Littelfuse, Inc. Datasheets for Protective Relays and Monitoring Relays
Protective relays and monitoring relays detect or monitor for abnormal power system conditions.
Protective Relays and Monitoring Relays: Learn more
| Product Name | Notes |
|---|---|
| 777-LR-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: 1–2 A (looped conductors required); 2.1–9.0 A... | |
| 777-MLR-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: 0.5–5 A (looped conductors required); 5–21 A... | |
| AF0100-00 is an arc-flash relay with a supply voltage ac of 100–240 and a supply voltage dc of 24–48; 100–240. | |
| AF0100-10 is an arc-flash relay with a supply voltage dc of 24–48 (none for ac). | |
| AF0500-00 is an arc-flash relay with a supply voltage ac of 100–240. | |
| AF0500-00-CC is an arc-flash relay with a supply voltage dc of 110–250. | |
| D0920.0060 is an arc detection unit with a supply voltage of 230 V ac +15, -30%. This unit offers a slide switch instead of a key switch and an electronic... | |
| High-resistance grounding prevents many of the problems that are associated with ungrounded and solidly grounded electrical distribution and utilization systems. High-resistance grounding can limit point-of-fault damage, eliminate transient overvoltages, reduce... | |
| MPU-32-SMK is a hardware kit that allows the FPU-32 or MPU-32 to be surface mounted inside an enclosure. | |
| Obsolete: 08/11/2020 The FlexMod electronic voltage sensing relay & timer monitors both battery voltage and ignition status. shutting down non-critical loads when the cutoff voltage is reached. or at the... | |
| Specialized OptoMOS® single-pole, normally open Solid State Relays (1-Form-A) with an integrated active current limit and thermal shutdown feature that can replace electromechanical relays while enhancing the robustness of wireline... | |
| The 102A is a 3-phase, auto-ranging, dual-range voltage monitor that protects 190-400VAC, 50/60Hz motors regardless of size. The product provides a user selectable nominal voltage setpoint and the voltage monitor... | |
| The 102A is a 3-phase, auto-ranging, dual-range voltage monitor that protects 190-600VAC, 50/60Hz motors regardless of size. The product provides a user selectable nominal voltage setpoint and the voltage monitor... | |
| The 111-Insider-P provides single-phase protection for submersible pumps with an input voltage of 115 V ac and input load range from ⅓–½ hp. Its output load rating is ½ hp... | |
| The 111P is a single-phase pump monitor with an input voltage value of 115 V ac and an input load range of ⅓–1 hp. The dimensions of this unit are... | |
| The 111P-ENCL is an enclosed single-phase pump monitor with an input voltage value of 115 V ac and an input load range of ⅓–1 hp. The dimensions of this unit... | |
| The 201-xxx-DPDT is an 11-pin octal base plug-in voltage monitor designed to protect 3-phase motors regardless of size. The 201-100-DPDT is used on 95-120VAC, 50/60Hz motors and the 201-200-DPDT is... | |
| The 201-xxx-SP is an 8-pin octal-base, plug-in voltage monitor designed to protect single-phase motors regardless of size. The 201-100-SP is used on 95-120VAC, 50/60Hz motors to prevent damage caused by... | |
| The 201-xxx-SP-DPDT is an 8-pin octal-base, plug-in voltage monitor designed to protect single-phase motors regardless of size. The 201-100-SP-DPDT is used on 95-120VAC, 50/60Hz motors to prevent damage caused by... | |
| The 201A is a 3-phase, auto-ranging, dual-range voltage monitor that protects 190-480VAC, 50/60Hz motors regardless of size. The product provides a user selectable nominal voltage setpoint and the voltage monitor... | |
| The 201A-AU is a 3-phase, auto-ranging, dual-range voltage monitor that protects 190-480VAC, 50/60Hz motors regardless of size. Has user adjustable 1-30 second trip delay, manual or 1-500 second restart delay,... | |
| The 202 series is a 3-phase, auto-ranging, dual-range voltage monitor that protects 190-600VAC, 50/60Hz motors regardless of size. The 202-RP monitors the phase rotation of 3-phase systems and trips on... | |
| The 202-200-SP voltage monitor is designed to protect single-phase motors regardless of size. It can be used with 190V-240VAC, 50/60Hz motors to prevent damage caused by incoming power problems. A... | |
| The 231-Insider-P provides single-phase protection for submersible pumps with an input voltage of 230 V ac and input load range from ⅓–1 hp. Its output load rating is 1 hp... | |
| The 233P pump monitor protects single-phase pumps with an input voltage value of 230 V ac, an input load range of ⅓–3 hp, and an output load rating of 3... | |
| The 233P-1.5 pump monitor protects single-phase pumps with an input voltage value of 230 V ac, an input load range of ⅓–1.5 hp, and an output load rating of 1.5... | |
| The 233P-ENCL is an enclosed single-phase pump monitor with an input voltage value of 230 V ac, an input load range of ⅓–3 hp, and an output load rating of... | |
| The 233P1.5-ENCL is an enclosed single-phase pump monitor with an input voltage value of 230 V ac, an input load range of ⅓–1.5 hp, and an output load rating of... | |
| 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... | |
| The 235P-ENCL is an enclosed single-phase pump monitor with an input voltage value of 230 V ac, an input load range of 5–15 hp (external current transformer required), and the... | |
| 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-pha se, and reverse-phase. The product provides a... | |
| 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-pha se, and reverse-phase. The product provides a... | |
| 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... | |
| The 355 is a 3-phase voltage monitor with adjustable trip and restart delay, adjustable voltage unbalance and multiple diagnostic lights. It is perfect for heavy-duty applications that need both protection... | |
| 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... | |
| The 460 is a 3-phase voltage monitor that protects 190-480VAC or 475-600V, 50/60Hz motors regardless of size. The product provides a user selectable nominal voltage set point and the voltage... | |
| The 460-100-SP is used on 95-120VAC, 50*/60Hz single-phase motors and the 190-240VAC, 50*/60Hz single-phase motors to protect them from damaging high and low voltage conditions. An adjustment knob allows the... | |
| The 50R single-phase voltage monitor has a voltage-sensing circuit which constantly monitors the single-phase power for a low voltage condition. Single-phase motors on fans, compressors, air conditioners, heat pumps, well... | |
| The 50R-400-ALT alternating relays are used to alternate between two loads, most commonly in duplex pumping and compressor applications to balance the runtime of both loads. When used in single... | |
| The 601-CS-D-P1 3-phase power monitor is a fully programmable electronic power monitor designed to monitor 3-phase systems. The 601-CS-D-P1 has a single relay that can be configured as a general... | |
| The 777-575-HRG-P2 three-phase current and voltage monitor provides motor protection with input voltage from 500–600 V ac and motor full load ampere range of 2–20 A (looped conductors required); 20–90... | |
| The 777-575-KW/HP-P2 three-phase current and voltage monitor provides protection with input voltage from 500–600 V ac and motor full load ampere range as follows: 2–20 A (looped conductors required); 20–90... | |
| The 777-575-LR-P2 three-phase current and voltage monitor provides motor protection with input voltage from 500–600 V ac and motor full load ampere range of 1–9 A (direct); 10–800 A (external... | |
| The 777-575-P2 three-phase current and voltage monitor provides motor protection with input voltage from 500–600 V ac and motor full load ampere range as follows: 2–20 A (looped conductors required); | |
| The 777-AccuPower three-phase motor and pump relay provides protection with input voltage from 190–480 V ac and full load ampere range as follows: 2–25 A: 3-phase (looped conductors required); 25–90... | |
| The 777-FT three-phase current and voltage monitor provides motor protection with input voltage from 200–480 V ac and motor full load ampere range as follows: 2–25 A: 3-phase (looped conductors... | |
| The 777-HRG-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 2–20 A (looped conductors required); 20–90... | |
| The 777-HVR-KW/HP-P2 three-phase current and voltage monitor provides protection with input voltage from 340–480 V ac and motor full load ampere range as follows: 2–20 A (looped conductors required); 20–90... | |
| The 777-HVR-LR-P2 three-phase current and voltage monitor provides motor protection with input voltage from 340–480 V ac and motor full load ampere range of 1–9 A (direct); 10–800 A (external... | |
| 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... | |
| The 777-HVR-SP single-phase relay provides motor protection with input voltage from 340–480 V ac and motor full load ampere range as follows: 2–25 A (looped conductors required); 26–90 A (direct); | |
| 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... | |
| 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... | |
| The 777-LR-TS three-phase current and voltage monitor provides motor protection with input voltage from 200–480 V ac and motor full load ampere range as follows: 1–4.5 A: 3-phase (looped conductors... | |
| The 777-MV-P2 three-phase current and voltage monitor provides motor protection with input voltage from 100–240 V ac and motor full load ampere range of 10–800 A (external CTs required). | |
| The 777-P2 three-phase current and voltage monitor provides motor protection with input voltage from 200–480 V ac and motor full load ampere range as follows: 2–20 A (looped conductors required):... | |
| The 777-TS three-phase current and voltage monitor provides motor protection with input voltage from 200–480 V ac and motor full load ampere range as follows: 2–25 A: 3-phase (looped conductors... | |
| The 777VA-02 three-phase current and voltage monitor provides motor protection with input voltage from 200–480 V ac and motor full load ampere range as follows: 2–25 A: (looped conductors required); | |
| The 777VA-03 three-phase current and voltage monitor provides motor protection with input voltage from 200–480 V ac and motor full load ampere range as follows: 2–25 A: (looped conductors required); | |
| The 77C single-phase relay provides motor protection with input voltage from 100–240 V ac and motor full load ampere range as follows: 2–25 A (looped conductors required); 26–90 A (direct); | |
| The 77C-KW/HP single-phase current and voltage monitor provides protection with voltage from 100–240 V ac and motor full load ampere range of 2–90 A (external CTs required above 90 A). | |
| The 77C-LR single-phase relay provides motor protection with input voltage from 100–240 V ac and motor full load ampere range as follows: 1.0–2.5 A (looped conductors required); 2.0–9.0 A (direct). | |
| The 77C-LR-KW/HP single-phase current and voltage monitor provides protection with voltage from 100–240 V ac and motor full load ampere range of 1–9 A (external CTs required above 9 A). | |
| The ALT alternating relays are used to alternate between two loads. The ALT is commonly used in duplex pumping applications to balance the runtime of both pumps. The ALT-S is... | |
| The ALT-xxx-1-SW and ALT-xxx-3-SW are used to alternate between two loads and are commonly used in duplex pump-up and pump-down applications to balance the runtime of both pumps. The ALT-xxx-1-SW... | |
| The ARP Series is used in systems where equal run time for two motors is desirable. The selector switch allows selection of alternation of either load for continuous operation. LED’s... | |
| The ASQU and ASTU Series of 17.5 mm, knob adjustable, universal solid-state timers offer multiple functions, voltages, and time delay ranges. Choose one of 5 functions and 4 time delay... | |
| The CP-5 is an undercurrent monitor designed to monitor one leg of a 3-phase system. It is commonly used as a tower monitor on center pivot irrigation systems to detect... | |
| The CT Series combines a delay-on-make and delay-on-break time delay into one unit and may be used to control fan delays in heating and/or cooling equipment. The CT includes bypass... | |
| The DLMU Series is a universal voltage, 3-phase voltage monitor. It continuously measures the voltage of each of the three phases with microcontroller accuracy and compares the value to preset... | |
| The DSQU and DSTU Series of 17.5 mm, switch adjustable, universal solid-state timers offer multiple functions, voltages, and time delay ranges. Choose one of 5 functions and 4 time delay... | |
| The EL3100 is a self-powered ground-fault and phasevoltage indication system for 3-phase systems. The EL3100 meets the National Electrical Code (NEC) and the Canadian Electrical Code (CEC) requirements for ground... | |
| The EL731 is a microprocessor-based AC/DC Sensitive Earth-Leakage Relay that offers complete coverage for all frequencies from 0-6,000 Hz. Two CT’s are required for the entire frequency range, or one... | |
| The EL731 series relay operates on ac resistance-grounded systems and dc grounded systems. This unit is a microprocessor-based ac, dc, sensitive, earth-leakage relay that offers complete coverage for all frequencies... | |
| The ERD Series is a combination of digital electronics and an electromechanical relay. DPDT relay output for relay logic circuits, and isolation of input to output voltages. For applications, such... | |
| The ERD3425A is a combination of digital electronics and a reliable electromechanical relay. DPDT relay output for relay logic circuits, and isolation of input to output voltages. Cost effective for... | |
| The ERDM Series are a combination of digital electronics and a reliable electromechanical relay. These devices offer a DPDT relay output for relay logic circuits, and isolation of input to... | |
| The ESDR Series offers independent time adjustment of both delay periods. Adjustment options include fixed, onboard or external adjust. The ESDR is recommended for air drying, automatic oiling, life testing,... | |
| The FlexMod electronic voltage sensing relay & timer monitors both battery voltage and ignition status. shutting down non-critical loads when the cutoff voltage is reached, or at the set time... | |
| The FPS (Feeder Protection System) is a feeder-protection relay that provides current, voltage, and temperature protection for feeder applications. It offers integrated breaker or contactor control, data logging, and a... | |
| The FPU-32 is a feeder-protection relay that provides integrated protection, metering, and data-logging functions. Features/Benefits:• Eight functions to protect against overcurrent, earthfaults, and phase loss; standard LSIG protection plus unbalance... | |
| The HLMU Series is a universal voltage, encapsulated, 3-phase voltage monitor. It continuously measures the voltage of each of the three phases with microcontroller accuracy and compares the value to... | |
| The HLV Series is a single-phase undervoltage monitor designed to protect sensitive equipment from brownout or undervoltage conditions. Time delays are included to prevent nuisance tripping and short cycling. The... | |
| The HRDB Series combines an electromechanical, relay output with microcontroller timing circuitry. The HRDB offers 12 to 230V operation in five options and factory fixed, external, or onboard adjustable time... | |
| The HRDI Series combines an electromechanical relay output with microcontroller timing circuitry. It offers 12 to 230V operation in five ranges and factory fixed, external, or onboard adjustable time delays... | |
| The HRDM Series combines an electromechanical relay output with microcontroller timing circuitry. It offers 12 to 230V operation in five ranges and factory fixed, onboard, or external adjustable time delays... | |
| The HRDR Series combines an electromechanical relay and microcontroller timing circuitry. It offers 12 to 230V operation in five ranges and factory fixed, onboard or externally adjustable time delays with... | |
| The HRDS Series combines an electromechanical relay output with microcontroller timing circuitry. It offers 12 to 230V operation in five options and factory fixed, onboard or external adjustable time delays... | |
| The HRPS and HRIS Series combine an electromechanical relay output with microcontroller timing circuitry. It is a factory programmed module available in any 1 of 13 standard functions. It offers... | |
| The HSPZ Series is a factory programmed module available in any 1 of 13 standard functions. The HSPZ offers dual switch adjustable timer or counter functions. Switch adjustment allows accurate... | |
| The ISS-100 switches are UL 913 listed as an associated apparatus for interfacing between hazardous and non-hazardous areas. These units must be installed in a non-hazardous area. | |
| The ISS-101 switches are UL 913 listed as an associated apparatus for interfacing between hazardous and non-hazardous areas. These units must be installed in a non-hazardous area. | |
| The ISS-102 is a two-channel, intrinsically-safe switch designed for multiple uses including a pump-up/pump-down (latching) controller or two-channel switch. Two LEDs indicate the state of the intrinsically-safe inputs and output... | |
| The ISS-105 is a “smart” five-channel intrinsically safe relay and pump controller. The ISS-105 can be configured for a wide variety of applications including alternating or non-alternating duplex, duplex separate... | |
| The KRD3 Series measures only 2 in. (50.8 mm) square. Its solid-state timing circuit provides excellent repeat accuracy and stability. Encapsulation protects against shock, vibration, and humidity. The KRD3 Series... | |
| The KRD9 Series microcontroller timing circuit provides excellent repeat accuracy and stability. Cost effective approach for OEM applications that require small size, isolation, reliability, and long life. Operation (Retriggerable Single... | |
| The KRDB Series is a compact time delay relay measuring only 2 in. (50.8 mm) square. Its microcontroller timing circuit provides excellent repeat accuracy and stability. Encapsulation protects against shock,... | |
| The KRDI Series is a compact time-delay relay measuring only 2 in. (50.8 mm) square. Its solid-state timing circuit provides excellent repeat accuracy and stability. Encapsulation protects against shock, vibration,... | |
| The KRDM Series is a compact time delay relay measuring only 2 in. (50.8 mm) square. Its solid-state timing circuit provides excellent repeat accuracy and stability. Encapsulation protects against shock,... | |
| The KRDR Series is a compact time-delay relay measuring only 2 in. (50.8 mm) square. Its solid-state timing circuit provides excellent repeat accuracy and stability. Encapsulation protects against shock, vibration,... | |
| The KRDS Series is a compact time delay relay measuring only 2 in. (50.8 mm) square. Its microcontroller timing circuit provides excellent repeat accuracy and stability. Encapsulation protects against shock,... | |
| The KRPD Series is a factory programmed time delay relay available with 1 of 12 standard dual functions. The time delays can be factory fixed, onboard or externally adjustable or... | |
| The KRPS Series is a factory programmed time delay relay available with 1 of 15 functions and measures only 2 inches square. The KRPS offers a wide range of fixed,... | |
| The KSD1 Series features two-terminal, series-connection with the load. The KSD1 Series is an ideal choice for delay-on make timing applications. This series is designed for general purpose commercial and... | |
| The KSD2 Series is designed for general purpose commercial and industrial applications where a small, cost effective, reliable, solid-state timer is required. The factory calibration for fixed time delays is... | |
| The KSD3 Series is a cost effective approach for ON/OFF recycling applications. The on time is equal to the off time. An adjustment of the RT will change the time... | |
| The KSDB is designed for general purpose commercial and industrial applications where a small, cost effective, reliable solid-state timer is required. The factory calibration for fixed time delays is within... | |
| The KSDR Series offers independent time adjustment of both delay periods. The KSDR is recommended for air drying, automatic oiling, life testing, chemical metering, and automatic duty cycling. This series... | |
| The KSDS Series is ideal for applications that require momentary start interval timing including dispensing, exposure timing, or pulse shaping. This series is available for both AC and DC voltages. | |
| The KSDU Series are encapsulated solid-state, delay-on-make timers that combine digital timing circuitry with universal voltage operation. The KSDU is factory fixed from 0.1s to 10,230s and does not include... | |
| The KSPD Series is a factory programmed module available with 1 of 12 standard dual functions. The time delays can be factory fixed, externally or onboard adjustable, or a combination... | |
| The KSPS Series is a factory programmed module available in any 1 of 14 standard functions. The KSPS offers a single, fixed, externally or onboard adjustable time delay. The 1A... | |
| The KVM Series is a single-phase undervoltage monitor designed to protect sensitive equipment against brownout undervoltage conditions. The compact design and encapsulated construction make the KVM an excellent choice for... | |
| The Model 601 is a fully-programmable voltage monitor designed to protect 3-phase motors. It can be used as a stand-alone product or networked with an RM-1000, RM-2000, PLC, computer or... | |
| The MP8000 is an advanced motor protection electronic overload relay that is fully programmable via Bluetooth® using an iPhone or Android smartphone/tablet with the Littelfuse app. It has an input... | |
| The MPS-469X Motor Protection Retrofit Kit replaces the GE Multilin 469 relay. It includes the MPS Motor Protection System and optional RTD and differential modules mounted on a panel that... | |
| The MPS-CTU-01-00 is a motor protection system with a supply voltage between 65–265 V ac and 80–275 V dc. This unit monitors voltage, current, and temperature with communication via RS/TIA-485. | |
| The MPS-CTU-02-00 is a motor protection system with a supply voltage between 65–265 V ac and 80–275 V dc. This unit monitors voltage, current, and temperature with communication via RS/TIA-485... | |
| The MPS-CTU-03-00 is a motor protection system with a supply voltage between 65–265 V ac and 80–275 V dc. This unit monitors voltage, current, and temperature with communication via RS/TIA-485... | |
| The MPS-CTU-04-00 is a motor protection system with a supply voltage between 65–265 V ac and 80–275 V dc. This unit monitors voltage, current, and temperature with communication via RS/TIA-485... | |
| The MPS-DIF-01-00 module adds differential protection to the MPS and MPU-32. It is compatible with 3-CT core balance and 6-CT summation current transformer connections (optional). | |
| The MPS-OPI-01-00 (MPS-OPI) is the recommended 4 x 20 vacuum-fluorescent operator interface display for the MPS Motor Protection System. | |
| The MPU-32-00-00 is a motor protection unit with a supply voltage between 65–265 V ac and 80–275 V dc. This unit provides current and temperature-based protection with communication via RS/TIA-232. | |
| The MPU-32-00-01 is a motor protection unit with a supply voltage between 65–265 V ac and 80–275 V dc. This unit provides current and temperature-based protection with communication via RS/TIA-232. | |
| The MPU-32-01-00 is a motor protection unit with a supply voltage between 65–265 V ac and 80–275 V dc. This unit provides current and temperature-based protection with communication via RS/TIA-232-RS/TIA-48... | |
| The MPU-32-01-01 is a motor protection unit with a supply voltage between 65–265 V ac and 80–275 V dc. This unit provides current and temperature-based protection with communication via RS/TIA-232-RS/TIA-48... | |
| The MPU-32-02-00 is a motor protection unit with a supply voltage between 65–265 V ac and 80–275 V dc. This unit provides current and temperature-based protection with communication via RS/TIA-232... | |
| The MPU-32-02-01 is a motor protection unit with a supply voltage between 65–265 V ac and 80–275 V dc. This unit provides current and temperature-based protection with communication via RS/TIA-232... | |
| The MPU-32-04-00 is a motor protection unit with a supply voltage between 65–265 V ac and 80–275 V dc. This unit provides current and temperature-based protection with communication via RS/TIA-232... | |
| The MPU-32-04-01 is a motor protection unit with a supply voltage between 65–265 V ac and 80–275 V dc. This unit provides current and temperature-based protection with communication via RS/TIA-232... | |
| The MPU-32-X69X Motor Protection Retrofit Kit is designed to replace GE Multilin 169, 269, and 369 relays. It includes the MPU-32 Motor Protection Relay, MPU-CIM Current Input Module, and optional... | |
| The MSM replaces bi-metal type timing with reliable solid-state circuitry. There are no moving parts to arc or wear. It is a cost effective solution for OEM designers. It is... | |
| The OptoMOS® line of solid state relays uses discrete semiconductor components and the patented OptoMOS® architecture to deliver fast, reliable, bounce-free switching in a compact design. From one of the... | |
| The OptoMOS® line of solid-state relays uses discrete semiconductor components and the patented OptoMOS® architecture to deliver fast, reliable, bounce-free switching in a compact design. From one of the world's... | |
| The PumpSaver® Plus Model 234-P protects single-phase pumps with an input voltage value of 230 V ac, an input load range of ⅓–3 hp, and an output load rating of... | |
| The single-phase 232-Insider PumpSaver® fits inside ⅓, ½, ¾, and 1 hp, 230 V Grundfos control boxes. Its input voltage is 230 V ac with an input load range of... |
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