systems, while the cUL Listed and UL508 certifications confirm compliance with North American safety standards. Installation is straightforward, with #8 screw mounting and support for 10–22 AWG solid or stranded wire, ensuring secure and efficient wiring in tight control panels. For enhanced diagnostics and troubleshooting, the 235P is compatible with the Littelfuse Informer IR Kit-12, a hand-held tool that uses infrared communication to access real-time system data. This feature is invaluable for maintenance teams seeking to quickly identify faults, verify settings, or optimize pump performance without interrupting operations. The compact footprint of the 235P further simplifies integration into existing control systems, reducing installation time and minimizing space requirements. Littelfuse, a global leader in circuit protection and industrial automation solutions, has built a legacy of innovation and reliability across diverse industries. The 235P Pump Monitor exemplifies this commitment, offering a cost-effective, high-performance solution for protecting critical pump infrastructure. Whether deployed in municipal water systems, agricultural irrigation, or manufacturing facilities, the 235P ensures uninterrupted operation, reduced downtime, and extended equipment life—making it an essential component for any single-phase pump protection strategy.
  • Protects single-phase pumps (5-15 HP) at 230V AC with advanced fault detection
  • Adjustable underload (dry-well) protection: 70% to 90% of calibrated run power
  • Overcurrent threshold at 125% of calibration point for motor overload protection
  • Overvoltage (265V AC) and undervoltage (190V AC) monitoring with 2-second restart delay
  • Compatible with external current transformers (50:5, 75:5, 100:5 ratios) for precise load monitoring
  • Compact design (2.93" H x 5.25" W x 2.91" D) for easy integration into control panels
  • Operates reliably in extreme temperatures (-40°C to 60°C / -40°F to 140°F)
  • cUL Listed, UL508 certified for North American safety compliance
  • SPST output contact rating: 300V AC, 720A (10A max) for versatile control system compatibility
  • Compatible with Littelfuse Informer IR Kit-12 for advanced diagnostics and troubleshooting

Specifications

Brand Name
Littelfuse
Connection Type
10-22 AWG solid or stranded wire, #8 screw mounting
Current Rating
5-15 HP (external CT required)
Mounting
#8 screws
Mounting Type
#8 Screw Mounting
Number Of Poles
#8 screws
Operating Temperature
-40 to 131
Operating Temperature, Maximum
131
Operating Temperature, Minimum
-40
Pickup Voltage
230 V
Series
235P
Size
2.93" H x 5.25" W x 2.91" D
Special Features
5YR WARR
Standard
UL
Sub Brand
Symcom
Voltage Rating
230 V AC
Package Dimensions (L x W x H)
2.91 IN x 5.25 IN x 2.93 IN
Package Dimensions (L x W x H)
74 mm x 133.4 mm x 73.7 mm
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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.