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Littelfuse 777-HVR-P2 - The 777-HVR-P2 three-phase current and voltage monitor provides motor protection with input voltage from 340–480 V ac and full load ampere range as follows: 2–20 A (looped conductors required); 20–90 A (direct); 90–800 A (external CTs required).

Littelfuse 777-HVR-P2 The 777-HVR-P2 three-phase current and voltage monitor provides motor protection with…

Alternate Item Number: 777-HVR-P2

UPC: 079458990973

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Contact for Pricing

Call +1 (262) 252-1600 (toll-free 877-268-3700) or email [email protected] for pricing and availability.

Overview

The Littelfuse 777-HVR-P2 is a three-phase current and voltage monitor designed for industrial motor protection in systems operating at 340–480V AC. It provides comprehensive monitoring for motors ranging from 2–800A, with flexible current sensing options: direct connection for 20–90A, looped conductors for 2–20A, and external current transformers (CTs) for 90–800A. This monitor detects critical faults including overload, undervoltage, phase loss, phase reversal, voltage/current unbalance, and power-based underload trips, making it ideal for applications with non-linear loads or minimal current change where nuisance tripping must be minimized. Key features include a 3-digit LED display for real-time monitoring of voltage, current, kW, and HP, along with fault diagnostics and programmable voltage/current settings. The unit offers three selectable restart options—automatic, semi-automatic, or manual—and three programmable restart delay timers for applications requiring rapid cycle protection, motor cool-down, or dry-well recovery. Remote monitoring and control are supported via optional communication modules (Modbus, DeviceNet™, Profibus, Ethernet), enabling integration with PC, PLC, or SCADA systems for up to 99 units. Remote reset functionality is available with the 777-MRSW or OL-RESET kits. The 777-HVR-P2 is engineered for harsh industrial environments, operating reliably from -40°C to 70°C with humidity tolerance of 10–95% non-condensing. It features SPDT (Form C) output rated at 470VA @ 600V AC (pilot duty) or 10A @ 240V AC (general purpose), ensuring robust control signal output. It protects critical equipment such as pumps, fans, compressors, and conveyors, providing reliable protection where control power transformers (CPTs) are not used in 480V systems. The 777-HVR-P2 is specifically required when a control power transformer (CPT) is not used with a 480V system. It provides low and high power trip*, linear overcurrent trip, and 470VA @ 600VAC output SPDT relay contacts.
  • Monitors three-phase current and voltage for motor protection
  • Input voltage range: 340–480V AC
  • Full load ampere range: 2–800A (direct, looped, or external CTs)
  • Detects overload, undervoltage, phase loss, phase reversal, and unbalance
  • Features 3-digit LED display for real-time monitoring and fault diagnostics

Specifications

Brand Name
Littelfuse
Connection Type
Looped Conductors/Direct/External CTs
Connection Type
Looped conductors, direct, external CTs
Current Rating
2–800 A
Current Rating
2-800 A
Frequency
50/60 Hz
IP Rating
IP20
Nema Rating
NEMA 1
Operating Temperature
-4 to 158
Operating Temperature, Maximum
158
Operating Temperature, Minimum
-4
Poles
SPDT (Form C)
Series
777-HVR-P2
Series
777-HVR
Series
777-HVR Series
Special Features
5YR WARR
Standard
UL/CE
Sub Brand
Symcom
Voltage Rating
340-480 V
Package Dimensions (L x W x H)
5.05 IN x 3.85 IN x 3.05 IN
Package Dimensions (L x W x H)
128.3 mm x 97.8 mm x 77.5 mm
The 777-LR-P2 three-phase current and voltage monitor provides motor protection with input voltage from 200–480 V ac and motor full load ampere range of 1–9 A (direct); 10–800 A (external CTs required).

777-LR-P2

The 777-LR-P2 three-phase current and voltage monitor provides motor protection with input voltage from 200–480 V ac and motor full load ampere range of 1–9 A (direct); 10–800 A (external CTs required).
CM-PVE UNDER & OVERVOLT. 3PH.

1SVR550871R9500

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

18883000015

Relay 460V 3 Phase Monitor
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
3-Phase VOLT Monitor/380-480V/480V relay. The 350 is a heavy-duty voltage monitor. This product should be used when high current relays or dual contacts are required, or 480V controls are used. Since the 350 uses heavy-duty relays, it comes in fixed voltage range models rather than a dual autoranging version like the Model 250. Has a 15A general purpose contact. It provides a SPDT (Form C) relay rated to switch up to 600V, allowing the use of 480V controls, eliminating the need for a control power transformer to step the voltage down to 120-240V. Several DPDT (two Form C contacts) relay models are also available. The 350 microcontroller-based family of products are low cost yet highly advanced solutions to heavy-duty problems. The 350 includes advanced single LED diagnostics. Five different light patterns distinguish faults and normal operating conditions. Other options such as high voltage trip and adjustable restart delay are available.

350-400

3-Phase VOLT Monitor/380-480V/480V relay. The 350 is a heavy-duty voltage monitor. This product should be used when high current relays or dual contacts are required, or 480V controls are used. Since the 350 uses heavy-duty relays, it comes in fixed voltage range models rather than a dual autoranging version like the Model 250. Has a 15A general purpose contact. It provides a SPDT (Form C) relay rated to switch up to 600V, allowing the use of 480V controls, eliminating the need for a control power transformer to step the voltage down to 120-240V. Several DPDT (two Form C contacts) relay models are also available. The 350 microcontroller-based family of products are low cost yet highly advanced solutions to heavy-duty problems. The 350 includes advanced single LED diagnostics. Five different light patterns distinguish faults and normal operating conditions. Other options such as high voltage trip and adjustable restart delay are available.
3PH Lin-Lod VltMon/475-600V/aj.VUB,TD,RD. The 455 Series are 3-phase voltage monitors that combine load and line side monitoring to offer complete protection. Monitoring the load side will alert the user of contactor failure or impending contactor failure. Line side monitoring will also protect the motor from damaging fault conditions that may be present prior to the motor starting. With other line/load side monitors, the motor must be started before a voltage fault is detected. With the 455, your motor is fully protected at all times. The 455 Series are 3-phase, dual range voltage monitors that protect 190-480VAC, 50/60Hz motors, regardless of their size. It automatically selects between the 200V and 400V rangewhen the user selects the nominal voltage setpoint. Other adjustments include a 2-30 second trip delay, a 2-300 second restart delay (and manual restart) and a voltage unbalance trip point of 2-8percent. The voltage monitor’s circuitry is powered through the line side connections, so there is no need for separate control power, making it easy to install. Equipped with an infrared LED, the 455 Series can communicate to the optional hand-held diagnostic tool, Informer-MS to obtain valuable information such as real-time voltage, voltage unbalance on both line and load sides, motor run hours, last 20 faults, last 32 motor starts, high and low voltage trip points, voltage unbalance trip.

455-575

3PH Lin-Lod VltMon/475-600V/aj.VUB,TD,RD. The 455 Series are 3-phase voltage monitors that combine load and line side monitoring to offer complete protection. Monitoring the load side will alert the user of contactor failure or impending contactor failure. Line side monitoring will also protect the motor from damaging fault conditions that may be present prior to the motor starting. With other line/load side monitors, the motor must be started before a voltage fault is detected. With the 455, your motor is fully protected at all times. The 455 Series are 3-phase, dual range voltage monitors that protect 190-480VAC, 50/60Hz motors, regardless of their size. It automatically selects between the 200V and 400V rangewhen the user selects the nominal voltage setpoint. Other adjustments include a 2-30 second trip delay, a 2-300 second restart delay (and manual restart) and a voltage unbalance trip point of 2-8percent. The voltage monitor’s circuitry is powered through the line side connections, so there is no need for separate control power, making it easy to install. Equipped with an infrared LED, the 455 Series can communicate to the optional hand-held diagnostic tool, Informer-MS to obtain valuable information such as real-time voltage, voltage unbalance on both line and load sides, motor run hours, last 20 faults, last 32 motor starts, high and low voltage trip points, voltage unbalance trip.
3PH VOLT mntr/190-240V/adj.restart Dly. The 350 is a heavy-duty voltage monitor. This product should be used when high current relays or dual contacts are required, or 480V controls are used. Since the 350 uses heavy-duty relays, it comes in fixed voltage range models rather than a dual autoranging version like the Model 250. The 350-200 has a 15A general purpose contact. The 350-400 provides a SPDT (Form C) relay rated to switch up to 600V, allowing the use of 480V controls, eliminating the need for a control power transformer to step the voltage down to 120-240V. Several DPDT (two Form C contacts) relay models are also available. The 350 microcontroller-based family of products are low cost yet highly advanced solutions to heavy-duty problems. The 350 includes advanced single LED diagnostics. Five different light patterns distinguish faults and normal operating conditions. Other options such as high voltage trip and adjustable restart delay are available.

350-200-2

3PH VOLT mntr/190-240V/adj.restart Dly. The 350 is a heavy-duty voltage monitor. This product should be used when high current relays or dual contacts are required, or 480V controls are used. Since the 350 uses heavy-duty relays, it comes in fixed voltage range models rather than a dual autoranging version like the Model 250. The 350-200 has a 15A general purpose contact. The 350-400 provides a SPDT (Form C) relay rated to switch up to 600V, allowing the use of 480V controls, eliminating the need for a control power transformer to step the voltage down to 120-240V. Several DPDT (two Form C contacts) relay models are also available. The 350 microcontroller-based family of products are low cost yet highly advanced solutions to heavy-duty problems. The 350 includes advanced single LED diagnostics. Five different light patterns distinguish faults and normal operating conditions. Other options such as high voltage trip and adjustable restart delay are available.
The 777-KW/HP-P2 three-phase current and voltage monitor provides protection with input voltage from 200–480 V ac and motor full load ampere range as follows: 2–20 A (looped conductors required); 20–90 A direct; 90–800 A (external CTs required).

777-KW/HP-P2

The 777-KW/HP-P2 three-phase current and voltage monitor provides protection with input voltage from 200–480 V ac and motor full load ampere range as follows: 2–20 A (looped conductors required); 20–90 A direct; 90–800 A (external CTs required).

Frequently Asked Questions

What voltage range does the 777-HVR-P2 support?

The device operates on 340–480V AC (50/60 Hz) three-phase input voltage.

What current ranges can the 777-HVR-P2 monitor?

It monitors 2–20A with looped conductors, 20–90A with direct connection, and 90–800A with external CTs.

What is the output rating of the 777-HVR-P2?

It features SPDT (Form C) output rated at 470VA @ 600V AC (pilot duty) or 10A @ 240V AC (general purpose).

What is the operating temperature range?

The device operates reliably from -40°C to 70°C.

What faults does the 777-HVR-P2 detect?

The monitor detects overload, undervoltage, phase loss, phase reversal, voltage/current unbalance, and power-based underload trips.

Is external wiring required for high current ranges?

Yes, external current transformers (CTs) are required for current ranges above 90A.

Does the 777-HVR-P2 support remote monitoring?

Yes, with optional communication modules (Modbus, DeviceNet, Profibus, Ethernet), it enables remote monitoring and control via PC, PLC, or SCADA.

Can the 777-HVR-P2 be used without a control power transformer?

Yes, it is designed for systems where a control power transformer (CPT) is not used with a 480V system.

What restart options are available?

The unit offers automatic, semi-automatic, or manual restart options with three programmable delay timers for recovery sequences.

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.