355 Series – Three-Phase Voltage Monitor Relay Series - Littelfuse 355 Voltage Monitoring Relays Provide Superior Protection

Series: 355 Series – Three-Phase Voltage Monitor Relay
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Littelfuse products are not designed for, and shall not be used for, any purpose (including, without limitation, automotive, military, aerospace, medical, life-saving, life-sustaining or nuclear facility applications, devices intended for surgical implant into the body, or any other application in which the failure or lack of desired operation of the product may result in personal injury, death, or property damage) other than those expressly set forth in applicable Littelfuse product documentation. Warranties granted by Littelfuse shall be deemed void for products used for any purpose not expressly set forth in applicable Littelfuse documentation. Littelfuse shall not be liable for any claims or damages arising out of products used in applications not expressly intended by Littelfuse as set forth in applicable Littelfuse documentation. The sale and use of Littelfuse products is subject to Littelfuse Terms and Conditions of Sale, unless otherwise agreed by Littelfuse. "Littelfuse" includes Littelfuse, Inc., and all of its affiliate entities.

The 355 series is a three-phase voltage monitor with adjustable trip and restart delay, adjustable voltage unbalance, and multiple diagnostic lights. It is ideal for heavy-duty applications that need both protection and simple user-friendly diagnostics. Suitable applications include pump panels, commercial HVAC, oil rigs, and many more. The 355 series uses microcontroller technology to monitor incoming voltage and de-energize its output relay if power problems exist. It can protect motors from damage caused by single-phasing, high- and low-voltage, phase reversal, and voltage unbalance. These relays have four diagnostic LEDs that clearly show overvoltage, undervoltage, voltage unbalance, reverse-phase, and normal conditions. The adjustable trip and restart settings prevent nuisance tripping due to rapidly fluctuating power line conditions and allow staggered start-up of multiple motors after a fault to prevent a low-voltage condition.

Series 355 models include the 355-200, which is equipped with a heavy-duty 10 A general purpose SPDT relay. The 355-400 and 355-600 models are equipped with a 470 VA @ 600 V ac pilot duty SPDT relay. A high-voltage (600 V) DPDT relay output option is available with the 400 V model.

Features

  • Proprietary microcontroller-based circuitry
  • Advanced LED indication
  • Adjustable trip and restart delay settings
  • 600 V rated relay contacts available on some models

Product Literature

For Technical Questions

Call +1 800-832-3873 or email us at relays@littelfuse.com 

Access specifications, certifications, check availability and order parts below

Catalog #Input
Voltage (V)		Output
Form		Termination TypeMounting MethodDimensionsWeight (lbs/g)Input AC Line Frequency (Hz)Maximum Input PowerOutput Load Rating (VA)Overvoltage Reset Voltage (%)Overvoltage Trip Voltage (%)Repeat Accuracy (%)Restart Delay RangeStorage Temperature (F/C)Trip Delay RangeStockSamplesCompare
355200190 - 240 VacSPDTTorque: 7 in-lbs; Wire Size: 12 - 18 AWG#8 screws2.93 H x 5.27 W x 2.95 D in. (74.4 x 133.9 x 74.9 mm)0 Kg50 / 60 (50 will increase all delay timers by 20%)6Pilot Duty: 480 VA @ 240 Vac; General Purpose: 10 A or 1 hp @ 240 Vac107%110%±0.1%After a Fault or power loss: Manual; 2 - 300 s adjustable-40° to 80°C (-40° to 176°F)Under/Over and Unbalance Voltage: 2 - 30 s adjustable; single-Phase faults (>25%UB): 2 sCheckOrder
355400380 - 480 VacSPDTTorque: 7 in-lbs; Wire Size: 12 - 18 AWG#8 screws2.93 H x 5.27 W x 2.95 D in. (74.4 x 133.9 x 74.9 mm)0 Kg50 / 60 (50 will increase all delay timers by 20%)6Pilot Duty: 470 VA @ 600 Vac; General Purpose: 10 A107%110%±0.1%After a Fault or power loss: Manual; 2 - 300 s adjustable-40° to 80°C (-40° to 176°F)Under/Over and Unbalance Voltage: 2 - 30 s adjustable; single-Phase faults (>25%UB): 2 sCheckOrder
3554005380 - 480 VacDPDTTorque: 7 in-lbs; Wire Size: 12 - 18 AWG#8 screws2.93 H x 5.27 W x 2.95 D in. (74.4 x 133.9 x 74.9 mm)0 Kg50 / 60 (50 will increase all delay timers by 20%)6Pilot Duty: 470 VA @ 600 Vac; General Purpose: 10 A107%110%±0.1%After a Fault or power loss: Manual; 2 - 300 s adjustable-40° to 80°C (-40° to 176°F)Under/Over and Unbalance Voltage: 2 - 30 s adjustable; single-Phase faults (>25%UB): 2 sCheckOrder
355600475 - 600 VacSPDTTorque: 7 in-lbs; Wire Size: 12 - 18 AWG#8 screws2.93 H x 5.27 W x 2.95 D in. (74.4 x 133.9 x 74.9 mm)0 Kg50 / 60 (50 will increase all delay timers by 20%)6Pilot Duty: 470 VA @ 600 Vac; General Purpose: 10 A107%110%±0.1%After a Fault or power loss: Manual; 2 - 300 s adjustable-40° to 80°C (-40° to 176°F)Under/Over and Unbalance Voltage: 2 - 30 s adjustable; single-Phase faults (>25%UB): 2 sCheckOrder
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