3554005 - 355 Series

Series: 355
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Littelfuse Voltage Monitoring Relays
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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 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.

Property (Mouseover for details) Value
Input Voltage (V) 380 - 480 Vac
Maximum Input Power 6
Input AC Line Frequency (Hz) 50 / 60 (50 will increase all delay timers by 20%)
Output Form DPDT
Output Load Rating (VA) Pilot Duty: 470 VA @ 600 Vac; General Purpose: 10 A
Restart Delay Range After a Fault or power loss: Manual; 2 - 300 s adjustable
Repeat Accuracy (%) ±0.1%
Trip Delay Range Under/Over and Unbalance Voltage: 2 - 30 s adjustable; single-Phase faults (>25%UB): 2 s
Trip Point Accuracy (%) ±1%
Overvoltage Trip Voltage (%) 110%
Overvoltage Reset Voltage (%) 107%
Undervoltage Trip Voltage 90%
Undervoltage Reset Voltage (%) 93%
Voltage Unbalance Trip Point (%) 2 - 8% adjustable
Voltage Unbalance Reset (%) Trip setting minus 1%
Termination Type Torque: 7 in-lbs; Wire Size: 12 - 18 AWG
Mounting Method #8 screws
Operating Temperature -40° to 70°C (-40° to 158°F)
Storage Temperature (F/C) -40° to 80°C (-40° to 176°F)
Dimensions 2.93 H x 5.27 W x 2.95 D in. (74.4 x 133.9 x 74.9 mm)
Weight (lbs/g) 0 Kg
Check Stock Yes
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