Littelfuse Monitoring Relays

Littelfuse monitoring relays for voltage and current protection in control panels.

Littelfuse monitoring relays are designed to supervise electrical power conditions and respond quickly to abnormal events to protect equipment and processes. These relays are widely used in industrial automation systems, control panels, motor control centers, and OEM machinery where accurate voltage, current, phase, and frequency monitoring is required. Leveraging its expertise in circuit protection, Littelfuse engineers monitoring relays for dependable performance in harsh industrial environments.

Voltage and phase monitoring relays detect overvoltage, undervoltage, phase loss, incorrect phase sequence, and phase imbalance in both single-phase and three-phase systems. These devices are commonly applied in motor protection circuits, pump and compressor controls, conveyor systems, HVAC equipment, and industrial power distribution panels to prevent motor damage, nuisance tripping, and electrical faults.

Littelfuse current monitoring relays measure load current to identify overload, underload, dry-run, and stalled motor conditions in rotating equipment such as pumps, fans, and conveyors. By detecting abnormal operating conditions early, they support predictive maintenance strategies and help reduce unplanned downtime. Additional specialty monitoring relays, including frequency monitoring models, are available for advanced protection requirements. Most Littelfuse monitoring relays feature adjustable setpoints, DIN-rail mounting, and compliance with widely recognized international standards.

Found 69 items
Normally In Stock
Littelfuse ECSL40AC Current Monitoring - 120 Volt, Double Throw, Single Pole
Free U.S Ground shipping
$223.09
$185.91
Normally In Stock
Littelfuse ECS4HBH Current Monitoring - 120 Volt, Double Throw, Single Pole
Free U.S Ground shipping
$216.97
$180.81
Normally In Stock
Littelfuse ECSW3LABT Current Monitoring - 24 Volt (DC), Double Throw, Single Pole
Free U.S Ground shipping
$313.74
$261.45
Normally In Stock
Littelfuse ECSW4LADT Current Monitoring - 120 Volt, Double Throw, Single Pole
Free U.S Ground shipping
$313.74
$261.45
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Littelfuse ECS60BC Current Monitoring - 230 Volt, Double Throw, Single Pole
Free U.S Ground shipping
$216.97
$180.81
Normally In Stock
Littelfuse ECSH41AD Current Monitoring - 120 Volt, Double Throw, Single Pole
Free U.S Ground shipping
$223.09
$185.91
Normally In Stock
Littelfuse DCSA20 AC Current Transducer
Free U.S Ground shipping
$187.74
$156.45
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Littelfuse TCSA50 AC Current Transducer
Free U.S Ground shipping
$199.81
$166.51
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Littelfuse ECSW6MBHT Current Monitoring - 230 Volt, Double Throw, Single Pole
Free U.S Ground shipping
$313.74
$261.45
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Littelfuse TCSH2B Current Monitoring - , Normally Closed
Free U.S Ground shipping
$133.54
$111.28
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Littelfuse TCSHAB Current Monitoring - , Normally Closed
Free U.S Ground shipping
$133.54
$111.28
Normally In Stock
Littelfuse TCSHAA Current Monitoring - , Normally Open
Free U.S Ground shipping
$133.54
$111.28
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Littelfuse CP5460 Current Monitoring - 480 Volt, Double Throw, Single Pole
Free U.S Ground shipping
$506.20
$421.83
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Littelfuse TCSG2A Current Monitoring - , Normally Open
Free U.S Ground shipping
$133.54
$111.28
Normally In Stock
Littelfuse TCSGAA Current Monitoring - , Normally Open
Free U.S Ground shipping
$133.54
$111.28
Normally In Stock
Littelfuse TCSGAB Current Monitoring - , Normally Closed
Free U.S Ground shipping
$133.54
$111.28
Normally In Stock
Littelfuse TCSH2A Current Monitoring - , Normally Open
Free U.S Ground shipping
$133.54
$111.28
Normally In Stock
Littelfuse DCSA5 AC Current Transducer
Free U.S Ground shipping
$187.74
$156.45
Normally In Stock
Littelfuse DCSA50 AC Current Transducer
Free U.S Ground shipping
$187.74
$156.45
Normally In Stock
Littelfuse LCSC10T12 Calibrated Current Sensor
Free U.S Ground shipping
$107.60
$89.67
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Littelfuse LPM12 Panel Mount Indicator
Free U.S Ground shipping
$17.30
$14.42
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Littelfuse LPMG12 Panel Mount Led
Free U.S Ground shipping
$17.30
$14.42
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Littelfuse LSR-0 Load Sensor/ Self-Powered/ 15-
Free U.S Ground shipping
$135.74
$113.12
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Littelfuse LSR-24 Current Monitoring - 24 Volt, Double Throw, Single Pole
Free U.S Ground shipping
$243.74
$203.12
Normally In Stock
Littelfuse LSRX Current Monitoring - , Single Throw, Single Pole
Free U.S Ground shipping
$109.25
$91.04
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Littelfuse LSRX-C Current Monitoring - , Single Throw, Single Pole
Free U.S Ground shipping
$109.25
$91.04
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Littelfuse LSRX-OEM Current Monitoring - , Single Throw, Single Pole
Free U.S Ground shipping
$1016.24
$846.87
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Littelfuse TCSA10 AC Current Transducer
Free U.S Ground shipping
$199.81
$166.51
Normally In Stock
Littelfuse TCSA20 AC Current Transducer
Free U.S Ground shipping
$199.81
$166.51
Normally In Stock
Littelfuse TCSA5 AC Current Transducer
Free U.S Ground shipping
$199.81
$166.51
Normally In Stock
Littelfuse ECSH41BC Current Monitoring - 120 Volt, Double Throw, Single Pole
Free U.S Ground shipping
$223.09
$185.91
Normally In Stock
Littelfuse ECSH41F.08D Current Monitoring - 120 Volt, Double Throw, Single Pole
Free U.S Ground shipping
$223.09
$185.91
Normally In Stock
Littelfuse ECSH4HAD Current Monitoring - 120 Volt, Double Throw, Single Pole
Free U.S Ground shipping
$223.09
$185.91
Normally In Stock
Littelfuse ECSH4HF.08D Current Monitoring - 120 Volt, Double Throw, Single Pole
Free U.S Ground shipping
$223.09
$185.91
Normally In Stock
Littelfuse ECSH61AD Current Monitoring - 230 Volt, Double Throw, Single Pole
Free U.S Ground shipping
$223.09
$185.91
Normally In Stock
Littelfuse ECSL31A Current Monitoring - 24 Volt (DC), Double Throw, Single Pole
Free U.S Ground shipping
$223.09
$185.91
Normally In Stock
Littelfuse ECS61BC Current Monitoring - 230 Volt, Double Throw, Single Pole
Free U.S Ground shipping
$216.97
$180.81
Normally In Stock
Littelfuse ECS6HAH Current Monitoring - 230 Volt, Double Throw, Single Pole
Free U.S Ground shipping
$216.97
$180.81
Normally In Stock
Littelfuse ECSH30AC Current Monitoring - 24 Volt (DC), Double Throw, Single Pole
Free U.S Ground shipping
$223.09
$185.91
Normally In Stock
Littelfuse ECSH40AC Current Monitoring - 120 Volt, Double Throw, Single Pole
Free U.S Ground shipping
$223.09
$185.91
Normally In Stock
Littelfuse ECSH40AD Current Monitoring - 120 Volt, Double Throw, Single Pole
Free U.S Ground shipping
$223.09
$185.91
Normally In Stock
Littelfuse ECSH41AC Current Monitoring - 120 Volt, Double Throw, Single Pole
Free U.S Ground shipping
$223.09
$185.91
Normally In Stock
Littelfuse ECS20BC Current Monitoring - 24 Volt, Double Throw, Single Pole
Free U.S Ground shipping
$216.97
$180.81
Normally In Stock
Littelfuse ECS21BC Current Monitoring - 24 Volt, Double Throw, Single Pole
Free U.S Ground shipping
$216.97
$180.81
Normally In Stock
Littelfuse ECS2HBC Current Monitoring - 24 Volt, Double Throw, Single Pole
Free U.S Ground shipping
$216.97
$180.81
Normally In Stock
Littelfuse ECS30AC Current Monitoring - 24 Volt (DC), Double Throw, Single Pole
Free U.S Ground shipping
$216.97
$180.81
Normally In Stock
Littelfuse ECS31AC Current Monitoring - 24 Volt (DC), Double Throw, Single Pole
Free U.S Ground shipping
$216.97
$180.81
Normally In Stock
Littelfuse ECS40A Current Monitoring - 120 Volt, Double Throw, Single Pole
Free U.S Ground shipping
$216.97
$180.81

FAQs

Q: What are Littelfuse monitoring relays used for in industrial applications?
Littelfuse monitoring relays continuously monitor voltage, current, phase, and frequency conditions to protect electrical equipment from abnormal operation. They are commonly installed in control panels, motor control centers, and industrial power systems.

Q: What types of monitoring relays does Littelfuse offer?
Littelfuse offers voltage monitoring relays, phase monitoring relays, current monitoring relays, and frequency monitoring relays for single-phase and three-phase systems.

Q: How do Littelfuse voltage and phase monitoring relays protect motors and equipment?
They detect overvoltage, undervoltage, phase loss, incorrect phase sequence, and phase imbalance. When abnormal conditions are detected, the relay output changes state to shut down equipment or activate an alarm.

Q: What are Littelfuse current monitoring relays used for?
Littelfuse current monitoring relays detect overload, underload, dry-run, and stalled motor conditions in rotating machinery, helping reduce downtime and equipment damage.

Q: Are Littelfuse monitoring relays suitable for control panels and motor protection circuits?
Yes. Littelfuse monitoring relays are designed for DIN-rail mounting, adjustable setpoints, and compatibility with industrial voltages, making them suitable for motor protection and automation panels.

Why Buy Littelfuse Monitoring Relays from RSP Supply

RSP Supply offers a comprehensive selection of Littelfuse monitoring relays for voltage, phase, current, and frequency protection applications. With adjustable and DIN-rail mountable solutions designed for motor protection and power quality supervision, customers can integrate reliable monitoring devices into industrial control systems. RSP Supply supports engineers and maintenance professionals with dependable electrical protection products and knowledgeable service for critical automation applications.