All SymCom voltage monitors are microcontroller based and are factory calibrated for highly accurate and precise voltage measurements to provide high sensitivity while minimizing nuisance tripping. The high accuracy and precision of SSAC devices allows them to detect a single-phase condition or voltage unbalance even with regenerated voltages present. Uncalibrated devices require low sensitivity to voltage faults to prevent nuisance trips, thus may not trip in the presence of regenerated voltages. SymCom MotorSaver voltage monitors are built with transformer power supplies which makes them highly resistant to damage caused by small voltage transients on the power system. Other types of power supplies such as switching, resistor limited, and capacitor limited, are typically more easily damaged by transients.
Littelfuse/SymCom 102 Voltage Monitoring Relays Distributors
102

The Littelfuse/SymCom MotorSaver 102 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 automatically selects between the 200V and 400V range. A unique microcontroller-based voltage and phase-sensing circuit constantly monitors the 3-phase voltages to detect harmful power line conditions. When a harmful condition is detected, the output relay is deactivated after a specified trip delay. The output relay reactivates after power line conditions return to acceptable levels. The Model 102 includes advanced single LED diagnostics. Five different light patterns distinguish between faults and normal conditions.

Littelfuse/SymCom 102A 3-Phase Voltage/Phase Monitors Distributors
102A

The Littelfuse/SymCom MotorSaver 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 automatically selects between the 200V and 400V range. A unique microcontroller-based voltage and phase-sensing circuit constantly monitors the 3-phase voltages to detect harmful power line conditions. When a harmful condition is detected, the output relay is deactivated after a specified trip delay. The output relay reactivates after power line conditions return to acceptable levels. The Model 102A includes advanced single LED diagnostics. Five different light patterns distinguish between faults and normal conditions.

Littelfuse/SymCom 201A 3-Phase Voltage/Phase Monitors Distributors
201A

The Littelfuse/SymCom 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 automatically selects between the 200V and 400V range. The 201A includes advanced single LED diagnostics, where color and different light patterns distinguish between faults and normal conditions. 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 201A’s output relay is deactivated after a specified trip delay. The output relay reactivates after power line conditions return to acceptable levels.

Littelfuse/SymCom 201A-AU 3-Phase Voltage/Phase Monitors Distributors
201A-AU

The Littelfuse/SymCom 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, and 2-8% voltage unbalance trip point. The product also provides a user selectable nominal voltage setpoint and the voltage monitor automatically selects between the 200V and 400V range. The Model 201A-AU includes advanced single LED diagnostics, where five different light patterns distinguish between faults and normal conditions. 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 201A-AU's output relay is deactivated after a specified trip delay. The output relay reactivates after power line conditions return to acceptable levels.

Littelfuse/SymCom 201-XXX-DPDT 3-Phase Voltage/Phase Monitors Distributors
201-XXX-DPDT

The Littelfuse/SymCom 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 used on 190-240VAC, 50/60Hz motors to prevent damage caused by incoming voltage problems. The units feature two isolated sets of contacts that are ideal for use with two control circuits with different voltages. The unique microcontroller-based voltage and phase-sensing circuit constantly monitors the voltages to detect harmful power line conditions. When a harmful condition is detected, the relay’s output relays are deactivated after a specified trip delay. The output relays reactivate after power line conditions return to an acceptable level and a specified amount of time has elapsed (restart delay). The trip delay prevents nuisance tripping due to rapidly fluctuating power line conditions. This unit is also available with a shorter trip delay and faster restart delay. The 201-xxx-DPDT-60mS has a trip delay of 0.5 seconds and a restart delay of 60 milliseconds.

littelfuse 201 monitor
201-XXX-SP
The 201-xxx-SP Series 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 low voltage. The 201-200-SP is used on 190-240VAC, 50/60Hz motors. The 201-200-SP-T-9 is a pin-forpin replacement for a Time Mark® #260 Series voltage monitor. High voltage protection is included in the 201-200-SP-T-9.
Littelfuse/SymCom 201-XXX-SP-DPDT 1-Phase Voltage/Phase Monitors Distributors
201-XXX-SP-DPDT

The Littelfuse/SymCom 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 low voltage. The 201-200-SP-DPDT is used on 190-240VAC, 50/60Hz motors. The units feature two isolated sets of contacts that are ideal for use with two control circuits with different voltages. The unique microcontroller-based voltage and voltage-sensing circuit constantly monitors the voltage to detect harmful power line conditions. When a harmful condition is detected, the relay’s output relays are deactivated after a specified trip delay. The output relays reactivate after power line conditions return to an acceptable level and a specified amount of time has elapsed (restart delay). The trip delay prevents nuisance tripping due to rapidly fluctuating power line conditions.

Littelfuse/SymCom 202/202-RP 3-Phase Voltage/Phase Monitors Distributors
202/202-RP

The Littelfuse/SymCom MotorSaver 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 reverse phase only. Critical applications include fan motors, scroll compressors, grinders, conveyor systems, elevators and escalators. Both products provide a user selectable nominal voltage setpoint and some models 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 202 series’s output relay is deactivated after a specified trip delay. The output relay reactivates after power line conditions return to acceptable levels. The 202 series includes advanced single LED diagnostics. Five different light patterns distinguish between faults and normal conditions. The 202-RP 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. The status light turns green and the relay is activated when rotation is correct.

Littelfuse/SymCom 250A 3-Phase Voltage/Phase Monitors Distributors
250A

The Littelfuse/SymCom MotorSaver 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.

Littelfuse/SymCom 350 3-Phase Voltage/Phase Monitors Distributors
350

The Littelfuse/SymCom MotorSaver 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.

Littelfuse/SymCom 355 3-Phase Voltage/Phase Monitors Distributors
355

The Littelfuse/SymCom 355 MotorSaver 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 and simple user-friendly diagnostics. Applications include pump panels, commercial HVAC, oil rigs and others. The 355 uses microcontroller technology to monitor incoming voltage and de-energize its output relay if power problems exist. The 355 can protect motors from damage caused by single-phasing, high and low voltage, phase reversal and voltage unbalance. It has four diagnostic LEDs that clearly show overvoltage, undervoltage, voltage unbalance, reverse-phase and normal conditions. The 355-200 is equipped with a heavy-duty 10A general purpose SPDT relay. The 355-400 and 355-600 are equipped with a 470VA @ 600VAC pilot duty SPDT relay. A high voltage (600V) DPDT relay output option is available with the 400V model.

Littelfuse/SymCom 455 3-Phase Voltage/Phase Monitors Distributors
455

The Littelfuse/SymCom Model 455 MotorSaver is a 3-phase, dual-range voltage monitor that automatically selects between 200V and 400V range to protect 190V-480VAC, 50/60Hz motors. The user-selectable nominal voltage setpoint and can be adjustment 2-30 second trip delay. a 2-300 second restart delay or manual restart, and a voltage unbalance trip point between 2-8%. The monitor's electronics are powered through the line side without the need for a separate power source making it easier to install. The 455 offers complete protection even before the motor starts by monitoring both the load and line side to detect impending power problems. Unlike other voltage monitors where voltage problems are detected only after the motor is started, the 455 will not allow the motor to start if a power problem is present. Equipped with an infrared LED, the 455 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 point, restart and trip delay settings, LED status and more.

Littelfuse/SymCom 460 Series 3-Phase Voltage Monitor Distributors
460 Series

The Littelfuse/SymCom 460 MotorSaver 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 setpoint and the voltage monitor automatically senses line voltage. This unique microcontroller-based voltage and phase-sensing device constantly monitors the 3-phase voltages to detect harmful power line conditions such as low, high, and unbalanced voltage, loss of any phase, and phase reversal. When a harmful condition is detected, the 460 output relay is deactivated after a specified trip delay. The output relay reactivates after power line conditions return to an acceptable level for a specified amount of time (restart delay). The trip and restart delays prevent nuisance tripping due to rapidly fluctuating power line conditions. All 460 models feature adjustable 1-30 second trip delay, 1-500 second restart delay, 2-8% voltage unbalance trip point, and one form C contact except where noted.

Littelfuse/SymCom 460-XXX-SP 1-Phase Voltage Monitors Distributors
460-XXX-SP

The Littelfuse/SymCom 460-100-SP MotorSaver 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 user to set a 1-500 second restart delay. The variable restart delay is also a power-up delay and can be utilized to stagger-start motors on the same system. A unique microcontroller-based, voltage-sensing circuit constantly monitors the voltage to detect harmful power line conditions. When a harmful condition is detected, the relay’s output relay is deactivated after a specified trip delay. The output relay reactivates after power line conditions return to an acceptable level and a specified amount of time has elapsed (restart delay). The trip delay prevents nuisance tripping due to rapidly fluctuating power line conditions.

Littelfuse/SymCom 50R 1-Phase Voltage Monitors Distributors
50R

The Littelfuse/SymCom 50R MotorSaver 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 pumps, sump pumps and small conveyor motors are all applicable to the Model 50R. When a harmful condition is detected, the output relay is deactivated after a specified trip delay. The output relay reactivates after power line conditions return to an acceptable level and a specified amount of time has elapsed (restart delay). The trip delay prevents nuisance tripping due to rapidly fluctuating power line conditions.

Littelfuse/SymCom 601 3-Phase Voltage & Frequency Monitors Distributors
601

The Littelfuse/SymCom Model 601 MotorSaver 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 SCADA system. When a harmful condition is detected, the 601’s output relay is deactivated after the specified trip delay. The output relay reactivates after power line conditions return to an acceptable level for the programmed restart delay (RD2). When used with the RS485MS-2W communications module, the 601 can communicate with most Modbus RTU master devices. Voltage conditions can be monitored and setpoints can be changed remotely using Solutions software, an RM-1000, RM-2000 or other device.

Littelfuse/SymCom 601-CS-D-P1 3-Phase Power Monitors Distributors
601-CS-D-P1

The Littelfuse/SymCom 601-CS-D-P1 MotorSaver 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 purpose network output or to trip on ground faults. The 601-CS-D-P1 monitors ground fault current, phase currents, phase voltages, power factor and frequency. The RS485MS-2W communications module allows the 601-CS-D-P1 to communicate using the Modbus RTU protocol. The Modbus connection can be used to monitor power parameters, setup the device or control the fault relay. A DeviceNet™ communications I/O module (CIO-601CS-DN-P1) is available as well. This CIO module only works with the 601-CS-D-P1 unit. It is used for sending the information from the 601-CS-D-P1 over a DeviceNet™ network. It also provides I/O capabilities and the ability to set the parameters of the 601-CS-D-P1.

Littelfuse/SSAC DLMU Voltage Monitors Distributors
DLMU

The Littelfuse/SSAC 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 trip points. It separately senses phase reversal and loss; over, under and unbalanced voltages; and over or under frequency. Protection is assured during periods of large average voltage fluctuations or when regenerated voltages are present. The unit trips within 200ms when phase loss is detected. Adjustable time delays are included to prevent nuisance tripping and short cycling of sensitive equipment. The isolated, 10A, SPDT and 2A alarm output relay contacts trip when a phase voltage exceeds the trip limits for the trip delay. Nominal line voltage, voltage unbalance, and time delays are knob adjustable. The phase loss setpoint and the acceptable frequency range are fixed. Both delta and wye systems can be monitored; no connection to neutral is required.

Littelfuse/SSAC HLMU Voltage Monitors Distributors
HLMU

The Littelfuse/SSAC 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 preset trip points. It separately senses phase reversal and loss; over, under and unbalanced voltages; and over or under frequency. Protection is assured during periods of large average voltage fluctuations, or when regenerated voltages are present. The unit trips within 200ms when phase loss is detected. Adjustable time delays are included to prevent nuisance tripping and short cycling of sensitive equipment. The isolated, 10A, DPDT relay contacts trip when a phase voltage exceeds the trip limits for the trip delay. Nominal line voltage, voltage unbalance, and time delays are knob adjustable. The phase loss setpoint and the acceptable frequency range are fixed. Both delta and wye systems can be monitored; no connection to neutral is required.

Littelfuse/SSAC HLV Voltage Monitors Distributors
HLV

The Littelfuse/SSAC 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 30A, 1hp rated, SPDT relay contacts allow direct control of motors, solenoids and valves. The output relay can be ordered with isolated SPDT contact to allow monitoring of one voltage and switching a separate voltage. Two undervoltage trip point ranges allow monitoring of 110 to 120VAC or 208 to 240VAC systems.

Littelfuse/SSAC KVM Voltage Monitors Distributors
KVM

The Littelfuse/SSAC 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 OEM equipment.

Littelfuse/SSAC PLM Voltage Monitors Distributors
PLM

The Littelfuse/SSAC PLM Series is a 3-phase voltage monitor that continuously monitors each of the three phases. Monitors both delta and wye systems and no connection to neutral is required. The microcontroller circuit design protects against undervoltage, voltage unbalance, phase loss and phase reversal. Protection is assured when regenerated voltages are present.

Littelfuse/SSAC PLR Voltage Monitors Distributors
PLR

The Littelfuse/SSAC PLR Series provides a cost effective means of preventing 3-phase motor startup during adverse voltage conditions. Proper A-B-C sequence must occur in order for the PLR’s output contacts to energize. In addition, the relay will not energize when an undervoltage or phase loss condition is present. The PLR protects a motor against undervoltage operation. The adjustment knob sets the undervoltage trip point.

Littelfuse/SSAC PLS Voltage Monitors Distributors
PLS

The Littelfuse/SSAC PLS Series is a low cost phase sensitive control that provides an isolated contact closure when the proper A-B-C phase sequence is applied. Protects sensitive 3-phase equipment and equipment operators from reverse rotation. Designed to be compatible with motor overloads or other 3-phase equipment protection devices. Protection for equipment control centers where frequent reconnection or electrical code makes reverse rotation protection essential. Examples include: mobile refrigerated containers, construction equipment, hoists, pumps, conveyors, elevators and escalators.

Littelfuse/SSAC TVM Voltage Monitors Distributors
TVM

The Littelfuse/SSAC TVM series provides protection for motors and other sensitive loads. ontinuously measures the voltage of each of the three phases using a microcomputer circuit design that senses under and overvoltage, voltage unbalance, phase loss, and phase reversal. Protection is provided even when regenerated voltages are present. Includes a trip delay to prevent nuisance tripping and a restart delay to prevent short cycling after a momentary power outage.

Littelfuse/SSAC TVW Voltage Monitors Distributors
TVW

The Littelfuse/SSAC TVW Series provides protection for motors and other sensitive loads. Continuously measures the voltage of each of the three phases using a microcontroller circuit design that senses under and overvoltage, voltage unbalance, phase loss, and phase reversal. Protection is provided even when regenerated voltages are present. Includes a trip delay to prevent nuisance tripping and a restart delay to prevent short cycling after a momentary power outage.

Littelfuse/SSAC WVM Voltage Monitors Distributors
WVM

The Littelfuse/SSAC WVM Series provides protection against premature equipment (motor) failure caused by voltage faults on the 3-phase line. The WVM’s microcontroller design provides reliable protection even if regenerated voltages are present. It combines dependable fault sensing with a 10 fault memory and a 6 LED status display. Part instrument, part control, the WVM protects your equipment when you’re not there and displays what happened when you return. The WVM is fully adjustable and includes time delays to prevent nuisance tripping and improve system operation. Time delays include a 0.25 to 30s adjustable trip delay, an adjustable 0.25 to 64m (in 3 ranges) restart delay, plus a unique 3 to 15s true random start delay. The random start delay prevents voltage sags caused by simultaneous restarting of numerous motor loads after a power outage.